tag:theconversation.com,2011:/global/topics/fatty-acids-26826/articlesFatty acids – The Conversation2024-02-27T12:30:24Ztag:theconversation.com,2011:article/2229702024-02-27T12:30:24Z2024-02-27T12:30:24ZOmega-3 fatty acids are linked to better lung health, particularly in patients with pulmonary fibrosis<figure><img src="https://images.theconversation.com/files/577659/original/file-20240223-30-2mxmmk.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C3840%2C2160&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Your diet may play a role in maintaining lung health.</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/human-respiratory-system-lungs-anatomy-royalty-free-image/1249730889">magicmine/iStock via Getty Images</a></span></figcaption></figure><p>Omega-3 fatty acids have garnered significant interest among patients and clinicians for their potential <a href="https://doi.org/10.3945/an.111.000893">protective health effects</a>, including lung health. In our recently published research, my colleagues and I found that higher dietary intake of omega-3 fatty acids is linked to <a href="https://doi.org/10.1016/j.chest.2023.09.035">better lung function and longer survival</a> in patients with pulmonary fibrosis, a chronic respiratory disease.</p>
<p>Found in foods such as fish and nuts and in some supplements, <a href="https://chem.libretexts.org/Courses/Willamette_University/WU%3A_Chem_199_-_Better_Living_Through_Chemistry/01%3A_Chemicals_in_Food/1.04%3A_Macro-_and_Micronutrients/1.4.02%3A_Fats_and_Cholesterol">omega-3 fatty acids</a> are polyunsaturated fats that are essential nutrients for people. They serve several important functions in the body, such as providing structure to cells and regulating inflammation.</p>
<p>Researchers believe two omega-3 fatty acids, <a href="https://doi.org/10.1042/bst20160474">docosahexaenoic and eicosapentaenoic acids, or DHA and EPA</a>, are the most beneficial to overall health. When the body breaks them down, their byproducts have <a href="https://doi.org/10.1016/j.atherosclerosis.2020.11.018">anti-inflammatory effects</a>. </p>
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<a href="https://images.theconversation.com/files/577668/original/file-20240223-26-i1nth6.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Chemical structure of EPA and DHA" src="https://images.theconversation.com/files/577668/original/file-20240223-26-i1nth6.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/577668/original/file-20240223-26-i1nth6.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=507&fit=crop&dpr=1 600w, https://images.theconversation.com/files/577668/original/file-20240223-26-i1nth6.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=507&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/577668/original/file-20240223-26-i1nth6.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=507&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/577668/original/file-20240223-26-i1nth6.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=637&fit=crop&dpr=1 754w, https://images.theconversation.com/files/577668/original/file-20240223-26-i1nth6.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=637&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/577668/original/file-20240223-26-i1nth6.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=637&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">EPA and DHA are two omega-3 fatty acids particularly linked to health benefits.</span>
<span class="attribution"><a class="source" href="https://med.libretexts.org/Courses/Allan_Hancock_College/Introduction_to_Nutrition_Science_(Bisson_et._al)/07%3A_Lipids/7.04%3A_Fatty_Acid_Types_and_Food_Sources">Minutemen/Wikimedia Commons via LibreTexts</a></span>
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<p>I <a href="https://scholar.google.com/citations?user=QeKA8ZoAAAAJ&hl=en">am a pulmonologist</a> at the University of Virginia School of Medicine, and my research team and I are working to identify risk factors that may contribute to the development of <a href="https://www.lung.org/lung-health-diseases/lung-disease-lookup/pulmonary-fibrosis/introduction#">pulmonary fibrosis</a>. In this disease, scarred lung tissue can lead to respiratory failure and death.</p>
<p>We examined whether higher levels of DHA and EPA in the blood of patients with pulmonary fibrosis in different groups of research participants in the U.S. were linked to disease progression. We found that patients with higher levels of omega-3 fatty acids in their blood had a <a href="https://doi.org/10.1016/j.chest.2023.09.035">slower decline in lung function and longer survival</a>. Notably, these findings persisted even after we accounted for other factors such as age and co-occurring diseases. </p>
<h2>Why it matters</h2>
<p>Currently, there are <a href="https://doi.org/10.1111/crj.13466">very few treatments</a> available for pulmonary fibrosis. Those that do exist have significant side effects. Our findings suggest that increasing omega-3 fatty acids in a patient’s diet may slow the progression of this devastating disease.</p>
<p>Researchers have investigated the role of nutrition in many other diseases, but it remains understudied in chronic lung diseases, including pulmonary fibrosis. Our study, along with other published research, suggests <a href="https://doi.org/10.1183/13993003.00262-2023">dietary modifications</a> may influence the trajectory of this disease and improve a patient’s ability to tolerate treatment.</p>
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<figcaption><span class="caption">Scarring in lung tissue makes it more difficult to breathe.</span></figcaption>
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<p>Furthermore, other studies using mice have shed light on how omega-3 fatty acids may <a href="https://doi.org/10.1186/1471-2466-14-64">protect against pulmonary fibrosis</a> by regulating the activity of inflammatory cells and slowing buildup of scar tissue in the lungs. </p>
<h2>What still isn’t known</h2>
<p>Since we were able to measure omega-3 fatty acid levels in the blood at only one point in time, we could not determine whether changing levels over time correlates with changes in pulmonary fibrosis. </p>
<p>Crucially, it remains unknown whether increasing omega-3 fatty acid levels in the blood will have a meaningful effect on the lives of patients with pulmonary fibrosis. Omega-3 fatty acids in the blood might not directly affect pulmonary fibrosis and may simply reflect healthier lifestyles and diets. </p>
<p>Clinical trials are necessary to actually determine whether omega-3 fatty acids are beneficial for patients with respiratory diseases.</p>
<h2>What’s next</h2>
<p>We plan to continue researching whether omega-3 fatty acids have a protective effect against pulmonary fibrosis. </p>
<p>Specifically, we hope to determine the mechanism by which omega-3-enriched interventions affect the lungs of patients with pulmonary fibrosis. </p>
<p>These will be important steps to identify patients who may be particularly responsive to omega-3 therapies and move these treatments toward clinical testing.</p><img src="https://counter.theconversation.com/content/222970/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>John Kim receives funding from the National Institute of Health and Chest Foundation. </span></em></p>Essential fats found in fish and nuts are tied to many protective health benefits. Researchers found they may also slow decline of lung function and prolong the lives of pulmonary fibrosis patients.John Kim, Assistant Professor of Medicine, University of VirginiaLicensed 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>
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<figcaption><span class="caption">Fats perform essential functions in your cells, but not all of them are good for you.</span></figcaption>
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<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>
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<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>
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<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>
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<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/1794542022-05-19T12:23:24Z2022-05-19T12:23:24ZIs intermittent fasting the diet for you? Here’s what the science says<figure><img src="https://images.theconversation.com/files/453968/original/file-20220323-23-zm8qqm.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C6000%2C3997&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Intermittent fasting could have an array of health benefits, but as of yet there are no long-term studies into its effects.</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/intermitted-farsting-diet-concept-royalty-free-image/1361961784?adppopup=true">neirfy/iStock via Getty Images Plus</a></span></figcaption></figure><p>What if I told you all you need to do to lose weight is read a calendar and tell time? These are the basics for successfully following an intermittent fasting diet. </p>
<p>Can it be that simple, though? Does it work? And what is the scientific basis for fasting? As a registered dietitian and <a href="https://experts.okstate.edu/mckale.montgomery">expert in human nutrition and metabolism</a>, I am frequently asked such questions.</p>
<p>Simply stated, intermittent fasting is defined by alternating set periods of fasting with periods in which eating is permitted. One method is <a href="https://doi.org/10.1093/ajcn/86.1.7">alternate-day fasting</a>. On “fast days,” followers of this form of fasting are restricted to consuming no more than 500 calories per day; on “feast days,” which occur every other day, they can eat freely, with no restrictions on the types or quantities of foods eaten. </p>
<p>Other methods include the increasingly popular <a href="https://doi.org/10.1038/s41574-022-00638-x">5:2 method</a>. This form of fasting involves five days of feasting and two days of fasting per week. </p>
<p>Another variation relies on time-restricted eating. That means followers should fast for a specified number of hours – typically 16 to 20 per day – while freely consuming foods within a designated four- to eight-hour period.</p>
<p>But what about eating breakfast and <a href="https://doi.org/10.1056/NEJM198910053211403">then small meals throughout</a> the day to keep the body’s metabolism running? After all, that’s the <a href="https://doi.org/10.1093/ajcn/81.1.16">conventional wisdom</a> that many of us grew up with. </p>
<p>To answer these questions, it helps to understand the basics of human metabolism. </p>
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<figcaption><span class="caption">A TV host went on a two-month intermittent fast to lose weight. Did it work?</span></figcaption>
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<h2>Human metabolism 101</h2>
<p>The human body requires a continual supply of energy to sustain life, and the foods we eat provide us with this energy. But because eating is often followed by periods of time without eating, an intricate set of biological pathways is in place to meet the body’s energy demands between meals. </p>
<p>Most of the pathways function at some level all the time, but they fluctuate following a meal in a predictable pattern called the <a href="https://doi.org/10.1007/s13679-018-0308-9">fed-fast cycle</a>. The time frames of the cycle can vary, depending on the food types eaten, the size of the meal and the person’s activity level.</p>
<p>So what happens, metabolically speaking, after we eat? Consuming carbohydrates and fats leads to a rise in blood glucose and also <a href="https://doi.org/10.1001/jama.2013.280593">lipid levels</a>, which include cholesterol and triglycerides. </p>
<p>This triggers the release of insulin from the pancreas. The insulin helps tissues throughout the body take up the glucose and lipids, which supplies the tissues with energy. </p>
<p>Once energy needs are met, leftover glucose is stored in the liver and skeletal muscle in a condensed form called glycogen. When glycogen stores are full, excess glucose converts to fatty acids and is stored in fat tissue. </p>
<p><a href="https://www.sciencedirect.com/topics/medicine-and-dentistry/absorptive-state">About three to 18 hours</a> after a meal – again, depending upon a person’s activity level and size the of the meal – the amount of circulating blood glucose and lipids returns to baseline levels. So tissues then must rely on fuel sources already in the body, which are the glycogen and fat. A hormone called glucagon, secreted by the pancreas, helps facilitate the breakdown of glycogen and fat to provide energy for the body between meals. </p>
<p>Glucagon also initiates a process known as <a href="https://www.sciencedirect.com/topics/medicine-and-dentistry/gluconeogenesis">gluconeogenesis</a>, which is the synthesis of glucose from nondietary sources. This helps maintain the right level of blood glucose levels.</p>
<p>When the body reaches a true fasting state – about 18 hours to two days without additional food intake – the body’s stores of glycogen are depleted, and tissues like the heart and skeletal muscle start to rely heavily on fats for energy. That means an increase in the breakdown of the stored fats. </p>
<p>“Aha!” you might say. “So intermittent fasting is the key to ultimate fat burning?” Well, it’s not that simple. Let’s go through what happens next.</p>
<h2>The starvation state</h2>
<p>Though many tissues adapt to using fats for energy, the brain and red blood cells need a continual supply of glucose. But when glucose is not available because of fasting, the body starts to break down its own proteins and <a href="https://doi.org/10.1152/ajpendo.1997.273.6.E1209">converts them to glucose instead</a>. However, because proteins are also critical for supporting essential bodily functions, this is not a sustainable process.</p>
<p>When the body enters the starvation state, the body goes into self-preservation mode, and a metabolic shift occurs in an effort to spare body protein. The body continues to synthesize glucose for those cells and tissue that absolutely need it, but the breakdown of stored fats increases as well to provide energy for tissues such as the skeletal muscle, heart, liver and kidneys. </p>
<p>This also <a href="https://www.ncbi.nlm.nih.gov/books/NBK493179/#">promotes ketogenesis</a>, or the formation of ketone bodies – molecules produced in the liver as an energy source when glucose is not available. In the starvation state, ketone bodies are important energy sources, because the body is not capable of solely utilizing fat for energy. This is why it is inaccurate when some proponents of intermittent fasting claim that fasting is a way of burning “just fat” - it’s not biologically possible.</p>
<p>What happens when you break the fast? The cycle starts over. Blood glucose and lipids return to basal levels, and energy levels in the body are seamlessly maintained by transitioning between the metabolic pathways described earlier. The neat thing is, we don’t even have to think about it. The body is well-equipped to adapt between periods of feasting and fasting. </p>
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<figcaption><span class="caption">Intermittent fasting – fact or fiction? What the science actually says.</span></figcaption>
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<h2>Possible downsides</h2>
<p>If an “all-or-nothing” dietary approach to weight loss sounds appealing to you, chances are it just might work. Indeed, intermittent fasting diets have produced <a href="https://doi.org/10.1001/jamainternmed.2017.0936">clinically significant</a> amounts of weight loss. Intermittent fasting may also <a href="https://doi.org/10.1038/s41574-022-00638-x">reduce disease risk</a> by lowering blood pressure and blood lipid levels.</p>
<p>On the flip side, numerous studies have shown that the weight reduction from intermittent fasting diets is <a href="https://doi.org/10.1001/jamainternmed.2017.0936">no greater than</a> the weight loss on a standard calorie-restricted diet.</p>
<p>In fact, the weight loss caused by intermittent fasting is due not to spending time in some sort of magic metabolic window, but rather to reduced overall calorie consumption. On feast days, dieters do not typically <a href="https://doi.org/10.1186/1475-2891-9-35">fully compensate</a> for lack of food on fasted days. This is what results in mild to moderate weight loss. Approximately 75% of the weight is fat mass; the rest is lean mass. That’s about the <a href="https://doi.org/10.1038/s41574-022-00638-x">same ratio as a standard low-calorie diet</a>.</p>
<p>Should you still want to go forward with intermittent fasting, keep a few things to keep in mind. First, there are no studies on the long-term safety and efficacy of following this type of diet. Second, studies show that intermittent fasters don’t get enough of <a href="https://doi.org/10.1016/j.clnu.2020.02.022">certain nutrients</a>. </p>
<p>Exercise is something else to consider. It helps preserve lean muscle mass and may also contribute to increased weight loss and long-term weight maintenance. This is important, because nearly a quarter of the weight lost on any diet is muscle tissue, and the efficacy of intermittent fasting for weight loss has been demonstrated <a href="https://doi.org/10.1038/s41574-022-00638-x">for only short durations</a>.</p>
<p>Also, once you stop following an intermittent-fasting diet, you will very likely gain the weight back. This is a critical consideration, because many people find the diet difficult to follow long-term. Imagine the challenge of planning six months’ worth of feasting and fasting around family dinners, holidays and parties. Then imagine doing it for a lifetime. </p>
<p>Ultimately, the best approach is to follow an eating plan that meets current dietary recommendations and fits into your lifestyle.</p><img src="https://counter.theconversation.com/content/179454/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>McKale Montgomery receives funding from the National Institutes of Health.</span></em></p>Proponents of intermittent fasting say the clock can help you win the battle of the bulge. But the science behind it is a little more complicated.McKale Montgomery, Assistant Professor of Nutritional Sciences, Oklahoma State UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1766412022-02-27T13:08:47Z2022-02-27T13:08:47ZUncovering the genetic causes of fatty liver disease — a growing health concern<figure><img src="https://images.theconversation.com/files/447843/original/file-20220222-17-1vieffq.jpg?ixlib=rb-1.1.0&rect=11%2C4%2C977%2C546&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Studying the genetic aspects of fatty liver disease can help identify its causes and consequences and find new treatments.</span> <span class="attribution"><span class="source">(Shutterstock)</span></span></figcaption></figure><p>Over the past 40 years, changes in our urban environment and diet have had a major impact on our lifestyles.</p>
<p>We are more sedentary and the quality of our diet and sleep is at its lowest in decades. These changes, coupled with an increase in life expectancy, are associated with an increase in the number of people with “cardiometabolic” diseases such as Type 2 diabetes, heart diseases, certain cancers and even certain neurodegenerative diseases.</p>
<p>Another cardiometabolic disease that frequently flies under the radar is non-alcoholic fatty liver disease. The liver is an important organ for food digestion, energy metabolism and nutrient management, and communicates with the intestine and the adipose tissue (the main component of our body fat). But non-alcoholic fatty liver disease is a fairly silent disease, as there are few or no symptoms associated with it.</p>
<p>Our lab uses human genetics to identify targets to treat and prevent non-alcoholic fatty liver disease and its complications. </p>
<h2>Fatty liver disease and its consequences</h2>
<p>Non-alcoholic fatty liver disease is a disease that affects, on average, <a href="https://doi.org/10.1002/hep.29367">one in four adults and nearly one in 10 children worldwide</a>. The disease progresses from reversible to irreversible stages. </p>
<p>The first stage is defined by the presence of steatosis (<a href="https://doi.org/10.1001/jama.2015.5370">excessive accumulation of lipids in the liver to at least five per cent of the total liver mass</a>). The next stage, which is also reversible, is characterized by inflammation of the liver cells (called hepatocytes). This inflammation may be accompanied by scar tissue (called fibrosis).</p>
<p>The development of the disease to irreversible stages, in more severe cases, can lead to cirrhosis and/or liver cancer. By 2025, <a href="https://doi.org/10.1016/j.cgh.2020.05.064">non-alcoholic fatty liver disease will be the leading cause of liver failure and transplantation</a>. Its complications, however, are not limited to liver disease. It is strongly associated with several other cardiometabolic diseases such as Type 2 diabetes and cardiovascular diseases (the leading cause of death of those with non-alcoholic fatty liver disease).</p>
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<img alt="" src="https://images.theconversation.com/files/448420/original/file-20220224-13-18pxb7e.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/448420/original/file-20220224-13-18pxb7e.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=420&fit=crop&dpr=1 600w, https://images.theconversation.com/files/448420/original/file-20220224-13-18pxb7e.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=420&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/448420/original/file-20220224-13-18pxb7e.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=420&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/448420/original/file-20220224-13-18pxb7e.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=528&fit=crop&dpr=1 754w, https://images.theconversation.com/files/448420/original/file-20220224-13-18pxb7e.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=528&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/448420/original/file-20220224-13-18pxb7e.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=528&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">Evolution of non-alcoholic fatty liver disease. Created with Biorender.</span>
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<h2>What are the risk factors?</h2>
<p>Non-alcoholic fatty liver disease develops gradually and may progress differently from one individual to another depending on genetic factors and certain risk factors, including diet.</p>
<p>Consuming added sugar, such as fructose in sweetened beverages, may contribute to its development, by <a href="https://doi.org/10.3390/nu9090981">activating a metabolic process called “de novo lipogenesis”</a>, the production of fatty acids from sugar. Ultra-processed products, common in the North American diet, <a href="https://doi.org/10.1007/s13679-021-00460-y">have a high energy density and provide a high intake of sugar, fat and salt</a>. Furthermore, alcohol consumption, even in the absence of alcoholism, could have a synergistic effect on liver metabolism and accelerate the progression of non-alcoholic fatty liver disease.</p>
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<img alt="" src="https://images.theconversation.com/files/448421/original/file-20220224-9042-cvjwr6.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/448421/original/file-20220224-9042-cvjwr6.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=420&fit=crop&dpr=1 600w, https://images.theconversation.com/files/448421/original/file-20220224-9042-cvjwr6.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=420&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/448421/original/file-20220224-9042-cvjwr6.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=420&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/448421/original/file-20220224-9042-cvjwr6.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=528&fit=crop&dpr=1 754w, https://images.theconversation.com/files/448421/original/file-20220224-9042-cvjwr6.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=528&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/448421/original/file-20220224-9042-cvjwr6.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=528&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">Risk factors of non-alcoholic fatty liver disease. Created with Biorender.</span>
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<p>Being overweight is also risk factor for non-alcoholic fatty liver disease: <a href="https://doi.org/10.1002/hep.29367">About half of obese individuals (people with a body mass index (BMI) greater than or equal to 30) could develop the disease</a>. However, non-alcoholic fatty liver disease is frequently observed in people who have a “healthy weight.” Although BMI may have some utility in measuring the consequences of high body weight, its clinical utility is increasingly being questioned. BMI gives little or no information on the location of fat tissue: fat has much more harmful consequences when located in the abdomen than in the arms, hips or thighs.</p>
<h2>Genetic factors</h2>
<p>Our research team believes that identifying the genetic factors that contribute to chronic diseases such as non-alcoholic fatty liver disease <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7178197/">will allow us to understand, prevent and treat them better</a>.</p>
<p>To this end, we have conducted the largest genetic study of this disease to date. We compared the <a href="https://doi.org/10.1016/j.xcrm.2021.100437">genome variations of 8,434 people with non-alcoholic fatty liver disease from four countries (Estonia, United States, Finland and the United Kingdom) with those of 770,180 people without the disease</a>, and identified several susceptibility genes, including an association between a gene called LPL and non-alcoholic fatty liver disease. This gene, which codes for an enzyme called lipoprotein lipase, plays an important role in the storage of blood lipids in our adipose tissue. A disruption in the activity of the LPL gene could increase the chances of lipids being deposited elsewhere in the body, such as in the liver.</p>
<p>This genetic study also allowed us to clarify the role of distribution or localization of adipose tissue and obesity in the development of non-alcoholic fatty liver disease. In a recent study, which is currently under peer-review, we investigated the <a href="https://doi.org/10.1101/2021.09.28.21264201">contribution of BMI and waist circumference to the presence of non-alcoholic fatty liver disease</a>. A larger waist circumference was strongly associated with having a greater risk of developing non-alcoholic fatty liver disease, independent of BMI. Conversely, BMI alone had no effect on risk after considering waist circumference.</p>
<p>So, is it necessary to lose weight in order to prevent fatty liver disease?</p>
<h2>Prevention or a cure?</h2>
<p>Although some the medications used to treat Type 2 diabetes could reduce inflammation in the liver of patients with non-alcoholic fatty liver disease, there is no specific treatment or recommended supplements for the disease at this time.</p>
<p>We believe that identifying the genes implicated in non-alcoholic fatty liver disease will accelerate its treatment. Until then, targeting risk factors associated with non-alcoholic fatty liver disease seems to be the most promising avenue. Interestingly, several studies have shown that improving nutrition and increasing physical activity levels can reduce liver fat accumulation, <a href="https://doi.org/10.1016/j.isci.2021.102995">although these factors were associated with relatively modest weight loss</a>.</p>
<p>Like other societal chronic diseases such as cardiovascular diseases and Type 2 diabetes, fatty liver disease can be prevented to some degree. Daily activity, cooking a good variety of foods, improving sleep and limiting screen time, the consumption of ultra-processed products and exposure to stress, can prevent or delay the development of such diseases.</p>
<p>We believe that by democratizing access to a healthy diet and transforming urban planning to promote active travel, it will be possible to slow down the progression of such diseases in the population as a whole.</p><img src="https://counter.theconversation.com/content/176641/count.gif" alt="La Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Benoit Arsenault receives funding from CIHR and Fondation de l'Institut Universitaire de cardiologie et de pneumologie de Québec.</span></em></p><p class="fine-print"><em><span>Émilie Gobeil receives funding from Fonds de recherche du Québec - Santé.</span></em></p>Non-alcoholic fatty liver disease is surprisingly common, affecting about one in four adults. Eating processed foods and sugary drinks can increase the risk of developing the disease.Benoit Arsenault, Chercheur au Centre de recherche de l’Institut universitaire de cardiologie et de pneumologie de Québec et Professeur agrégé au Département de médecine, Université LavalÉmilie Gobeil, Étudiante à la maîtrise en sciences cliniques et biomédicales, Université LavalLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1660222021-08-18T22:53:42Z2021-08-18T22:53:42ZIndividual dietary choices can add – or take away – minutes, hours and years of life<figure><img src="https://images.theconversation.com/files/416466/original/file-20210817-27-105w4xv.jpg?ixlib=rb-1.1.0&rect=130%2C74%2C6064%2C3130&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Eating more fruits, vegetables and nuts can make a meaningful impact on a person's health – and the planet's too.</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/ingredients-for-the-healthy-foods-selection-the-royalty-free-image/1179272859?adppopup=true">kerdkanno/iStock via Getty Images Plus</a></span></figcaption></figure><p>Vegetarian and vegan options have become standard fare in the American diet, from upscale restaurants to fast-food chains. And many people know that the food choices they make affect <a href="https://theconversation.com/confused-about-what-to-eat-science-can-help-118745">their own health</a> as well as that <a href="https://www.theguardian.com/environment/2018/may/31/avoiding-meat-and-dairy-is-single-biggest-way-to-reduce-your-impact-on-earth">of the planet</a>. </p>
<p>But on a daily basis, it’s hard to know how much individual choices, such as buying mixed greens at the grocery store or ordering chicken wings at a sports bar, might translate to overall personal and environmental health. That’s the gap we hope to fill with our research.</p>
<p>We are part of a team of researchers with expertise in <a href="https://scholar.google.com/citations?user=vVPGeT0AAAAJ&hl=en&oi=ao">food sustainability and environmental life cycle assessment</a>, <a href="https://scholar.google.com/citations?user=JKdT2e0AAAAJ&hl=en&oi=ao">epidemiology and environmental health</a> and <a href="https://www.researchgate.net/profile/Victor-Fulgoni">nutrition</a>. We are working to gain a deeper understanding beyond the often overly simplistic animal-versus-plant diet debate and to identify environmentally sustainable foods that also promote human health. </p>
<p>Building on this multi-disciplinary expertise, we combined 15 nutritional health-based dietary risk factors with <a href="https://doi.org/10.3390/su12229466">18 environmental indicators</a> to evaluate, classify and prioritize more than 5,800 individual foods.</p>
<p>Ultimately, we wanted to know: Are drastic dietary changes required to improve our individual health and reduce environmental impacts? And <a href="https://www.youtube.com/watch?v=evL7GvmaQWo">does the entire population need to become vegan</a> to make a meaningful difference for human health and that of the planet?</p>
<h2>Putting hard numbers on food choices</h2>
<p>In our <a href="https://doi.org/10.1038/s43016-021-00343-4">2021 study</a> published in the research journal Nature Food, we provide some of the first concrete numbers for the health burden of various food choices. We analyzed the individual foods based on their composition to calculate each food item’s net benefits or impacts. </p>
<p>The <a href="http://myumi.ch/pdryj">Health Nutritional Index</a> that we developed turns this information into minutes of life lost or gained per serving size of each food item consumed. For instance, we found that eating one hot dog costs a person 36 minutes of “healthy” life. In comparison, we found that eating a serving size of 30 grams of nuts and seeds provides a gain of 25 minutes of healthy life – that is, an increase in good-quality and disease-free life expectancy. </p>
<p>Our study also showed that substituting only 10% of daily caloric intake of beef and processed meats for a diverse mix of whole grains, fruits, vegetables, nuts, legumes and select seafood could reduce, on average, the dietary carbon footprint of a U.S. consumer by one-third and add 48 healthy minutes of life per day. This is a substantial improvement for such a limited dietary change.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/416694/original/file-20210818-13-1enqh5y.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Relative positions of select foods on a carbon footprint versus nutritional health map" src="https://images.theconversation.com/files/416694/original/file-20210818-13-1enqh5y.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/416694/original/file-20210818-13-1enqh5y.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=557&fit=crop&dpr=1 600w, https://images.theconversation.com/files/416694/original/file-20210818-13-1enqh5y.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=557&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/416694/original/file-20210818-13-1enqh5y.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=557&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/416694/original/file-20210818-13-1enqh5y.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=699&fit=crop&dpr=1 754w, https://images.theconversation.com/files/416694/original/file-20210818-13-1enqh5y.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=699&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/416694/original/file-20210818-13-1enqh5y.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=699&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">Relative positions of select foods, from apples to hot dogs, are shown on a carbon footprint versus nutritional health map. Foods scoring well, shown in green, have beneficial effects on human health and a low environmental footprint.</span>
<span class="attribution"><span class="source">Austin Thomason/Michigan Photography and University of Michigan</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
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<h2>How did we crunch the numbers?</h2>
<p>We based our Health Nutritional Index on a large epidemiological study called the <a href="https://doi.org/10.1016/S0140-6736(17)32366-8">Global Burden of Disease</a>, a comprehensive global study and database that was developed with the help of <a href="http://www.healthdata.org/gbd/about">more than 7,000 researchers around the world</a>. The Global Burden of Disease determines the risks and benefits associated with multiple environmental, metabolic and behavioral factors – including 15 dietary risk factors. </p>
<p>Our team took that population-level epidemiological data and adapted it down to the level of individual foods. Taking into account more than 6,000 risk estimates specific to each age, gender, disease and risk, and the fact that there are about a half-million minutes in a year, we calculated the health burden that comes with consuming one gram’s worth of food for each of the dietary risk factors.</p>
<p>For example, we found that, on average, 0.45 minutes are lost per gram of any processed meat that a person eats in the U.S. We then multiplied this number by the corresponding <a href="https://doi.org/10.3390/nu10101441">food profiles</a> that we previously developed. Going back to the example of a hot dog, the 61 grams of processed meat in a hot dog sandwich results in 27 minutes of healthy life lost due to this amount of processed meat alone. Then, when considering the other risk factors, like the sodium and trans fatty acids inside the hot dog – counterbalanced by the benefit of its polyunsaturated fat and fibers – we arrived at the final value of 36 minutes of healthy life lost per hot dog. </p>
<p>We repeated this calculation for more than 5,800 foods and mixed dishes. We then compared scores from the health indices with 18 different environmental metrics, including carbon footprint, water use and air pollution-induced human health impacts. Finally, using this health and environmental nexus, we color-coded each food item as green, yellow or red. Like a traffic light, green foods have beneficial effects on health and a low environmental impact and should be increased in the diet, while red foods should be reduced.</p>
<h2>Where do we go from here?</h2>
<p>Our study allowed us to identify certain priority actions that people can take to both improve their health and reduce their environmental footprint. </p>
<p>When it comes to environmental sustainability, we found striking variations both within and between animal-based and plant-based foods. For the “red” foods, beef has the largest carbon footprint across its <a href="https://doi.org/10.1201/b19138">entire life cycle</a> – twice as high as pork or lamb and four times that of poultry and dairy. From a health standpoint, eliminating processed meat and reducing overall sodium consumption provides the largest gain in healthy life compared with all other food types. </p>
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<a href="https://images.theconversation.com/files/416696/original/file-20210818-19-rjp2yz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Cattle in feedlot or feed yard" src="https://images.theconversation.com/files/416696/original/file-20210818-19-rjp2yz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/416696/original/file-20210818-19-rjp2yz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/416696/original/file-20210818-19-rjp2yz.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/416696/original/file-20210818-19-rjp2yz.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/416696/original/file-20210818-19-rjp2yz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/416696/original/file-20210818-19-rjp2yz.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/416696/original/file-20210818-19-rjp2yz.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>
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<span class="caption">Beef consumption had the highest negative environmental impacts, and processed meat had the most important overall adverse health effects.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/feedlot-cattle-29-royalty-free-image/1303979847?adppopup=true">Clinton Austin/iStock via Getty Images Plus</a></span>
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<p>Therefore, people might consider eating less of foods that are high in processed meat and beef, followed by pork and lamb. And notably, among plant-based foods, greenhouse-grown vegetables scored poorly on environmental impacts due to the combustion emissions from heating.</p>
<p>Foods that people might consider increasing are those that have high beneficial effects on health and low environmental impacts. We observed a lot of flexibility among these “green” choices, including whole grains, fruits, vegetables, nuts, legumes and low-environmental impact fish and seafood. These items also offer options for all income levels, tastes and cultures.</p>
<p>Our study also shows that when it comes to food sustainability, it is not sufficient to only consider the amount of greenhouse gases emitted – the so-called carbon footprint. Water-saving techniques, such as drip irrigation and the reuse of gray water – or domestic wastewater such as that from sinks and showers – can also make important steps toward lowering the water footprint of food production.</p>
<p>A limitation of our study is that the epidemiological data does not enable us to differentiate within the same food group, such as the health benefits of a watermelon versus an apple. In addition, individual foods always need to be considered within the context of one’s individual diet, considering the maximum level above which foods are not any more beneficial – one cannot live forever by just increasing fruit consumption. </p>
<p>At the same time, our Health Nutrient Index has the potential to be regularly adapted, incorporating new knowledge and data as they become available. And it can be customized worldwide, as has already <a href="https://doi.org/10.3390/nu12092745">been done in Switzerland</a>.</p>
<p>It was encouraging to see how small, targeted changes could make such a meaningful difference for both health and environmental sustainability – one meal at a time.</p><img src="https://counter.theconversation.com/content/166022/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>This research was funded by an unrestricted grant from the National Dairy Council and the University of Michigan Dow Sustainability Fellowship. Olivier Jolliet. has received funding on unrelated projects from US EPA, USDA, American Chemistry Council Long-Range Research Initiative, and Unilever, and became part, after submission of the present manuscript of the Sustainable Nutrition Scientific Board created with the unrestricted support from Nutella. The funding organizations did not have a role in the manuscript development.
</span></em></p><p class="fine-print"><em><span>This research was funded by an unrestricted grant from the National Dairy Council and the University of Michigan Dow Sustainability Fellowship.</span></em></p>A new study puts numbers to the health and environmental benefits – or impacts – of individual foods and shows how small changes can make a significant difference.Olivier Jolliet, Professor of Environmental Health Sciences, University of MichiganKaterina S. Stylianou, Research Associate in Environmental Health Sciences, University of MichiganLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1364342020-05-12T12:35:50Z2020-05-12T12:35:50ZThe dirty history of soap<figure><img src="https://images.theconversation.com/files/333754/original/file-20200508-49546-dx6y3a.jpg?ixlib=rb-1.1.0&rect=126%2C364%2C4404%2C3169&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">How many times a day do you use soap?</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/bar-soap-royalty-free-image/530859976">Paul Linse/The Image Bank via Getty Images</a></span></figcaption></figure><p>“<a href="https://www.cdc.gov/coronavirus/2019-ncov/prevent-getting-sick/prevention.html">Wash your hands often with soap and water for at least 20 seconds</a>.” That’s what the CDC has advised all Americans to do to prevent the spread of COVID-19 during this pandemic.</p>
<p>It’s common-sense advice. The <a href="https://www.washingtonpost.com/news/speaking-of-science/wp/2017/03/20/dear-science-how-does-soap-make-things-clean/">surfactants found in soap lift germs from the skin</a>, and water then washes them away. Soap is inexpensive and ubiquitous; it’s a consumer product found in every household across the country.</p>
<p>Yet few people know the long and dirty history of making soap, the product we all rely on to clean our skin. <a href="https://scholar.google.com/citations?user=ZG3N6Cr_wT0C&hl=en&oi=ao">I’m a historian who focuses on material culture</a> in much of my research. As I started digging into what’s known about soap’s use in the past, I was surprised to discover its messy origins.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/333755/original/file-20200508-49546-550d2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/333755/original/file-20200508-49546-550d2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/333755/original/file-20200508-49546-550d2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=395&fit=crop&dpr=1 600w, https://images.theconversation.com/files/333755/original/file-20200508-49546-550d2.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=395&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/333755/original/file-20200508-49546-550d2.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=395&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/333755/original/file-20200508-49546-550d2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=496&fit=crop&dpr=1 754w, https://images.theconversation.com/files/333755/original/file-20200508-49546-550d2.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=496&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/333755/original/file-20200508-49546-550d2.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=496&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">From animal fat to coal tar, what goes in tends to be pretty dirty.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/advertising-during-the-first-world-war-in-1915-wrights-coal-news-photo/1080227192">SeM/Universal Images Group via Getty Images</a></span>
</figcaption>
</figure>
<h2>Gross ingredients to clean things up</h2>
<p><a href="https://doi.org/10.1021/bk-2015-1211.ch009">Ancient Mesopotamians were first to produce</a> a kind of soap by cooking fatty acids – like the fat rendered from a slaughtered cow, sheep or goat – together with water and an alkaline like <a href="https://www.britannica.com/science/lye">lye</a>, a caustic substance derived from wood ashes. The result was a greasy and smelly goop that lifted away dirt.</p>
<p>An early mention of soap comes in <a href="https://www.researchgate.net/publication/282650616_An_Ancient_Cleanser_Soap_Production_and_Use_in_Antiquity">Roman scholar Pliny the Elder’s</a> book “<a href="https://books.google.com/books?id=nvBDAQAAMAAJ&q=sapo#v=onepage&accltump;q=soap&f=false">Naturalis Historia</a>” from A.D. 77. He described soap as a pomade made of tallow – typically derived from beef fat – and ashes that the Gauls, particularly the men, applied to their hair to give it “a reddish tint.”</p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/333756/original/file-20200508-49550-1mcaftr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/333756/original/file-20200508-49550-1mcaftr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/333756/original/file-20200508-49550-1mcaftr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=1276&fit=crop&dpr=1 600w, https://images.theconversation.com/files/333756/original/file-20200508-49550-1mcaftr.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=1276&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/333756/original/file-20200508-49550-1mcaftr.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=1276&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/333756/original/file-20200508-49550-1mcaftr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1603&fit=crop&dpr=1 754w, https://images.theconversation.com/files/333756/original/file-20200508-49550-1mcaftr.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1603&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/333756/original/file-20200508-49550-1mcaftr.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1603&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">A strigil and flask.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/strigil-and-flask-roman-a-strigil-was-a-curved-blade-used-news-photo/464504797">Heritage Images/Hulton Archive via Getty Images</a></span>
</figcaption>
</figure>
<p>Ancient people used these early soaps to clean wool or cotton fibers before weaving them into cloth, rather than for human hygiene. Not even the Greeks and Romans, who pioneered running water and public baths, <a href="https://www.thoughtco.com/hygiene-in-ancient-rome-and-baths-119136">used soap to clean their bodies</a>. Instead, men and women immersed themselves in water baths and then smeared their bodies with scented olive oils. They used a <a href="https://doi.org/10.1098/rstb.1976.0080">metal or reed scraper called a strigil</a> to remove any remaining oil or grime.</p>
<p>By the Middle Ages, new vegetable-oil-based soaps, which were hailed for their mildness and purity and smelled good, had come into use as luxury items among Europe’s most privileged classes. The first of these, <a href="https://www.reuters.com/article/us-syria-soap/modern-threat-to-syrias-ancient-aleppo-soap-industry-idUSTRE69L1ID20101022">Aleppo soap, a green, olive-oil-based bar soap</a> infused with aromatic laurel oil, was produced in Syria and brought to Europe by Christian crusaders and traders.</p>
<p>French, Italian, Spanish and eventually English versions soon followed. Of these, <a href="https://www.pharmaceutical-journal.com/opinion/comment/a-short-history-of-soap/20066753.article?firstPass=false">Jabon de Castilla</a>, or Castile soap, named for the region of central Spain where it was produced, was the best known. The white, olive-oil-based bar soap was a wildly popular toiletry item among European royals. Castile soap became <a href="https://www.pharmaceutical-journal.com/opinion/comment/a-short-history-of-soap/20066753.article?firstPass=false">a generic term for any hard soap of this type</a>.</p>
<p>The settlement of the American colonies coincided with an age (1500s-1700s) when most Europeans, whether privileged or poor, had turned away from regular bathing out of <a href="https://yalebooks.yale.edu/book/9780300171556/foul-bodies">fear that water actually spread disease</a>. Colonists used soap primarily for domestic cleaning, and soap-making was part of the seasonal domestic routine overseen by women.</p>
<p><a href="http://www.gutenberg.org/files/22675/22675-h/22675-h.htm">As one Connecticut woman described it in 1775</a>, women stored fat from butchering, grease from cooking and wood ashes over the winter months. In the spring, they made lye from the ashes and then boiled it with fat and grease in a giant kettle. This produced a soft soap that women used to wash the <a href="https://yalebooks.yale.edu/book/9780300171556/foul-bodies">linen shifts that colonists wore as undergarments</a>.</p>
<p>In the new nation, the founding of soap manufactories like New York-based <a href="https://www.supplytime.com/Blogs/Blog/History-of-Colgate-Palmolive-Company_23.aspx">Colgate, founded in 1807</a>, or the Cincinnati-based <a href="https://www.pg.com/en_US/downloads/media/Fact_Sheets_CompanyHistory.pdf">Procter & Gamble, founded in 1837</a>, increased the scale of soap production but did little to alter its ingredients or use. Middle-class Americans <a href="https://doi.org/10.2307/1894408">had resumed water bathing, but still shunned soap</a>.</p>
<p><a href="https://doi.org/10.1111/j.1468-0289.2007.00388.x">Soap-making remained an extension of the tallow trade</a> that was closely allied with candle making. Soap itself was for laundry. At the first P&G factory, laborers used large cauldrons to <a href="https://oac.cdlib.org/ark:/28722/bk000401r2p/?brand=oac4">boil down fat collected from homes, hotels and butchers</a> to make the candles and soap they sold.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/333757/original/file-20200508-49565-mm0nq7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/333757/original/file-20200508-49565-mm0nq7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/333757/original/file-20200508-49565-mm0nq7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=453&fit=crop&dpr=1 600w, https://images.theconversation.com/files/333757/original/file-20200508-49565-mm0nq7.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=453&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/333757/original/file-20200508-49565-mm0nq7.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=453&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/333757/original/file-20200508-49565-mm0nq7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=569&fit=crop&dpr=1 754w, https://images.theconversation.com/files/333757/original/file-20200508-49565-mm0nq7.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=569&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/333757/original/file-20200508-49565-mm0nq7.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=569&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Workers tended to soap in large tanks in a French factory circa 1870.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/the-manufacture-of-soap-in-large-tanks-in-the-19th-century-news-photo/929239368">Universal History Archive/Universal Images Group via Getty Images</a></span>
</figcaption>
</figure>
<h2>From cleaning objects to cleaning bodies</h2>
<p><a href="https://doi.org/10.1021/ed079p1172">The Civil War was the watershed</a>. Thanks to reformers who touted regular washing with water and soap as a sanitary measure to aid the Union war effort, bathing for personal hygiene caught on. <a href="https://ohiohistorycentral.org/w/Procter_%26_Gamble">Demand for inexpensive toilet soaps increased</a> dramatically among the masses.</p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/333758/original/file-20200508-49558-6zabpn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/333758/original/file-20200508-49558-6zabpn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/333758/original/file-20200508-49558-6zabpn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=862&fit=crop&dpr=1 600w, https://images.theconversation.com/files/333758/original/file-20200508-49558-6zabpn.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=862&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/333758/original/file-20200508-49558-6zabpn.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=862&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/333758/original/file-20200508-49558-6zabpn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1083&fit=crop&dpr=1 754w, https://images.theconversation.com/files/333758/original/file-20200508-49558-6zabpn.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1083&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/333758/original/file-20200508-49558-6zabpn.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1083&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Palmolive ads, like this one from 1900, stressed the exotic ingredients in the green bar.</span>
<span class="attribution"><a class="source" href="https://www.loc.gov/pictures/item/2018696682/">Library of Congress Prints and Photographs Division</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>Companies began to develop and market a variety of new products to consumers. In 1879, P&G introduced <a href="https://oac.cdlib.org/ark:/28722/bk000401r2p/?brand=oac4">Ivory soap</a>, one of the first perfumed toilet soaps in the U.S. B.J. Johnson Soap Company of Milwaukee followed with their own palm-and-olive-oil-based <a href="https://www.milwaukeemag.com/story-behind-this-bar-of-palmolive-soap/">Palmolive soap</a> in 1898. It was the <a href="https://www.supplytime.com/Blogs/Blog/History-of-Colgate-Palmolive-Company_23.aspx">world’s best-selling soap by the early 1900s</a>.</p>
<p>Soap chemistry also began to change, paving the way for the modern era. At P&G, <a href="https://oac.cdlib.org/ark:/28722/bk000401r2p/?brand=oac4">decades of laboratory experiments</a> with imported coconut and palm oil, and then with domestically produced cottonseed oil, led to the <a href="https://www.ars.usda.gov/research/publications/publication/?seqNo115=210614">discovery of hydrogenated fats in 1909</a>. These solid, vegetable-based fats revolutionized soap by making its manufacture less dependent on animal byproducts. <a href="https://www.cleaninginstitute.org/understanding-products/why-clean/soaps-detergents-history">Shortages of fats and oils for soap</a> during World Wars I and II also led to the discovery of synthetic detergents as a <a href="https://www.britannica.com/science/soap/Early-synthetic-detergents">“superior” substitute</a> for fat-based laundry soaps, household cleaners and shampoos.</p>
<p>Today’s commercially manufactured soaps are <a href="http://www.soaphistory.net/soap-facts/soap-types/">highly specialized</a>, lab-engineered products. Synthesized animal fats and plant-based oils and bases are combined with <a href="https://www.bare-soaps.com/blogs/your-impact/116431557-what-s-in-a-bar-of-soap">chemical additives</a>, including moisturizers, conditioners, lathering agents, colors and scents, to make soaps more appealing to the senses. But they cannot fully mask its mostly foul ingredients, including <a href="http://www.soaphistory.net/soap-history/history-of-liquid-soap-and-shower-gel/">shower gels’</a> petroleum-based contents.</p>
<p>As a 1947 history of P&G observed: “<a href="https://oac.cdlib.org/ark:/28722/bk000401r2p/?brand=oac4">Soap is a desperately ordinary substance to us</a>.” As unremarkable as it is during normal times, soap has risen to prominence during this pandemic.</p>
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<p class="fine-print"><em><span>Judith Ridner 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>With hand-washing top of mind, soap is an integral part of keeping clean. But people through the ages relied on earlier forms of soap more for cleaning objects than for personal hygiene.Judith Ridner, Professor of History, Mississippi State UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1064092019-01-08T11:40:10Z2019-01-08T11:40:10ZLet them eat more fat? Researcher argues that a balance of types of fat is the key<figure><img src="https://images.theconversation.com/files/252690/original/file-20190107-32124-vlzf8b.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption"> A mix of fats, such as those found in nuts, avocados, salmon and olives, could be healthy and more satisfying.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/selection-healthy-fat-sources-on-wooden-396446890?src=ekSdGUl72cn3WGKgPd-dZQ-1-2">Craevschii Family/Shutterstock.com</a></span></figcaption></figure><p>Public health guidelines, such as the <a href="https://health.gov/dietaryguidelines/2010/">Dietary Guidelines for Americans</a>, have long emphasized reducing dietary fat intake, but nutritionists and other health scientists now have more recent evidence that not all fats have adverse effects. Dietary fats differ with regard to their effects on health and risk for chronic diseases, particularly in regard to effects on risk for heart disease. </p>
<p>Indeed, <a href="https://www.hsph.harvard.edu/nutritionsource/what-should-you-eat/fats-and-cholesterol/dietary-fat-and-disease/">some nutrition experts</a> now believe that certain types of dietary fat may even reduce cardiovascular risk. Some dietary fats may lower fats in the blood called <a href="https://www.mayoclinic.org/diseases-conditions/high-blood-cholesterol/in-depth/triglycerides/art-20048186">triglycerides</a>. They may also increase levels of HDL, or what is known as the “good” cholesterol, and <a href="https://www.heart.org/en/healthy-living/healthy-eating/eat-smart/fats/the-facts-on-fats">reduce LDL-cholesterol</a>, or the less healthy type of cholesterol, thus improving the HDL to <a href="https://www.sciencedirect.com/science/article/pii/S0735109707032597?via%3Dihub">total cholesterol ratio</a>. </p>
<p>Also, many diet plans that do not strictly limit the total amount of dietary fat a person consumes have been associated with <a href="https://onlinelibrary.wiley.com/doi/full/10.1177/0884533611405791">better diet satisfaction</a>, weight loss, and preservation of muscle mass. </p>
<p>As a research professor in the field of nutrition and dietetics, I am convinced that findings <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4306330/">from our work</a>, along with other published current evidence, show that the concept that dietary fat is “toxic” is very much outdated and misguided. </p>
<p>Although there is conclusive evidence that one type of fat, trans fat, has no place in a healthy diet, it’s important to learn how to balance the other types of fats in the diet.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/ro4UObvPpdo?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Prof. Heidi Silver discusses the role of dietary fat.</span></figcaption>
</figure>
<h2>A balancing act</h2>
<p>While not all fats are alike, they do share some things in common. They provide energy with approximately <a href="https://www.heart.org/en/healthy-living/healthy-eating/eat-smart/fats/monounsaturated-fats">nine calories per each gram of fat</a>, they are all broken down during digestion by enzymes in the gastrointestinal tract, and they are well absorbed as fatty acids, or <a href="https://www.britannica.com/science/hydrocarbon">chains of hydrogen and carbon</a>. </p>
<p>But these carbon chains vary in length and their degree of saturation. As a result, dietary fats vary in their effects on the body.</p>
<p>In some instances, the carbon molecules bind to other carbon molecules. In others, they bind to hydrogen molecules. You likely have heard names for these two types of fats – unsaturated and saturated. Unsaturated fats are those in which carbon molecules bind to other carbon molecules. <a href="https://www.heart.org/en/healthy-living/healthy-eating/eat-smart/fats/saturated-fats">Saturated fats</a> are those in which carbon molecules bind to hydrogen molecules. Within the two broad types of fat, there are differences still.</p>
<p>Among the unsaturated fats, there are those that are <a href="https://www.heart.org/en/healthy-living/healthy-eating/eat-smart/fats/monounsaturated-fats">mono-unsaturated</a>, or those that have one unsaturated carbon bond, which are found in olive oil and certain kinds of nuts, and there are those that are <a href="https://www.heart.org/en/healthy-living/healthy-eating/eat-smart/fats/polyunsaturated-fats">poly-unsaturated</a> and are found in such foods as walnuts, plant oils, salmon and sardines. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/252693/original/file-20190107-32127-7th6aw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/252693/original/file-20190107-32127-7th6aw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=260&fit=crop&dpr=1 600w, https://images.theconversation.com/files/252693/original/file-20190107-32127-7th6aw.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=260&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/252693/original/file-20190107-32127-7th6aw.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=260&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/252693/original/file-20190107-32127-7th6aw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=327&fit=crop&dpr=1 754w, https://images.theconversation.com/files/252693/original/file-20190107-32127-7th6aw.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=327&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/252693/original/file-20190107-32127-7th6aw.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=327&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">This illustration of stearic acid shows the 18 carbon molecules binding to 36 hydrogen molecules and to two oxygen molecules.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-illustration/stearic-acid-molecular-formula-c18h36o2-saturated-1085497997?src=14tXPwxJ0chL73lBWd85aw-1-15">Orange Deer Studios/Shutterstock.com</a></span>
</figcaption>
</figure>
<p>We also have learned that different kinds of saturated fats affect the body in different ways. For example, the 12-carbon lauric acid, 14-carbon myristic acid, 16-carbon palmitic acid and 18-carbon stearic acid are all saturated fats. But, <a href="https://www.nejm.org/doi/full/10.1056/NEJM198805123181905?url_ver=Z39.88-2003&rfr_id=ori%3Arid%3Acrossref.org&rfr_dat=cr_pub%3Dpubmed">stearic acid</a> does not increase LDL-cholesterol levels like the other saturated fats. </p>
<p>While these differences are not new, the understanding of their effects is new, mostly due to findings from more recent studies like <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4306330/">my own</a>. </p>
<p>Thus, the amount of total fat in the diet no longer is the sole measure of the health effects of dietary fat. It’s also about the type of fatty acid, how long the carbon chain is, and whether the fat is saturated, mono-unsaturated or poly-unsaturated. </p>
<h2>The link to heart health</h2>
<p>The scientific discourse about the potentially toxic role of dietary fat and cholesterol on human health started in the late 1950s and early 1960s, when scientists discovered how to analyze fats in the lab. They also discovered the link between <a href="https://www.ncbi.nlm.nih.gov/pubmed/13376806">dietary fat intake</a>, serum levels of total and LDL-cholesterol, and risk for cardiovascular diseases in animals. </p>
<p>Because heart disease has been the leading cause of death in the U.S. since the 1930s, the Nutrition Committee of the American Heart Association in 1968 recommended <a href="https://www.heart.org/-/media/files/healthy-living/company-collaboration/inap/dietary-fat-recommendations-timeline-pdf-ucm_474998.pdf">reducing total and saturated fat intake</a>. The emphasis on <a href="https://health.gov/dietaryguidelines/dga95/12DIETAP.HTM">lowering dietary fat</a> intake was advanced further in 1977 with the publication of the first Dietary Guidelines for Americans by the Senate Select Committee on Nutrition and Human Needs. </p>
<p>Health care professionals in turn shifted their nutrition counseling efforts toward encouraging a low-fat diet. And, the food industry began to develop and produce of a wide-ranging assortment of “low-fat,” “reduced-fat,” “light” and “fat-free” items. </p>
<p>In the mid-1980s, advice to consume a low-fat diet also became a strategy for weight control. Evidence from the landmark <a href="https://www.framinghamheartstudy.org">Framingham Heart Study</a> uncovered that obesity increased risk for heart disease, and national data showed that the entire population was getting heavier. </p>
<p>Americans responded with a <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4598942/">substantial reduction</a> in the percentage of calories consumed as fat. But humans have a <a href="https://www.ncbi.nlm.nih.gov/books/NBK53528/">biological preference</a> for the taste of fat. And with fat off the table, millions increased their consumption of dietary carbohydrates to compensate for the loss in flavor and appeal of foods. As a result, there has been a substantial increase in the waistlines of Americans. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/252709/original/file-20190107-32145-gp9s07.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/252709/original/file-20190107-32145-gp9s07.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=401&fit=crop&dpr=1 600w, https://images.theconversation.com/files/252709/original/file-20190107-32145-gp9s07.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=401&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/252709/original/file-20190107-32145-gp9s07.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=401&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/252709/original/file-20190107-32145-gp9s07.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=504&fit=crop&dpr=1 754w, https://images.theconversation.com/files/252709/original/file-20190107-32145-gp9s07.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=504&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/252709/original/file-20190107-32145-gp9s07.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">
<figcaption>
<span class="caption">Studies have shown that humans have a preference for foods that contain fat, such as this slab of steak.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/against-sliced-raw-steak-344404673?src=ph6BufMyu5FU49Nb8xZ90A-1-20">Paolo Santos/Shutterstock.com</a></span>
</figcaption>
</figure>
<h2>An alternative approach</h2>
<p>Given the mixed scientific evidence on fat, and the diverse roles of dietary fatty acids in health and disease, about four years ago I designed a diet that is moderately high in fat but the types of fat are <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4306330/">proportionally balanced</a>, that is, one-third of total fat comes from saturated fats; one-third comes from monounsaturated fats; and one-third comes from polyunsaturated fats. </p>
<p>Based on this balanced moderately-high fat diet approach, my research team developed a 14-day cycle of menus comprised of three meals and two snacks per day that increases intake of foods high in the 18-carbon monounsaturated fat, oleic acid, and the 18-carbon and longer chain polyunsaturated fats (more commonly known as omega-3 and omega-6 fatty acids). To do this, we replaced high simple carbohydrate snacks with nuts, we replaced croutons in salads with avocado slices, and we used salad dressings high in safflower oil, canola oil and olive oil. </p>
<p>We have been studying the effects of this balanced moderately high fat diet in adults who are overweight or obese. In a study with 144 women over a period lasting 16 weeks, we found that study participants had <a href="https://www.ncbi.nlm.nih.gov/pubmed/24559846">significant reductions</a> in abdominal fat and waist circumference; a 6 percent improvement in blood pressure; reduced blood levels of markers of inflammation; and overall a 6 percent reduction in their five- and 10-year cardiovascular risk. </p>
<p>Study participants reported that they found our diet to be highly palatable, satisfying and economically feasible to adhere to. The firm adherence to our balanced moderately high fat diet in the four-month study was reflected by significant changes in participants’ plasma fatty acid profiles (the array of saturated and unsaturated fats in the blood) that reflected the fatty acid composition of the diet menus.</p>
<p>In a follow-up study using more in-depth analysis of the lipid response to the balanced moderately high fat diet, we found a difference in response between Caucasian females and African-American females. While the Caucasian females had improvements in serum triglyceride and LDL-cholesterol levels, African-American females had the <a href="https://www.ncbi.nlm.nih.gov/pubmed/29382504">most significant improvement</a> in HDL-cholesterol levels. These data support the concept that not all people respond to a dietary approach in the same way and there is no one optimal diet for all people. </p>
<p>In another follow-up study of the response to a higher fat diet, we also found that people with a specific genotype had a stronger response, and that response differed by sex, particularly with regard to improvements in HDL-cholesterol being <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4306330/">stronger in females versus males</a>. </p>
<p>Thus, I believe the choice of an effective dietary approach must be determined based on an individual’s goals and an individual’s clinical and metabolic response to the interaction between genes and environment. </p>
<p>There are limited studies on the strategy of balancing the type of dietary fat. While current scientific consensus is that extremes of dietary fat intake, too high or too low, are unhealthy, I believe that a paradigm shift focusing on the types of dietary fats consumed may offer the opportunity to modify our cardiometabolic risk factors without requiring major changes in the amount of fat or calories we consume.</p><img src="https://counter.theconversation.com/content/106409/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Heidi J. Silver received funding to study dietary fat from the Atkins Foundation. </span></em></p>When did eating become so confusing? In the 1960s, studies began to show a link between heart disease and dietary fat, and fat was demonized. As it turns out, fat is nuanced and may not be so bad.Heidi Silver, Associate Professor of Medicine, Vanderbilt UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/978132018-06-27T10:43:05Z2018-06-27T10:43:05ZHow does your body ‘burn’ fat?<figure><img src="https://images.theconversation.com/files/224095/original/file-20180620-137714-1dcd549.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Increasing the amount of exercise is one way to use the energy stored in fat cells, or to 'burn' fat.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/three-friends-spinning-class-gym-133394168?src=II9xoptT9KKCDRMW0fq98A-1-3">HoonQ/Shutterstock.com</a></span></figcaption></figure><p>Many of us may be considering “burning some fat” so we feel better in our bathing suits out on the beach or at the pool. What does that actually mean, though? </p>
<p>The normal <a href="http://www.sportsci.org/encyc/adipose/adipose.html">fat cell</a> exists primarily to store energy. The body will expand the number of fat cells and the size of fat cells to accommodate excess energy from high-calorie foods. It will even go so far as to start depositing fat cells on our muscles, liver and other organs to create space to store all this extra energy from calorie-rich diets – especially when combined with a low activity lifestyle.</p>
<p>Historically, <a href="https://theconversation.com/stored-fat-is-a-feat-of-evolution-and-your-body-will-fight-to-keep-it-52468">fat storage</a> worked well for humans. The energy was stored as small packages of molecules called <a href="https://www.britannica.com/science/fatty-acid">fatty acids</a>, which are released into the bloodstream for use as fuel by muscles and other organs when there was no food available, or when a predator was chasing us. Fat storage actually conferred a survival advantage in these situations. Those with a tendency to store fat were able to survive longer periods without food and had extra energy for hostile environments.</p>
<p>But when was the last time you ran from a predator? In modern times, with an overabundance of food and safe living conditions, many people have accumulated an excess storage of fat. In fact, more than <a href="https://www.cdc.gov/obesity/data/adult.html">one-third</a> of the adult population in the United States is obese. </p>
<p>The major problem with this excess fat is that the <a href="https://academic.oup.com/ajcn/article/83/2/461S/4650268">fat cells</a>, called adipocytes, do not function normally. They store energy at an abnormally high rate and release energy at an abnormally slow rate. What’s more, these extra and enlarged fat cells <a href="https://www.acs.org/content/acs/en/pressroom/presspacs/2010/acs-presspac-october-13-2010/new-evidence-that-fat-cells-are-not-just-dormant-storage-depots-for-calories.html">produce abnormal amounts</a> of different hormones. These hormones increase inflammation, slow down metabolism, and contribute to disease. This complicated pathological process of excess fat and dysfunction is called <a href="https://link.springer.com/chapter/10.1007%2F978-3-319-39409-1_5">adiposopathy</a>, and it makes the treatment of obesity very difficult. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/224092/original/file-20180620-137734-dar3fv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/224092/original/file-20180620-137734-dar3fv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/224092/original/file-20180620-137734-dar3fv.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/224092/original/file-20180620-137734-dar3fv.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/224092/original/file-20180620-137734-dar3fv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/224092/original/file-20180620-137734-dar3fv.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/224092/original/file-20180620-137734-dar3fv.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">A fat cell is loaded with triglycerides, or fatty deposits, and does not resemble other cells in our body.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-illustration/fat-cells-adipose-tissue-adipocytes-3d-400777933?src=sQKjdYuIWnE-T4fN1dwbfw-1-7">Pavel Chagochkin/Shutterstock.com</a></span>
</figcaption>
</figure>
<p>When a person begins and maintains a new exercise regimen and limits calories, the body does two things to “burn fat.” First, it uses the energy stored in the fat cells to fuel new activity. Second, it stops putting away so much for storage. </p>
<p>The brain signals fat cells to release the energy packages, or fatty acid molecules, to the bloodstream. The muscles, lungs and heart pick up these fatty acids, break them apart, and use the energy stored in the bonds to execute their activities. The scraps that remain are discarded as part of respiration, in the outgoing <a href="https://www.merckmanuals.com/home/lung-and-airway-disorders/biology-of-the-lungs-and-airways/exchanging-oxygen-and-carbon-dioxide">carbon dioxide</a>, or in urine. This leaves the fat cell empty and renders it useless. The cells actually have a short lifespan so when they die the body absorbs the empty cast and doesn’t replace them. Over time, the body directly extracts the energy (i.e., calories) from food to the organs that need them instead of storing it first.</p>
<p>As a result, the body readjusts by decreasing the number and size of fat cells, which subsequently <a href="https://jamanetwork.com/journals/jama/fullarticle/196344">improves baseline metabolism</a>, decreases inflammation, treats disease, and prolongs lives. If we maintain this situation over time, the body reabsorbs the extra empty fat cells and discards them as waste, leaving us leaner and healthier on multiple levels.</p><img src="https://counter.theconversation.com/content/97813/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>David Prologo is the founder of The Catching Point Transformation.</span></em></p>Trainers and fitness gurus often tell their charges how to ‘burn fat.’ But what does that actually involve? Here’s a Speed Read on something that actually takes a fairly long time.J. David Prologo, Associate Professor, Department of Radiology and Imaging Sciences, Emory UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/890322018-05-07T22:33:55Z2018-05-07T22:33:55ZHow fish may reduce your child’s breast cancer risk<figure><img src="https://images.theconversation.com/files/217220/original/file-20180502-153873-qoqwhc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Exposure to omega-3 fatty acids during a child’s early years may play a role in reducing breast cancer risk later in life.</span> <span class="attribution"><span class="source">(Shutterstock)</span></span></figcaption></figure><p>Omega-3 fatty acids are commonly found in plant and seafood sources. If you don’t have high enough <a href="http://www.dx.doi.org/10.1371/journal.pmed.1000058">levels of omega-3s in your diet, it’s a leading risk factor for death</a> globally, contributing to the development of chronic diseases like cancer.</p>
<p>A healthy diet can <a href="https://www.cancer.org/cancer/cancer-causes/diet-physical-activity/diet-and-physical-activity.html">significantly reduce your risk of developing cancer</a>. This has led to great interest in the role of omega-3 fatty acids — especially in <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4245586/">the prevention of breast cancer</a>. </p>
<p>In experimental studies, it has been shown that <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3096965/">omega-3 fatty acids during early years of growth and development may play a role in reducing breast cancer risk later in life</a>. </p>
<p>But not all omega-3s are created equal. </p>
<h2>Seafood sources eight times more potent</h2>
<p>Structurally, omega-3 fatty acids found in plants and seafood are different molecules. </p>
<p>Much of our research to date suggests that the benefits of omega-3 fats can be attributed to those found in seafood including eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). In contrast, omega-3 fatty acids in plants such as flax and canola containing alpha-linolenic acid (ALA) are thought to be less potent. </p>
<p>But scientists have never been sure exactly how much more potent seafood omega-3s are — until recently, when our team at the University of Guelph helped to shed light on this question. </p>
<p>We conducted a study in mice that compared the impacts of ALA versus EPA+DHA on tumour development. The results show that both were beneficial in altering mammary gland development to decrease the risk of developing breast cancer. They also decreased tumour size and multiplicity following the onset of breast cancer. </p>
<p>The study shows <a href="https://doi.org/10.1016/j.jnutbio.2017.12.011">EPA+DHA to be eight times more potent than ALA</a>, however. This suggests that omega-3s from seafood sources may be significantly more effective at reducing breast cancer risk and improving prognosis.</p>
<h2>How much fish is enough?</h2>
<p>So are we getting enough seafood-based omega-3s in our diet? </p>
<p><a href="https://www.ncbi.nlm.nih.gov/pubmed/15524182">A typical North American diet</a> provides approximately one to three grams of ALA per day and only 100-150 mg of EPA/DHA per day. </p>
<p>These amounts fall in line with <a href="https://www.nal.usda.gov/sites/default/files/fnic_uploads/energy_full_report.pdf">recommendations by the Institute of Medicine</a>.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/217961/original/file-20180507-46328-1gvs6l8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/217961/original/file-20180507-46328-1gvs6l8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/217961/original/file-20180507-46328-1gvs6l8.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/217961/original/file-20180507-46328-1gvs6l8.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/217961/original/file-20180507-46328-1gvs6l8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/217961/original/file-20180507-46328-1gvs6l8.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/217961/original/file-20180507-46328-1gvs6l8.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">
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<span class="caption">A study in the United States showed [84 per cent of children consume less than one serving of fish or seafood per week.</span>
<span class="attribution"><span class="source">(Shutterstock)</span></span>
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<p>A growing body of research suggests, however, that dietary intakes of EPA and DHA should be much higher in order to promote optimal health and prevent chronic disease. </p>
<p>This is not a new concept. In 1999, the National Institutes of Health’s report recommended that, in order to promote optimal health and prevent disease, EPA+DHA should make up 0.3 per cent of our daily energy intake. </p>
<p>Based on this recommendation, the <a href="http://www.dhaomega3.org/Life-Stages/Childhood">DHA-EPA Omega-3 Institute reports</a> that this corresponds to 433 to 600 milligrams of EPA+DHA for children between the ages of one and eight years old. </p>
<p>This level can be attained in the diet by consuming two to three servings of fish per week, or by supplementing with a high quality EPA+DHA supplement.</p>
<h2>Optimal doses for children</h2>
<p>Intakes of seafood-based omega-3s in children differ from adults. </p>
<p>Previous studies have shown that <a href="http://agris.fao.org/agris-search/search.do?recordID=US201300947566">North American children have even lower intakes of EPA and DHA than adults</a>. </p>
<p>In fact, a study in the United States revealed that <a href="https://doi.org/10.1016/j.envres.2006.05.011">84 per cent of children consume less than one serving of fish or seafood per week</a>. </p>
<p>So by incorporating more seafood or foods high in omega-3 fatty acids — such as omega-3 milk and eggs — early on in a child’s life, it may be possible to reduce long-term risk of developing breast cancer and other common chronic diseases later in life.</p><img src="https://counter.theconversation.com/content/89032/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>David Ma has received research funding from NSERC, CIHR, SSHRC, CFI, OMAFRA, Dairy Farmers of Canada, Helderleigh Foundation and Canola Council of Canada. David has consulted and reviewed grants previously for Heinz Infant Nutrition Institute, Mead Johnson, PepsiCo, Vegetable Oils Industry of Canada, Unilever, CIHR, NSERC, Alberta Heritage Foundation, and MITACs. In addition, he has served on the Board of the Canadian Nutrition Society and currently in the role as Past-President (2013-Present).</span></em></p><p class="fine-print"><em><span>Jessie Burns 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>New research suggests omega-3s from seafood to be more effective at reducing breast cancer risk than those from plant-based sources.David W.L. Ma, Professor of Human Health and Nutritional Sciences, University of GuelphJessie Burns, PhD Candidate in Human Health and Nutritional Sciences, University of GuelphLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/824452017-09-13T03:10:51Z2017-09-13T03:10:51ZHealth Check: is margarine actually better for me than butter?<figure><img src="https://images.theconversation.com/files/184150/original/file-20170831-9954-9bteez.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The type of fatty acid is what's most important when choosing a spread. </span> <span class="attribution"><span class="source">from www.shutterstock.com.au</span></span></figcaption></figure><p>Only 20 years ago butter was the public villain – contributing to raised cholesterol levels and public concern over an increased risk of heart disease. Now this public perception seems to have been reversed, and reality cooking shows seem to use butter in every recipe. But what has caused this shift in perceptions and is it based on scientific evidence? </p>
<p>In the domestic market more people buy margarine than butter, with 27% of <a href="http://www.abs.gov.au/ausstats/abs@.nsf/Lookup/by%20Subject/4364.0.55.012%7E2011-12%7EMain%20Features%7EUnsaturated%20spreads%20and%20oils%7E10002">respondents in an ABS survey</a> eating margarine the day before, and 15% consuming butter. </p>
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Read more:
<a href="https://theconversation.com/eat-food-not-nutrients-why-healthy-diets-need-a-broad-approach-45823">Eat food, not nutrients: why healthy diets need a broad approach</a>
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<p>Do we still need to be concerned about butter’s links to heart disease, and is there any evidence to suggest butter is better for our health compared to margarine? To answer this we first need to look more closely at the make-up of butter and margarine.</p>
<h2>Where do our favourite yellow spreads come from?</h2>
<p>Butter is made from the processing of cream. The cream is churned until the liquid (buttermilk) separates from the fat solids. These fat solids are then rinsed, a little salt added, and shaped to form the butter we all love. </p>
<p>Margarine was first developed <a href="https://en.wikipedia.org/wiki/Margarine">in France by Napoleon</a> as a substitute for butter to feed the armed forces and lower classes. Margarine is made from vegetable oils, beta-carotene (added for colour), emulsifiers (to help the oil and water mix), salt and flavours (which can include milk solids). Vitamins A and D are also added to the same level present in butter.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/185770/original/file-20170913-3737-16hxocw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/185770/original/file-20170913-3737-16hxocw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/185770/original/file-20170913-3737-16hxocw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=458&fit=crop&dpr=1 600w, https://images.theconversation.com/files/185770/original/file-20170913-3737-16hxocw.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=458&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/185770/original/file-20170913-3737-16hxocw.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=458&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/185770/original/file-20170913-3737-16hxocw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=575&fit=crop&dpr=1 754w, https://images.theconversation.com/files/185770/original/file-20170913-3737-16hxocw.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=575&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/185770/original/file-20170913-3737-16hxocw.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=575&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">We have Napoleon to thank for the advent of margarine.</span>
<span class="attribution"><span class="source">from shutterstock.com</span></span>
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</figure>
<p>Any diet app will tell you margarine has about 10-15% fewer kilojoules than butter. But whether this is significant will largely depend on the amount you consume each day.</p>
<p>A national nutrition survey indicates the average person over 19 years <a href="http://www.abs.gov.au/ausstats/abs@.nsf/Lookup/by%20Subject/4364.0.55.012%7E2011-12%7EMain%20Features%7EUnsaturated%20spreads%20and%20oils%7E10002">consumes 20 grams a day</a> of spreads (either butter or margarine), which equates to a difference of 100kj. This difference is largely insignificant in a usual daily intake of 8700kj/day. </p>
<h2>It’s all in the fatty acids</h2>
<p>The significant nutritional difference actually lies in the fatty acid profiles of the two products. The health differences between butter and margarine are based on the presence of different types of fats. </p>
<p>There are three types of fats in our food: saturated fat, monounsaturated fats and polyunsaturated fats. The difference between these lies in their chemical structure. The structure of saturated fats has no double bonds in between the carbon atoms, monounsaturated fats have one double bond between the carbon atoms, and polyunsaturated fats have two or more double bonds between the carbon atoms. </p>
<p>These subtle differences in structure lead to differences in the way our body metabolises these fats, and hence how they affect our health, in particular our heart health. </p>
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Read more:
<a href="https://theconversation.com/viewpoints-is-saturated-fat-really-the-killer-its-made-out-to-be-76698">Viewpoints: is saturated fat really the killer it's made out to be?</a>
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<p>Margarine can be made from a number of different oils. If coconut oil is used the margarine will be mainly saturated fat, if sunflower oil is used it will mainly be a polyunsaturated fat, and if olive oil or canola oil is used it will mainly be a monounsaturated fat. </p>
<p>Butter, derived from dairy milk, is mainly saturated fat, and the main saturated fats are palmitic acid (about 31%) and myristic acid (about 12%). Studies have shown these <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5492032/">raise blood cholesterol levels</a>. </p>
<p>While there is <a href="https://theconversation.com/health-check-are-saturated-fats-good-or-bad-21524">debate in the scientific world</a> about the relative contributions of saturated fats (and the different types of saturated fatty acids) to heart disease, <a href="https://www.heartfoundation.org.au/images/uploads/publications/Dietary-fats-summary-evidence.pdf">the consensus</a> is that replacing saturated fats with monounsaturated or polyunsaturated fats will lower the risk of heart disease. </p>
<p>The <a href="https://www.nrv.gov.au/chronic-disease/macronutrient-balance">Australian Dietary Guidelines</a> and <a href="http://www.who.int/nutrition/publications/nutrientrequirements/fatsandfattyacids_humannutrition/en/">World Health Organisation</a> recommend the lowering of saturated fats to below 10% of daily energy intake. Depending on the overall quality of your diet and intake of saturated fats, you may need to swap your butter for margarine. </p>
<h2>Check the labels</h2>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/185769/original/file-20170913-3737-1g25arr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/185769/original/file-20170913-3737-1g25arr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/185769/original/file-20170913-3737-1g25arr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=762&fit=crop&dpr=1 600w, https://images.theconversation.com/files/185769/original/file-20170913-3737-1g25arr.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=762&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/185769/original/file-20170913-3737-1g25arr.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=762&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/185769/original/file-20170913-3737-1g25arr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=958&fit=crop&dpr=1 754w, https://images.theconversation.com/files/185769/original/file-20170913-3737-1g25arr.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=958&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/185769/original/file-20170913-3737-1g25arr.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=958&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">Extra-virgin oil protects against heart disease.</span>
<span class="attribution"><span class="source">from shutterstock.com</span></span>
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<p>There is <a href="http://www.nejm.org/doi/full/10.1056/NEJMoa1200303#t=abstract">strong evidence</a> extra-virgin olive oil (a monounsaturated fat) provides strong benefits for heart disease protection – but there isn’t enough extra-virgin olive oil in margarine products to confer this benefit. Using olive-oil-based margarines is going to contribute very little to your daily intake of extra-virgin olive oil. </p>
<p>And this is why it’s confusing for the consumer – despite a margarine being labelled as being made from olive oil, it may contain only small amounts of olive oil and not be as high in monounsaturated fats as expected. It’s best to read the <a href="https://www.eatforhealth.gov.au/eating-well/how-understand-food-labels">nutrition information panel</a> to determine which margarine is highest in monounsaturated fats.</p>
<p>Another point of difference between butter and margarine is that margarine may contain <a href="https://www.heartfoundation.org.au/images/uploads/.../Stanols-QA-General.pdf">plant sterols</a>, which help reduce cholesterol levels.</p>
<p>At the end of the day, if you consume butter only occasionally and your diet closely adheres to the <a href="https://www.eatforhealth.gov.au/">Australian guidelines</a> for healthy eating, there is no harm in continuing to do so. </p>
<p>Another option to consider would be the butter blends. These provide the taste of butter while reducing saturated fat intake to half, and they are easier to spread. Of course, if you consume lots of butter, swapping for a low saturated fat margarine is your healthier option – perhaps reserve the butter for special occasions.</p>
<p>If you’re concerned about saturated fat levels in your diet, you should read the nutrition information panel to determine which margarine is lowest in saturated fat, regardless of which oil is used in the product. </p>
<p>As always, people need to base their decision on their family and medical history and obtain advice from their <a href="https://daa.asn.au/maintaining-professional-standards/register-of-apds/">dietitian</a> or GP.</p><img src="https://counter.theconversation.com/content/82445/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Evangeline Mantzioris 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>Depending on the overall quality of your diet and intake of saturated fats, you may need to swap your butter for margarine.Evangeline Mantzioris, Lecturer in Nutrition, University of South AustraliaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/632322016-08-07T15:16:02Z2016-08-07T15:16:02ZWhy being able to distinguish between a good and a bad fat matters so much<figure><img src="https://images.theconversation.com/files/132802/original/image-20160802-17190-q4isc8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Few people know what fatty acids are, which ones are harmful or beneficial, and how to identify them. </span> <span class="attribution"><span class="source">Shutterstock</span></span></figcaption></figure><p>Food, nutrition and human health institutes around the world have been fighting to reduce the risks associated with consuming detrimental fatty acids that are linked to cardiovascular diseases. But few people know what fatty acids are, which ones are harmful or beneficial, and how to identify them. </p>
<p>Fatty acids are a component of the fat found in foodstuffs such as meat, eggs, milk, vegetables, snacks, vegetable oils and most spreads. There are both “good” and “bad” fatty acids. </p>
<p>On average, fatty acids make up about 45% of people’s daily calorie intake. This is much more than the recommended <a href="http://www.fao.org/3/a-i1953e.pdf">20% to 35%</a>. </p>
<p>Globally, the amount of fatty acids people consume is influenced by age, sex, country and region. Some <a href="http://www.bmj.com/content/348/bmj.g2272">reviews</a> show that populations in Zimbabwe and Botswana consume too few “good” fatty acids. These make up less than 11% of their total daily energy intake.</p>
<p>Other studies have shown that young working-class adults in the developing world have high intakes of “bad” fatty acids – taking up more than <a href="https://www.karger.com/Article/FullText/355437">10%</a> of their daily energy intake. This is similar to those in western countries. </p>
<p>The challenge is to improve dietary options so that fatty acid intakes are within the recommendations, which are set to help people reduce their risk of developing diet-related chronic diseases. These have been on the rise, especially in developing nations. </p>
<p>The reason for poor knowledge of fatty acids is simply due to not enough being done to improve awareness. For example, if fatty acids aren’t labelled, consumers can’t make informed decisions about the food they buy. In addition, a recent <a href="http://www.sciencedirect.com/science/article/pii/S0963996915300211">study</a> around South Africa has shown that information is not the only deciding factor in the purchasing of foods. Cost also plays a role. </p>
<h2>How customers make their choices</h2>
<p>“Good” fatty acids include unsaturated omega 3 fatty acids. They are considered good because they help reduce the risks of cardiovascular diseases and cognitive decline. These are found in <a href="http://www.sciencedirect.com/science/article/pii/S0963996915300211">foods</a> such as olive and flax seed oil, walnuts, seafood and fatty fish, such as salmon and tuna. </p>
<p>Saturated and trans fatty acids are considered bad. They have been <a href="http://apps.who.int/iris/bitstream/10665/42665/1/WHO_TRS_916.pdf?ua=1">clinically linked to increases</a> in cholesterol levels and they increase the risk of several chronic diseases, such as type 2 diabetes, strokes, heart diseases and cancer. They emanate from increased dietary proportions of foods prepared using partially hydrogenated vegetable oil, dairy foods, fatty and processed meat cuts, and lard. The consumption of these foods is increasing significantly among resource-poor individuals, and fast-food and ready-to-eat-food consumers.</p>
<p>To gauge people’s knowledge of fatty acids our study was conducted at grocery stores in the Eastern Cape province of South Africa. A great many of the food products, such as meat and vegetable oils, carried information about “good” fatty acids, including the fact that they contribute to a healthy heart and blood system. </p>
<p>Shoppers were asked if they trusted brand adverts that highlighted the perceived benefits of “good” fatty acids. Opinions varied among demographic groups.</p>
<p>In high-end neighbourhoods most participants knew the function and health benefits associated with omega 3. They used this knowledge to choose food products. But in poorer areas like townships and villages only a few people knew of omega 3 fatty acids. They admitted to using this kind of information rarely when deciding what products to buy.</p>
<p>All those interviewed had one thing in common: they attested to the importance of television adverts. It improved their knowledge of food products and influenced their decisions to select food products that contained “good” fatty acids, especially in high-end neighbourhoods.</p>
<p>But none of the participants had seen an advert from the country’s national public health protecting agencies, such as the <a href="https://www.phasa.org.za/">Public Health Association of South Africa</a>. These bodies have the mandate to improve consumer awareness on health issues associated with fatty acids.</p>
<p>Although there is a strong inclination to promote “good” fatty acids, whose responsibility is it to explain the existence and dangers of “bad” saturated and trans fatty acids?</p>
<h2>Protecting the public</h2>
<p>In the US, the Food and Drug Administration has forced mandatory <a href="http://www.fda.gov/food/guidanceregulation/guidancedocumentsregulatoryinformation/ucm053479.htm">saturated fatty acids labelling</a> on all packages to protect consumers.</p>
<p>Other developed nations, including those of the European Union, and Australia and Canada, have followed suit by promoting the voluntary reduction of “bad” fatty acids in food production. </p>
<p>But much remains to be done in sub-Saharan African states, where these fats have caused an unprecedented increase in cardiovascular diseases, which account for <a href="http://www.ncbi.nlm.nih.gov/books/NBK2294/">11% of deaths</a> on the continent.</p>
<p>There is no pressure on food producers to reduce fatty acids in food. In addition, there are limited regulations to force food producers or processors to label the type and amount of “bad” fatty acids on their products.</p>
<p>South Africa has a <a href="http://www.capetown.gov.za/en/CityHealth/Documents/Legislation/Regulations%20-%20Relating%20to%20the%20Labelling%20and%20Advertising%20of%20Foodstuffs%20-%20R%201055%20of%202002%20-%20DRAFT.pdf">law</a> that requires the labelling of trans fat in artificial “partially hydrogenated oils” and that it is kept at maximum of 2% of total energy. However, the maximum allowed fats are well higher than recommended levels (maximum 1%), exposing the consumer to health risks. There is very little public protection in other African countries.</p>
<p>In addition, consumers aren’t warned that cooking food in particular ways – such as deep frying – can change the fatty acid profile from “good” to “bad”.</p>
<p>Drastic changes in the advertising and labelling of foods are needed to improve awareness of the effects of processing and handling on the fatty acid quality of both raw and ready-to-eat food.</p>
<h2>The way forward</h2>
<p>The global economic downturn has directly increased the risks of food insecurity and nutritional inadequacy by reducing the quantity, quality and food choices of poor and vulnerable groups. This is particularly true for people living in sub-Saharan African countries.</p>
<p>Economic pressures have led to people shifting from traditional foods to cheaper and processed starchy, monotonous diets that are characterised by low micro-nutrient and high energy levels. In addition, foods prepared by <a href="http://www.iol.co.za/news/south-africa/hiv-people-at-risk-from-abused-cooking-oil-300269">re-used cooking oil</a> have been reported in some establishments. </p>
<p>What this shows is that governments should prioritise the needs of poor consumers by running awareness campaigns about a safer fatty acid balance in their diets. </p>
<p>Food literacy campaigns are also important. These would help consumers understand more about fat and fatty acids.</p>
<p>The challenge is to improve nutrition and safety standards, while not destabilising access to food, through harsh penalties or obsessive labelling laws. The point is to reach a compromise that allows the consumer to make better and better-informed decisions.</p><img src="https://counter.theconversation.com/content/63232/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Voster Muchenje receives funding from the National Research Foundation (NRF) of South Africa. He is affiliated with South African Society for Animal Science (SASAS) and the South African Young Academy of Science (SAYAS). </span></em></p><p class="fine-print"><em><span>Carlos Nantapo receives funding from National Research Foundation (NRF) of South Africa. </span></em></p>Despite the increase in cardiovascular disease in the developing world, not enough is being been done to improve public awareness of the benefits and harms of ‘good’ and ‘bad’ fatty acids.Voster Muchenje, Professor of Meat Science and the co-host of the NRF SARChI Chair in Meat Science, University of Fort HareCarlos Nantapo, PhD Student, Animal Sciences Department, University of Fort HareLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/579132016-04-21T14:25:50Z2016-04-21T14:25:50ZBreast milk is a marvel of nature but that doesn’t mean adults should drink it to see off disease<figure><img src="https://images.theconversation.com/files/119440/original/image-20160420-25601-1cxpj2y.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Don't give it to grandad.</span> <span class="attribution"><a class="source" href="http://www.shutterstock.com/cat.mhtml?lang=en&language=en&ref_site=photo&search_source=search_form&version=llv1&anyorall=all&safesearch=1&use_local_boost=1&autocomplete_id=&searchterm=breast%20milk&show_color_wheel=1&orient=&commercial_ok=&media_type=images&search_cat=&searchtermx=&photographer_name=&people_gender=&people_age=&people_ethnicity=&people_number=&color=&page=1&inline=271722359">www.shutterstock.com</a></span></figcaption></figure><p>A woman’s claim that she <a href="http://www.dailymail.co.uk/news/article-3542866/Helen-swears-breast-milk-gave-dying-dad-extra-year-life-right.html">extended her father’s life</a> by more than a year by feeding him expressed milk has led many to ask whether human milk can really delay the growth of cancer. The gold standard nutrition for infants, human milk is not, however, a replacement for conventional medicine in the treatment of adult diseases.</p>
<p>Human milk is perfectly composed for babies, including both nutrient and bioactive components that promote growth and development. <a href="http://www.nhs.uk/Conditions/pregnancy-and-baby/Pages/benefits-breastfeeding.aspx">Official guidance</a> in the UK recommends exclusive human milk feeding for the first six months of life. Continued breastfeeding for one to two years or longer is then endorsed by various organisations, <a href="http://www.who.int/topics/breastfeeding/en/">including the WHO</a>.</p>
<h2>Changeable milk</h2>
<p>The composition of human milk varies. <a href="http://www.cell.com/trends/biochemical-sciences/fulltext/S0968-0004%2816%2900045-1">Research</a> shows that it changes within feeds, across the day, across lactation, and between different women. This variability benefits the infant as they grow and develop. </p>
<p>The first fluid produced after delivery is colostrum. It is produced in low quantities and is rich in compounds that boost the immune system (such as leukocytes, secretory immunoglobulin A, and lactoferrin), as well as others that support growth and development (like epidermal growth factor). However, colostrum is relatively low in lactose, potassium, and calcium, leading <a href="http://ssu.ac.ir/cms/fileadmin/user_upload/Mtahghighat/tfood/ARTICLES/milk/Human_Milk_Composition.pdf">researchers</a> to conclude its function is not primarily to provide nutrition. </p>
<p>Within days the composition changes, lactose increases, marking the production of what many call “<a href="http://ajcn.nutrition.org/content/53/5/1197.short">transitional milk</a>”. This change in the milk can be delayed if the baby is delivered preterm or if the mother has a metabolic condition or is obese.</p>
<p>Across the next few weeks, milk production increases rapidly. This is to support the changing nutritional and developmental needs of the growing infant. Within a month to six weeks, the milk becomes fully mature. </p>
<h2>Complex stuff</h2>
<p><a href="http://ssu.ac.ir/cms/fileadmin/user_upload/Mtahghighat/tfood/ARTICLES/milk/Human_Milk_Composition.pdf">Mature milk</a> provides around 65 to 70 calories per 100g, which come from about 4g of fat, 7g of carbohydrate, and 1g of protein. But this composition is constantly changing. The variation in calories is primarily due to differences in fat content. Fat content is significantly lower at night and morning compared with afternoon or evening milk. It also varies within the feed itself. Milk at the end of the feed has <a href="https://www.researchgate.net/profile/Chantal_Lau/publication/12944835_Feeding_strategies_for_premature_infants_Beneficial_outcomes_of_feeding_fortified_human_milk_versus_preterm_formula/links/0deec536d7c743b2d0000000.pdf">higher levels</a> than the initial flow.</p>
<p>The composition of milk also varies with maternal diet, especially the amount and type of fatty acid. Many women in developed countries aren’t getting enough fatty acid – important for infant brain development – in their diet and this affects the composition of their breast milk. For example, low levels of docosahexaenoic acid (DHA) – an omega 3 fatty acid – consumed by North American mothers translates to low levels in their milk. This has led some <a href="http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3566653/">researchers</a> to suggest that mothers should take appropriate supplements. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/119449/original/image-20160420-25615-1udeamm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/119449/original/image-20160420-25615-1udeamm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=416&fit=crop&dpr=1 600w, https://images.theconversation.com/files/119449/original/image-20160420-25615-1udeamm.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=416&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/119449/original/image-20160420-25615-1udeamm.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=416&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/119449/original/image-20160420-25615-1udeamm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=523&fit=crop&dpr=1 754w, https://images.theconversation.com/files/119449/original/image-20160420-25615-1udeamm.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=523&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/119449/original/image-20160420-25615-1udeamm.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=523&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">Some mothers might benefit from taking fatty acid supplements.</span>
<span class="attribution"><a class="source" href="http://www.shutterstock.com/cat.mhtml?lang=en&language=en&ref_site=photo&search_source=search_form&version=llv1&anyorall=all&safesearch=1&use_local_boost=1&autocomplete_id=&search_tracking_id=TU9ndqjQrevZ5pNRYs_6nA&searchterm=fish%20oil%20supplement&show_color_wheel=1&orient=&commercial_ok=&media_type=images&search_cat=&searchtermx=&photographer_name=&people_gender=&people_age=&people_ethnicity=&people_number=&color=&page=1&inline=288277154">www.shutterstock.com</a></span>
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<h2>More than just nutrition</h2>
<p>But human milk doesn’t just contain nutrition; it contains a variety of compounds with medicinal qualities that are important for the baby’s survival. These “growth factors” are numerous and have wide-ranging effects. For instance, epidermal growth factor is important for the development and repair of the gastrointestinal tract. Insulin-like growth factors are critical in stimulating growth and development, with high levels of some <a href="https://www.researchgate.net/publication/16992978_Immunoreactive_Somatomedin-CInsulin-Like_Growth_Factor_I_and_Its_Binding_Protein_in_Human_Milk">linked</a> to neural, and cochlea development in the ear. There are many growth factors, and they affect many important functions, including the development of the blood vessels, metabolism, intestinal system, nervous system, and endocrine (hormone) system. </p>
<p>Human milk also has important immune impacts, protecting against inflammation and infection. Oligosaccharides (a carbohydrate) encourage the growth of organisms that plays an essential role in early bacterial colonisation of the intestine which have important impacts on gut health and general well-being in later life, while also reducing vulnerability to some pathogens, such as <a href="http://jid.oxfordjournals.org/content/190/10/1850.full">noroviruses</a>.</p>
<h2>Not for sharing</h2>
<p>Containing a variety of <a href="http://www.bbc.co.uk/schools/gcsebitesize/science/21c_pre_2011/disease/diseaseresistancerev4.shtml">white blood cells</a>, human milk stimulates the development of the infant immune system while providing protection from germs. <a href="http://adc.bmj.com/content/84/5/381.full">Research</a> reveals that such transmission, however, opens up the potential for infection with HIV, syphilis, hepatitis and herpes, among other viruses, which can pass along with these cells.</p>
<p>This viral transmission, along with the risk of contamination with bacteria and toxins, creates a need for careful management of milk sharing <a href="http://www.bmj.com/content/350/bmj.h1485">and selling</a>. The nutrient and bioactive compounds are affected by the mother’s consumption of food, drink, medicines and illicit drugs. The presence of toxins and contaminants are introduced by a mother’s environmental exposure, as well as during expression and storage of the milk. Expressing and pasteurising milk <a href="http://ajcn.nutrition.org/content/96/3/544.full.pdf+html">changes its composition</a> which can reduce or even eliminate some bioactive components. </p>
<p>Such impacts make oversight crucial for babies fed with another mother’s milk, but also mean a careful approach is needed by those adults who think human milk might hold medicinal value. While a liquid gold, awareness of the risks as well as the benefits of human milk is crucial, both for adult and infant consumers.</p><img src="https://counter.theconversation.com/content/57913/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Sarah Steele 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>Most people are aware of the benefits of breastmilk, but few are aware of the risks.Sarah Steele, Queen Mary University of LondonLicensed as Creative Commons – attribution, no derivatives.