tag:theconversation.com,2011:/global/topics/longevity-20168/articlesLongevity – The Conversation2024-01-24T17:56:15Ztag:theconversation.com,2011:article/2214632024-01-24T17:56:15Z2024-01-24T17:56:15ZPeople in the world’s ‘blue zones’ live longer – their diet could hold the key to why<figure><img src="https://images.theconversation.com/files/571182/original/file-20240124-29-m0xvd7.jpg?ixlib=rb-1.1.0&rect=58%2C0%2C6477%2C4314&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Many blue zone diets are rich in plant foods.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/happy-senior-couple-aprons-cutting-fresh-1857483013">Studio Romantic/ Shutterstock</a></span></figcaption></figure><p>Ageing is an inevitable part of life, which may explain our <a href="https://time.com/4672969/why-do-people-want-to-live-so-long/">strong fascination</a> with the <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2726954">quest for longevity</a>. The allure of <a href="https://pubmed.ncbi.nlm.nih.gov/26566891/">eternal youth</a> drives a <a href="https://www.alliedmarketresearch.com/longevity-and-anti-senescence-therapy-market-A14010">multi-billion pound industry</a> ranging from anti-ageing products, supplements and <a href="https://www.everydayhealth.com/diet-nutrition/longevity-diet">diets</a> for those hoping to extend their lifespan. </p>
<hr>
<iframe id="noa-web-audio-player" style="border: none" src="https://embed-player.newsoveraudio.com/v4?key=x84olp&id=https://theconversation.com/people-in-the-worlds-blue-zones-live-longer-their-diet-could-hold-the-key-to-why-221463&bgColor=F5F5F5&color=D8352A&playColor=D8352A" width="100%" height="110px"></iframe>
<p><em>You can listen to more articles from The Conversation <a href="https://theconversation.com/us/topics/audio-narrated-99682">narrated by Noa</a>.</em></p>
<hr>
<p>If you look back to the turn of the 20th century, average life expectancy in the UK was around 46 years. Today, it’s closer to <a href="https://population.un.org/wpp/">82 years</a>. We are in fact <a href="https://pubmed.ncbi.nlm.nih.gov/27706136/">living longer than ever before</a>, possibly due to medical advancements and improved <a href="https://www.health.org.uk/publications/reports/mortality-and-life-expectancy-trends-in-the-uk">living and working conditions</a>. </p>
<p>But living longer has also come at a price. We’re now seeing higher rates of <a href="https://www.who.int/data/gho/data/themes/mortality-and-global-health-estimates/ghe-leading-causes-of-death">chronic and degenerative diseases</a> – with heart disease consistently topping the list. So while we’re fascinated by what may help us live longer, maybe we should be more interested in being healthier for longer. Improving our “<a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4632858/">healthy life expectancy</a>” remains a global challenge. </p>
<p>Interestingly, certain locations around the world have been discovered where there are a high proportion of centenarians who display remarkable physical and mental health. The <a href="https://pubmed.ncbi.nlm.nih.gov/15489066/">AKEA study of Sardinia, Italy</a>, as example, identified a “blue zone” (named because it was marked with blue pen), where there was a higher number of locals living in the central-eastern mountainous areas who had reached their 100th birthday compared with the wider Sardinian community.</p>
<p>This longevity hotspot has since been expanded, and now includes several other areas around the world which also have greater numbers of longer-living, healthy people. Alongside Sardinia, these blue zones are now <a href="https://www.netflix.com/gb/title/81214929">popularly recognised</a> as: Ikaria, Greece; Okinawa, Japan; Nicoya, Costa Rica; and Loma Linda, California.</p>
<p>Other than their long lifespans, people living in these zones also appear to share certain other commonalities, which centre around being <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3874460">part of a community</a>, having a <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4224996/">life purpose</a>, eating <a href="https://pubmed.ncbi.nlm.nih.gov/33514872/">nutritious, healthy foods</a>, keeping <a href="https://www.nature.com/articles/s41398-021-01735-7">stress levels</a> low and undertaking purposeful daily <a href="https://pubmed.ncbi.nlm.nih.gov/30202288/">exercise or physical tasks</a>. </p>
<p>Their longevity could also relate to their <a href="https://pubmed.ncbi.nlm.nih.gov/9010380/">environment</a>, being mostly rural (or less polluted), or because of <a href="https://pubmed.ncbi.nlm.nih.gov/22253498/">specific longevity genes</a>. </p>
<p>However, studies indicate genetics may only account for <a href="https://pubmed.ncbi.nlm.nih.gov/8786073">around 20-25% of longevity</a> – meaning a person’s lifespan is a complex interaction between lifestyle and genetic factors, which contribute to a long and healthy life.</p>
<h2>Is the secret in our diet?</h2>
<p>When it comes to diet, each blue zone has its own approach – so one specific food or nutrient does not explain the remarkable longevity observed. But interestingly, a diet rich in <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3662288">plant foods</a> (such as locally-grown vegetables, fruits and legumes) does appear to be reasonably consistent across these zones. </p>
<p>For instance, the Seventh-day Adventists of Loma Linda are <a href="https://pubmed.ncbi.nlm.nih.gov/10641813/">predominately vegetarian</a>. For centenarians in Okinawa, <a href="https://pubmed.ncbi.nlm.nih.gov/20234038/">high intakes of flavonoids</a> (a chemical compound typically found in plants) from purple sweet potatoes, soy and vegetables, have been linked with <a href="https://pubmed.ncbi.nlm.nih.gov/11710359/">better cardiovascular health</a> – including lower cholesterol levels and lower incidences of stroke and heart disease.</p>
<p>In Nicoya, consumption of locally produced rice and beans has been associated with <a href="https://pubmed.ncbi.nlm.nih.gov/34444746/">longer telomere length</a>. Telomeres are the structural part at the end of our chromosomes which protect our genetic material. Our telomeres get shorter each time a cell divides – so get progressively shorter as we age.</p>
<p>Certain <a href="https://pubmed.ncbi.nlm.nih.gov/21102320/">lifestyle factors</a> (such as smoking and poor diet) can also shorten telomere length. It’s thought that telomere length acts as a <a href="https://pubmed.ncbi.nlm.nih.gov/31728493/">biomarker of ageing</a> – so having longer telomeres could, in part, be linked with longevity. </p>
<p>But a plant-based diet isn’t the only secret. In Sardinia, for example, meat and fish is consumed in moderation in addition to locally grown vegetables and <a href="https://journalofethnicfoods.biomedcentral.com/articles/10.1186/s42779-022-00152-5">traditional foods</a> such as acorn breads, pane carasau (a sourdough flatbread), honey and soft cheeses. </p>
<figure class="align-center ">
<img alt="An elderly woman inspects greens in a plastic bowl." src="https://images.theconversation.com/files/571183/original/file-20240124-15-kda5as.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/571183/original/file-20240124-15-kda5as.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=439&fit=crop&dpr=1 600w, https://images.theconversation.com/files/571183/original/file-20240124-15-kda5as.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=439&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/571183/original/file-20240124-15-kda5as.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=439&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/571183/original/file-20240124-15-kda5as.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=552&fit=crop&dpr=1 754w, https://images.theconversation.com/files/571183/original/file-20240124-15-kda5as.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=552&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/571183/original/file-20240124-15-kda5as.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=552&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Many blue zone residents also prepare their own food at home.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/old-woman-scarf-preparing-parsley-dinner-2148151393">Huseyin Eren Obuz/ Shutterstock</a></span>
</figcaption>
</figure>
<p>Also observed in several blue zone areas is the inclusion of <a href="https://www.jacc.org/doi/10.1016/j.jacc.2021.10.041">olive oil</a>, <a href="https://pubmed.ncbi.nlm.nih.gov/33669360/">wine</a> (in moderation – around 1-2 glasses a day), as well as <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3830687/">tea</a>. All of these contain powerful antioxidants which may help <a href="https://ncbi.nlm.nih.gov/pmc/articles/PMC10049696/">protect our cells</a> from damage <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6273542/">as we age</a>.</p>
<p>Perhaps then, it’s a combination of the protective effects of various nutrients in the diets of these centenarians, which explains their exceptional longevity.</p>
<p>Another striking observation from these longevity hot spots is that meals are typically <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7232892">freshly prepared at home</a>. Traditional blue zone diets also don’t appear to contain <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6538973/">ultra-processed foods</a>, fast foods or sugary drinks which may <a href="https://pubmed.ncbi.nlm.nih.gov/32330232/">accelerate ageing</a>. So maybe it’s just as important to consider what these longer-living populations are not doing, as much as what they are doing. </p>
<p>There also appears to be a pattern of eating until 80% full (in other words partial <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9036399/">caloric reduction</a>. This could be important in also supporting how our cells deal with damage as we age, which could mean a longer life.</p>
<p>Many of the factors making up these blue zone diets – primarily plant-based and natural whole foods – are associated with <a href="https://pubmed.ncbi.nlm.nih.gov/35706591/">lower risk of chronic diseases</a> such as <a href="https://pubmed.ncbi.nlm.nih.gov/28728684/">heart disease</a> and <a href="https://pubmed.ncbi.nlm.nih.gov/37589638/">cancer</a>. Not only could such diets contribute to a <a href="https://pubmed.ncbi.nlm.nih.gov/37836577/">longer, healthier life</a>, but could support a more <a href="https://pubmed.ncbi.nlm.nih.gov/33397404/">diverse gut microbiome</a>, which is also associated with healthy ageing.</p>
<p>Perhaps then we can learn something from these remarkable centenarians. While diet is only one part of the bigger picture when it comes to longevity, it’s an area we can do something about. In fact, it might just be at the heart of improving not only the quality of our health, but the quality of how we age.</p><img src="https://counter.theconversation.com/content/221463/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Professor Justin Roberts works for Danone Nutricia Research and Anglia Ruskin University, and has previously received external research funding unrelated to this article.</span></em></p><p class="fine-print"><em><span>Joseph Lillis receives funding from Anglia Ruskin University and Fattoria La Vialla as part of a funded doctoral programme in the area of nutritional physiology.</span></em></p><p class="fine-print"><em><span>Mark Cortnage does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Centenarians living in the world’s ‘blue zones’ share a surprising number of similarities when it comes to their usual diet.Justin Roberts, Professor of Nutritional Physiology, Anglia Ruskin UniversityJoseph Lillis, PhD Candidate in Nutritional Physiology, Anglia Ruskin UniversityMark Cortnage, Senior Lecturer in Public Health and Nutrition, Anglia Ruskin UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2019272024-01-22T13:27:25Z2024-01-22T13:27:25ZBreaking down fat byproducts could lead to healthier aging − researchers identify a key enzyme that does just that<figure><img src="https://images.theconversation.com/files/569661/original/file-20240116-25-w3uhfy.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C2121%2C1412&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">A buildup of fat byproducts like glycerol may contribute to accelerated aging.</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/oily-water-royalty-free-image/492968264">MagicColors/iStock via Getty Images Plus</a></span></figcaption></figure><p>The journey of aging brings with it an unavoidable reality for many: an increased accumulation of body fat. Though much of society seems mostly focused on the aesthetics of being overweight, doctors look past any cosmetic concerns to focus on the health implications of fat byproducts in the body.</p>
<p><a href="https://www.britannica.com/science/fatty-acid">Fatty acids</a> are one of the molecular building blocks that make up fats. Though essential for various bodily functions, excessive amounts of fatty acids in the body <a href="https://doi.org/10.1111/acel.13048">can be harmful</a>, shortening a person’s <a href="https://theconversation.com/are-you-a-rapid-ager-biological-age-is-a-better-health-indicator-than-the-number-of-years-youve-lived-but-its-tricky-to-measure-198849">health span and life span</a> by increasing their risk of chronic disease, disrupting metabolic processes and promoting inflammation. </p>
<p>Fatty acids are <a href="https://medlineplus.gov/lab-tests/triglycerides-test/">routinely checked</a> during medical examinations, such as blood tests measuring your lipid profile. But clinicians and researchers often overlook the other key component of fat despite its potentially harmful effects: <a href="https://doi.org/10.1016/j.cmet.2009.10.003">glycerol</a>, a compound that links fatty acids to make a fat molecule. </p>
<p>Both of these fat byproducts disrupt cellular and organ function, mirroring the effects of aging. In fact, researchers are increasingly seeing obesity as a <a href="https://doi.org/10.3389%2Ffendo.2019.00266">catalyst for accelerated aging</a>.</p>
<p>The role that fats play in aging is one of the focuses of my work as a <a href="https://scholar.google.com/citations?user=O3qOkKsAAAAJ&hl=en">genomicist and biochemist</a>. My <a href="https://www.agingobesitylab.org">research team</a> and I wondered whether reducing harmful fat byproducts might help slow the aging process and consequently stave off common diseases. </p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/QhUrc4BnPgg?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Fats perform essential functions in your cells, but not all of them are good for you.</span></figcaption>
</figure>
<h2>Breaking down fat byproducts</h2>
<p>In studying ways to extend the life span and improving the health at late age of lab animals, my colleagues and I saw a <a href="https://doi.org/10.1016/j.cub.2023.01.059">consistent pattern</a>: All the anti-aging interventions we tested led to reduced glycerol levels.</p>
<p>For instance, when placed on a calorie-restricted diet, the nematode <em>Caenorhabditis elegans</em> <a href="https://doi.org/10.1073/pnas.95.22.13091">lives about 40% longer</a>. We found that the glycerol levels in the body of these long-lived worms were lower than in shorter-lived worms that were not food restricted. Calorie restriction also <a href="https://doi.org/10.1016/j.cub.2023.01.059">heightened the activity of an enzyme</a> responsible for breaking down glycerol, ADH-1, in their intestine and muscles.</p>
<p>We saw similar <a href="https://doi.org/10.1016/j.cub.2023.01.059">high ADH-1 activity levels in people</a> undergoing dietary restriction or treated with an anti-aging drug called rapamycin. This finding suggests there may be a common mechanism underlying healthy aging across species, with ADH-1 at its core.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/569663/original/file-20240116-20-gctpab.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Figure showing the chemical structure of glycerol, a fatty acid, and a triglycerol" src="https://images.theconversation.com/files/569663/original/file-20240116-20-gctpab.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/569663/original/file-20240116-20-gctpab.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=792&fit=crop&dpr=1 600w, https://images.theconversation.com/files/569663/original/file-20240116-20-gctpab.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=792&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/569663/original/file-20240116-20-gctpab.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=792&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/569663/original/file-20240116-20-gctpab.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=995&fit=crop&dpr=1 754w, https://images.theconversation.com/files/569663/original/file-20240116-20-gctpab.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=995&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/569663/original/file-20240116-20-gctpab.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=995&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Triacylglycerols, also known as triglycerides, are composed of a glycerol linked to three fatty acids.</span>
<span class="attribution"><a class="source" href="https://bio.libretexts.org/Bookshelves/Microbiology/Microbiology_(Boundless)/02%3A_Chemistry/2.05%3A_Organic_Compounds/2.5.02%3A_Lipid_Molecules">Lumen Learning (formerly Boundless) via LibreTexts</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<p>We hypothesized that elevated ADH-1 activity promotes health in old age by decreasing harmful levels of glycerol. Supporting this hypothesis were <a href="https://doi.org/10.1016/j.cub.2023.01.059">two critical observations</a>. First, we found that adding glycerol to the diet of worms <a href="https://doi.org/10.1016/j.cmet.2009.10.003">shortened their life span by 30%</a>. By contrast, animals genetically modified to boost levels of the glycerol-busting enzyme ADH-1 had low glycerol levels and remained lean and healthy with longer lives, even on unrestricted diets. </p>
<p>The simple molecular structure and wealth of research on ADH-1 make it an attractive target for developing drugs that boost its activity. My lab’s long-term goal is to explore how compounds that activate ADH-1 affect the health and longevity of both mice and people.</p>
<h2>A long-lived society</h2>
<p>Anti-aging research generates both excitement and debate. On the one hand, the benefits of <a href="https://theconversation.com/aging-is-complicated-a-biologist-explains-why-no-two-people-or-cells-age-the-same-way-and-what-this-means-for-anti-aging-interventions-202096">healthy aging</a> are clear. On the other hand, extending life span through healthier aging will likely introduce new societal challenges. </p>
<p>If life spans extending to 120 years become the norm, <a href="https://doi.org/10.1016/S2666-7568(21)00250-6">social structures</a>, including retirement ages and economic models, will need to evolve to accommodate an aging population. Legal and social frameworks regarding the elderly and family care may need revision. The <a href="https://www.washingtonpost.com/parenting/2023/03/22/caregivers-sandwich-generation/">sandwich generation</a>, those with children and living parents and grandparents, might find themselves caring for even more generations simultaneously. Longer lives will require society to rethink and reshape how we integrate and support an increasingly older population in our communities.</p>
<p>Whether through ADH-1 or dietary adjustments, the quest for the solution to healthy aging is not just a medical journey but a societal one.</p><img src="https://counter.theconversation.com/content/201927/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Eyleen Jorgelina O'Rourke does not receive funding from any organization that would benefit from this article. </span></em></p>Although you get your fatty acid levels routinely checked at the doctor’s, rarely do clinicians and researchers consider the effects of their potentially harmful byproducts.Eyleen Jorgelina O'Rourke, Associate Professor of Biology and Cell Biology, University of VirginiaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2193742024-01-09T13:24:10Z2024-01-09T13:24:10ZWhat Taoism teaches about the body and being healthy<figure><img src="https://images.theconversation.com/files/568087/original/file-20240105-15-9ngj1j.jpg?ixlib=rb-1.1.0&rect=0%2C7%2C1759%2C1095&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Daoism, which emphasizes harmony with nature, can inform individuals on their relationship with the environment.</span> <span class="attribution"><a class="source" href="https://en.wikipedia.org/wiki/Ma_Yuan_(painter)#/media/File:Ma_Yuan_Walking_on_Path_in_Spring.jpg">Ma Yuan 'Walking on Path in Spring.' National Palace Museum via Wikimedia Commons</a></span></figcaption></figure><p>New Year’s resolutions often come with a renewed investment in making our bodies healthier. Many may take to the newest diet plan or sign up for a health club membership, but it is worth taking some time to consider what actually constitutes a healthy, happy body. </p>
<p>Taoist visions of the body <a href="https://religion.utk.edu/people/michael-naparstek/">form a central part of my research</a>. Taoism, (also spelled Daoism) an indigenous tradition of China, understands humans to be an integral part of the larger cosmos. </p>
<p>Rituals and bodily techniques are used to align one’s individual body with surrounding social and natural environments. These concepts of the body can inform individuals on their relationship with our environment and on what it means to be healthy. </p>
<h2>Taoism, the body and cosmos</h2>
<p>Accounts of Taoism begin sometime in the fourth century B.C.E., starting with the text “Tao Te Ching,” attributed to Lao Tzu. Though scholars do not believe there was an actual person called Lao Tzu, this figure, whose name means “old master” or “old child,” would become the model for bodily practice. Taoists would later develop rituals designed to mirror their body with that of Lao Tzu’s <a href="https://doi.org/10.1163/157342009X12526658783817">as a way to align themselves with the Tao,</a> or the source of all things.</p>
<p>Taoist texts described Lao Tzu’s body as a kind of map for the entire cosmos, visualizing their own individual body like a smaller version of the entire cosmos, and likening the entire cosmos to a larger mirror of one’s own body. Bringing one’s body in alignment with the cosmos was understood to grant Taoists the ability to transform the environment around them by transforming their own bodies. </p>
<p>What happened in the body was understood to have an effect on the entire universe, just as the environment has an effect on one’s body.</p>
<h2>Physical exercises for longevity</h2>
<p>Some of the earliest examples of Taoist practices describe a series of body movements and postures to help align one’s body with their environment. </p>
<p>Historian of Taoism, <a href="https://www.jstor.org/stable/40727453">Isabelle Robinet</a>, notes that dating back to the second century B.C.E., the physical exercises were used to help <a href="https://www.sup.org/books/title/?id=3024">cultivate one’s qi</a>, or breath, in order to better achieve harmony with the patterns of nature, nourish one’s health and increase longevity. Contemporary practices such as qigong continue to be informed by these concepts to this day.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/568052/original/file-20240105-15-mfuii6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A banner showing different postures of exercise." src="https://images.theconversation.com/files/568052/original/file-20240105-15-mfuii6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/568052/original/file-20240105-15-mfuii6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=333&fit=crop&dpr=1 600w, https://images.theconversation.com/files/568052/original/file-20240105-15-mfuii6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=333&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/568052/original/file-20240105-15-mfuii6.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=333&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/568052/original/file-20240105-15-mfuii6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=419&fit=crop&dpr=1 754w, https://images.theconversation.com/files/568052/original/file-20240105-15-mfuii6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=419&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/568052/original/file-20240105-15-mfuii6.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=419&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Reconstruction of a silk painting from the second century B.C.E showing early ritualized bodily postures, excavated at Mawangdui, Hunan Province, China.</span>
<span class="attribution"><a class="source" href="https://wellcomecollection.org/works/rrb7c7cm?wellcomeImagesUrl=/indexplus/image/L0036007.html">Wellcome Images, a website operated by Wellcome Trust, a global charitable foundation based in the United Kingdom.</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<p>In addition to practicing bodily techniques, early Taoists also sought out a connection to the environment through alchemy, a process of mixing rare natural elements together to create a refined substance that they believed was an elixir of health. According to renowned scholar of Taoist alchemy <a href="https://www.fabriziopregadio.com/">Fabrizio Pregadio</a>, practitioners sought out rare and powerful elements from the earth, which they mixed and <a href="https://www.goldenelixir.com/jindan.html">consumed in an attempt to attain longevity or even immortality</a>.</p>
<h2>Integrating with the outer landscape</h2>
<p>By the eighth century C.E., Taoists would look inward for these alchemical benefits. Taoist masters developed meditative and bodily practices called “neidan,” or inner alchemy, to help replicate the landscape within their own body.</p>
<p>Rather than seeking out rare elements in the earth, inner alchemy taught how to find the power to refine one’s vital essences from within one’s own body.</p>
<figure class="align-left ">
<img alt="A detailed Taoist chart with intricate black etchings and inscriptions in Chinese." src="https://images.theconversation.com/files/568086/original/file-20240105-20-pl5vqh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/568086/original/file-20240105-20-pl5vqh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=1417&fit=crop&dpr=1 600w, https://images.theconversation.com/files/568086/original/file-20240105-20-pl5vqh.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=1417&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/568086/original/file-20240105-20-pl5vqh.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=1417&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/568086/original/file-20240105-20-pl5vqh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1781&fit=crop&dpr=1 754w, https://images.theconversation.com/files/568086/original/file-20240105-20-pl5vqh.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1781&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/568086/original/file-20240105-20-pl5vqh.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1781&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">The Taoist inner landscape diagram of the human body.</span>
<span class="attribution"><a class="source" href="https://upload.wikimedia.org/wikipedia/commons/thumb/d/d2/%E5%86%85%E7%BB%8F%E5%9B%BE_Diagram_of_the_Internal_Texture_of_Man_%D0%94%D0%B8%D0%B0%D0%B3%D1%80%D0%B0%D0%BC%D0%BC%D0%B0_%D0%B8%D0%B7_%22%D0%A2%D1%80%D0%B0%D0%BA%D1%82%D0%B0%D1%82%D0%B0_%D0%96%D0%B5%D0%BB%D1%82%D0%BE%D0%B3%D0%BE_%D0%98%D0%BC%D0%BF%D0%B5%D1%80%D0%B0%D1%82%D0%BE%D1%80%D0%B0_%D0%BE_%D0%B2%D0%BD%D1%83%D1%82%D1%80%D0%B5%D0%BD%D0%BD%D0%B5%D0%BC%22_%289441066681%29.jpg/1024px-thumbnail.jpg">Nikolaj Potanin from Russia via Wikimedia Commons</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<p>Fully developed ritual programs instructed Taoists to undertake an inner journey within themselves. Along the way, they would visualize their old self encountering temples tucked away within lush mountain forests, discover hidden grottoes, and even find divine figures mixing elixirs of immortality. </p>
<p>This internal climb was believed to eventually lead one’s old self to the peak located at the crown of one’s head. From there, Taoists would visualize a new immortal self emerging out from atop their skull.</p>
<h2>Taoist priests and community</h2>
<p>This concept of a body fully integrated with the cosmos informs the logic for how contemporary Taoist priests conduct rituals to benefit the broader community today.</p>
<p>According to <a href="https://www.nytimes.com/2021/04/04/world/asia/kristofer-schipper-dead.html">Kristofer Schipper</a>, a scholar of Taoist ritual, the body is seen as the primary medium that can <a href="https://www.ucpress.edu/book/9780520082243/the-taoist-body">fulfill their duty to reconnect the local community</a> with the original source of the cosmos – the Dao itself.</p>
<p>Taoist priests will envision a different kind of journey, this time across the cosmos but still all within their own body. They seek an audience with the highest gods of Taoism, known as the Three Pure Ones, to whom they will report the merits of the local community. </p>
<p>It is understood that in so doing, the Taoist priest helps reaffirm the connection between the people and the Tao itself. Thus, the community becomes integrated into the “Taoist Body.”</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/rcUzbNrXPeY?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Taoists performing a ritual at Longhushan, sacred mountain of Taoism, Jiangxi Province, China.</span></figcaption>
</figure>
<p>While an audience with the purest forms of the Tao is reserved only for trained Taoist priests, notions of the Taoist body ultimately provide a way for everyone to understand one’s body to be transformed both inside and out. </p>
<p>As the new year brings new resolutions for healthier bodies, we may gain from added perspectives on what transforming our body can mean – not just for ourselves, but for those around us.</p><img src="https://counter.theconversation.com/content/219374/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Michael Naparstek does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>A scholar of Daoist rituals explains how the indigenous tradition of China understands the human body as being part of the larger cosmos.Michael Naparstek, Lecturer in Religious Studies, University of TennesseeLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2194352023-12-20T16:05:40Z2023-12-20T16:05:40ZCould dinosaurs be the reason humans can’t live for 200 years?<figure><img src="https://images.theconversation.com/files/565275/original/file-20231212-17-7baa92.jpg?ixlib=rb-1.1.0&rect=0%2C23%2C4000%2C2640&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/human-hand-compare-real-dinosaur-footprint-1205774944">Rattana/Shutterstock</a></span></figcaption></figure><p>All human beings age. It is part of our biology and <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4010874/">limits our lifespan</a> to slightly over 120 years.</p>
<p>Not all animals <a href="https://www.sciencedirect.com/science/article/pii/S0925443917302193">experience ageing</a> during their lives. Some animals’ bodies do not gradually degenerate as they get older the way our bodies do.</p>
<p>But for humans once they reach about age 30 their <a href="https://www.smithsonianmag.com/smart-news/your-probability-of-dying-doubles-every-eight-years-180948228/">chance of dying</a> <a href="https://arxiv.org/PS_cache/q-bio/pdf/0411/0411019v3.pdf">doubles roughly</a> every eight years. So even if you are fortunate enough to become a centenarian, your chance of dying each year will be high. </p>
<p>This high mortality reflects numerous other health problems, such as <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2804956/#R4">loss of muscle mass</a> and general frailty, <a href="https://www.thieme-connect.de/products/ejournals/abstract/10.1055/s-0035-1555115">cognitive decline</a>, loss of vision and hearing and many other degenerative changes that characterise the <a href="https://www.ncbi.nlm.nih.gov/books/NBK10041/#:%7E:text=Aging%20is%20the%20time%2Drelated,disease%20(which%20affect%20individuals).">human ageing process</a>. </p>
<p>And the reason humans age so markedly may be due to the fact our ancestors evolved during the <a href="https://www.embopress.org/doi/full/10.15252/embr.202051617">time of the dinosaurs</a>.</p>
<p>Compared to other mammals, humans have a long life. We have the longest lifespan of all land-based mammals, and of all mammals <a href="https://news.liverpool.ac.uk/2015/01/06/scientists-sequence-genome-longest-lived-mammal/">only whales probably</a> outlive us. I say “probably” because you need to keep animals in captivity to do a detailed study on lifespan, which for whales is virtually impossible due to their size and longevity. </p>
<p>We know that species of whales and dolphins <a href="https://www.pnas.org/doi/10.1073/pnas.1903844116">exhibit menopause</a>, and all mammals show some form of reproductive decline with age. In fact, all studied mammals show physiological ageing and increased mortality with age, even if some species – like mice and voles – age much faster than others – such as humans, whales, and elephants. </p>
<p>But many species of reptiles, amphibians and fish do not show signs of ageing. <a href="https://genomics.senescence.info/species/nonaging.php">Examples include</a> turtles and tortoises, salamanders and rockfishes. </p>
<p>One study of 77 species of reptiles and amphibians published in Science in 2022 showed that age-related increases in mortality <a href="https://www.science.org/doi/10.1126/science.abm0151">are not seen</a> in many species of reptiles and amphibians. It is as if these animals do not age at all. Some of these animals, such as turtles, probably live longer than humans.</p>
<p>Perhaps if we study these apparently non-ageing species for long enough they will show signs of ageing. But good luck studying animals such as the <a href="https://www.science.org/doi/10.1126/science.aaf1703">Greenland shark</a>, which has been estimated to live nearly 400 years. </p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/H3al2YI_128?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
</figure>
<p>For now we can at least say that among reptiles, amphibians and fish, some species not only live longer than the longest living mammals, but they age substantially slower. Besides, some of these non-ageing species grow throughout their lives, which means that older females <a href="https://www.sciencedirect.com/science/article/pii/S0531556500002424">lay more eggs</a>, again in stark contrast to what happens in mammals. </p>
<p>These animals die mainly from being eaten by predators and diseases. Indeed, most animals in the wild do not die of old age and, until the 20th century, of course, most people died of infectious diseases.</p>
<p>Some reptiles, amphibians and fish are also known for their <a href="https://www.mdpi.com/2221-3759/9/3/36">ability to regenerate</a> tissue. </p>
<h2>Pressure on mammals</h2>
<p>Amphibians evolved from fish about 370 million years ago, and about 50 million years later reptiles evolved from amphibians. <a href="https://bio.libretexts.org/Bookshelves/Introductory_and_General_Biology/Introductory_Biology_(CK-12)/12%3A_Vertebrates/12.07%3A_Vertebrate_Evolution">Mammals then evolved</a> from reptiles about 250-300 million years ago. </p>
<p>We are all products of evolution, which we see in relics such as <a href="https://www.biorxiv.org/content/10.1101/2021.09.14.460388v1">our tailbone</a>. Our evolutionary history can have a profound influence in modern times. For example, humans maintain evolutionary traits from when our ancestors roamed the savannah that are no longer fit for the modern world, from <a href="https://theconversation.com/the-science-of-sugar-why-were-hardwired-to-love-it-and-what-eating-too-much-does-to-your-brain-podcast-175272">craving sugar</a> to <a href="https://theconversation.com/how-morbid-curiosity-can-lead-people-to-conspiracy-theories-214532">behaviour</a> that leads to prejudices. </p>
<p>About 200 million years ago, massive volcanic eruptions <a href="https://www.britannica.com/science/end-Triassic-extinction">wiped out 76%</a> of marine and land species. Afterwards, the dinosaurs became the dominant predators in the land. To survive and avoid being hunted to extinction by dinosaurs, mammals became small, nocturnal and short-lived. </p>
<p>Our ancestors of this time were not like us at all. They were more like <a href="https://www.livescience.com/60888-rat-creatures-were-earliest-eutherian-mammal-ancestors.html">voles and mice</a>, small animals going out in the dark to catch insects. Under the pressure from the dinosaurs, ancestral mammals had to reproduce rapidly, just like mice and rats do now. And just like mice, rats and voles, our ancestors had short lifespans. </p>
<p>For 100 million years, during the time of the dinosaurs, mammals were at or near the bottom of the food chain. Mammals were more often prey than predators. During this time there was no reason for mammals to keep processes and genes related to long life, such as DNA repair and tissue regeneration systems. </p>
<p>My <a href="https://onlinelibrary.wiley.com/doi/full/10.1002/bies.202300098">longevity bottleneck hypothesis</a> proposes that repair and regeneration systems were lost, mutated or inactivated by the evolution of early mammals. This imposed biological constraints that shape how mammals age to this day. </p>
<p>After the dinosaurs disappeared when an asteroid hit the Earth <a href="https://www.nhm.ac.uk/discover/how-an-asteroid-caused-extinction-of-dinosaurs.html">66 million years</a> ago, mammals conquered the world. An astonishing diversity of species evolved with a variety of lifespans. Some species, like humans, evolved a long lifespan, but they may have done it under constraints, remnants from the time of the dinosaurs.</p>
<h2>Why dinosaurs made a difference</h2>
<figure class="align-center ">
<img alt="Lizard rests on the ground" src="https://images.theconversation.com/files/564332/original/file-20231207-15-xjtuw7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/564332/original/file-20231207-15-xjtuw7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=362&fit=crop&dpr=1 600w, https://images.theconversation.com/files/564332/original/file-20231207-15-xjtuw7.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=362&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/564332/original/file-20231207-15-xjtuw7.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=362&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/564332/original/file-20231207-15-xjtuw7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=455&fit=crop&dpr=1 754w, https://images.theconversation.com/files/564332/original/file-20231207-15-xjtuw7.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=455&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/564332/original/file-20231207-15-xjtuw7.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=455&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">The Tuatara lives for over a hundred years.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/tuatara-310936394">BeautifulBlossoms/Shutterstock</a></span>
</figcaption>
</figure>
<p>We can take a guess by looking at species that did not undergo the same evolutionary pressures as early mammals. For example, the tuatara, a reptile endemic to New Zealand, may look like a lizard but it diverged from snakes and lizards about 250 million years ago. It is sometimes referred to as a “living fossil”, due to its slow evolution. </p>
<p>Tuataras are thought to live for more than 100 years and age much slower than human beings, as a <a href="https://www.science.org/doi/10.1126/science.abm0151">2022 DNA analysis study showed</a>. Perhaps they have kept their anti-ageing genes, unlike even the longest lived mammals. </p>
<p>Our lifespan may be limited because of our evolutionary history.</p><img src="https://counter.theconversation.com/content/219435/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Joao Pedro de Magalhaes receives funding from the Wellcome Trust, Longevity Impetus Grants, LongeCity, and the Biotechnology and Biological Sciences Research Council.</span></em></p>Our mammal ancestors evolved to compete with dinosaurs but may have lost something in the process.Joao Pedro de Magalhaes, Chair of Molecular Biogerontology, University of BirminghamLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2199862023-12-19T10:55:22Z2023-12-19T10:55:22ZHypochondriacs die earlier than those who worry less about their health – what might explain this paradox?<figure><img src="https://images.theconversation.com/files/566295/original/file-20231218-17-biar6k.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C5592%2C3756&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/young-model-blonde-woman-white-shirt-1279482784">HBRH/Shutterstock</a></span></figcaption></figure><p>People who worry excessively about their health tend to die earlier than those who don’t, a <a href="https://jamanetwork.com/journals/jamapsychiatry/article-abstract/2812786">recent study</a> from Sweden has found. It seems strange that hypochondriacs who, by definition, worry yet have nothing wrong with them, should enjoy shorter lifespans than the rest of us. Let’s find out more.</p>
<p>First, a word about terminology. The term “hypochondriac” is fast becoming pejorative. Instead, we medical professionals are encouraged to use the term <a href="https://www.ncbi.nlm.nih.gov/books/NBK554399/">illness anxiety disorder</a> (IAD). So, to avoid triggering our more sensitive readership, we ought to use this term.</p>
<p>We can define IAD as a mental health condition characterised by <a href="https://www.ncbi.nlm.nih.gov/books/NBK519704/table/ch3.t32/">excessive worry about health</a>, often with an unfounded belief that a serious medical condition is present. It may be associated with frequent visits to a doctor, or it may involve avoiding them altogether on the grounds that a real and quite possibly fatal condition might be diagnosed. </p>
<p>The latter variant strikes me as quite rational. A hospital is a <a href="https://www.who.int/news-room/fact-sheets/detail/patient-safety">dangerous place</a> and you can die in a place like that.</p>
<p>IAD can be quite debilitating. A person with the condition will spend a lot of time worrying and visiting clinics and hospitals. It is <a href="https://bmcpublichealth.biomedcentral.com/articles/10.1186/s12889-023-17159-5">costly to health systems</a> because of time and diagnostic resources used and is quite stigmatising. </p>
<p>Busy healthcare professionals would much rather spend time treating people with “real conditions” and can often be quite <a href="https://www.webmd.com/mental-health/news/20230120/medical-gaslighting-what-to-know">dismissive</a>. So can the <a href="https://www.theguardian.com/commentisfree/2013/mar/24/placebos-great-for-hypochondriacs">public</a>.</p>
<h2>Now, about that study</h2>
<p>The Swedish researchers tracked around 42,000 people (of whom 1,000 had IAD) <a href="https://www.jstage.jst.go.jp/article/ace/4/2/4_22005/_html/-char/en">over two decades</a>. During that period, people with the disorder had an increased risk of death. (On average, worriers died five years younger than those who worried less.) Furthermore, the risk of death was increased from both natural and unnatural causes. Perhaps people with IAD have something wrong with them after all.</p>
<p>People with IAD dying of natural causes had increased mortality from cardiovascular causes, respiratory causes and unknown causes. Interestingly, they did not have an increased mortality from cancer. This seems odd because <a href="https://www.treatmyocd.com/blog/constantly-worried-cancer-ocd">cancer anxiety is rife</a> in this population.
The principal cause of unnatural death in the IAD cohort was from suicide, with at least a fourfold increase over those without IAD.</p>
<p>So how do we explain these curious findings?</p>
<p>IAD is known to have a strong association with psychiatric disorders. As suicide risk is increased by <a href="https://www.rcpsych.ac.uk/docs/default-source/improving-care/better-mh-policy/college-reports/college-report-cr229-self-harm-and-suicide.pdf?sfvrsn=b6fdf395_10">psychiatric illness</a>, then this finding seems quite reasonable. If we add in the fact that people with IAD may feel stigmatised and dismissed, then it follows that this may contribute to anxiety and depression, leading ultimately to suicide in some cases.</p>
<p>The increased risk of death from natural causes seems less easy to explain. There may be lifestyle factors. Alcohol, smoking and drug use are <a href="https://www.helpguide.org/articles/addictions/substance-abuse-and-mental-health.htm#:%7E:text=Roughly%2050%20percent%20of%20individuals,percent%20abuse%20alcohol%20or%20drugs.">more common</a> in anxious people and those with a psychiatric disorder. It is known that such vices can limit one’s longevity and so they may contribute to the increased mortality from IAD.</p>
<p>IAD is known to be more common in those who have had a family member with a serious illness. Since many serious illnesses have a genetic component, there may be good constitutional causes for this increase in mortality: lifespan is shortened by “faulty” genes.</p>
<figure class="align-center ">
<img alt="Man sitting on a sofa pouring hard liquor from a bottle." src="https://images.theconversation.com/files/566307/original/file-20231218-21-1wwzug.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/566307/original/file-20231218-21-1wwzug.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/566307/original/file-20231218-21-1wwzug.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/566307/original/file-20231218-21-1wwzug.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/566307/original/file-20231218-21-1wwzug.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/566307/original/file-20231218-21-1wwzug.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/566307/original/file-20231218-21-1wwzug.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Anxious people are more likely to drink alcohol.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/handsome-depressed-man-drinking-whisky-home-585761300">Africa Studio/Shutterstock</a></span>
</figcaption>
</figure>
<h2>What can we learn?</h2>
<p>Doctors need to be alert to the underlying health problems of patients and must listen with greater care. When we are dismissive of our patients, we can often be badly caught out. People with IAD may well have a hidden underlying disorder – an unpopular conclusion, I accept. </p>
<p>Perhaps we can illustrate this point with the case of the French novelist, <a href="https://en.wikipedia.org/wiki/Marcel_Proust">Marcel Proust</a>. Proust is often described by his biographers as a hypochondriac, yet he died in 1922 at the age of 51 at a time when the <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9844828/#:%7E:text=In%201922%2C%20a%2020%2Dyear,38%2Dyear%2Dold%20man.">life expectancy of a Frenchman was 63</a>. </p>
<p>During his life, he complained of numerous gastrointestinal <a href="https://www.rsm.ac.uk/media/2060/marcel-proust-exhibition-booklet.pdf">symptoms</a> such as fullness, bloating and vomiting, yet his medical attendants could find little wrong. In fact, what he described is consistent with <a href="https://my.clevelandclinic.org/health/diseases/15522-gastroparesis">gastroparesis</a>. </p>
<p>This is a condition in which motility of the stomach is reduced and it empties more slowly than it should, causing it to overfill. This can lead to vomiting and with that comes a risk of inhaling vomit, leading to aspiration pneumonia and Proust is known to have died of complications of pneumonia.</p>
<p>Finally, a word of caution: writing about IAD can be quite risky. The French playwright Molière wrote <a href="https://www.encyclopedia.com/arts/educational-magazines/imaginary-invalid">Le Malade Imaginaire</a> (The Imaginary Invalid), a play about a hypochondriac called Argan who tries to get his daughter to marry a doctor in order to reduce his medical bills. As for Molière, he died at the <a href="https://www.britannica.com/question/How-did-Moliere-die">fourth performance of his work</a>. Mock hypochondriacs at your peril.</p><img src="https://counter.theconversation.com/content/219986/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Stephen Hughes does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Hypochondriacs live, on average, five years less than those who don’t have the condition.Stephen Hughes, Senior Lecturer in Medicine, Anglia Ruskin UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2193442023-12-08T14:53:05Z2023-12-08T14:53:05ZDoes exercise really do nothing for longevity, as a Finnish twins study suggests?<figure><img src="https://images.theconversation.com/files/564483/original/file-20231208-25-jfdagi.jpg?ixlib=rb-1.1.0&rect=8%2C0%2C5742%2C3828&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/fitness-woman-jumping-outdoor-urban-environment-1080117269">BGStock72/Shutterstock</a></span></figcaption></figure><p>Surveys on lifestyle and longevity consistently find that people who do more exercise live longer. So it is surprising to see a report from the <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10274991/">Finnish Twins Cohort Study</a> that there is little direct effect of “leisure time physical activity” on lifespan. What makes this study different from others – and is it right?</p>
<p>Human behaviour and biology are complex and interact with wider society and the environment. How much exercise a person gets could be linked to their genetics, diet, disabilities, education, wealth, or just whether they have enough leisure time and a safe green space. Each of these factors could also be linked to lifespan in different ways. </p>
<p>You can probably think of a dozen other things that might be associated both with a person’s health and the amount of exercise that they do. The direction of the causation will not always be clear. Although it is certainly true that people who exercise more will, on average, live longer, it is far more difficult to know how much is caused by the exercise itself, versus these other factors. </p>
<p>How can we hope to isolate this single causal effect from the complexity of people’s lives?</p>
<p>Studies of twins can help us here. Twins have similar or identical genetics and early life experiences, so we can more directly test how differences in their later-life behaviour affect lifespan.</p>
<p>This is precisely the approach taken by researchers at the University of Jyväskylä in Finland. They used exercise questionnaires given to 11,000 pairs of adult same-sex twins in 1975, 1981 and 1990, and linked this to death records up to the year 2020. </p>
<figure class="align-center ">
<img alt="Young identical blond twins." src="https://images.theconversation.com/files/564485/original/file-20231208-25-4vzws2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/564485/original/file-20231208-25-4vzws2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/564485/original/file-20231208-25-4vzws2.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/564485/original/file-20231208-25-4vzws2.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/564485/original/file-20231208-25-4vzws2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=502&fit=crop&dpr=1 754w, https://images.theconversation.com/files/564485/original/file-20231208-25-4vzws2.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=502&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/564485/original/file-20231208-25-4vzws2.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=502&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Studying twins can help scientists determine whether a certain trait, illness or disorder is influenced more heavily by genes or the environment.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/close-portrait-twin-girls-two-beautiful-2292761521">Andrey Zhernovoy/Shutterstock</a></span>
</figcaption>
</figure>
<h2>Least and most active groups biologically older</h2>
<p>They found that, as expected, the most active had a 24% lower rate of death compared with the least active. This effect is smaller than suggested by previous studies, and most of the excess risk was confined to the least active 10% of the study participants. </p>
<p>They also looked at biological age, measured by the degree of DNA damage (<a href="https://www.nature.com/articles/d41586-022-00077-8">methylation</a>) and, surprisingly, found that both the most and the least active groups appeared biologically older than the others. </p>
<p>Pairing twins deals with genetics and early life differences, but what about other aspects of health behaviour? </p>
<p>When smoking, alcohol consumption and body mass index (BMI) were taken into account in the analysis, the link between exercise and longevity was much reduced, with only a 9% difference in death rate between the least active group and others – and no difference between the highly and moderately active. In other words, for a hypothetical twin pair with very different activity levels but the same smoking history, alcohol use and BMI, there would be very little difference in life expectancy. </p>
<p>But what does it mean to change exercise levels while all other aspects of health remain constant? For example, if the effect of exercise on death was mediated by weight loss, then this analysis would not reveal that link. And if exercise increases but weight does not change, then must something else be compensating? </p>
<p>There was also some evidence that the effect of exercise was stronger in the first 20 years after the assessment compared to the subsequent decade. So it is possible that exercise needs to be maintained to keep its longevity benefits into later life. </p>
<p>This would agree with <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1402378/">evidence from clinical trials</a> that show more immediate benefits of exercise interventions on health in people with existing conditions.</p>
<h2>Smaller role than previously thought</h2>
<p>So what can we safely conclude from these new findings – which have won a national sports medicine prize in Finland, but are yet to be peer-reviewed? </p>
<p>Clearly, people who exercise more live longer on average. Genetics, social factors, existing health and other aspects of lifestyle explain some of the association. We should not rule out a direct link between exercise and longevity, but this study suggests that it may have a smaller role than previously thought.</p>
<p>Nevertheless, experimental evidence shows that exercise can prevent illness and disability, <a href="https://bjsm.bmj.com/content/57/18/1203">improve mood</a> and <a href="https://jamanetwork.com/journals/jamainternalmedicine/fullarticle/414776">overall quality of life</a>, which many would regard as more meaningful outcomes than lifespan alone. </p>
<p>It can be difficult for people to <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4988401/">maintain lifestyle changes</a>, and so social and environmental efforts, such as <a href="https://www.kingsfund.org.uk/projects/improving-publics-health/access-green-and-open-spaces-and-role-leisure-services">maintaining high-quality green spaces</a>, to support healthy lifestyles are important. </p>
<p>Social inequalities in health and lifespan <a href="https://www.health.org.uk/publications/reports/the-marmot-review-10-years-on">exist and are growing</a> so it’s vital that we continue to refine our understanding of the reasons why and what we should do about it.</p><img src="https://counter.theconversation.com/content/219344/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>George M. Savva does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>We should not rule out a direct link between exercise and longevity, but it may have a smaller role than previously thought.George M. Savva, Senior research scientist, Quadram InstituteLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2167662023-11-13T11:52:56Z2023-11-13T11:52:56ZWhat the world’s oldest dog can tell us about ageing<p>If you have ever cared for a pet dog, it is a sad truth that you are likely to outlive them. So it’s no wonder that people may be asking how to increase their pet’s longevity following the news that a dog in Portugal lived longer than 30 years. </p>
<p>The <a href="https://www.guinnessworldrecords.com/news/2023/2/oldest-dog-ever-record-broken-by-30-year-old-bobi-from-portugal-736224">Guinness World Record Holder of the title of World’s Oldest Dog</a>, Bobi, <a href="https://www.bbc.co.uk/news/world-europe-67194721">has recently died</a> aged 31. This is an impressive age for any dog. <a href="https://www.cell.com/cell-reports/pdf/S2211-1247(12)00418-4.pdf">Smaller dogs typically live longer than larger breeds</a> but the average dog will get to around 13 years old before age inevitably catches up with them. </p>
<p>Bobi apparently lived a relatively unrestricted life in the Portuguese countryside, eating the same food as his human caregivers and enjoying free roam of the nearby forestland. His unusual longevity has been attributed to this lifestyle. While there is <a href="https://www.skeptic.org.uk/2023/11/bobi-the-supposed-worlds-oldest-dog-at-31-is-little-more-than-a-shaggy-dog-story/">some debate about Bobi’s actual age</a>, his diet and lifestyle, unsurprisingly, has attracted much attention from canine caregivers.</p>
<p>There is a lot we don’t understand about ageing but there are <a href="https://www.nature.com/articles/s41580-021-00411-4">common factors associated with longevity</a> for many species. These factors seem to help increase lifespans in species as varied as the microscopic worm <em><a href="https://www.mdpi.com/1420-3049/26/23/7323">Caenorhabditis elegans</a></em>, <a href="https://www.mdpi.com/2073-4425/10/7/518">dogs and humans</a>. This suggests that other species can be <a href="https://www.frontiersin.org/articles/10.3389/fvets.2021.655191/full?app=true#B50">useful models in helping us understand our own ageing process</a>. </p>
<p>So, what practical measures can we take to help ourselves and our dogs live as long and healthy lives as possible?</p>
<h2>Eat a nutritious diet</h2>
<p>Bobi reportedly ate the same food as his owners. But dogs and humans have different nutritional needs. This means that feeding your dog the same food you eat is unlikely to meet their requirements and could even be dangerous. </p>
<p>However, diet does affect ageing. In humans, a <a href="https://www.sciencedirect.com/science/article/pii/S0022316622100957?via%3Dihub">diet low in saturated fat and high in fruit and vegetables </a> supports healthy ageing. </p>
<p>For dogs, <a href="https://www.mdpi.com/2076-3271/9/4/72">increased levels of antioxidants</a> support energy generation in the body’s cells and aid learning and brain health in older dogs. These include vitamins C and E, and nutrients such as alpha-lipoic acid (found in red meat and organ meats) and L-carnitine (also found in red meat). These nutrients are typically provided in fortified, prepared dog food. </p>
<p>If you feed your dog a commercial diet, check it is labelled as “complete”. This ensures that if you feed <a href="https://www.ukpetfood.org/resource/different-pet-food-formats.html">the recommended amount</a>, your dog will be getting all the nutrients at the right levels to meet their needs. <a href="https://onlinelibrary.wiley.com/doi/abs/10.1002/9781119375241.ch8">Home-prepared dog diets are often deficient in key nutrients</a>, unless they are carefully prepared.</p>
<figure class="align-center ">
<img alt="Brown and white dog lying in grass with a playful expression" src="https://images.theconversation.com/files/558001/original/file-20231107-29-1w4b8j.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/558001/original/file-20231107-29-1w4b8j.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=399&fit=crop&dpr=1 600w, https://images.theconversation.com/files/558001/original/file-20231107-29-1w4b8j.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=399&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/558001/original/file-20231107-29-1w4b8j.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=399&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/558001/original/file-20231107-29-1w4b8j.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=502&fit=crop&dpr=1 754w, https://images.theconversation.com/files/558001/original/file-20231107-29-1w4b8j.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=502&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/558001/original/file-20231107-29-1w4b8j.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=502&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Wouldn’t you want this dog to stay healthy as long as possible?</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/adorable-welsh-springer-spaniel-dog-breed-1823409425">el-ka/Shutterstock</a></span>
</figcaption>
</figure>
<h2>Keep active</h2>
<p>Physical activity is often <a href="https://ijbnpa.biomedcentral.com/articles/10.1186/s12966-020-00995-8">linked to healthy ageing</a>. Studies suggest that dogs living in <a href="https://www.journals.uchicago.edu/doi/epdf/10.1086/724384">rural areas and large dogs are more active</a> than their older, smaller and urban counterparts. Interestingly, <a href="https://www.journals.uchicago.edu/doi/epdf/10.1086/724384">older caregivers also have more active dogs</a> compared to younger dog owners.</p>
<p>Walking is a simple way to <a href="https://www.cambridge.org/core/journals/journal-of-nutritional-science/article/overweight-dogs-exercise-less-frequently-and-for-shorter-periods-results-of-a-large-online-survey-of-dog-owners-from-the-uk/01E2D6FBCDD05069E3557C10A1CC5945">support maintenance of a healthy body weight in dogs</a> and their caregivers, leading to mutual health benefits. Age, size, breed, health and other variables will affect the amount of exercise a dog needs. For example, dogs originally bred to work and be highly active, <a href="https://www.ingentaconnect.com/content/cvma/cjvr/2012/00000076/00000003/art00013">such as collies and spaniels</a>, are likely to need more physical activity (intensity and duration) than toy breeds such as pugs, who might be happy with a gentle wander around the neighbourhood. </p>
<p>But almost without exception, walking and other activity is good for our dogs. It can also mean that <a href="https://www.mdpi.com/1660-4601/14/8/936">you and your dog are happier</a>, another key factor linked to <a href="https://link.springer.com/article/10.1007/s11205-020-02424-6">healthy ageing</a>. </p>
<h2>Maintain a healthy body weight</h2>
<p>Excess body weight is associated with <a href="https://www.cambridge.org/core/journals/british-journal-of-nutrition/article/characteristics-of-ageing-pets-and-their-owners-dogs-v-cats/39D988E0453ABF129B8740263CC61504">reduced health and lifespan</a> in dogs and people. Research consistently indicates that a degree of calorie restriction and a lean body weight is <a href="https://www.sciencedirect.com/science/article/abs/pii/S1568163719304076?via%3Dihub">associated with increased longevity</a> in a range of species. Somewhat paradoxically, photographs of Bobi suggest that he was carrying rather more body weight that would be considered healthy for a typical dog of his size. </p>
<p>Regular monitoring of your dog’s (and your own!) body weight is <a href="https://www.mdpi.com/2306-7381/4/2/30/htm">a good way to maintain a healthy waistline</a> and support longevity. It is important to know what a healthy body weight and shape looks and feels like for your own dog. Many caregivers <a href="https://www.mdpi.com/2306-7381/10/7/447">fail to recognise</a> what a healthy, lean animal should look like and others underestimate how much excess weight their pets are carrying. </p>
<p>With practice, you can become familiar with a healthy body shape by checking that your dog has a defined <a href="https://www.youtube.com/watch?v=tf_-rwxqHYU">waistline when viewed from above</a>, that you can feel (but not necessarily see) their ribs and that their abdomen tucks up when viewed from the side. You can use <a href="https://www.vet.cam.ac.uk/files/media/Pug_health_scheme_BCS_v2.jpg">breed specific resources</a> to understand more about the physical shapes of some dogs.</p>
<p>Feeding your dog a suitable amount to meet their nutritional needs while maintaining a lean body weight can help <a href="https://www.vettimes.co.uk/app/uploads/wp-post-to-pdf-enhanced-cache/1/clinical-impact-of-obesity-on-osteoarthritis-in-canines.pdf">reduce the chances</a> they will develop painful and distressing conditions such as osteoarthritis.</p>
<p>With some simple dietary and lifestyle interventions, we can make sure our shared lives with our dogs are as happy, healthy and long as possible. Our companion dogs might not reach 31 years old, but we can certainly make mutual longevity an aim.</p><img src="https://counter.theconversation.com/content/216766/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Jacqueline Boyd is affiliated with The Kennel Club (UK) through membership, as Chair of the Activities Health and Welfare Subgroup and member of the Dog Health Group. Jacqueline also writes, consults and coaches on canine matters on an independent basis in addition to her academic affiliation.</span></em></p>There’s a surprising amount of crossover in what things help human and dog longevity.Jacqueline Boyd, Senior Lecturer in Animal Science, Nottingham Trent UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2151662023-10-09T12:17:28Z2023-10-09T12:17:28ZCentenarian blood tests give hints of the secrets to longevity<figure><img src="https://images.theconversation.com/files/552718/original/file-20231009-28-ftpqy8.jpg?ixlib=rb-1.1.0&rect=103%2C17%2C3725%2C2132&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/portrait-hundred-years-old-woman-centenarian-1022974105">Dan Negureanu/Shutterstock</a></span></figcaption></figure><p>Centenarians, once considered rare, have become commonplace. Indeed, they are the <a href="https://www.weforum.org/agenda/2021/02/living-to-one-hundred-life-expectancy/">fastest-growing demographic group</a> of the world’s population, with numbers roughly doubling every ten years since the 1970s.</p>
<p>How long humans can live, and what determines a long and healthy life, have been of interest for as long as we know. Plato and Aristotle discussed and <a href="https://pubmed.ncbi.nlm.nih.gov/12092789/">wrote about the ageing process</a> over 2,300 years ago. </p>
<p>The pursuit of understanding the secrets behind exceptional longevity isn’t easy, however. It involves <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7105197/">unravelling the complex interplay</a> of genetic predisposition and lifestyle factors and how they interact throughout a person’s life. Now our recent study, <a href="https://link.springer.com/article/10.1007/s11357-023-00936-w">published in GeroScience</a>, has unveiled some common biomarkers, including levels of cholesterol and glucose, in people who live past 90.</p>
<p>Nonagenarians and centenarians have long been of intense interest to scientists as they may help us understand how to live longer, and perhaps also how to age in better health. So far, studies of centenarians have often been small scale and focused on a selected group, for example, excluding centenarians who live in care homes. </p>
<h2>Huge dataset</h2>
<p>Ours is the largest study comparing biomarker profiles measured throughout life among exceptionally long-lived people and their shorter-lived peers to date. </p>
<p>We compared the biomarker profiles of people who went on to live past the age of 100, and their shorter-lived peers, and investigated the link between the profiles and the chance of becoming a centenarian. </p>
<p>Our research included data from 44,000 Swedes who underwent health assessments at ages 64-99 - they were a sample of <a href="https://pubmed.ncbi.nlm.nih.gov/28158674/">the so-called Amoris cohort</a>. These participants were then followed through Swedish register data for up to 35 years. Of these people, 1,224, or 2.7%, lived to be 100 years old. The vast majority (85%) of the centenarians were female. </p>
<p>Twelve blood-based biomarkers related to inflammation, metabolism, liver and kidney function, as well as potential malnutrition and anaemia, were included. All of these <a href="https://www.nature.com/articles/s41591-019-0719-5">have been associated</a> with ageing or mortality in previous studies.</p>
<p>The biomarker related to inflammation was uric acid – a waste product in the body caused by the digestion of certain foods. We also looked at markers linked to metabolic status and function including total cholesterol and glucose, and ones related to liver function, such as alanine aminotransferase (Alat), aspartate aminotransferase (Asat), albumin, gamma-glutamyl transferase (GGT), alkaline phosphatase (Alp) and lactate dehydrogenase (LD). </p>
<p>We also looked at creatinine, which is linked to kidney function, and iron and total iron-binding capacity (TIBC), which is linked to anaemia. Finally, we also investigated albumin, a biomarker associated with nutrition. </p>
<h2>Findings</h2>
<p>We found that, on the whole, those who made it to their hundredth birthday tended to have lower levels of glucose, creatinine and uric acid from their sixties onwards. Although the median values didn’t differ significantly between centenarians and non-centenarians for most biomarkers, centenarians seldom displayed extremely high or low values.</p>
<p>For example, very few of the centenarians had a glucose level above 6.5 earlier in life, or a creatinine level above 125.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/552719/original/file-20231009-27-cn0vqz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Image of Villagrande Strisaili in the Ogliastra Province of Sardinia, Italy, which has the world's highest population of centenarian men." src="https://images.theconversation.com/files/552719/original/file-20231009-27-cn0vqz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/552719/original/file-20231009-27-cn0vqz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/552719/original/file-20231009-27-cn0vqz.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/552719/original/file-20231009-27-cn0vqz.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/552719/original/file-20231009-27-cn0vqz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/552719/original/file-20231009-27-cn0vqz.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/552719/original/file-20231009-27-cn0vqz.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Villagrande Strisaili in the Ogliastra Province of Sardinia, Italy, has the world’s highest population of centenarian men.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/villagrande-strisaili-italy-october-2019-scenic-1543489556">Sabino Parente/Shutterstock</a></span>
</figcaption>
</figure>
<p>For many of the biomarkers, both centenarians and non-centenarians had values outside of the range considered normal in clinical guidelines. This is probably because these guidelines are set based on a younger and healthier population. </p>
<p>When exploring which biomarkers were linked to the likelihood of reaching 100, we found that all but two (alat and albumin) of the 12 biomarkers showed a connection to the likelihood of turning 100. This was even after accounting for age, sex and disease burden. </p>
<p>The people in the lowest out of five groups for levels of total cholesterol and iron had a lower chance of reaching 100 years as compared to those with higher levels. Meanwhile, people with higher levels of glucose, creatinine, uric acid and markers for liver function also decreased the chance of becoming a centenarian. </p>
<p>In absolute terms, the differences were rather small for some of the biomarkers, while for others the differences were somewhat more substantial.</p>
<p>For uric acid, for instance, the absolute difference was 2.5 percentage points. This means that people in the group with the lowest uric acid had a 4% chance of turning 100 while in the group with the highest uric acid levels only 1.5% made it to age 100.</p>
<p>Even if the differences we discovered were overall rather small, they suggest a potential link between metabolic health, nutrition and exceptional longevity. </p>
<p>The study, however, does not allow any conclusions about which lifestyle factors or genes are responsible for the biomarker values. However, it is reasonable to think that factors such as nutrition and alcohol intake play a role. Keeping track of your kidney and liver values, as well as glucose and uric acid as you get older, is probably not a bad idea.</p>
<p>That said, chance probably plays a role at some point in reaching an exceptional age. But the fact that differences in biomarkers could be observed a long time before death suggests that genes and lifestyle may also play a role.</p><img src="https://counter.theconversation.com/content/215166/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Karin Modig receives funding from The Swedish Research Council and Swedish Research Council for Health, Working Life, and Welfare.</span></em></p>Centenarians tend to have lower levels of glucose, creatinine and uric acid from their sixties onwards.Karin Modig, Associate Professor, Epidemiology, Karolinska InstitutetLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2068522023-06-25T13:35:00Z2023-06-25T13:35:00ZFinding joy at age 100: Talking to centenarians about living their best life at any age<figure><img src="https://images.theconversation.com/files/530460/original/file-20230606-27-okg1ov.png?ixlib=rb-1.1.0&rect=143%2C0%2C1657%2C1003&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Centenarian Clementina Ripplinger with researcher Heather Nelson. Researchers spoke to very elderly people about what brings them joy and how they plan for the future.</span> <span class="attribution"><span class="source">(Shane Luhning)</span>, <span class="license">Author provided</span></span></figcaption></figure><p>Aging is seen as a period of loss, and there are unhelpful <a href="https://www.nia.nih.gov/health/10-myths-about-aging">myths about older adults</a>. Myths lead to treatable conditions being considered normal parts of aging, including cognitive decline, dementia, depression and loneliness. Some even consider exercise dangerous in older adults.</p>
<p>At the same time, mainstream media promotes the message that <a href="https://doi.org/10.4236/jss.2017.58015">being young is central to a person’s value</a>. These ideas lead to ageism and older adults being seen as lesser.</p>
<p>After spending time with six female centenarians in assisted living facilities, our research team — which included four nursing researchers and a documentary filmmaker — learned there is plenty still worth living for. </p>
<p>Centenarians are a small but growing segment of the population with <a href="https://www150.statcan.gc.ca/n1/en/daily-quotidien/220928/dq220928c-eng.pdf?st=LrkfjZE_">13,844 centenarians in Canada</a>, and our findings debunk myths about the experience of aging.</p>
<figure>
<iframe src="https://player.vimeo.com/video/800973319" width="500" height="281" frameborder="0" webkitallowfullscreen="" mozallowfullscreen="" allowfullscreen=""></iframe>
<figcaption><span class="caption">Trailer for documentary film about talking to centenarians.</span></figcaption>
</figure>
<p>We asked the centenarians questions about what brings them joy and how they plan for the future because we wanted to learn how the very elderly plan for and find ways to live their best lives. The results of this study were <a href="https://vimeo.com/showcase/looking-forward-at-100">turned into a 32-minute documentary</a> that captures participants’ long and interesting lives and offers insight into continued meaning experienced by centenarians in their daily lives. Three of the centenarians died shortly after the interviews took place.</p>
<h2>Long and interesting lives</h2>
<p>The participants were born between the years 1919 and 1922. They were children during the Great Depression and young adults during the Second World War. </p>
<p>One of the women helped build bullet casings and worked on the <a href="https://www.britannica.com/technology/Lancaster-airplane">Lancaster bomber</a>. Another woman helped her husband protect the blueprints of the ill-fated <a href="https://www.thecanadianencyclopedia.ca/en/article/avro-arrow">Avro Arrow aircraft</a> when he brought them home from work. Two women lost their husbands when their children were small and had to go to work to support their families. They all experienced love and adventure. </p>
<p>Our team was fascinated by their stories and wanted to further explore what their lives look like today. </p>
<p>Betty, 101, saw happiness as a choice. “I don’t know what’s really to complain about. I went through life staying happy,” she said.</p>
<h2>Joy and challenges</h2>
<p>This study used a research method called <a href="https://www.scribd.com/doc/151684840/Braun-Clarke-2006-Using-Thematic-Analysis">thematic analysis</a> to find four themes: Finding Joy, Act your Age, Looking Forward and Putting Challenges into Perspective.</p>
<p>The centenarians found joy each day and enjoyed the little things such as activities, visits and treats. Betty enjoyed cheating at solitaire and Jean, 100, played the piano. Clementina, 101, had fun gambling and Joyce, 100, continued to write stories and watch her grandchildren in music concerts.</p>
<p>Family was central to their lives and they enjoyed spending time with their children, grandchildren and great-grandchildren. Two of the women stated that raising their children was the biggest accomplishment in their lives.</p>
<p>The centenarians also found great joy in reminiscing about their interesting lives. However, one of the challenges was that there was no one left alive who had the same shared experiences.</p>
<h2>Limitations</h2>
<p>The centenarians were constrained by the limitations of society, their bodies and their self-perceptions. “You have to act your age,” said Clementina. She physically described this phenomenon by clasping her hands together in her lap and sitting still. </p>
<p>Some participants found life to be boring at 100 compared to their lives as younger adults. They had limited opportunities to do what they would like. “We had homes,” said Joyce, 100, describing how they had known better lives, which made it hard to accept the constraints of their current existence. </p>
<p>In spite of these feelings, many of the participants continued to be busy and live life fully despite limitations. Jean, despite needing a wheelchair for mobility, continues to do people’s taxes for a volunteer organization, plays piano for church services and leads choirs within her facility. </p>
<p>“I am constantly rebelling against my situation physically,” she said.</p>
<figure>
<iframe src="https://player.vimeo.com/video/791224058" width="500" height="281" frameborder="0" webkitallowfullscreen="" mozallowfullscreen="" allowfullscreen=""></iframe>
</figure>
<p>The other women in this study also continued to challenge norms of what their age and disabilities meant. Joyce writes and submits short stories for publication, and has a poem in the war archives in Ottawa.</p>
<p>Assisted living facilities often prioritize resident safety, but this can come at a cost to personal freedom. Some residents only leave their facility accompanied by a facility employee or a family member. Clementina rebelled against this restriction and at the age of 97, snuck out of her assisted living facility in a cab to go to the casino, pretending that she was going to meet her son.</p>
<p>All of the participants put their life challenges into perspective. They all had lost spouses, friends and some had lost their children. “I was broken,” Clementina said about losing her husband. </p>
<p>Christine, 102, was asked how she managed after losing her husband when her children were still small. “I am still here,” she said.</p>
<h2>The future</h2>
<p>Most of the centenarians had few plans for themselves for the future and were more interested in leading their day-to-day lives. Betty jokingly described the inevitability of her death and that she was “looking for the bucket.” Most described being prepared to die except for Jean, who laughed and said she didn’t have time to die. “I have too many plans.”</p>
<p>The centenarians looked to the future of their families and the larger community and entrusted the next generation to make good choices.</p>
<p>Participants in this study had long and interesting lives and continued to find meaning each day. This study supports the idea that older adults continue to lead engaging lives and that we need to support older adults to live their best lives at any age.</p>
<p><em>This article was also co-authored by journalist and filmmaker Kelly-Anne Riess and retired nursing instructor Susan Page.</em></p><img src="https://counter.theconversation.com/content/206852/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Heather Joyce Nelson receives funding from the Saskatchewan Health Research Foundation and the Social Sciences and Humanities Research Council.</span></em></p><p class="fine-print"><em><span>Beverlee Ziefflie receives funding from the Saskatchewan Health Research Foundation and the Social Sciences and Humanities Research Council. </span></em></p><p class="fine-print"><em><span>Paula Mayer receives funding from the Saskatchewan Health Research Foundation and the Social Sciences and Humanities Research Council. </span></em></p>What is life like at 100? Centenarians shared their joys and future hopes with a team of Saskatchewan researchers.Heather Joyce Nelson, Assistant Professor of Nursing, University of ReginaBeverlee Ziefflie, Instructor, Nursing, Saskatchewan PolytechnicPaula Mayer, Associate Research Scientist, Nursing, Saskatchewan PolytechnicLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1990822023-05-02T21:44:36Z2023-05-02T21:44:36ZDoes our gut microbiota really influence our health and life expectancy?<figure><img src="https://images.theconversation.com/files/507937/original/file-20230202-11974-o90i7b.jpg?ixlib=rb-1.1.0&rect=5%2C0%2C991%2C561&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Certain factors can disrupt the gut microbiota. These include our diet, alcohol consumption, antibiotics and inflammatory bowel disease.</span> <span class="attribution"><span class="source">(Shutterstock)</span></span></figcaption></figure><p>The intestinal microbiota is the set of bacteria and viruses that live inside your gut. Microbiota perform a variety of functions, including digesting food and protecting against specific pathogens. </p>
<p>There are several things that can <a href="https://www.hopkinsmedicine.org/health/treatment-tests-and-therapies/fecal-transplant">disrupt the gut microbiota</a>, including diet, alcohol consumption, antibiotics and inflammatory bowel disease. These cause imbalances, known as “dysbiosis” which, in turn, are associated with a <a href="https://doi.org/10.1128/mBio.01492-17">wide array of chronic diseases</a>. </p>
<p>In the last decade, the results of hundreds of studies in animal models have suggested that gut dysbiosis may play a role in several metabolic disturbances. Furthermore, in rodents, the implantation of certain bacteria <a href="https://doi.org/10.1038/nm.4236">could influence weight and metabolic profile</a>. What’s more, transferring the gut microbiota from a thin mouse to a heavy mouse allows it to lose weight. Is this too good to be true?</p>
<p>Respectively a student and a full professor in the Department of Medicine at Université Laval, our goal is to identify new therapeutic targets for chronic diseases and healthy life expectancy by using an approach based on genetic epidemiology. This short article aims to summarize and contextualize our recent research work <a href="https://doi.org/10.1186/s12967-022-03799-5">on the gut microbiota</a>.</p>
<h2>The importance of a causal link</h2>
<p>Scientists have suggested that eating certain foods such as dietary fibre, antioxidant-rich fruits and red meat may have an effect <a href="https://doi.org/10.1056/NEJMoa1109400">on the gut microbiota</a>. Some even suggest that microbiota could become a therapeutic target for the prevention or treatment of certain chronic diseases. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/507397/original/file-20230131-16-arvjen.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="conceptual illustration of the gut microbiome" src="https://images.theconversation.com/files/507397/original/file-20230131-16-arvjen.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/507397/original/file-20230131-16-arvjen.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/507397/original/file-20230131-16-arvjen.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/507397/original/file-20230131-16-arvjen.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/507397/original/file-20230131-16-arvjen.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/507397/original/file-20230131-16-arvjen.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/507397/original/file-20230131-16-arvjen.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The gut microbiota is the set of bacteria and viruses in our gut. It is involved in various functions, such as the digestion of food and protection against certain pathogens.</span>
<span class="attribution"><span class="source">(Shutterstock)</span></span>
</figcaption>
</figure>
<p>For the microbiota to become a therapeutic target of interest, it is essential to establish a causal link between the characteristics of the gut microbiota and chronic diseases. A causal link suggests that modifying the microbiota <a href="https://doi.org/10.1016/j.cell.2019.12.025">would decrease the risk of developing a disease</a>. However, while several observational (non-experimental) studies in humans have identified statistical associations between <a href="https://doi.org/10.1016/j.febslet.2014.09.039">various markers of gut microbiota and chronic disease</a>, causality has not been clearly established. </p>
<p>For example, it is not known whether gut dysbiosis is the cause or consequence of disease (reverse causation). It is also not known whether both are influenced by other “confounding” factors that are associated with both gut microbiota and chronic disease. One could think, for example, of the quality of <a href="https://doi.org/10.1038/s41586-020-2881-9">our diet, our weight or our alcohol consumption</a>. </p>
<p>So, the aim of our work was to determine whether there is a direct and causal relationship between gut microbiota and metabolic markers such as weight, eight chronic diseases and human longevity using a genetic approach called Mendelian randomization.</p>
<h2>The power of genetic data</h2>
<p>Mendelian randomization attempts to establish causal links from genetic data. To do this, Mendelian randomization uses genetic variants (frequent changes in our genome sequence called nucleotide polymorphisms) that are strongly associated with a risk factor (gut microbiota), to establish a causal link with a dependent variable (health markers and diseases), <a href="https://theconversation.com/voici-comment-les-lois-de-la-genetique-nous-aident-a-prevenir-les-maladies-chroniques-144153">as described in a recent article</a>. Since the variations in our genome are established at the time of embryo formation and remain stable throughout our lives, this natural randomization experiment is not subject to reverse causality bias, since the presence of disease does not influence our genetic code. It is also not subject to the effect of confounding factors, since the genetic variations used are specifically associated with the characteristics of the gut microbiota. </p>
<p>We included genetic data from tens of thousands of individuals from several cohorts. We identified genetic variants associated with 10 fecal and blood metabolites. The metabolites included are small molecules produced by the gut microbiota that have previously been associated with gut dysbiosis and certain diseases. We also identified genetic variants of dozens of microbial taxa (e.g. a species, genus or family of bacteria). We studied nine cardiometabolic traits (weight, blood pressure, blood lipids, insulin, etc.) as well as eight chronic diseases: Alzheimer’s disease, depression, Type 2 diabetes, fatty liver disease, atherosclerotic coronary artery disease, stroke, osteoporosis and renal failure. We also studied the effect of these factors associated with gut microbiota on healthy life expectancy and longevity.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/507393/original/file-20230131-12649-n9up99.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="figure representing several molecules" src="https://images.theconversation.com/files/507393/original/file-20230131-12649-n9up99.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/507393/original/file-20230131-12649-n9up99.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=642&fit=crop&dpr=1 600w, https://images.theconversation.com/files/507393/original/file-20230131-12649-n9up99.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=642&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/507393/original/file-20230131-12649-n9up99.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=642&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/507393/original/file-20230131-12649-n9up99.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=807&fit=crop&dpr=1 754w, https://images.theconversation.com/files/507393/original/file-20230131-12649-n9up99.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=807&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/507393/original/file-20230131-12649-n9up99.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=807&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Small organic molecules called metabolites are produced by gut bacteria. These molecules could reach organs such as the liver and the brain. However, their role in the development of chronic diseases and life expectancy is controversial.</span>
<span class="attribution"><span class="source">(Benoît Arsenault)</span>, <span class="license">Fourni par l'auteur</span></span>
</figcaption>
</figure>
<p>We hypothesised that, in the light of previously published data, a causal link would be revealed between gut dysbiosis and chronic diseases associated with aging.</p>
<p>However, contrary to our hypothesis, this Mendelian randomization analysis did not show significant effects of gut microbiota on metabolic factors and chronic diseases. Seven associations between certain microbial parameters and chronic diseases associated with aging appear to be potentially causal, but their effect is small and we cannot rule out the possibility that these associations happened by chance. Overall, the results offer little support for the hypothesis that the gut microbiota has a significant effect on our weight, metabolism and risk of developing chronic diseases.</p>
<h2>Results that call for caution</h2>
<p>These results suggest that the previously observed associations may not be causal. The associations could be explained by the diseases themselves (reverse causality bias) or by confounding factors (confounding bias) such as diet, medication, smoking, metabolic health, or others. However, these findings are consistent with the results of four recent randomized clinical trials showing that transferring gut microbiota from thin to heavyweight individuals does not lead to <a href="https://doi.org/10.3390/nu11102291">any weight loss or significant improvement in metabolic profile</a>.</p>
<p>Mendelian randomization is a method that has several advantages over observational studies. However, these results need to be contextualized. It is entirely possible that the genetic parameters we used to predict the metabolites and microbial species associated with gut dysbiosis do not fully capture the complexity of the gut microbiota. This would diminish our ability to identify meaningful associations. Therefore, studies with larger sample sizes and better characterization of the gut microbiota and its metabolites will be needed to determine whether certain gut bacteria play a key role in the etiology (the study of causes) of chronic disease and longevity.</p>
<p>Although the impact of gut dysbiosis on chronic disease appears to be limited, gut health is important for other aspects of human health. For example, the microbiota prevents other harmful bacteria from colonizing our gut. In addition, it allows us to digest certain nutrients (e.g. dietary fibre) that would otherwise <a href="https://doi.org/10.1136/bmj.k2179">be rejected by our bodies</a>. </p>
<p>Therapies that modulate the gut microbiota have recently been approved by U.S. health authorities for the prevention of <em>C. difficile</em> infections (a bacterium that causes diarrhea and other serious intestinal diseases). Our results, along with results from clinical studies less prone to reverse causality and confounding bias, do not, however, support a significant effect of gut dysbiosis on chronic disease. </p>
<p>These results support the conclusion that the potential of the microbiota as a therapeutic target for chronic diseases is, at present, low. We urge health professionals and the general public to be cautious about diagnostic tests based on gut microbiota to diagnose health problems that are not validated by the relevant health authorities. </p>
<p>Most importantly, we urge health professionals to avoid recommending specific interventions based on the mere fact that they would influence the parameters of the gut microbiota.</p><img src="https://counter.theconversation.com/content/199082/count.gif" alt="La Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Éloi Gagnon has received funding from the Fonds de recherche du Québec - Santé (FRQS).</span></em></p><p class="fine-print"><em><span>Benoit Arsenault has received research funding from the Canadian Institutes of Health Research, the Fonds de recherche du Québec - Santé, the Institut universitaire de cardiologie et de pneumologie de Québec Foundation, Pfizer and Silence Therapeutics.</span></em></p>A new study shows that the gut microbiota has little or no effect on our weight, metabolism and risk of developing chronic diseases.Éloi Gagnon, PhD Candidate, Université LavalBenoit Arsenault, Chercheur au Centre de recherche de l’Institut universitaire de cardiologie et de pneumologie de Québec et Professeur titulaire au Département de médecine, Université LavalLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1988492023-03-15T12:21:15Z2023-03-15T12:21:15ZAre you a rapid ager? Biological age is a better health indicator than the number of years you’ve lived, but it’s tricky to measure<figure><img src="https://images.theconversation.com/files/514749/original/file-20230310-2079-5uhxpf.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C2122%2C1410&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Healthspan measures incorporate quality of life in ways that lifespan does not.</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/female-babyboomer-jumping-into-lake-royalty-free-image/92930493">Ira T. Nicolai/The Image Bank via Getty Images</a></span></figcaption></figure><p>Do you ever wake up some days and think, “When I was younger, I could survive on just four hours of sleep, but now it seems like I need 10”? Or have you ever walked out of the gym and “felt” your knees?</p>
<p>Almost everyone experiences these kinds of signs of aging. But there are some people who seem to defy their age. The late U.S. Supreme Court Justice <a href="https://www.cbsnews.com/news/remembering-rbg-justice-ruth-bader-ginsburg-a-woman-who-lived-a-life-defying-expectations/">Ruth Bader Ginsberg</a> stayed on the bench until her death at age 87. The “Great British Bake Off” judge <a href="https://www.bbc.com/news/entertainment-arts-58982697">Mary Berry</a>, now in her 80s, continues to inspire people all over the world to bake and enjoy life. And actor <a href="https://www.washingtonpost.com/arts-entertainment/2021/11/10/paul-rudd-sexiest-man-alive-people/">Paul Rudd</a> was named People magazine’s “Sexiest Man Alive” in 2021 at age 52 while still looking like he’s in his 30s. Is age just a number then? </p>
<p>Researchers have focused a lot of attention on understanding the causes and risk factors of age-related diseases like Alzheimer’s, dementia, osteoporosis and cancer. But many ignore the major risk factor for all of these diseases: aging itself. More than any individual risk factor such as smoking or lack of exercise, the number of years you’ve lived predicts onset of disease. Indeed, aging increases the risk of multiple chronic diseases <a href="https://doi.org/10.1016/j.cub.2012.07.024">by up to a thousandfold</a>. </p>
<p>However, <a href="https://doi.org/10.1038/s41586-018-0457-8">no two people age the same</a>. Although age is the principal risk factor for several chronic diseases, it is an unreliable indicator of how quickly your body will decline or how susceptible you are to age-related disease. This is because there is a difference between your chronological age, or the number of years you’ve been alive, and your biological age – your physical and functional ability.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/9eOofp64IYI?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">As the author notes in her TED Talk, aging is not just a number.</span></figcaption>
</figure>
<p>I am a <a href="https://scholar.google.com/citations?user=tqI8C_UAAAAJ&hl=en">scientist interested in redefining “age.”</a> Instead of benchmarking chronological age, my lab is invested in <a href="http://agresearchlab.com">measuring biological age</a>. Biological age is a <a href="https://doi.org/10.1016/j.jacc.2019.11.062">more accurate measure of healthspan</a>, or years lived in good health, than chronological age, and doesn’t directly correlate with wrinkles and gray hairs. Rapid agers experience a faster rate of functional deterioration relative to their chronological age. </p>
<p>My grandmother, who lived to be 83 but was bedridden and could not remember who I was for the last few years of her life, was a rapid ager. My grandfather, on the other hand, also lived until he was 83, but he was active, functional and even did my homework with me until he passed away – he was a healthy ager.</p>
<p>With the unprecedented <a href="https://www.who.int/news-room/fact-sheets/detail/ageing-and-health">growth of the world’s aging population</a>, I believe that figuring out ways to measure biological age and how to maintain or delay its advance is critical not only for individual health, but also for the social, political and economic health of our society. Detecting rapid agers early on presents an opportunity to delay, change or even reverse the trajectory of biological aging. </p>
<h2>Genetics and biological age</h2>
<p>Biological aging is multifaceted. It arises from a complex mix of genetic traits and is <a href="https://doi.org/10.1016/j.jacc.2019.11.062">influenced by factors</a> like microbiome composition, environment, lifestyle, stress, diet and exercise.</p>
<p>Genetics were once thought to have no influence on aging or longevity. However, in the early 1990s, researchers reported the first studies identifying <a href="https://doi.org/10.1098/rstb.2010.0276">genes that were able to extend the lifespan</a> of a small roundworm. Since then, multiple observations support the influence of genetics on aging.</p>
<p>For example, children of long-lived parents and even those with long-lived siblings <a href="https://doi.org/10.1038/ejhg.2011.40">tend to live longer</a>. Researchers have also <a href="https://doi.org/10.1038/s41576-019-0183-6">identified multiple genes</a> that influence longevity and play a role in resilience and protection from stress. These include genes that repair DNA, protect cells from free radicals and regulate fat levels.</p>
<p>However, it is clear from studies in identical twins – who share the same genes but not the same exact lifespans – that genes are not the only factor that influences aging. In fact, genes probably account for only <a href="https://www.scientificamerican.com/article/genetic-factors-associated-with-increased-longevity-identified/">20% to 30% of biological age</a>. This suggests that other parameters can strongly influence biological aging.</p>
<h2>Environmental and lifestyle effects</h2>
<p>Researchers have found that environmental and lifestyle factors heavily influence biological age, including social connectedness, <a href="https://doi.org/10.1001/jamanetworkopen.2021.24387">sleeping habits</a>, <a href="https://www.cnn.com/2023/01/02/health/hydration-disease-aging-death-risk-study-wellness/index.html">water consumption</a>, exercise and diet. </p>
<p><a href="https://doi.org/10.1016/j.alcr.2019.02.002">Social connectedness</a> is essential for well-being throughout life. But social connections can be challenging to maintain over time due to loss of family and friends, depression, chronic illness or other factors. Several studies have reported a <a href="https://doi.org/10.1073/pnas.1219686110">strong link</a> between social isolation and increased stress, morbidity and mortality.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/514754/original/file-20230310-449-nugrkx.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Three women dancing together in a park" src="https://images.theconversation.com/files/514754/original/file-20230310-449-nugrkx.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/514754/original/file-20230310-449-nugrkx.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/514754/original/file-20230310-449-nugrkx.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/514754/original/file-20230310-449-nugrkx.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/514754/original/file-20230310-449-nugrkx.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/514754/original/file-20230310-449-nugrkx.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/514754/original/file-20230310-449-nugrkx.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Social connectedness and physical activity are linked to well-being throughout life.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/three-ladies-listening-to-music-and-dancing-royalty-free-image/1152656857">Filippo Bacci/E+ via Getty Images</a></span>
</figcaption>
</figure>
<p>Similarly, diet and exercise are strong influencers of biological age. <a href="https://doi.org/10.1177/1559827616637066">Blue zones</a>, which are areas around the world where people live long lives, attribute their successful aging to diet, exercise and social connectedness. Mostly plant-based meals and spurts of activity throughout the day are well-known “secrets” of healthspan and longevity. Although newer studies on the effects of diet interventions such as intermittent fasting and time-restricted feeding on longevity have not been rigorously tested, they do show multiple health benefits, including <a href="https://doi.org/10.1007/s00125-022-05752-z">better glucose</a> and <a href="https://doi.org/10.1186/s12986-021-00613-9">insulin regulation</a> </p>
<p>While genetics is difficult to control, diet and exercise can be modified to delay biological aging.</p>
<h2>How to measure biological age</h2>
<p>Currently, there is no effective test to predict an individual’s health trajectory early enough in life in order to intervene and improve quality of life with age. Scientists are interested in identifying a molecule that is sensitive and specific enough to serve as a <a href="https://doi.org/10.1038/s41576-022-00511-7">unique fingerprint for biological age</a>. </p>
<p>Considering the health and resilience of the individual instead of focusing solely on disease state is important in discussions on biological age. Resilience is the state of <a href="https://doi.org/10.1093%2Fgeroni%2Figab046.621">adapting and bouncing back</a> from a health challenge and is often more predictive of functional health. A molecular aging fingerprint may provide a tool to help identify people who are less resilient and require more aggressive monitoring and early intervention to preserve their health and help <a href="https://doi.org/10.1038%2Fs43587-021-00044-4">reduce gender, racial and ethnic health disparities</a>.</p>
<p>There are several promising molecular markers that may serve as biological age fingerprints.</p>
<p>One of these markers are epigenetic clocks. <a href="https://www.cdc.gov/genomics/disease/epigenetics.htm">Epigenetics</a> are chemical modifications of DNA that control gene function. Several scientists have found that DNA can get “marked” by methyl groups in a pattern that changes with age and could potentially act as a <a href="https://theconversation.com/epigenetic-and-social-factors-both-predict-aging-and-health-but-new-research-suggests-one-might-be-stronger-200153">readout for aging</a>.</p>
<p>It is important to note, however, that while epigenetic clocks have been valuable in predicting chronological age, they do not equate to biological age. In addition, it is unclear how these epigenetic marks work or how they contribute to aging.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/514752/original/file-20230310-140-5j83gz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Older adult holding gold balloons of the number 70 in a backyard" src="https://images.theconversation.com/files/514752/original/file-20230310-140-5j83gz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/514752/original/file-20230310-140-5j83gz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/514752/original/file-20230310-140-5j83gz.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/514752/original/file-20230310-140-5j83gz.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/514752/original/file-20230310-140-5j83gz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/514752/original/file-20230310-140-5j83gz.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/514752/original/file-20230310-140-5j83gz.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Age is so much more than a number.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/happy-man-with-number-70-helium-balloons-in-royalty-free-image/1187298370">Klaus Vedfelt/DigitalVision via Getty Images</a></span>
</figcaption>
</figure>
<p>Another well-regarded marker of biological age is the build-up of dysfunctional cells called senescent or <a href="https://theconversation.com/cells-become-zombies-when-the-ends-of-their-chromosomes-are-damaged-a-tactic-both-helpful-and-harmful-for-health-186445">zombie cells</a>. Cells become senescent when they experience multiple types of stress and become so damaged that they cannot divide anymore, releasing molecules that cause chronic low-grade inflammation and disease.</p>
<p><a href="https://doi.org/10.1111/acel.12344">Animal studies</a> have shown that getting rid of these cells can improve healthspan. However, what clearly defines senescent cells in humans is still unknown, making them challenging to track as a measure of biological age.</p>
<p>Lastly, the body <a href="https://doi.org/10.1126/sciadv.add6155">releases unique metabolites</a>, or chemical fingerprints, as byproducts of normal metabolism. These metabolites play a dynamic and direct role in physiological regulation and can inform functional health. My lab and others are figuring out the exact makeup of these chemicals in order to figure out which can best measure biological age. A lot of work still remains on not only identifying these metabolites, but also understanding how they affect biological age.</p>
<p>People have long sought a fountain of youth. Whether such an elixir exists is still unknown. <a href="https://doi.org/10.1038/s43587-022-00278-w">But research</a> <a href="https://doi.org/10.1038/ncomms3192">is starting</a> <a href="https://doi.org/10.1073/pnas.2107621118">to show</a> that delaying biological age may be one way to live healthier, fuller lives.</p><img src="https://counter.theconversation.com/content/198849/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Aditi Gurkar receives funding from National Institute on Health, Richard King Mellon Foundation, AFAR/Hevolution. </span></em></p>Aging is a major risk factor for many chronic diseases. Figuring out what influences longevity and how to identify rapid agers could lead to healthier and longer lives for more people.Aditi Gurkar, Assistant Professor of Geriatric Medicine, University of PittsburghLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1907312023-01-13T13:32:03Z2023-01-13T13:32:03ZMarriage provides health benefits – and here’s why<figure><img src="https://images.theconversation.com/files/502228/original/file-20221220-20-6x1y81.jpg?ixlib=rb-1.1.0&rect=17%2C17%2C5674%2C3097&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">In relationships, women tend to take the lead in promoting healthy behaviors.</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/bride-and-groom-wedding-figurines-royalty-free-image/1133833685">Peter Dazeley/The Image Bank via Getty Images</a></span></figcaption></figure><p>The new year is traditionally a time when many people feel a renewed commitment to create healthy habits, such as <a href="https://theconversation.com/hate-exercise-small-increases-in-physical-activity-can-make-a-big-difference-127679">exercising regularly</a>, drinking more water or eating more healthfully.</p>
<p>It turns out that when it comes to health, married people have an edge, especially married men. But surely the act of walking down the aisle is not what provides this health advantage. </p>
<p>So what exactly is at play?</p>
<p>As a team, we study how relationships affect health. One of us is a <a href="https://hhs.purdue.edu/directory/elizabeth-libby-richards/">nursing professor</a> who studies how social support influences health behaviors. One is a <a href="https://hhs.purdue.edu/directory/rosie-shrout/">social health psychologist</a> who explores how stress affects couples’ relationships and health, and one is a <a href="https://hhs.purdue.edu/directory/melissa-franks/">social psychologist</a> who researches how relationships influence health behavior changes. Together, we examine how partners influence each other’s health, taking gender into account in this equation.</p>
<h2>Health benefits of marriage, for men and women</h2>
<p>It’s important to note that most marriage and health studies have been limited to married men and women. But <a href="https://theconversation.com/marriage-could-be-good-for-your-health-unless-youre-bisexual-121865">more recent studies</a> are examining these relationships in partners who have the same gender identity, the same biological sex and who are gender diverse.</p>
<p>One theory that seeks to explain the link between marriage and health is the <a href="https://doi.org/10.1016/j.euroecorev.2018.02.005">act of self-selection</a>. Simply put, people who are wealthier and healthier than average are more likely not only to get married but also to find a partner who is wealthier and healthier than average. Men and women with poorer health and wealth than average <a href="https://doi.org/10.1016/j.euroecorev.2018.02.005">are less likely</a> to marry at all.</p>
<p>While this may be part of the story, marriage also provides partners <a href="https://doi.org/10.1177/2047487316643441">with a sense of belonging</a>, more opportunities for social engagement and reduced feelings of loneliness. <a href="https://link.springer.com/referenceworkentry/10.1007/978-3-319-69892-2_646-2#Sec5">This social integration</a>, or the extent to which people participate in social relationships and activities, can greatly influence health – from <a href="https://doi.org/10.1177/0898264314551172">reducing the risk of hypertension</a> and <a href="https://doi.org/10.1161/CIRCRESAHA.116.309443">heart disease</a> to <a href="https://doi.org/10.1177/0898264311432310">lowering one’s risk of death</a> or <a href="https://doi.org/10.1001/jamapsychiatry.2015.1002">suicide</a>.</p>
<figure class="align-center ">
<img alt="Middle-aged woman with long gray hair riding a bicycle in foreground and middle-aged man riding a bike in background." src="https://images.theconversation.com/files/502004/original/file-20221219-13540-5oeq00.jpg?ixlib=rb-1.1.0&rect=60%2C0%2C6720%2C4466&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/502004/original/file-20221219-13540-5oeq00.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/502004/original/file-20221219-13540-5oeq00.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/502004/original/file-20221219-13540-5oeq00.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/502004/original/file-20221219-13540-5oeq00.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/502004/original/file-20221219-13540-5oeq00.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/502004/original/file-20221219-13540-5oeq00.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">A spouse’s healthy habits, like eating well and exercising, tend to improve a partner’s health too.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/senior-mexican-couple-riding-bikes-royalty-free-image/1143944592">adamkaz/E+ via Getty Images</a></span>
</figcaption>
</figure>
<p>Another important connection between marriage and health involves the body’s inflammatory process. Research links <a href="https://doi.org/10.1016/j.neubiorev.2020.02.002">loneliness and lack of close relationships</a> with <a href="https://theconversation.com/what-is-inflammation-two-immunologists-explain-how-the-body-responds-to-everything-from-stings-to-vaccination-and-why-it-sometimes-goes-wrong-193503">inflammation</a>, or the body’s way of reacting to illness, injury or disease. Though inflammation is needed for healing, chronic inflammation is associated with <a href="https://doi.org/10.1016/j.neubiorev.2020.02.002">heart disease, arthritis, cancers</a> and <a href="https://www.autoimmuneinstitute.org/inflammation-a-driving-force-of-autoimmune-disease/">autoimmune diseases</a>. While single adults undoubtedly have very meaningful close relationships too, a healthy marriage by nature provides more opportunities for closeness and socialization, <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3971932/">supporting the link between marriage and inflammation</a>.</p>
<p>When you dig deeper, gender seems to play a role as well. One study related to <a href="https://doi.org/10.1111/j.1741-3737.2012.01023.x">marital quality, gender and inflammation</a> found a connection between lower levels of spousal support and higher levels of inflammation for women, but not men. In another study, if couples used negative communication patterns, such as one partner making demands while the other partner withdraws, <a href="https://doi.org/10.1016/j.psyneuen.2022.105989">women but not men experienced heightened inflammation</a>.</p>
<h2>Marriage and longevity</h2>
<p>Married men and married women live, on average, <a href="https://doi.org/10.1016/j.ssmph.2020.100642">two years longer than their unmarried counterparts</a>. One reason for this longevity benefit is the <a href="https://doi.org/10.1186/1471-2458-14-533">influence of marital partners on healthy behaviors</a>. Study after study shows that married people <a href="https://www.theguardian.com/lifeandstyle/2016/apr/17/couples-healthier-wealthier-marriage-good-health-single-survey-research">eat better and are less likely to smoke and drink excessively</a>. All of these healthy behaviors help explain why married people tend to live longer. However, men married to women tend to see <a href="https://doi.org/10.1007/s13524-011-0032-5">additional longevity benefits than women married to men</a>, for several possible reasons.</p>
<p>For example, female spouses may be looking out for their male partners, <a href="https://doi.org/10.1177/0022146518790560">reinforcing healthy behaviors</a> and providing more opportunities for healthy choices. On the flip side, married men are <a href="https://doi.org/10.1037/0033-2909.127.4.472">less likely to attempt to influence</a> their wives’ health behaviors. </p>
<p>Women tend to <a href="https://doi.org/10.1093/geroni/igx025">take the lead in promoting healthy behaviors</a>, benefiting their husbands. Data suggests that men and women in same-gender relationships <a href="https://doi.org/10.1016/j.socscimed.2011.11.011">tend to engage in teamwork</a> to mutually promote positive health behaviors. Further, married men and women are <a href="https://doi.org/10.1177/0022146518790560">more likely to want to change their partners’ health behaviors</a>, such as exercise, especially if the spouses’ habits are worse than their own. These findings suggest that both the person and the partner’s gender matter.</p>
<figure class="align-center ">
<img alt="middle-aged man kisses neck of male partner while he is washing dishes at kitchen sink" src="https://images.theconversation.com/files/502227/original/file-20221220-11-m98bch.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/502227/original/file-20221220-11-m98bch.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/502227/original/file-20221220-11-m98bch.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/502227/original/file-20221220-11-m98bch.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/502227/original/file-20221220-11-m98bch.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/502227/original/file-20221220-11-m98bch.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/502227/original/file-20221220-11-m98bch.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Data suggests that people in same-gender relationships engage in teamwork when it comes to health.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/senior-gay-couple-washing-dishes-together-royalty-free-image/1183447121">NicolasMcComber/E+ via Getty Images</a></span>
</figcaption>
</figure>
<p><a href="https://doi.org/10.1177/0963721414549043">Relationship quality</a> can also influence health behaviors. For example, in the context of exercise, both men and women who reported higher levels of marital support <a href="https://doi.org/10.1177/08982643221083083">were more likely to walk for exercise</a>. However, as men aged, the association between marital support and walking <a href="https://doi.org/10.1177/08982643221083083">became even stronger for them</a>, but the same was not true for married women.</p>
<h2>Cultural norms and caregiving</h2>
<p>To further understand how men’s health benefits from their wives, consider cultural norms that foster expectations that women will be the <a href="https://www.aarp.org/home-family/caregiving/info-01-2014/caregiving-family-gender-siblings-jacobs.html">primary caretaker in committed relationships</a>.</p>
<p>Middle-aged people, and in particular women, have also been described as the “<a href="https://www.kiplinger.com/personal-finance/604449/why-the-sandwich-generation-just-got-worse-for-women">sandwich generation</a>,” since they are often “sandwiched” between taking care of growing children and aging parents. Caregiving can take a <a href="https://doi.org/10.1016/j.cobeha.2019.02.002">toll on the immune system and one’s overall health</a>. Additionally, <a href="https://www.whiteswanfoundation.org/caregiving/how-the-role-of-caring-disproportionately-burdens-women">invisible labor related to child care</a> and household duties, which often disproportionately fall to women, can leave women with less time for self-care, <a href="https://doi.org/10.1177/00221465211028910">such as being physically active</a>.</p>
<p><a href="https://doi.org/10.1016/j.socscimed.2011.11.011">Women also take on more responsibilities</a> in terms of coordinating doctors’ appointments and promoting adherence to medical advice for their husbands than husbands do for their wives. However, <a href="https://doi.org/10.1093/geronb/gby087">men often increase their time spent caregiving</a> when their wives are ill. </p>
<h2>Of course, not all marriages are created equal</h2>
<p><a href="https://doi.org/10.1177/0963721414549043">Relationship quality</a> and <a href="https://doi.org/10.1177/00221465211028910">relationship conflict</a> also play important roles when it comes to marriage and health. Gendered socialization and power differences often lead to women’s thinking and <a href="https://www.unicef-irc.org/evidence-for-action/what-is-gender-socialization-and-why-does-it-matter/">caring about their relationships more than men</a>, causing women to take primary responsibility for managing relationship issues, while men take on less of the burden.</p>
<p>Research shows that women are also more likely to <a href="https://doi.org/10.1037/0033-2909.122.1.5">base their identities on their relationships</a>, and so when they experience marital conflict or other relationship issues, they experience more negative <a href="https://doi.org/10.1111/pere.12292">emotional and physical health</a> effects than men. This can include increased risk of <a href="https://doi.org/10.1037/a0019547">metabolic syndrome</a>, <a href="https://doi.org/10.1037/a0026902">inflammation</a> and <a href="https://doi.org/10.1097/PSY.0b013e3180f62357">cardiovascular disease</a>.</p>
<p>Does this mean that all men should get married to protect their health or that unmarried people can’t enjoy the same health benefits as those who have said “I do”?</p>
<p>Not at all. Unmarried people can, of course, enjoy good health and longevity. Creating and <a href="https://doi.org/10.1016/j.ssmph.2019.100425">maintaining strong social ties</a> and <a href="https://doi.org/10.1016/j.ssmph.2020.100676">engaging with one’s community</a> go a long way when it comes to health. Further, making the best lifestyle choices available, seeking preventive health care and reducing stress can help everyone live a longer, healthier life.</p><img src="https://counter.theconversation.com/content/190731/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Libby Richards has received funding from the National Institutes of Health, The American Nurses Foundation, and is currently funded through the Indiana Clinical and Translational Sciences Institute. She is affiliated with the American Public Health Association and the International Society of Behavioral Nutrition and Physical Activity. </span></em></p><p class="fine-print"><em><span>Melissa Franks receives funding from the Indiana Clinical and Translational Sciences Institute.</span></em></p><p class="fine-print"><em><span>Rosie Shrout receives funding from the Indiana Clinical and Translational Sciences Institute. She is affiliated with several organizations, including the International Association for Relationships Research, National Council on Family Relations, American Psychosomatic Society, Gerontological Society of America, and Society for Personality and Social Psychology. </span></em></p>Most marriage and health studies have focused on married men and women. But more recent studies examine relationships in which partners have the same gender identity, the same biological sex and who are gender diverse.Libby Richards, Associate Professor of Nursing, Purdue UniversityMelissa Franks, Associate Professor of Human Development and Family Studies, Purdue UniversityRosie Shrout, Assistant Professor of Human Development and Family Studies, Purdue UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1892872022-12-06T21:35:54Z2022-12-06T21:35:54ZHeads or tails: What statistical models tell us about the probability of living beyond 110<figure><img src="https://images.theconversation.com/files/483348/original/file-20220907-4832-q9y5k0.jpeg?ixlib=rb-1.1.0&rect=8%2C2%2C988%2C663&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Is there a limit to human life expectancy?</span> <span class="attribution"><span class="source">(Shutterstock)</span></span></figcaption></figure><p>The world’s presumed oldest person, Kane Tanaka of Japan, died in April in her native country <a href="https://www.nytimes.com/2022/04/27/world/asia/kane-tanaka-japan-worlds-oldest-person.html">at the age of 119</a>. Despite her spectacular longevity, she could not surpass the record set by France’s <a href="https://academic.oup.com/biomedgerontology/article/74/Supplement_1/S13/5569844">Jeanne Calment</a> 25 years ago.</p>
<p>Calment died on August 4, 1997 at the age of 122 years and five months (or precisely <a href="https://www.nytimes.com/1997/08/05/world/jeanne-calment-world-s-elder-dies-at-122.html">44,724 days</a>).</p>
<p>What are the chances of this record being beaten?</p>
<p>My area of expertise, a branch of statistics that deals with the modelling of rare events, can provide some answers to such questions.</p>
<h2>The question is, how many candidates for a new world record?</h2>
<p>It is worth noting that the phenomenon under study is exceedingly rare: according to the last census, only 0.3 per cent of the Canadian population is centenarian, or just over <a href="https://www12.statcan.gc.ca/census-recensement/2021/as-sa/98-200-X/2021004/98-200-x2021004-eng.cfm">9,500 people</a>. That’s less than in Japan, which boasted nearly <a href="https://www.stat.go.jp/english/data/jinsui/tsuki/index.html">87,000 people over 100 years old</a> in 2021.</p>
<p>Only a handful of these centenarians, less than one in a thousand, will reach 110. People who live beyond this age, the “<a href="https://www.genome.gov/27559848/researchers-examine-supercentenarians-genomes-for-longevity-key">supercentenarians</a>”, are rare exceptions.</p>
<h2>Statistical models to the rescue</h2>
<p>To determine whether or not the longevity record could be shattered, it is essential to build statistical models that describe mortality beyond 110 years.</p>
<p>For this, we need <a href="https://link.springer.com/book/10.1007/978-3-030-49970-9">quality data</a>. For example, the age at death of supercentenarians must be validated by analyzing registers and birth certificates, among other things, particularly to <a href="https://link.springer.com/book/10.1007/978-3-642-11520-2">identify inconsistencies</a>. This involves archival work: errors are frequent (bad transcription, identity theft, <a href="https://www.yourdictionary.com/necronym">necronyms</a>) and several applications are rejected because of insufficient evidence to establish identity or date of birth with certainty. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/466651/original/file-20220601-20-exsvqb.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Handwriting on old paper" src="https://images.theconversation.com/files/466651/original/file-20220601-20-exsvqb.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/466651/original/file-20220601-20-exsvqb.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/466651/original/file-20220601-20-exsvqb.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/466651/original/file-20220601-20-exsvqb.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/466651/original/file-20220601-20-exsvqb.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/466651/original/file-20220601-20-exsvqb.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/466651/original/file-20220601-20-exsvqb.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Obtaining quality data on the actual age of supercentenarians is sometimes difficult.</span>
<span class="attribution"><span class="source">(Shutterstock)</span></span>
</figcaption>
</figure>
<p>The main source of information for my research is the <a href="https://www.supercentenarians.org/en/">International Longevity Database</a> (IDL), a joint effort of gerontologists and demographers who have recorded the age at death of more than 1,041 supercentenarians from several central European countries, Japan, Canada and the United States. </p>
<p>There are significantly <a href="https://www.supercentenarians.org/en/publications/">more female than male supercentenarians</a> on record, but this imbalance is shrinking over time in several countries, including the <a href="https://www.ons.gov.uk/peoplepopulationandcommunity/birthsdeathsandmarriages/ageing/bulletins/estimatesoftheveryoldincludingcentenarians/2002to2020">United Kingdom</a>. </p>
<p>Data validation requires going back 150 years, a period when administration and census taking were of mixed quality. Countries that provide data have teams of demographers actively working on longevity, as well as archives that facilitate validation. Without a robust system, the data cannot be used.</p>
<p>Once we have acquired the necessary data on people living beyond 110 years, we can then tackle the modelling of their lifetimes. The simplest statistical model that is compatible with the data is roughly equivalent to a coin toss. If the coin comes up heads, the person will survive until their next birthday; if not, they will die within a year.</p>
<p>This model also implies that the risk of dying is stable and does not depend on the person’s past history. <a href="https://royalsocietypublishing.org/doi/10.1098/rsos.202097">According to our calculations</a>, the life expectancy of a supercentenarian person would be about a year and five months, a very short period.</p>
<p>Surviving from 110 to 122 years, like Calment, would therefore be like tossing 12 heads in a row, an event that occurs less than once in a million. In light of the number of living supercentenarians, it is not surprising that Calment’s record still stands after a quarter of a century.</p>
<h2>Jeanne Calment, unbeatable?</h2>
<p>This makes our initial question all the more intriguing: will <a href="https://academic.oup.com/biomedgerontology/article/74/Supplement_1/S13/5569844">Calment’s record</a> ever be broken? If so, what will be the new record? To answer these questions, we need demographic projections of supercentenarians that take into account the world population increase.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/466652/original/file-20220601-48776-4z2nb3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="vieil homme sur fond noir" src="https://images.theconversation.com/files/466652/original/file-20220601-48776-4z2nb3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/466652/original/file-20220601-48776-4z2nb3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=399&fit=crop&dpr=1 600w, https://images.theconversation.com/files/466652/original/file-20220601-48776-4z2nb3.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=399&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/466652/original/file-20220601-48776-4z2nb3.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=399&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/466652/original/file-20220601-48776-4z2nb3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=501&fit=crop&dpr=1 754w, https://images.theconversation.com/files/466652/original/file-20220601-48776-4z2nb3.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=501&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/466652/original/file-20220601-48776-4z2nb3.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=501&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Will Jeanne Calment’s record age at death ever be surpassed?</span>
<span class="attribution"><span class="source">(Shutterstock)</span></span>
</figcaption>
</figure>
<p>Based on these demographic projections and the coin toss model, researchers at the University of Washington have concluded that there is a good chance that Calment’s record will be broken by 2100, but that it is unlikely that the winner will live <a href="https://www.demographic-research.org/volumes/vol44/52/">past 130 years</a>.</p>
<h2>Is there a limit to human life expectancy?</h2>
<p>Several scientific studies have argued recently that human longevity is limited. <a href="https://www.annualreviews.org/doi/10.1146/annurev-statistics-040120-025426">These studies often have one feature in common</a>: they ignore how the data are collected, which skews their conclusions. </p>
<p>While life expectancy varies from country to country, longevity is an intrinsic characteristic of humankind. It is therefore illogical that a Dutch person cannot survive beyond 114 years while a Japanese person has survived to 119 years.</p>
<p>If we compare life to a long-distance race, a limit to longevity would be the equivalent of an insurmountable obstacle at the end of the run. A more logical explanation from a biological standpoint is that the person stops once his or her resources are exhausted.</p>
<p>Extrapolating the maximum age is fraught with uncertainty because of the small number of supercentenarians whose age at death has been validated. The increase in the number of countries offering reliable and validated historical data on centenarians is nevertheless promising for future research. </p>
<p><a href="https://www.annualreviews.org/doi/10.1146/annurev-statistics-040120-025426">Our analysis</a> of several reliable databases suggests that a limit to life expectancy would be well beyond Calment’s age, and that it would be surprising if it were less than 130 years.</p>
<p>Having no limit does not mean that a person could live forever: while it is possible to get tails on any coin toss, a long sequence where each throw falls on the same side is unlikely. </p>
<p>Even with the increase in the world’s population, the high mortality rate of supercentenarians limits the possibility of breaking Calment’s record. Only time will tell if the record will be beaten.</p><img src="https://counter.theconversation.com/content/189287/count.gif" alt="La Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Léo R. Belzile's research is funded by the Natural Sciences and Engineering Research Council of Canada (NSERC) and IVADO.</span></em></p>The oldest person in the world, Kane Tanaka of Japan, died in April 2022 at 119 years. The record of Jeanne Calment of France, who died at 122, has stood for almost 25 years. Will it be beaten?Léo R. Belzile, Professeur adjoint de sciences de la décision, HEC MontréalLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1855832022-06-23T20:08:24Z2022-06-23T20:08:24ZWe helped track 77 species for up to 60 years to try to reveal the secrets of long life. And some don’t seem to age at all<figure><img src="https://images.theconversation.com/files/470484/original/file-20220623-7584-nu1tiw.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Mike Gardner</span>, <span class="license">Author provided</span></span></figcaption></figure><p>Ever wondered about the secret to a long life? Perhaps understanding the lifespans of other animals with backbones (or “vertebrates”) might help us unlock this mystery.</p>
<p>You’ve probably heard turtles live a long (and slow) life. At 190 years, <a href="https://www.smithsonianmag.com/smart-news/at-190-jonathan-the-tortoise-is-the-worlds-oldest-living-land-animal-180979514/">Jonathan</a> the Seychelles giant tortoise might be the oldest land animal alive. But why do some animals live longer than others?</p>
<p>Research <a href="https://www.science.org/doi/10.1126/science.abm0151">published today</a> by myself and colleagues in the journal Science investigates the various factors that may affect longevity (lifespan) and ageing in reptiles and amphibians.</p>
<p>We used long-term data from 77 different species of reptiles and amphibians – all cold-blooded animals. Our work is a collaboration between more than 100 scientists with up to 60 years of data on animals that were caught, marked, released and re-caught.</p>
<p>These data were then compared to existing information on warm-blooded animals, and several different ideas about ageing emerged.</p>
<h2>What factors might be important?</h2>
<h1>Cold-blooded or warm-blooded</h1>
<p>One popular line of thought we investigated is the <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4843886/">idea</a> that cold-blooded animals such as frogs, salamanders and reptiles live longer because they age more <em>slowly</em>.</p>
<p>These animals have to rely on external temperatures to help regulate their body temperature. As a result they have slower “metabolisms” (the rate at which they convert what they eat and drink into energy).</p>
<p>Animals that are small and warm-blooded, such as mice, age quickly since they have faster metabolisms – and turtles age slowly since they have slower metabolisms. By this logic, cold-blooded animals should have lower metabolisms than similar-sized warm-blooded ones. </p>
<p>However, we found cold-blooded animals don’t age more slowly than similar-sized warm-blooded ones. In fact, the variation in ageing in the reptiles and amphibians we looked at was much greater than previously predicted. So the reasons vertebrates age are more complex than this idea sets out. </p>
<h1>Environmental temperature</h1>
<p>Another related <a href="https://academic.oup.com/biolinnean/article/125/4/730/5145102?login=true">theory</a> is that environmental temperature itself could be a driver for longevity. For instance, animals in colder areas might be processing food more slowly and have periods of inactivity, such as with hibernation – leading to an overall increase in lifespan. </p>
<p>Under this scenario, both cold and warm-blooded animals in colder areas would live longer than animals in warmer areas. </p>
<p>We found this was true for reptiles as a group, but not for amphibians. Importantly, this finding has implications for the effects of global warming, which might lead to reptiles ageing faster in permanently warmer environments.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/470478/original/file-20220623-51865-930myg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="The stripy brown small lizard sits on a rock" src="https://images.theconversation.com/files/470478/original/file-20220623-51865-930myg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/470478/original/file-20220623-51865-930myg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=401&fit=crop&dpr=1 600w, https://images.theconversation.com/files/470478/original/file-20220623-51865-930myg.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=401&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/470478/original/file-20220623-51865-930myg.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=401&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/470478/original/file-20220623-51865-930myg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=504&fit=crop&dpr=1 754w, https://images.theconversation.com/files/470478/original/file-20220623-51865-930myg.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=504&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/470478/original/file-20220623-51865-930myg.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=504&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The Viviparous lizard (<em>Zootoca vivipara</em>) is one of the cold-blooded species we studied.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/viviparous-lizard-zootoca-vivipara-34699252">Shutterstock</a></span>
</figcaption>
</figure>
<h1>Protection</h1>
<p>One <a href="https://onlinelibrary.wiley.com/doi/full/10.1111/jeb.12143">suggestion</a> is that animals with certain types of protections, such as protruding spines, armour, venom or shells, also don’t age as fast and therefore live longer. </p>
<p>A lot of energy is put into producing these protections, which can allow animals to live longer by making them less vulnerable to predation. However, could it be the very fact of having these protections allows animals to age more slowly?</p>
<p>Our work found this to be true. It seems having such protections does lead to animals living longer. This is especially true for turtles, which have hard shell protection and incredibly long lifespans.</p>
<p>We’ll need to conduct more research to figure out why just having protections is linked to a longer life.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/470483/original/file-20220623-51187-mpi2xr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A crocodile sits on the bank of a river with its mouth open" src="https://images.theconversation.com/files/470483/original/file-20220623-51187-mpi2xr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/470483/original/file-20220623-51187-mpi2xr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/470483/original/file-20220623-51187-mpi2xr.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/470483/original/file-20220623-51187-mpi2xr.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/470483/original/file-20220623-51187-mpi2xr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/470483/original/file-20220623-51187-mpi2xr.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/470483/original/file-20220623-51187-mpi2xr.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">One species of crocodile studied, <em>Crocodylus johnsoni</em>, has a powerful armoured body with protruding scales that protect it from predation.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/freshwater-crocodile-crocodylus-johnstoni-species-endemic-1541741615">Shutterstock</a></span>
</figcaption>
</figure>
<h1>Reproduction</h1>
<p>Finally, it has been <a href="https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0066670">posited</a> that perhaps longevity is linked to how late into life an animal reproduces. </p>
<p>If they can keep reproducing later into life, then natural selection would drive this ability, generation to generation, allowing these animals to live longer than those that reproduce early and can’t continue to do so.</p>
<p>Indeed, we found animals that start producing offspring at a later age do seem to live longer lives. Sleepy lizards (or shinglebacks) are a great example. They don’t reproduce until they’re about five years old, and live until they’re close to 50!</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/breakthrough-allows-scientists-to-determine-the-age-of-endangered-native-fish-using-dna-162084">Breakthrough allows scientists to determine the age of endangered native fish using DNA</a>
</strong>
</em>
</p>
<hr>
<h2>The challenge in understanding ageing</h2>
<p>To understand ageing, we need a lot of data on the same animals. That’s simply because if we want to know how long a species lives, we have to keep catching the same individuals over and over, across large spans of time. </p>
<p>This is “longitudinal” research. Luckily, it’s exactly what some scientists have committed themselves to. It’s also what my team is doing with sleepy lizards, <em>Tiliqua rugosa</em>. These lizards have been studied continuously at Bundey Bore station in the Mid North of South Australia since 1982. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/470225/original/file-20220622-3398-sv0ijc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/470225/original/file-20220622-3398-sv0ijc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/470225/original/file-20220622-3398-sv0ijc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/470225/original/file-20220622-3398-sv0ijc.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/470225/original/file-20220622-3398-sv0ijc.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/470225/original/file-20220622-3398-sv0ijc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/470225/original/file-20220622-3398-sv0ijc.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/470225/original/file-20220622-3398-sv0ijc.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The sleepy lizard is one of the species used in the longevity study. As far as we know, this species lives up to 50 years.</span>
<span class="attribution"><span class="source">Mike Gardner</span></span>
</figcaption>
</figure>
<p>Here, more than 13,000 lizards have been caught over 40 years of study. Some have been caught up to 60 times! But given the 45-year longevity of these lizards, we’ve been studying them for a shorter time than some of them live. By keeping the survey work going we might find they live even longer. </p>
<h2>Some animals’ chance of dying isn’t linked to age</h2>
<p>Another interesting part of this research was finding, for a range of animals, that their chance of dying is just as small when they’re quite old compared to when they’re young. This “negligible ageing” is found in at least one species across each of frogs, salamanders, lizards, crocodiles and, of course, in tortoises like Jonathon. </p>
<p>We’re not quite sure why this is. The next challenge is to find out – perhaps by analysing species genomes. Knowing some animals have negligible ageing means we can target these species for future investigations. </p>
<p>Understanding what drives long life in other animals might lead to different biomedical targets to study humans too. We might not live to Jonathan the tortoise’s age, but we could theoretically use this knowledge to develop therapies that help stop some of the ageing process in us. </p>
<p>For now, healthy eating and exercising remain surer ways to a longer life.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/the-search-to-extend-lifespan-is-gaining-ground-but-can-we-truly-reverse-the-biology-of-ageing-75127">The search to extend lifespan is gaining ground, but can we truly reverse the biology of ageing?</a>
</strong>
</em>
</p>
<hr>
<img src="https://counter.theconversation.com/content/185583/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Mike Gardner receives funding from the Australian Research Council. He is affiliated with The South Australian Museum. </span></em></p>Our research is countering some previous ideas about what factors might slow down ageing. Further study could help us create targeted treatments in humans too.Mike Gardner, Flinders UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1847852022-06-21T10:12:45Z2022-06-21T10:12:45ZDo optimists really live longer? Here’s what the research says<figure><img src="https://images.theconversation.com/files/469985/original/file-20220621-16-b1wwi2.jpg?ixlib=rb-1.1.0&rect=13%2C20%2C4642%2C3078&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Women who reported themselves to have high levels of optimism lived longer on average.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/happy-senior-lady-sitting-on-wooden-458894395">FamVeld/ Shutterstock</a></span></figcaption></figure><p>Do you tend to see the glass as half full, rather than half empty? Are you always looking on the bright side of life? If so, you may be surprised to learn that this tendency could actually be good for your health.</p>
<p>A <a href="https://content.apa.org/record/2020-71981-001">number of studies</a> have shown that optimists enjoy higher levels of wellbeing, better sleep, lower stress and even better cardiovascular health and immune function. And now, <a href="https://pubmed.ncbi.nlm.nih.gov/35674052/">a recent study</a> has shown that being an optimist is linked to longer life. </p>
<p>To conduct their study, researchers tracked the lifespan of nearly 160,000 women aged between 50 to 79 for a period of 26 years. At the beginning of the study, the women completed a <a href="https://local.psy.miami.edu/people/faculty/ccarver/availbale-self-report-instruments/lot-r/">self-report measure of optimism</a>. Women with the highest scores on the measure were categorised as optimists. Those with the lowest scores were considered pessimists.</p>
<p>Then, in 2019, the researchers followed up with the participants who were still living. They also looked at the lifespan of participants who had died. What they found was that those who had the highest levels of optimism were more likely to live longer. More importantly, the optimists were also more likely than those who were pessimists to live into their nineties. Researchers refer to this as “exceptional longevity”, considering the average lifespan for women is about 83 years in developed countries. </p>
<p>What makes these findings especially impressive is that the results remained even after accounting for other factors known to predict a long life – including education level and economic status, ethnicity, and whether a person suffered from depression or other chronic health conditions. </p>
<p>But given this study only looked at women, it’s uncertain whether the same would be true for men. However, <a href="https://www.pnas.org/doi/abs/10.1073/pnas.1900712116">another study</a> which looked at both men and women also found that people with the highest levels of optimism enjoyed a lifespan that was between 11% and 15% longer than those who were the least optimistic. </p>
<h2>The fountain of youth?</h2>
<p>So why is it that optimists live longer? At first glance it would seem that it may have to do with their healthier lifestyle. </p>
<p>For example, <a href="https://www.ahajournals.org/doi/10.1161/CIRCRESAHA.117.310828">research from several studies</a> has found that optimism is linked to eating a healthy diet, staying physically active, and being less likely to smoke cigarettes. These healthy behaviours are well known to improve heart health and <a href="https://www.who.int/news-room/fact-sheets/detail/noncommunicable-diseases">reduce the risk</a> for cardiovascular disease, which is a <a href="https://www.who.int/news-room/fact-sheets/detail/cardiovascular-diseases-(cvds)">leading cause of death</a> globally. Adopting a healthy lifestyle is also <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3857242/">important for reducing the risk</a> of other potentially deadly diseases, such as diabetes and cancer. </p>
<figure class="align-center ">
<img alt="Two elderly women out for a walk together on a pier on a sunny day." src="https://images.theconversation.com/files/469986/original/file-20220621-11-wty41p.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/469986/original/file-20220621-11-wty41p.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/469986/original/file-20220621-11-wty41p.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/469986/original/file-20220621-11-wty41p.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/469986/original/file-20220621-11-wty41p.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/469986/original/file-20220621-11-wty41p.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/469986/original/file-20220621-11-wty41p.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Optimists tend to have healthier lifestyle habits.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/action-portrait-elderly-women-jogging-together-162594119">karelnoppe/ Shutterstock</a></span>
</figcaption>
</figure>
<p>But having a healthy lifestyle may only be part of the reason optimists live a longer than average life. This latest study found that lifestyle only accounted for 24% of the link between optimism and longevity. This suggests a number of other factors affect longevity for optimists.</p>
<p>Another possible reason could be due to the way optimists manage stress. When faced with a stressful situation, optimists tend to deal with it head-on. They <a href="https://pubmed.ncbi.nlm.nih.gov/16859439/">use adaptive coping strategies</a> that help them resolve the source of the stress, or view the situation in a less stressful way. For example, optimists will problem-solve and plan ways to deal with the stressor, call on others for support, or try to find a “silver lining” in the stressful situation.</p>
<p>All of these approaches are well-known to reduce feelings of stress, as well as the biological reactions that occur when we feel stressed. It’s these <a href="https://www.apa.org/topics/stress/body">biological reactions to stress</a> –- such as elevated cortisol (sometimes called the “stress hormone”), increased heart rate and blood pressure, and impaired immune system functioning –- that can take a toll on health over time and increase the risk for developing <a href="https://www.sciencedirect.com/science/article/pii/S0889159115004316?via%3Dihub">life-threatening diseases</a>, such as cardiovascular disease. In short, the way optimists cope with stress may help protect them somewhat against its harmful effects. </p>
<h2>Looking on the bright side</h2>
<p>Optimism is typically viewed by researchers as a relatively stable personality trait that is determined by both <a href="https://www.cambridge.org/core/journals/twin-research-and-human-genetics/article/sex-differences-in-the-genetic-architecture-of-optimism-and-health-and-their-interrelation-a-study-of-australian-and-swedish-twins/58F21AA11943D44B4BA4C63A966E6AC7#">genetic</a> and early childhood influences (such as having a <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6541423/">secure and warm relationship</a> with your parents or caregivers). But if you’re not naturally prone to seeing the glass as half full, there are some ways you can increase your <a href="https://www.tandfonline.com/doi/abs/10.1080/17439760.2016.1221122?journalCode=rpos20">capacity to be optimistic</a>.</p>
<p>Research shows optimism can change over time, and can be cultivated by engaging in simple exercises. For example, visualising and then writing about your “<a href="https://www.psychologytoday.com/us/blog/what-matters-most/201303/what-is-your-best-possible-self">best possible self</a>” (a future version of yourself who has accomplished your goals) is a technique that studies have found can <a href="https://www.tandfonline.com/doi/full/10.1080/17439760.2016.1221122">significantly increase optimism</a>, at least temporarily. But for best results, the goals need to be both positive and reasonable, rather than just wishful thinking. Similarly, simply <a href="https://www.tandfonline.com/doi/abs/10.3200/SOCP.149.3.349-364">thinking about positive future events</a> can also be effective for boosting optimism.</p>
<p>It’s also crucial to temper any expectations for success with an accurate view of what you can and can’t control. Optimism is reinforced when we experience the positive outcomes that we expect, and <a href="https://psycnet.apa.org/record/1970-20680-001">can decrease</a> when these outcomes aren’t as we want them to be. Although more research is needed, it’s possible that regularly envisioning yourself as having the best possible outcomes, and taking realistic steps towards achieving them, can help develop an optimistic mindset. </p>
<p>Of course, this might be easier said than done for some. If you’re someone who isn’t naturally optimistic, the best chances to improve your longevity is by <a href="https://journals.plos.org/plosmedicine/article?id=10.1371/journal.pmed.1003332">living a healthy lifestyle</a> by staying physically active, eating a healthy diet, managing stress, and getting a good night’s sleep. Add to this cultivating a more optimistic mindset and you might further increase your chances for a long life.</p><img src="https://counter.theconversation.com/content/184785/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Fuschia Sirois receives funding from Economic and Social Research Council, UK.</span></em></p>According to a recent study, optimists were more likely to live into their nineties.Fuschia Sirois, Professor in Social & Health Psychology, Durham UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1830562022-05-27T14:30:33Z2022-05-27T14:30:33ZEating sea squirts reverses signs of ageing in mice – new research<figure><img src="https://images.theconversation.com/files/465747/original/file-20220527-19-xdw67z.jpg?ixlib=rb-1.1.0&rect=4%2C2%2C994%2C663&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Sea squirts.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/ascidia-purple-underwater-photo-coral-reef-732753811">Kichigin/Shutterstock</a></span></figcaption></figure><p>Mice fed extracts of a creature called a sea squirt – so-called because they tend to squirt water when plucked from their briny home – reversed some of the signs of ageing, according to a <a href="https://www.frontiersin.org/articles/10.3389/fmolb.2022.815320/full">recent study</a> from China. </p>
<p>The extracts fed to the mice are called plasmalogens – a type of lipid (fat) found in the membrane of cells in human organs such as the brain, kidneys, muscle and lungs. They have a variety of functions, including regulating how cells exchange information, protecting the cells from DNA damage and decreasing inflammation. </p>
<p><a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6357979/">Past research</a> has shown that the amount of plasmalogens in the blood decreases with age and especially <a href="https://pubmed.ncbi.nlm.nih.gov/25858158/">in people with Alzheimer’s disease</a>, the most common form of dementia. </p>
<p>Significant amounts of plasmalogens are found in foods such as chicken, pork, beef, mussels, scallops and, of course, sea squirts, which are eaten in Korea and Japan.</p>
<figure class="align-center ">
<img alt="Sea squirt bibimbap." src="https://images.theconversation.com/files/462987/original/file-20220513-14-h05gna.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C6000%2C3988&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/462987/original/file-20220513-14-h05gna.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/462987/original/file-20220513-14-h05gna.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/462987/original/file-20220513-14-h05gna.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/462987/original/file-20220513-14-h05gna.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/462987/original/file-20220513-14-h05gna.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/462987/original/file-20220513-14-h05gna.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">A Korean dish: sea squirt bibimabap.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/korean-food-called-sea-squirt-bibimbap-1702191028">loveallyson/Shutterstock</a></span>
</figcaption>
</figure>
<p>In this latest study, researchers gave plasmalogens to middle-aged female mice in much higher concentrations (around 300 to 500 times higher) than would normally be found in a portion of, say, chicken or scallops. They then assessed the mice’s memory and some important parameters that change in the brain with age. </p>
<p>This included the number of neural stem cells, which generate new neurons (brain cells), and the number of connections between neurons. These are both important for maintaining the ability to learn, remember and reason. </p>
<p>They found that all of these parameters were improved when the mice were fed plasmalogens for two months. Also, inflammation was greatly decreased in the mice given plasmalogen compared with those on a normal diet (the control group). Inflammation increases with age and is thought to be an important cause of <a href="https://www.nature.com/articles/s41598-021-81705-7">worsening symptoms of Alzheimer’s disease</a>.</p>
<p>The researchers also showed that mice had improved memory. To do this, they used a test – called a Morris water maze – that uses sensory skills, including good eyesight, to learn to perform a task. </p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/ScfOE1qMIFY?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">How a Morris water maze task works.</span></figcaption>
</figure>
<p>Unfortunately, mice tend to suffer a loss of sensory skills such as blindness and hearing with age and therefore these findings need to be treated with caution. The perceived improvement in memory could be the result of improved sensory skills rather than memory. </p>
<p>However, these latest findings are supported by <a href="https://www.thelancet.com/journals/ebiom/article/PIIS2352-3964(17)30071-3/fulltext">an earlier study</a> in which people with mild cognitive impairment were fed plasmalogens (this time from scallops) twice a day for 24 weeks. The participants given the plasmalogens showed improved memory. However, this improvement was only observed in a subgroup of patients who were female and younger than 77 years old. The reason it only worked for this subgroup is not clear and needs to be studied further with a larger group of participants.</p>
<h2>Geroprotectors</h2>
<p>Although these findings are interesting, more work is needed to find out if plasmalogens really are “geroprotectors” – drugs that delay cellular ageing, thereby reducing the risk of developing many age-related diseases. It’s important to find out how plasmalogens delay ageing and whether their effects go beyond the brain to include other important organs, such as the heart, the muscle and the immune system. </p>
<p><a href="http://geroprotectors.org/">Over 200 geroprotectors</a> have been tested in animals. In many studies, researchers have shown that geroprotectors can improve the function of vital organs. A handful of these have also been shown to delay the onset and severity of age-related chronic conditions such as osteoarthritis, heart disease, osteoporosis and Alzheimer’s disease in lab animals. </p>
<p>The next step is to test these drugs in patients, but this is difficult because of the way drugs are tested and approved for use. This is usually in patients with a specific disease and once the disease has been diagnosed. However, these drugs are more likely to give the best results when taken to stave off age-related diseases.</p>
<p>They may even prevent more than one disease at the same time. To test them, researchers need to identify who is at risk of developing one or more age-related diseases and then undertake a long and expensive trial to find out who gets the disease and who is protected.</p>
<p>To reduce the time of testing, researchers are now developing ways to identify who will develop specific age-related diseases in advance. But even if these studies are successful, the question remains of whether using geroprotectors to prevent diseases is cost-effective and safe. Perhaps other measures, such as an improved diet and exercise, may be just as good, if not better.</p><img src="https://counter.theconversation.com/content/183056/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Ilaria Bellantuono is an employee of the University of Sheffield and receives funding from Horizon2020, MRC, BBSRC</span></em></p>A compound in sea squirts seemed to reverse some of the signs of ageing in middle-aged mice, but will it work in humans?Ilaria Bellantuono, Professor of Musculoskeletal Ageing, University of SheffieldLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1782092022-03-02T11:45:41Z2022-03-02T11:45:41ZJust 30-90 minutes of resistance training weekly decreases risk of premature death – new research<figure><img src="https://images.theconversation.com/files/449504/original/file-20220302-21-1uavg31.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C5943%2C3709&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">It's important to do resistance training alongside other types of exercise.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/senior-people-trainer-using-resistance-band-1454696495">Leszek Glasner/ Shutterstock</a></span></figcaption></figure><p>There’s long been evidence that moderate aerobic exercise (think walking, running, or cycling) are good for your lifelong health and well-being. Research even shows us more active people also <a href="https://www.sciencedirect.com/science/article/pii/S0140673617316343?via%3Dihub">tend to live longer, healthier lives</a> with lower rates of disease – <a href="https://academic.oup.com/jpubhealth/article/41/3/e253/5139677">including cancers, diabetes and cardiovascular disease</a>. </p>
<p>But what about resistance exercise – like lifting weights? While it’s thought these kinds of exercises are probably also good for health and longevity, less evidence has existed showing the benefits. But a recent study now shows that <a href="https://bjsm.bmj.com/content/early/2022/01/19/bjsports-2021-105061">30-90 minutes of resistance training a week</a> is enough to potentially decrease risk of premature death from all causes by 10%-20%.</p>
<p>The team of researchers from three universities in Japan conducted a meta-analysis – meaning they pooled data from 16 separate studies looking at longevity, disease risk and resistance exercise. This allowed them to look at tens of thousands of participants altogether.</p>
<p>They found that 30-90 minutes of resistance exercise per week was optimal for lowering overall risk of dying from all causes. More strikingly, they also found regularly performing more than three hours of strength training per week could actually increase risk of premature death by about 10%. </p>
<p>They also found that the optimal amount of time spent resistance training varied when it came to preventing different diseases. For example, while 40-60 minutes of strength training per week is optimal for reducing risk of cardiovascular disease, the risk of diabetes continues to drop the more time a person spent resistance training each week. However, resistance training was shown to have no effect on the risk of some specific types of cancer, such as bowel, kidney or pancreatic. </p>
<p>The findings of this study are largely in line with what the NHS already recommends. According to them, adults aged 19 to 64 should aim to do <a href="https://www.nhs.uk/live-well/exercise/">two strength training sessions</a> per week in order to benefit their overall health. But given public health guidelines are often a compromise between what’s optimal to perform and what people won’t be put off by, it’s promising to see that the optimal amount of strength training per week to benefit health so closely mirrors current guidelines. </p>
<figure class="align-center ">
<img alt="A middle-aged man performs an arm exercise at the gym using a weight machine." src="https://images.theconversation.com/files/449505/original/file-20220302-12454-tkhu4z.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/449505/original/file-20220302-12454-tkhu4z.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/449505/original/file-20220302-12454-tkhu4z.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/449505/original/file-20220302-12454-tkhu4z.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/449505/original/file-20220302-12454-tkhu4z.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/449505/original/file-20220302-12454-tkhu4z.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/449505/original/file-20220302-12454-tkhu4z.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Resistance exercise doesn’t just have to mean lifting weights.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/adult-age-man-working-training-gym-1289966182">VH-studio/ Shutterstock</a></span>
</figcaption>
</figure>
<p>There are a couple of limitations with this study. While the number of people pooled across the studies is large, the number of studies actually included in the analysis is still quite small. The participants of the study were also primarily North American or western European – so the findings may not be as relevant for people of many different ethnic backgrounds. Another limitation is that most of the studies included in the analysis relied on questionnaires of large groups of people asking about their exercise habits. The problem with this is that people may overestimate or lie about the amount of exercise they actually do. </p>
<h2>Optimal exercise</h2>
<p>Strength training is good for your overall health in many more ways than you might expect.</p>
<p>Besides the obvious – that it makes you stronger, for example – researchers are beginning to learn more about the role certain hormones and cells that are released during resistance exercise play in our body. </p>
<p>For example, myokines are hormones that our muscles release in response to all sorts of stimuli – <a href="https://pubmed.ncbi.nlm.nih.gov/32393961/">including exercise</a>. Circulating around the body, myokines are able to regulate metabolism, as well as liver, brain and kidney function. One specific myokine I’ve spent a career studying is myostatin. While we know that <a href="https://pubmed.ncbi.nlm.nih.gov/22340904/">it regulates muscle size</a>, there’s all sorts of new evidence that it also influences <a href="https://pubmed.ncbi.nlm.nih.gov/34856088/">metabolism</a> and <a href="https://pubmed.ncbi.nlm.nih.gov/34634123/">fat cell growth</a> – which all play a role in helping us keep healthy and live longer. </p>
<p>Research also shows us that <a href="https://pubmed.ncbi.nlm.nih.gov/34650440/">resistance exercise</a> releases tiny cell fragments from our muscle cells called “extracellular vesicles”. These allow our muscle tissues to better communicate with each other. While we don’t entirely know what they’re doing, we do know that they’re carrying RNA (a molecule similar to DNA), proteins and even mitochondria (which help convert food into energy our cells can use) from <a href="https://www.frontiersin.org/articles/10.3389/fimmu.2018.00738/full">cell to cell</a>. So although we aren’t entirely clear of their function yet, this is just another reminder of the influence our muscles have on many aspects of our health and body function.</p>
<p>However, the authors of this recent study only looked at the relationship between strength training and longevity. This means they didn’t look at why it has a protective effect – and why more than three hours of strength training per week was also linked to slightly greater risk of premature death. While we may be able to speculate on why strength training has this protective effect based on what other research has shown, more follow-up studies will be needed that really seek to explore these questions. </p>
<p>But while this study has shown strength training to be beneficial for preventing premature death from many harmful diseases, that doesn’t mean you should only strength train. It’s important to also do moderate intensity aerobic exercise (such as walking, jogging or cycling) most days of the week to optimise your chances of living a longer, healthier life.</p><img src="https://counter.theconversation.com/content/178209/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Bradley Elliott receives funding from The Endocrine Society, The Physiological Society, the Quintin Hogg Charitable Trust and private philanthropic donors. He is affiliated with The Physiological Society, and is a Trustee of the British Society for Research on Ageing.</span></em></p>The study found that short amounts of weekly resistance exercise lowered risk of premature death from many different diseases by around 10-20%.Bradley Elliott, Senior Lecturer in Physiology, University of WestminsterLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1764942022-02-08T19:03:46Z2022-02-08T19:03:46ZChanging your diet could add ten years to your life – new research<p>Everyone wants to live longer. And we’re often told that the key to doing this is making healthier lifestyle choices, such as exercising, avoiding smoking and not drinking too much alcohol. Studies have also shown that diet can <a href="https://content.iospress.com/articles/mediterranean-journal-of-nutrition-and-metabolism/mnm180225">increase lifespan</a>. </p>
<p>A <a href="http://journals.plos.org/plosmedicine/article?id=10.1371/journal.pmed.1003889">new study</a> has found that eating healthier could extend lifespan by six to seven years in middle-aged age adults, and in young adults, could increase lifespan by about ten years. </p>
<p>The researchers brought together data from many studies that looked at diet and longevity, alongside data from the <a href="https://www.healthdata.org/gbd/2019">Global Burden of Disease</a> study, which provides a summary of population health from many countries. Combining this data, the authors were then able to estimate how life expectancy varied with continuous changes in intake of fruit, vegetables, whole grains, refined grains, nuts, legumes, fish, eggs, dairy, red meat, processed meat and sugary drinks. </p>
<p>The authors were then able to produce an optimal diet for longevity, which they then compared with the typical western diet – which mostly contains high amounts of processed foods, red meat, high-fat dairy products, high-sugar foods, pre-packed foods and low fruit and vegetable intake. According to their research, an optimal diet included more legumes (beans, peas and lentils), whole grains (oats, barley and brown rice) and nuts, and less red and processed meat. </p>
<p>The researchers found that eating an optimal diet from age 20 would increase life expectancy by more than a decade for women and men from the US, China and Europe. They also found that changing from a western diet to the optimal diet at age 60 would increase life expectancy by eight years. For 80-year-olds, life expectancy could increase by almost three and a half years. </p>
<p>But given it isn’t always possible for people to completely change their diet, the researchers also calculated what would happen if people changed from a western diet to a diet that was halfway between the optimal diet and the typical western diet. They found that even this kind of diet – which they called a “feasibility approach diet” – could still increase life expectancy for 20-year-olds by just over six years for women and just over seven years for men.</p>
<figure class="align-center ">
<img alt="A table which shows how many grams of each food group a person should aim to consume on each of the three diets the researchers looked at in their study." src="https://images.theconversation.com/files/445094/original/file-20220208-21-2q91vx.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/445094/original/file-20220208-21-2q91vx.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=376&fit=crop&dpr=1 600w, https://images.theconversation.com/files/445094/original/file-20220208-21-2q91vx.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=376&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/445094/original/file-20220208-21-2q91vx.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=376&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/445094/original/file-20220208-21-2q91vx.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=473&fit=crop&dpr=1 754w, https://images.theconversation.com/files/445094/original/file-20220208-21-2q91vx.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=473&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/445094/original/file-20220208-21-2q91vx.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=473&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">A table showing the typical amount of foods people should aim to consume daily on each type of diet.</span>
<span class="attribution"><span class="source">Laura Brown</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>These results show us that making long-term diet changes at any age may have substantial benefits to life expectancy. But the gains are largest if these changes start early in life. </p>
<h2>Full picture?</h2>
<p>The life expectancy estimates this study makes come from the most thorough and recent meta-analyses (a study that combines the results of multiple scientific studies) on diet and mortality. </p>
<p>While meta-analyses are, in many cases, the best evidence because of the amount of data analysed, they still produce assumptions with the data, which may cause important differences between studies to be ignored. It’s also worth noting that the evidence for reducing consumption of eggs and white meat was of a lower quality than the evidence they had for whole grains, fish, processed meats and nuts. </p>
<p>There are also a few things the study didn’t take into account. First, to see these benefits, people needed to make changes to their diet within a ten-year period. This means it’s uncertain if people may still see benefits to their lifespan if they make changes to their diet over a longer period of time. The study also didn’t take past ill-health into account, which can affect life expectancy. This means that the benefits of diet on life expectancy only reflect an average and may be different for each person depending on a variety of other factors, such as ongoing health issues, genetics and lifestyle, such as smoking, drinking alcohol and exercise.</p>
<p>But the evidence the researchers looked at was still robust and drawn from many studies on this subject. These findings also align with <a href="https://content.iospress.com/articles/mediterranean-journal-of-nutrition-and-metabolism/mnm180225#ref181">previous research</a> which has shown that modest but long-term improvements to diet and lifestyle can have <a href="https://pubmed.ncbi.nlm.nih.gov/20421558/">significant health benefits</a> – including longevity.</p>
<p>It’s not yet entirely clear all the mechanisms that explain why diet can improve lifespan. But the optimal diet that the researchers uncovered in this study includes many foods that are high in antioxidants. <a href="https://content.iospress.com/articles/mediterranean-journal-of-nutrition-and-metabolism/mnm180225#ref18">Some research</a> in human cells suggests that these substances may slow or prevent damage to cells, which is one cause of ageing. However, research in this area is still ongoing, so it’s uncertain whether antioxidants that we consume as part of our diet will have the same effect. Many of the foods included within this study also have anti-inflammatory properties, which may also delay the onset of various diseases – and the ageing process. </p>
<p>Of course, changing your diet completely can be difficult. But even introducing some of the foods shown to increase longevity may still have some benefit.</p><img src="https://counter.theconversation.com/content/176494/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Laura Brown does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Diets high in legumes, whole grains, nuts and less red and processed meat were shown to be more beneficial for longevity.Laura Brown, Senior Lecturer in Nutrition, Food, and Health Sciences, Teesside UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1753792022-01-21T13:00:46Z2022-01-21T13:00:46ZJeff Bezos is looking to defy death – this is what we know about the science of ageing<p>Jeff Bezos is on a mission to conquer ageing. He has just <a href="https://www.thetimes.co.uk/article/bezos-hire-joins-quest-for-eternal-youth-cckjmrjp0">recruited Hal Barron</a> from GlaxoSmithKline to help lead Altos Labs, the ambitious new anti-ageing company with billions of investment. So what does science really say about this? Could we beat ageing?</p>
<hr>
<iframe id="noa-web-audio-player" style="border: none" src="https://embed-player.newsoveraudio.com/v4?key=x84olp&id=https://theconversation.com/jeff-bezos-is-looking-to-defy-death-this-is-what-we-know-about-the-science-of-ageing-175379&bgColor=F5F5F5&color=D8352A&playColor=D8352A" width="100%" height="110px"></iframe>
<p><em>You can listen to more articles from The Conversation, narrated by Noa, <a href="https://theconversation.com/uk/topics/audio-narrated-99682">here</a>.</em></p>
<hr>
<p>Ageing isn’t just a change in how we feel or look, ageing happens at a cellular level. In a lab culture dish, adult skin cells divide roughly 50 times before stopping. But skin cells from a newborn baby can divide 80 or 90 times. And on the flip side, cells from someone elderly divide only around <a href="https://www.penguin.co.uk/books/1109946/the-beautiful-cure/9781784702212.html">twenty times</a>.</p>
<p>Ageing is also evident in our genes. Our genetic material is modified over time – chemicals can be attached that change which genes are switched on or off. These are called <a href="https://www.nature.com/articles/s41580-019-0204-5">epigenetic changes</a>, and they build up as we age. Another kind of change takes place at the ends of our cell’s DNA. Repeating segments of DNA called telomeres act like the plastic tip of a shoelace, preventing the twisted coils of genetic material from fraying at the ends or knotting together. But these telomeres shorten each time a cell divides. We don’t know if short telomeres are merely a mark of ageing, like grey hair, or are part of the process by which cells age.</p>
<p><strong>Cells, chromosomes and telomeres</strong></p>
<figure class="align-center ">
<img alt="Graphic showing telomeres." src="https://images.theconversation.com/files/441952/original/file-20220121-21-1ww2v70.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/441952/original/file-20220121-21-1ww2v70.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/441952/original/file-20220121-21-1ww2v70.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/441952/original/file-20220121-21-1ww2v70.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/441952/original/file-20220121-21-1ww2v70.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/441952/original/file-20220121-21-1ww2v70.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/441952/original/file-20220121-21-1ww2v70.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Telomeres are like the protective caps on the ends of shoelaces.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/editor/image/telomeres-protective-caps-on-end-chromosomes-710795275">Fancy Tapis/Shutterstock</a></span>
</figcaption>
</figure>
<p>To keep alive and keep dividing, immune cells stop their telomeres shortening when they multiply, <a href="https://www.nature.com/articles/nrm.2016.171">as do cancer cells</a>. This is probably a contributing factor in their apparent immortality. Drugs that stop telomerase from working also show <a href="https://www.nature.com/articles/s41388-020-01405-w">promise against cancer</a> (although cancer cells can evolve resistance).</p>
<h2>Bigger question</h2>
<p>Given that ageing has such a profound effect on our cells and genes – the effects mentioned here being just some examples – a much bigger question emerges: why does this happen? Why do we age?</p>
<p>It was once thought that ageing happened for the continuing evolution of species. In other words, the evolution of a species requires a turnover of individuals. However, one problem with this idea is that most life on Earth doesn’t ever reach old age. Most animals are killed by predators, disease, the climate or starvation. So an inbuilt limit on an animal’s lifespan may not be important to evolution.</p>
<p>Another view is that ageing is simply a side-effect of the damage that builds up over time caused by metabolism or exposure to ultraviolet light from the Sun. We do know that genes are damaged as we age, but it is not proven that this drives ageing directly. Another possibility is that ageing might have evolved as a defence against cancer. Since cells accumulate genetic damage over time, they may have evolved a process to not persist in the body for too long, in case this damage eventually causes a cell to turn cancerous.</p>
<p>As we age, some of the body’s cells enter a state called senescence, in which a cell stays alive but stops dividing. Senescent cells accumulate in the body over a lifetime – especially in the skin, liver, lung and spleen – and have both beneficial and detrimental effects. </p>
<p>They are beneficial because they secrete chemicals that help repair damaged tissue, but over a long period of time, as senescent cells increase in number, they can disrupt the normal structure of organs and tissues. These cells could be an underlying cause of many of the problems we associate with ageing. Mice in which senescent cells were cleared were profoundly delayed in showing <a href="https://www.nature.com/articles/nature10600">signs of ageing</a>.</p>
<p>We can describe a lot of what happens during ageing at the level of what physically happens to our genes, cells and organs. But the fundamental question of why we age is still open. In all likelihood, there is more than one correct answer.</p>
<p>Of course, nobody knows whether Bezos’s company can succeed in helping extend the human lifespan. But what is clear is that by studying ageing, exciting new discoveries are bound to emerge. Never listen to anyone who says the big questions have already been answered. As I’ve recently detailed in a book about new technology and the human body, <a href="https://www.penguin.co.uk/books/1117386/the-secret-body/9781847925695.html">The Secret Body</a>, I’m confident that dramatic breakthroughs will profoundly change the experience of being human in the coming century.</p><img src="https://counter.theconversation.com/content/175379/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Daniel M Davis is the author of three books published by Penguin Random House: The Compatibility Gene, The Beautiful Cure and most recently, The Secret Body. He receives research funding from The Medical Research Council, Cancer Research UK, The Wellcome Trust, GSK, Bristol Myers Squibb and Continuum Life Sciences. He tweets at @dandavis101</span></em></p>Amazon founder is funding a biotechnology startup that is looking to reverse ageing.Daniel M Davis, Professor of Immunology, University of ManchesterLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1698812021-10-21T12:10:20Z2021-10-21T12:10:20ZLife extension: the five most promising methods – so far<figure><img src="https://images.theconversation.com/files/427578/original/file-20211020-19-1loljgc.jpg?ixlib=rb-1.1.0&rect=121%2C55%2C7227%2C4847&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Exercise is still one of the best ways to boost longevity.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/senior-group-friends-exercise-relax-concept-494089063">Rawpixel.com/Shutterstock</a></span></figcaption></figure><p>Most people want to live a long and happy life – or at least avoid a short and miserable one. If you’re in that majority, then you’re in luck. Over the last decade, <a href="https://theconversation.com/is-150-years-really-the-limit-of-human-life-span-162209">a quiet research revolution</a> has occurred in our understanding of the biology of ageing. </p>
<p>The challenge is to turn this knowledge into advice and treatments we can benefit from. Here we bust the myth that lengthening healthy life expectancy is science fiction, and show that it is instead scientific fact.</p>
<h2>1. Nutrition and lifestyle</h2>
<p>There’s plenty of evidence for the benefits of doing the boring stuff, such as eating right. A <a href="https://journals.plos.org/plosmedicine/article?id=10.1371/journal.pmed.0050012">study of large groups of ordinary people</a> show that keeping the weight off, not smoking, restricting alcohol to moderate amounts and eating at least five servings of fruit and vegetable a day can increase your life expectancy by seven to 14 years compared with someone who smokes, drinks too much and is overweight.</p>
<figure class="align-center ">
<img alt="Image of fruit and vegetables." src="https://images.theconversation.com/files/427579/original/file-20211020-18022-1wnwsz7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/427579/original/file-20211020-18022-1wnwsz7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=267&fit=crop&dpr=1 600w, https://images.theconversation.com/files/427579/original/file-20211020-18022-1wnwsz7.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=267&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/427579/original/file-20211020-18022-1wnwsz7.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=267&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/427579/original/file-20211020-18022-1wnwsz7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=335&fit=crop&dpr=1 754w, https://images.theconversation.com/files/427579/original/file-20211020-18022-1wnwsz7.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=335&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/427579/original/file-20211020-18022-1wnwsz7.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=335&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Your five a day is essential.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/healthy-food-clean-eating-selection-fruit-722718097">Natalia Lisovskaya/Shutterstock</a></span>
</figcaption>
</figure>
<p>Cutting down calories even more - by about a third, so-called dietary restriction - improves health and extends life in mice and monkeys, as long as they eat the right stuff, though that’s a tough ask for people constantly exposed to food temptation. The less extreme versions of <a href="https://www.nature.com/articles/s43587-020-00013-3.pdf?proof=t">time-restricted or intermittent fasting</a> – only eating during an eight-hour window each day, or fasting for two days every week – is thought to reduce the risk of middle-aged people getting age-related diseases. </p>
<h2>2. Physical activity</h2>
<p>You can’t outrun a bad diet, but that doesn’t mean that exercise does not do good things. Globally, inactivity directly causes roughly 10% of all premature <a href="https://www.sciencedirect.com/science/article/pii/S0140673612610319?via%3Dihub">deaths from chronic diseases</a>, such as coronary heart disease, type 2 diabetes and various cancers. If everyone on Earth got enough exercise tomorrow, the effect would probably be to increase healthy human life expectancy by almost a year. </p>
<p>But how much exercise is optimal? Very high levels are actually bad for you, not simply in terms of torn muscles or sprained ligaments. It can suppress the immune system and <a href="https://pubmed.ncbi.nlm.nih.gov/2266764/">increase the risk</a> of upper respiratory illness. Just over <a href="https://www.bmj.com/content/368/bmj.l6669.long">30 minutes</a> a day of moderate to vigorous physical activity is enough for most people. Not only does that make you stronger and fitter, it has been shown to <a href="https://onlinelibrary.wiley.com/doi/10.1111/acel.12750">reduce harmful inflammation</a> and even improve mood.</p>
<h2>3. Boosting the immune system</h2>
<p>However fit you are and well you eat, your immune system will, unfortunately, get less effective as you get older. Poor responses to vaccination and an inability to fight infection are consequences of this “immunosenescence”. It all starts to go downhill in early adulthood when the thymus – a bowtie-shaped organ in your throat – starts to wither. </p>
<p>That sounds bad, but it’s even more alarming when you realise that the thymus is where immune agents called T cells learn to fight infections. Closing such a major education centre for T cells means that they <a href="https://immunityageing.biomedcentral.com/articles/10.1186/s12979-020-0173-8;%20https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7203483/">can’t learn to recognise</a> new infections or fight off cancer effectively in older people. </p>
<p>You can help – a bit – by making sure you have enough key vitamins, especially A and D. A promising area of research is looking at signals that the body sends to help make more immune cells, particularly a molecule called <a href="https://www.genecards.org/cgi-bin/carddisp.pl?gene=IL7">IL-7</a>. We may soon be able to produce <a href="https://www.nature.com/articles/nri2970">drugs that contain this molecule</a>, potentially boosting the immune system in older people. Another approach is to use the food supplement spermidine to trigger immune cells to clear out their internal garbage, such as damaged proteins, which improves the elderly immune system so much <a href="https://elifesciences.org/articles/57950">that it’s now being tested</a> as a way of getting better responses to COVID vaccines in older people. </p>
<h2>4. Rejuvenating cells</h2>
<p>Senescence is a toxic state that cells enter into as we get older, wreaking havoc across the body and generating chronic low-grade inflammation and disease – essentially causing biological ageing. In 2009, scientists showed that middle-aged mice <a href="https://www.nature.com/articles/nature08221">lived longer and stayed healthier</a> if they were given small amounts of a drug called rapamycin, which inhibits a key protein called mTOR that helps regulate cells’ response to nutrients, stress, hormones and damage. </p>
<p>In the lab, drugs like rapamycin (called mTOR inhibitors) make senescent (aged) human cells <a href="https://www.aging-us.com/article/100872/text">look and behave like their younger selves</a>. Though it’s too early to prescribe these drugs for general use, a new clinical trial has just been set up to test whether low-dose rapamycin <a href="https://clinicaltrials.gov/ct2/show/NCT04488601">can really slow down ageing in people</a>. </p>
<figure class="align-center ">
<img alt="Image of the structural chemical formula of sirolimus (rapamycin) molecule with white tablets and pills." src="https://images.theconversation.com/files/427576/original/file-20211020-19039-r1jref.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/427576/original/file-20211020-19039-r1jref.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=438&fit=crop&dpr=1 600w, https://images.theconversation.com/files/427576/original/file-20211020-19039-r1jref.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=438&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/427576/original/file-20211020-19039-r1jref.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=438&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/427576/original/file-20211020-19039-r1jref.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=551&fit=crop&dpr=1 754w, https://images.theconversation.com/files/427576/original/file-20211020-19039-r1jref.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=551&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/427576/original/file-20211020-19039-r1jref.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=551&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">The sirolimus (rapamycin) molecules may help us live longer.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/structural-chemical-formula-sirolimus-molecule-white-1645943026">Danijela Maksimovic/Shutterstock</a></span>
</figcaption>
</figure>
<p>Discovered in the soil of Easter Island, Chile, rapamycin carries with it significant mystique and [has been hailed] in the popular press as a possible “elixir of youth”. It can even <a href="https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0009979">improve the memory of mice</a> with dementia-like disease. </p>
<p>But all drugs come with pros and cons – and as too much rapamycin suppresses the immune system, many doctors are averse to even consider it to stave off age-related diseases. However, the dose is critical and newer drugs such as <a href="https://clinicaltrials.gov/ct2/show/NCT04668352">RTB101</a> that work in a similar way to rapamycin support the immune system in older people, and can even <a href="https://www.thelancet.com/journals/lanhl/article/PIIS2666-7568(21)00062-3/fulltext">reduce COVID infection rates</a> and severity. </p>
<h2>5. Clearing out old cells</h2>
<p>Completely getting rid of senescent cells is another promising way forward. A growing number of lab studies in mice using drugs to kill senescent cells - so-called “senolytics” - show overall improvements in health, and as the mice aren’t dying of disease, <a href="https://www.science.org/doi/10.1126/science.aaw1299">they end up living longer too</a>. </p>
<p>Removing senescent cells also helps people. In a small clinical trial, people with severe lung fibrosis reported better overall function, including how far and fast they could walk, <a href="https://www.sciencedirect.com/sdfe/reader/pii/S2352396418306297/pdf">after they had been treated</a> with senolytic drugs. But this is only the tip of the iceberg. Diabetes and obesity, as well as infection with some bacteria and viruses, can lead to more senescent cells forming. Senescent cells also make the lungs more susceptible to COVID infection, and COVID <a href="https://www.science.org/doi/10.1126/science.abe4832">makes more cells become senescent</a>. Importantly, getting rid of senescent cells in old mice <a href="https://www.science.org/doi/10.1126/science.abi4474">helps them to survive COVID infection</a>.</p>
<p>Ageing and infection are a two-way street. Older people get more infectious diseases as their immune systems start to run out of steam, while infection drives faster ageing through senescence. Since ageing and senescence are inextricably linked with both chronic and infectious diseases in older people, treating senescence is likely to improve health across the board. </p>
<p>It is exciting that some of these new treatments are already looking good in clinical trials and may be available to us all soon.</p><img src="https://counter.theconversation.com/content/169881/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Richard Faragher has received funding from the BBSRC. He serves on the Scientific Advisory Board of the Longevity Vision Fund and is a Director of the American Federation for Aging Research </span></em></p><p class="fine-print"><em><span>Lynne Cox runs a lab studying ageing at the University of Oxford. She receives research funding from Diabetes UK, BIRAX, Research England (UK SPINE), Public Health England, Elysium Health and the Mellon Longevity Science Programme at Oriel College, Oxford. She is affiliated with The British Society for Research on Ageing, The European Geriatric Medicine Society and serves on the Strategic Advisory Board of the All Party Parliamentary Group for Longevity. The views expressed are her own.</span></em></p>Life-extension therapies may be coming sooner than you think.Richard Faragher, Professor of Biogerontology, University of BrightonLynne Cox, Associate Professor of Biochemistry, University of OxfordLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1663062021-08-27T09:32:32Z2021-08-27T09:32:32ZFive ways to help your dog live a longer, healthier life<figure><img src="https://images.theconversation.com/files/418210/original/file-20210827-15-3870ez.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C4600%2C3070&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Golden years. </span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/happy-beagle-dog-flying-ears-running-1780700213">tetiana_u/ Shutterstock</a></span></figcaption></figure><p>As anyone who has ever lived with a dog will know, it often feels like we don’t get enough time with our furry friends. Most dogs only live around ten to 14 years on average – though some may <a href="https://link.springer.com/article/10.1007/s10592-019-01240-x">naturally live longer</a>, while others may be <a href="https://www.sciencedirect.com/science/article/pii/S1090023309004407?casa_token=5tbOKsCCaZIAAAAA:x6uo_y2Zq2u3w7bHbEp6tbHArFbp3Zcy60_jzCr-Aap_9ESp8D8TVqHXvhmBMzObbBQ_OROIOA">predisposed to</a> certain diseases that can limit their lifespan. </p>
<p>But what many people don’t know is that humans and dogs share many genetic similarities – including a predisposition to <a href="https://academic.oup.com/epirev/article/20/2/204/435975">age-related cancer</a>. This means that many of the things humans can do to be healthier and longer lived may also work for dogs. </p>
<p>Here are just a few ways that you might help your dog live a longer, healthier life. </p>
<h2>1. Watch their waistline</h2>
<p>One factor that’s repeatedly linked with longevity across a <a href="https://www.sciencedirect.com/science/article/pii/S1568163719304076?via%3Dihub">range of species</a> is maintaining a healthy bodyweight. That means ensuring dogs aren’t carrying excess weight, and managing their calorie intake carefully. Not only will a lean, healthy bodyweight be better for your dog in the long term, it can also help to limit the impact of certain health conditions, <a href="https://www.thieme-connect.com/products/ejournals/abstract/10.3415/VCOT-08-08-0069">such as osteoarthritis</a>. </p>
<p>Carefully monitor and manage your dog’s bodyweight through regular weighing or <a href="https://academic.oup.com/jn/article/136/7/2031S/4664816?login=true">body condition scoring</a> – where you look at your dog’s physical shape and “score” them on a scale to check whether they’re overweight, or at a healthy weight. Using both of these <a href="https://www.mdpi.com/2306-7381/4/2/30/htm">methods together</a> will allow you to identify weight changes and alter their diet as needed.</p>
<p>Use feeding guidelines as a starting point for how much to feed your dog, but you might need to change food type or the amount you feed to maintain a healthy weight as your dog gets older, or depending on how much activity they get. Knowing exactly how much you are feeding your dog is also a crucial weight-management tool – so weigh their food rather than <a href="https://pubmed.ncbi.nlm.nih.gov/31409751/">scooping it in</a> by eye. </p>
<p>More generally, <a href="https://link.springer.com/article/10.1007/s00394-018-1723-0">good nutrition</a> can be linked to a healthy ageing process, suggesting that what you feed can be as important as how much you feed. “Good” nutrition will vary for each dog, but be sure to look for foods that are safe, tasty and provide all the nutrients your dog needs.</p>
<h2>2. Plenty of walks</h2>
<p>Exercise has many physiological and psychological benefits, both for our dogs (<a href="https://www.mdpi.com/2076-2615/9/9/674/htm">and us</a>). Physical activity can help to manage a <a href="https://www.cambridge.org/core/journals/journal-of-nutritional-science/article/overweight-dogs-exercise-less-frequently-and-for-shorter-periods-results-of-a-large-online-survey-of-dog-owners-from-the-uk/01E2D6FBCDD05069E3557C10A1CC5945">dog’s bodyweight</a>, and is also associated with <a href="https://www.liebertpub.com/doi/abs/10.1089/rej.2014.1623">anti-ageing effects</a> in other genetically similar species. </p>
<p>While exercise alone won’t increase your dog’s lifespan, it might help protect you both from carrying excess bodyweight. And indeed, research suggests that “happy” dog walks lead to both <a href="https://www.mdpi.com/1660-4601/14/8/936">happy dogs and people</a>.</p>
<h2>3. Teach them new tricks</h2>
<p>Ageing isn’t just physical. Keeping your dog’s mind active is also helpful. Contrary to the popular adage, you can teach old dogs new tricks – and you might just keep their brain and body <a href="https://dl.acm.org/doi/abs/10.1145/3152130.3152146">younger as a result</a>. </p>
<p>Even when physical activity <a href="https://bmcvetres.biomedcentral.com/articles/10.1186/s12917-020-02293-8">might be limited</a>, explore alternative low-impact games and pursuits, <a href="https://www.sciencedirect.com/science/article/pii/S0168159118304325?via%3Dihub">such as scentwork</a> that you and your dog can do together. Using their nose is an inherently rewarding and fun thing for dogs to do, so training dogs to find items by scent will exercise them both <a href="https://www.sciencedirect.com/science/article/pii/S1558787821000381#bib0027">mentally and physically</a>.</p>
<figure class="align-center ">
<img alt="A dog looking for a hidden treat in three cups on the floor. He has his paw placed on one of them." src="https://images.theconversation.com/files/418211/original/file-20210827-33514-120cad8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/418211/original/file-20210827-33514-120cad8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/418211/original/file-20210827-33514-120cad8.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/418211/original/file-20210827-33514-120cad8.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/418211/original/file-20210827-33514-120cad8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/418211/original/file-20210827-33514-120cad8.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/418211/original/file-20210827-33514-120cad8.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Even old dogs can learn new tricks.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/dog-playing-shell-game-her-human-1617533356">Aleksey Boyko/ Shutterstock</a></span>
</figcaption>
</figure>
<p>Other exercise such as <a href="https://www.sciencedirect.com/science/article/abs/pii/S0195561697500866?via%3Dihub">hydrotherapy</a> – a type of <a href="https://youtu.be/vE_SVWXQMbU">swimming exercise</a> – might be a good option – especially for dogs who have conditions which affect their <a href="https://www.tandfonline.com/doi/full/10.1080/17415349.2017.1322476">ability to exercise</a> as normal.</p>
<h2>4. Bonding</h2>
<p>Like many companion animals, dogs develop a <a href="https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0078455">clear attachment</a> to their caregivers. The human-dog bond likely <a href="https://www.mdpi.com/1660-4601/17/11/3789">provides companionship</a> – and often, dog lovers describe them as a <a href="https://www.tandfonline.com/doi/full/10.1080/14649360802217790">family member</a>.</p>
<p>A stable caregiver-dog bond can help maintain a happy and mutually <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4348122/pdf/prbm-8-071.pdf">beneficial partnership</a> between you and your dog. It can also help you recognise subtle changes in your dog’s behaviour or movement that might signal potential concerns. </p>
<p>Where there is <a href="https://www.mdpi.com/2076-2615/9/9/674">compatability between</a> caregiver and dog, this leads to a better relationship – and even benefits for owners, too, including <a href="https://onlinelibrary.wiley.com/doi/full/10.5694/j.1326-5377.2006.tb00116.x">stress relief</a> and <a href="https://journals.sagepub.com/doi/full/10.1177/1559827616643686">exercise</a>. Sharing positive, fun experiences with your dog, including <a href="https://www.magonlinelibrary.com/doi/full/10.12968/coan.2019.24.3.150">playing with them</a>, are great for cementing your bond.</p>
<h2>5. Don’t skip vet visits</h2>
<p>Modern veterinary medicine has seen substantial improvements in preventing and managing health concerns in dogs. Successful vaccination and parasite management programmes have effectively <a href="https://www.cambridge.org/core/journals/epidemiology-and-infection/article/estimating-the-effectiveness-of-vaccine-programs-in-dog-populations/E0D25E5DFB352731121EDBA5DEFEF7EE">reduced the incidence</a> of disease in both dogs and humans – including <a href="https://www.sciencedirect.com/science/article/pii/S0304401712006838?via%3Dihub">toxocariasis</a>, which can be transmitted from dog faeces to humans, and <a href="https://veterinaryresearch.biomedcentral.com/articles/10.1186/s13567-018-0554-6">rabies</a>, which can be transmitted dog-to-dog or dog-to-human. </p>
<p>Having a good relationship with your vet will allow you to tailor treatments and discuss your dog’s needs. Regular health checks can also be useful in identifying any potential problems <a href="https://www.cabdirect.org/cabdirect/abstract/20123062274">at a treatable stage</a> – such as <a href="https://bmcvetres.biomedcentral.com/articles/10.1186/s12917-021-02775-3">dental issues</a> or <a href="https://www.nature.com/articles/s41598-018-23940-z">osteoarthritis</a> – which can cause pain and negatively impact the dog’s wellbeing. </p>
<p>At the end of the day, it’s a combination of our dog’s genetics and the environment they live in that impacts their longevity. So while we can’t change their genetics, there are many things we can do to <a href="https://www.magonlinelibrary.com/doi/full/10.12968/coan.2018.23.1.12?casa_token=W_tXozEkyI0AAAAA%3A46agHczj8LV9jWm-DaEU9Ifc-cuQAN-O0HNdRhDj7Cvxfb2ZB0t7iyEiD7hAXmTv6ucQWEB_kVbL">improve their health</a> that may just help them live a longer, healthier life.</p><img src="https://counter.theconversation.com/content/166306/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Jacqueline Boyd is affiliated with The Kennel Club (UK) through membership, as Chair of the Activities Health and Welfare Subgroup, member of the Dog Health Group and Chair of the Heelwork to Music Working Party. Jacqueline also writes, consults and coaches on canine matters on an independent basis. </span></em></p>Many of the advice given to humans works for dogs, too.Jacqueline Boyd, Senior Lecturer in Animal Science, Nottingham Trent UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1658312021-08-09T16:33:02Z2021-08-09T16:33:02ZGut bacteria rewind ageing brain in mice<figure><img src="https://images.theconversation.com/files/415227/original/file-20210809-19-w3x08f.jpg?ixlib=rb-1.1.0&rect=0%2C35%2C3994%2C1958&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/white-mouse-maze-looking-over-walls-259521779">Neil Lockhart/Shutterstock</a></span></figcaption></figure><p>In 1895, on turning 50, <a href="https://pubmed.ncbi.nlm.nih.gov/26836137/">Elie Metchnikoff</a> became increasingly anxious about ageing. As a result, the Russian Nobel prize-winning scientist, and one of the founders of immunology, turned his attention away from immunology and towards gerontology – a term that he coined. </p>
<p>He was fascinated by the role that intestinal bacteria play in health and disease and suggested that people from parts of eastern Europe lived longer because they ate a lot of fermented foods containing lactic acid bacteria. Although popular at the time, this theory linking gut microbes to healthy ageing was largely ignored by scientists until relatively recently. We now recognise the <a href="https://theconversation.com/keen-to-be-healthier-in-old-age-tend-your-inner-garden-53902">importance</a> that the trillions of bacteria, known as the gut microbiome, have in regulating health and disease. </p>
<figure class="align-center ">
<img alt="Elie Metchnikoff" src="https://images.theconversation.com/files/415225/original/file-20210809-21-uxb9vw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/415225/original/file-20210809-21-uxb9vw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=432&fit=crop&dpr=1 600w, https://images.theconversation.com/files/415225/original/file-20210809-21-uxb9vw.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=432&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/415225/original/file-20210809-21-uxb9vw.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=432&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/415225/original/file-20210809-21-uxb9vw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=543&fit=crop&dpr=1 754w, https://images.theconversation.com/files/415225/original/file-20210809-21-uxb9vw.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=543&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/415225/original/file-20210809-21-uxb9vw.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=543&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Elie Metchnikoff was ahead of his time in recognising the role of the gut microbiome on health and longevity.</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/w/index.php?curid=83326921">Gallica Digital Library/Wikimedia Commons</a></span>
</figcaption>
</figure>
<p>Evidence has been accumulating for almost a decade that the microbiome composition changes with age. In 2012, <a href="https://www.nature.com/articles/nature11319">research by my colleagues at University College Cork</a> showed that diversity in the microbiome was linked to health outcomes in later life, including frailty. But we still didn’t know much about the effect of the microbiome on brain ageing. </p>
<p>In 2017, we revisited Metchnikoff’s ideas, putting them in the context of brain ageing, and showed that ageing <a href="https://www.sciencedirect.com/science/article/pii/S088915911730034X">induced changes in the microbiota</a> and immune system, and was associated with cognitive decline and anxiety. However, this study, like many in the field, only showed an association between ageing and these factors. It did not prove that one thing caused the other. </p>
<p>In a subsequent study, we went <a href="https://www.nature.com/articles/s41380-019-0425-1">a step further</a> in showing that a microbiota-targeted diet enriched with the prebiotic inulin (a prebiotic feeds the beneficial bacteria in the gut) could lessen the effects of ageing in the brains of middle-aged mice. Yet it still wasn’t clear whether the microbiota itself caused the slowing of brain ageing. </p>
<p>In our <a href="https://www.nature.com/articles/s43587-021-00093-9">latest study</a>, we show that by taking the microbiome from young mice and transplanting them into old mice, many of the effects of ageing on learning and memory and immune impairments can be reversed. Using a maze, we showed that this faecal microbiota transplant from young to old mice led to the old mice finding a hidden platform faster. </p>
<h2>The immune connection</h2>
<p>Ageing is associated with an increase in inflammation <a href="https://www.sciencedirect.com/science/article/pii/S0166223614001982">across all systems in the body</a>, including the brain. It is clear that immune processes play a key role in brain ageing, with a growing emphasis on the role of a specific immune cell, the <a href="https://theconversation.com/microglia-the-brains-immune-cells-protect-against-diseases-but-they-can-also-cause-them-139232">microglia</a>. </p>
<p>Ironically, these are the same class of cells that Metchnikoff visualised down the microscope, albeit in other tissues, in the late 1800s. We now also know that the activation of these cells is under <a href="https://www.nature.com/articles/nrgastro.2015.127">constant regulation</a> by the gut microbiome. </p>
<p>So the next part of the puzzle was to see if the negative effects of ageing on immunity are also reversible by transplanting the microbiota from young mice to old. Indeed, a lot of the inflammation was lessened. </p>
<p>Finally, we showed that chemicals in a region of the brain involved in learning and memory (the hippocampus) were more like that of young mice following the microbiota transplant. Our results show conclusively that the microbiome is important for a healthy brain in old age.</p>
<p>Was Metchnikoff’s step away from immunology premature in understanding the secrets of ageing? Indeed, the relative contribution of the immune changes seen in the mice receiving young microbiota to the overall rejuvenation effects deserves further study. But two big questions remain. What are the exact mechanisms at play? And can we translate these remarkable findings to humans? </p>
<h2>Mice aren’t humans</h2>
<p>Working with a controlled situation of mice – which have very defined genetics, diets and microbiome – is very different from looking at humans. We need to be careful to not over-interpret these findings. We are not advocating faecal transplants for people who want to rejuvenate their brain. Instead, these studies point towards a future where there will be a focus on microbiota-targeted dietary or bacteria-based treatments that will promote optimum gut health and immunity in order to keep the brain young and healthy. Such strategies will be a more palatable elixir indeed. </p>
<p>Metchnikoff’s overall tenets appear to be correct: protecting your gut microbes may be the secret to the fountain of youth. With advances in healthcare, longevity has markedly increased. And although we cannot stop the march of time, we can develop treatments that will protect our brains from deterioration and we have more than a gut feeling targeting the microbiome may be one such way. However, much work is still needed, though, to better understand how gut microbes are able to press rewind on some of the hallmarks of an ageing brain.</p><img src="https://counter.theconversation.com/content/165831/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>John Cryan receives funding from Science Foundation Ireland (SFI) through the Irish Government’s National Development Plan (grants SFI/12/RC/2273 and SFI/12/RC/ 2273_P2) and through the Joint Programming Initiative: a healthy diet for a healthy life; investigating Nutrition and Cognitive Function (NutriCog) by SFI Grant ‘A Menu for Brain Responses Opposing Stress Induced Alternations in Cognition’ (AMBROSIAC) 15/JPHDHL/3270. He also receives funding from the Saks-Kavanaugh Foundation.
The author receives research funding, has been a consultant and been on the Speakers Bureau of food and pharmaceutical companies in the microbiome and neuroscience arena. </span></em></p>Mice given a faecal transplant from young mice, rejuvenated their brains and were better able to complete a maze task.John Cryan, Vice President for Research & Innovation, University College CorkLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1622092021-06-08T14:03:41Z2021-06-08T14:03:41ZIs 150 years really the limit of human life span?<figure><img src="https://images.theconversation.com/files/405025/original/file-20210608-135197-180jtty.jpg?ixlib=rb-1.1.0&rect=32%2C16%2C5347%2C3540&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">How long could a human really live?</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/old-couple-miniature-standing-before-number-1199942233">Hyejin Kang/ Shutterstock</a></span></figcaption></figure><p>While most of us can expect to live to around 80, some people defy expectations and live to be over 100. In places such as Okinawa, Japan and Sardinia, Italy, there are many <a href="https://www.nationalgeographic.com/travel/article/uncover-the-secrets-of-longevity-in-this-japanese-village">centenarians</a>. The oldest person in history – a French woman named <a href="https://www.bbc.co.uk/news/world-europe-49746060">Jeanne Calment</a> – lived to 122. When she was born in 1875, the average life expectancy was roughly 43. </p>
<p>But just how long could a human actually live? It’s a question people have been asking for centuries. While average life expectancy (the number of years a person can expect to live) is relatively easy to calculate, maximum life span estimates (the greatest age a human could possibly reach) are much harder to make. Previous studies have placed this limit close to <a href="https://theconversation.com/is-there-a-natural-limit-to-how-long-humans-can-live-66460">140 years of age</a>. But a more recent study proposes that the limit to human life span is <a href="https://pubmed.ncbi.nlm.nih.gov/34035236/">closer to 150</a>.</p>
<h2>Calculating life span</h2>
<p>The oldest and still most widely used method for calculating life expectancy, and thus life span, relies on the <a href="https://pubmed.ncbi.nlm.nih.gov/6821142/">Gompertz equation</a>. This is the observation, first made in the 19th century, that human death rates from disease increase exponentially with time. Essentially, this means your chance of death – from cancer, heart disease and many infections, for example – roughly doubles every eight to nine years. </p>
<p>There are <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4850073/">many ways</a> the formula can be tweaked to account for how different factors (such as sex or disease) affect the life span within a population. Gompertz calculations are even used to calculate health insurance premiums – which is why these companies are so interested in whether <a href="https://pubmed.ncbi.nlm.nih.gov/18544745/">you smoke</a>, whether you are <a href="https://pubmed.ncbi.nlm.nih.gov/28539178/">married</a> and anything else that might allow them to more accurately judge the <a href="https://link.springer.com/article/10.1007/s13385-015-0110-y">age at which you will die</a>.</p>
<p>Another approach to figuring out how long we can live is to look at how our organs decline with age, and run that rate of decline against the age at which they stop working. For example, <a href="https://pubmed.ncbi.nlm.nih.gov/25311652/">eye function</a> and how much oxygen we use while exercising <a href="https://www.amazon.co.uk/Biology-Aging-Observations-Robert-Arking/dp/0195167392">show a general pattern of decline</a> with ageing, with most calculations indicating organs will only function until the average person is around 120 years old. </p>
<p>But these studies also unmask increasing variation between people as they grow older. For example, some peoples’ kidney function declines rapidly with age while in others it <a href="https://global.oup.com/academic/product/biology-of-longevity-and-aging-9780199387960?cc=gb&lang=en&">hardly changes at all</a>.</p>
<figure class="align-center ">
<img alt="A 100-year-old woman blows out the candles on her birthday cake." src="https://images.theconversation.com/files/405027/original/file-20210608-21-net384.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/405027/original/file-20210608-21-net384.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=338&fit=crop&dpr=1 600w, https://images.theconversation.com/files/405027/original/file-20210608-21-net384.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=338&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/405027/original/file-20210608-21-net384.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=338&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/405027/original/file-20210608-21-net384.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=424&fit=crop&dpr=1 754w, https://images.theconversation.com/files/405027/original/file-20210608-21-net384.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=424&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/405027/original/file-20210608-21-net384.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=424&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Few people make it to 100.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/portrait-hundred-years-old-woman-centenarian-1022974096">Dan Negureanu/ Shutterstock</a></span>
</figcaption>
</figure>
<p>Now researchers in Singapore, Russia, and the US have taken a different approach to estimate the maximum human life span. Using a computer model, they estimate that the limit of human life span is <a href="https://pubmed.ncbi.nlm.nih.gov/34035236/">about 150 years</a>. </p>
<h2>Living to 150</h2>
<p>Intuitively, there should be a relationship between your chance of death and how rapidly and completely you recover from illness. This parameter is a measure of your ability to maintain homeostasis – your normal physiological equilibrium – and is known as <a href="https://pubmed.ncbi.nlm.nih.gov/31498881/">resilience</a>. In fact, ageing can be defined as the loss of ability to maintain homeostasis. Typically, the younger the person, the better they are at recovering rapidly from illness.</p>
<p>To conduct the modelling study, the researchers took blood samples from over 70,000 participants aged up to 85 and looked at short-term changes in their blood cell counts. The number of <a href="https://pubmed.ncbi.nlm.nih.gov/33918155/">white blood cells</a> a person has can indicate the level of inflammation (disease) in their body, while the <a href="https://pubmed.ncbi.nlm.nih.gov/32894755/">volume of red blood cells</a> can indicate a person’s risk of heart disease or stroke, or <a href="https://pubmed.ncbi.nlm.nih.gov/33602086/">cognitive impairment</a>, such as memory loss. The researchers then simplified this data into a single parameter, which they called the dynamic organisms state indicator (Dosi).</p>
<p>Changes in Dosi values across the participants predicted who would get age-related diseases, how this varied from person to person, and modelled the loss of resilience with age. These calculations predicted that for everyone – regardless of their health or genetics – resilience failed completely at 150, giving a theoretical limit to human life span.</p>
<p>But estimates of this type assume that nothing new will be done to a population, such as, no new medical treatments will be found for common diseases. This is a major flaw, since significant progress occurs over a lifetime and this benefits some people more than others.</p>
<p>For example, a baby born today can rely on about 85 years of medical progress to enhance their life expectancy, while an 85-year-old alive now is limited by current medical technologies. As such, the calculation used by these researchers will be relatively accurate for old people but will become progressively less so the younger the person you’re looking at. </p>
<p>The Dosi limit for maximum life span is about 25% longer than Jeanne Calment lived. So if you’re planning to beat it (and her), you need three important things. First is <a href="https://pubmed.ncbi.nlm.nih.gov/29890178/">good genes</a>, which makes living to be <a href="https://pubmed.ncbi.nlm.nih.gov/26937346/">more than a hundred unassisted</a> a good bet. Second, <a href="https://pubmed.ncbi.nlm.nih.gov/18184033/">an excellent diet and exercise plan</a>, which can add up to 15 years to life expectancy. And lastly, a breakthrough in turning our knowledge of the biology of ageing into <a href="https://theconversation.com/anti-ageing-treatments-these-two-drug-types-are-being-investigated-153409">treatments and medicines</a> that can increase healthy life span. </p>
<p>Currently, adding more than 15-20% to <a href="https://pubmed.ncbi.nlm.nih.gov/33037985/">healthy life span in normal mammals</a> is extremely difficult, partly because our understanding of the biology of ageing <a href="https://pubmed.ncbi.nlm.nih.gov/31914446/">remains incomplete</a>. But it’s possible to increase the life span of much simpler organisms – such as roundworms – by <a href="https://pubmed.ncbi.nlm.nih.gov/22021389/">up to ten times</a>. </p>
<p>Even given the current pace of progress, we can confidently expect life expectancy to increase because it has been doing this since Gompertz was alive in the 1860s. In fact, if you spend <a href="https://publications.parliament.uk/pa/ld200506/ldselect/ldsctech/20/20i.pdf">half an hour reading this article</a> average life expectancy will have increased by six minutes. Unfortunately, at that rate, the average person won’t live to 150 for another three centuries.</p><img src="https://counter.theconversation.com/content/162209/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Richard Faragher is a member of the Board of Directors of the American Federation for Aging Research (AFAR) and the Biogerontology Research Foundation. He is a member of the scientific advisory board of the Longevity Vision Fund.</span></em></p>Researchers think they’ve calculated the limit of human life span – but there’s more to it.Richard Faragher, Professor of Biogerontology, University of BrightonLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1605772021-05-19T10:30:14Z2021-05-19T10:30:14ZThirty minutes’ exercise won’t counteract sitting all day, but adding light movement can help – new research<figure><img src="https://images.theconversation.com/files/401549/original/file-20210519-15-9xtou9.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C6793%2C3819&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The more you sit, the more movement you need.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/get-fit-home-full-length-shot-1796986867">BAZA Production/ Shutterstock</a></span></figcaption></figure><p>It’s recommended we do at least 30 minutes of exercise a day – or <a href="https://bjsm.bmj.com/content/54/24/1451">150 minutes a week</a> – to stay healthy. But 30 minutes accounts for just 2% of the day. And many of us spend most of the rest of the time sitting.</p>
<p>Research shows that sitting can be bad for our health in many ways – with some even suggesting it’s as bad for us as <a href="https://ajph.aphapublications.org/doi/10.2105/AJPH.2019.305183">smoking</a>. And <a href="https://bjsm.bmj.com/content/early/2021/05/09/bjsports-2020-102345">our new study</a> has revealed that 30 minutes of daily exercise is not enough to overcome the health risks of sitting too much. But we also revealed that with the right balance of time spent exercising and moving, it may be possible to counteract the negatives of sitting.</p>
<p>We combined data from six different studies from the UK, US and Sweden, looking at a total of over 130,000 adults. Each of the studies used a physical activity monitor (like a Fitbit) to measure a person’s movements and sitting time throughout the day. Each study then followed the participants for an average of four to 14 years to track whether any participants died. </p>
<p>As expected, we found that 30 minutes of daily exercise decreased the risk of early death by up to 80% for those who also spent less than seven hours a day sitting. But it didn’t have the same effect for people who spent between 11 and 12 hours a day sitting. In other words, it’s not as simple as checking off the exercise box on the to-do list. A healthy lifestyle requires more than 30 minutes of exercise if you spend a lot of time sitting.</p>
<p>For those who sat a lot, 30 minutes of daily exercise would only lower risk of early death by 30% if combined with four to five hours of light movement a day (such as shopping, cooking, or yard work) – spending less than 11 hours sitting total. We can think of this mixture of light activity, exercise and sitting as a “cocktail”. And when it comes to living an active lifestyle, there are different recipes you can choose to to get the same benefits.</p>
<p>For example, one person might exercise daily for 30 minutes, move throughout the day for about six hours doing activities like housework or walking to work, but spend around ten hours a day sitting. They would have the same risk of death as someone who exercised 55 minutes daily, moved throughout the day for about four hours, and sat for about 11 hours. In other words, different combinations of exercise and movement can be used to offset the harms of sitting.</p>
<h2>Personalised recommendations</h2>
<p>Our findings provide new insights on what constitutes a healthy and active lifestyle. For decades, scientists have studied the health benefits of exercise – but this research has largely ignored the fact that how you spend the rest of the day also matters. Instead of the recommendation that everyone should strive to achieve 30 minutes of daily exercise, our results show physical activity recommendations can been more personalised. People can adopt a mixture of activity that works best for them.</p>
<figure class="align-center ">
<img alt="Woman crouches while she gardens." src="https://images.theconversation.com/files/401552/original/file-20210519-15-fr6cmt.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/401552/original/file-20210519-15-fr6cmt.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/401552/original/file-20210519-15-fr6cmt.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/401552/original/file-20210519-15-fr6cmt.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/401552/original/file-20210519-15-fr6cmt.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=502&fit=crop&dpr=1 754w, https://images.theconversation.com/files/401552/original/file-20210519-15-fr6cmt.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=502&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/401552/original/file-20210519-15-fr6cmt.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=502&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Gardening and yard work are easy ways to get more light activity into your day.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/african-american-woman-picking-vegetables-garden-1503195074">Rido/ Shutterstock</a></span>
</figcaption>
</figure>
<p>For many of us, our jobs require us to sit for eight hours or more a day. But when you get home, exercising for one hour and doing light activities for a few hours in the evening (such as housework or yard work) could still yield health benefits. If you’re a stay-at-home parent who’s typically too busy to get to the gym, moving around throughout the day while doing essential tasks (such as playing with the kids or putting away groceries) can also improve your health.</p>
<p>The caveat, however, is that our study found that six minutes of light activity was equivalent to one minute of moderate to intense exercise. So you would need to do three hours of light activity to yield the same benefit as 30 minutes of exercise. </p>
<p>While our study adds important new insights about the ideal balance of movement, we are missing one ingredient: sleep. It’s unclear if the health benefits of exercise and movement are the same if you don’t get enough sleep. As well, key questions on how to spend your day – like whether you should wake up 30 minutes earlier to exercise – still need to be studied.</p>
<p>Ultimately, our findings show that a healthy and active lifestyle is more than just exercising for 30 minutes, and that there are many different ways of achieving better health and longevity. While exercise still provides the best “bang for your buck” in terms of the amount of time required, our findings are still good news for people who may not have the time, ability or desire to exercise. The road to an active lifestyle is more accessible and achievable than we thought – and is not just for gym regulars.</p><img src="https://counter.theconversation.com/content/160577/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>The authors do not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Choosing the right “cocktail” of light activity, exercise and sitting, can improve health and decrease risk of premature death.Sebastien Chastin, Professor Health Behaviour Dynamics of People, Places and Systems, Glasgow Caledonian UniversityKeith Diaz, Assistant Professor of Behavioral Medicine, Columbia UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1552722021-03-24T12:25:52Z2021-03-24T12:25:52ZRaising the minimum wage is a health issue, too<figure><img src="https://images.theconversation.com/files/385410/original/file-20210221-13-15c3ba2.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C3971%2C2649&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">More than 22 million Americans lost their jobs at the start of the pandemic. </span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/banner-against-renters-eviction-reading-no-job-no-rent-is-news-photo/1227988534?adppopup=true">Eric Baradat/AFP via Getty Images</a></span></figcaption></figure><p>Congress just missed one of its best shots at improving health when the Senate failed to advance a bill that <a href="https://www.nytimes.com/2021/03/05/us/minimum-wage-senate.html">would have raised the minimum wage to US$15 an hour</a>. Study after study has linked higher income <a href="https://doi.org/10.1186/s13561-017-0163-5">to better health</a>.</p>
<p>Consider that a well-paying job, by definition, increases household income. That, in turn, means increased access to good nutrition, heat and a safe environment. It also means adequate <a href="http://www.leadcenter.org/system/files/resource/downloadable_version/impact_of_employment_health_status_health_care_costs_0.pdf">health care</a>. With that job, you’ll likely make more visits to primary care doctors, dentists and specialists who work in preventive care. </p>
<p>An inadequate income does none of these things. Instead, <a href="https://doi.org/10.1093/ije/28.1.95">it increases susceptibility</a> to psychological stress, malaise, <a href="https://doi.org/10.1186/s13561-017-0163-5">illness and disease</a>. This is one reason those who move off welfare benefits and gain employment improve their <a href="https://doi.org/10.1186/s13561-017-0163-5">well-being</a>.</p>
<p>I am not an economist. But I am a <a href="https://scholar.google.com/citations?user=n2n9ZSUAAAAJ&hl=en">physician and public health scientist</a>. I can tell you that research shows that a well-paying job translates to <a href="https://www.rwjf.org/en/library/research/2012/12/how-does-employment--or-unemployment--affect-health-.html">a longer life</a>. For example, researchers in 2016 found that the <a href="https://doi.org/10.1001/jama.2016.4226">richest 1% of men in the U.S. lived 14.6 years longer</a> on average than the poorest 1% of men.</p>
<figure class="align-center ">
<img alt="A young man, cleaning tables at a coffee shop." src="https://images.theconversation.com/files/385411/original/file-20210221-13-j73u7t.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/385411/original/file-20210221-13-j73u7t.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/385411/original/file-20210221-13-j73u7t.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/385411/original/file-20210221-13-j73u7t.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/385411/original/file-20210221-13-j73u7t.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/385411/original/file-20210221-13-j73u7t.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/385411/original/file-20210221-13-j73u7t.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Being employed, even at a low-paying job, can improve your health and happiness.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/young-man-barista-with-face-mask-and-gloves-royalty-free-image/1251291518?adppopup=true">Halfpoint Images via Getty Images</a></span>
</figcaption>
</figure>
<h2>Employment benefits</h2>
<p>Numerous studies show <a href="https://doi.org/10.1037/0090-5550.49.3.241">employment is linked</a> to self-esteem, purpose and identity. It provides relationships, social connections, social status and regular productive activity; a job is an integral part of a person’s identity. Its loss threatens that identity, which is why <a href="https://doi.org/10.1037/0021-9010.90.1.53">unemployment typically causes a decline</a> in mental health. When compared with their employed counterparts, unemployed Americans <a href="https://www.rwjf.org/en/library/research/2012/12/how-does-employment--or-unemployment--affect-health-.html">are far more likely</a> to receive a diagnosis of depression.</p>
<p>One study found that people with a disability who were employed were less likely to have frequent <a href="https://doi.org/10.1093/occmed/kql177">mental distress, including anxiety and depression</a>, than those with a disability who were not employed (18% vs. 40%). This finding held up even when accounting for demographics and individual characteristics.</p>
<h2>A possible solution</h2>
<p>Many economists have long criticized unemployment benefits because of their <a href="https://doi.org/10.1016/0047-2727(92)90056-L">negative impact</a> on the willingness to work. The <a href="https://www.cnbc.com/2020/07/23/average-unemployment-insurance-payment-in-each-us-state.html">average unemployment benefit</a> is $320 weekly; the amount varies by state. The American Rescue Plan, recently passed to provide economic aid to million of Americans hit hard by the pandemic, <a href="https://www.dol.gov/newsroom/releases/eta/eta20210316">adds an additional $300 to unemployment benefits through Sept. 6</a>. </p>
<p>Compare that to the current federal <a href="https://www.dol.gov/general/topic/wages/minimumwage">minimum wage</a>: $7.25 an hour. That’s $290 for a 40-hour week, less than what unemployment benefits pay. That means, for millions of Americans, being employed means less income. With the federal supplement, 63% of workers currently <a href="https://www.americanactionforum.org/research/unemployment-benefits-and-returning-to-work/">make more on unemployment</a> than they would with a minimum-wage job. Reduce the federal supplement to only $100 a week, and 25% of the workforce would still make more on unemployment.</p>
<p>Which raises the question: Why not increase the minimum wage – at least enough to make it more than unemployment benefits? That way, more people would be motivated to seek jobs. </p>
<p>That may not happen soon, if at all. President Biden’s plan to raise the federal minimum wage to $15 per hour <a href="https://www.cbsnews.com/news/minimum-wage-15-dollars-amendment-fails-covid-relief-bill/">was not a part</a> of the $1.9 trillion COVID-19 aid package. And it’s true there’s a downside: Raising the minimum wage can reduce the number of jobs available. A <a href="https://www.cbo.gov/system/files/2021-02/56975-Minimum-Wage.pdf">Congressional Budget Office estimate</a> on Biden’s proposal says the raise would lift 900,000 people out of poverty, but it would also kill 1.4 million jobs over four years.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/_M3vTvm2cfM?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">A brief history of the minimum wage.</span></figcaption>
</figure>
<p>That said, people who are fit to work should be encouraged to seek, not shun, employment. With unemployment benefits more than the basic minimum wage in many states, we are sending the wrong message to millions. There’s more to a higher minimum wage than just more money. It also means more happiness, better health and a longer life.</p>
<p>[<em>Get the best of The Conversation, every weekend.</em> <a href="https://theconversation.com/us/newsletters/weekly-highlights-61?utm_source=TCUS&utm_medium=inline-link&utm_campaign=newsletter-text&utm_content=weeklybest">Sign up for our weekly newsletter</a>.]</p><img src="https://counter.theconversation.com/content/155272/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Utibe Effiong does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>It’s not just about the money. Raising the minimum wage would lead to happier and healthier lives for millions of Americans.Utibe Effiong, Board Certified Internal Medicine Physician and Public Health Scientist, MidMichigan Health, University of MichiganLicensed as Creative Commons – attribution, no derivatives.