tag:theconversation.com,2011:/fr/topics/western-diet-14524/articlesWestern diet – The Conversation2024-01-21T12:59:06Ztag:theconversation.com,2011:article/2213842024-01-21T12:59:06Z2024-01-21T12:59:06ZDietary fibre affects more than your colon: How the immune system, brain and overall health benefit too<figure><img src="https://images.theconversation.com/files/570412/original/file-20240119-19-bkynf2.jpg?ixlib=rb-1.1.0&rect=66%2C6%2C3923%2C2249&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Most people only consume about half of the recommended amount of dietary fibre, and it can negatively affect overall health.</span> <span class="attribution"><span class="source">(Shutterstock)</span></span></figcaption></figure><iframe style="width: 100%; height: 100px; border: none; position: relative; z-index: 1;" allowtransparency="" allow="clipboard-read; clipboard-write" src="https://narrations.ad-auris.com/widget/the-conversation-canada/dietary-fibre-affects-more-than-your-colon-how-the-immune-system-brain-and-overall-health-benefit-too" width="100%" height="400"></iframe>
<p>There’s no shortage of advice about what to eat, including hype about the latest <a href="https://www.hsph.harvard.edu/nutritionsource/superfoods/">superfoods</a> that will help you <a href="https://www.npr.org/sections/thesalt/2015/04/11/398325030/eating-to-break-100-longevity-diet-tips-from-the-blue-zones">live to 100</a>, or about the newest <a href="https://food-guide.canada.ca/en/tips-for-healthy-eating/diets-food-trends/#section-2">restrictive diets</a> that claim to help you lose weight and look beautiful. As a researcher from the <a href="https://farncombe.mcmaster.ca/">Farncombe Family Digestive Health Research Institute</a>, I’m well aware that there is no universal “healthy diet” that will work for everyone. </p>
<p>However, most professionals would agree that a diet should be well balanced between the food groups, and it’s better to include more things like vegetables and <a href="https://doi.org/10.3390%2Fnu11081806">fermented foods</a> in your diet than restrict yourself unnecessarily. Eating foods that promote gut health improves your overall health too.</p>
<h2>Why is everyone so concerned about fibre?</h2>
<p>The importance of fibre has been known for decades. The late great surgeon and fibre researcher <a href="https://doi.org/10.1017/S0954422417000117">Denis Burkitt</a> once said, “If you pass small stools, you have to have large hospitals.” But dietary fibre does more than just help move your bowels. Fibre can be considered a <a href="https://www.mayoclinic.org/healthy-lifestyle/nutrition-and-healthy-eating/expert-answers/probiotics/faq-20058065">prebiotic nutrient</a>. </p>
<p>Prebiotics aren’t actively digested and absorbed, rather they are selectively used to promote the growth of a beneficial species of microbes in our gut. <a href="https://doi.org/10.3390%2Ffoods8030092">These microbes then help digest foods</a> for us so we can obtain more nutrients, promote gut barrier integrity and prevent the growth of harmful bacteria. </p>
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<img alt="High-fibre foods against the outline of intestines" src="https://images.theconversation.com/files/570413/original/file-20240119-17-wpd6x9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/570413/original/file-20240119-17-wpd6x9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/570413/original/file-20240119-17-wpd6x9.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/570413/original/file-20240119-17-wpd6x9.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/570413/original/file-20240119-17-wpd6x9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/570413/original/file-20240119-17-wpd6x9.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/570413/original/file-20240119-17-wpd6x9.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">Prebiotics aren’t actively digested and absorbed, rather they are selectively used to promote the growth of a beneficial species of microbes in our gut.</span>
<span class="attribution"><span class="source">(Shutterstock)</span></span>
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<p>Fibres can also have microbe-independent effects on our immune system when they <a href="https://doi.org/10.1111/bph.14871">interact directly with receptors expressed by our cells</a>. These beneficial effects may even help teach the immune system to be more tolerant and reduce inflammation.</p>
<h2>Getting enough dietary fibre?</h2>
<p>Probably not. The so-called <a href="https://doi.org/10.3390%2Fnu15122749">western diet</a> is low in fibre and filled with ultra-processed foods. The <a href="https://www.canada.ca/en/health-canada/services/nutrients/fibre.html">recommendation for daily fibre</a> is between <a href="https://doi.org/10.1038/s41575-020-00375-4">25-38 grams depending on factors like age, sex and activity level</a>. Most people consume about half of the recommendation, and it can negatively affect overall health. </p>
<p>Good sources of dietary fibre include whole grains, fruits and vegetables, beans and legumes, and nuts and seeds. There is a lot of emphasis on soluble fibres and less on insoluble fibres, but in reality, most foods will contain a mixture of both, and they each <a href="https://www.healthline.com/health/soluble-vs-insoluble-fiber%23risks">have their merits</a>. </p>
<p>High fibre snacks are also gaining popularity. With an estimated global value of US$7 billion in 2022, the <a href="https://www.precedenceresearch.com/prebiotic-ingredients-market#:%7E:text=The%2520global%2520prebiotic%2520ingredients%2520market,13.25%2525%2520from%25202022%2520to%25202030">value of the prebiotic ingredient market</a> is expected to triple by 2032.</p>
<h2>The benefits of dietary fibre</h2>
<figure class="align-right ">
<img alt="Diagram of a human with arrows linking brain and intestines" src="https://images.theconversation.com/files/570414/original/file-20240119-17-fwfmrl.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/570414/original/file-20240119-17-fwfmrl.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/570414/original/file-20240119-17-fwfmrl.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/570414/original/file-20240119-17-fwfmrl.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/570414/original/file-20240119-17-fwfmrl.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/570414/original/file-20240119-17-fwfmrl.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/570414/original/file-20240119-17-fwfmrl.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=754&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">Fibre is associated with overall health and brain health through the gut-brain axis.</span>
<span class="attribution"><span class="source">(Shutterstock)</span></span>
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<p>There’s plenty of evidence supporting the benefits of dietary fibre. Fibre isn’t just associated with colon health; it’s associated with overall health and brain health through the <a href="https://my.clevelandclinic.org/health/body/the-gut-brain-connection">gut-brain axis</a>. Diets low in fibre have been associated with gastrointestinal disorders such as irritable bowel syndrome or inflammatory bowel disease. </p>
<p>On the other hand, consuming adequate fibre also <a href="https://doi.org/10.1038/s41575-020-00375-4">reduces the risk and mortality associated with cardiovascular diseases and obesity</a>. There are studies that show <a href="https://doi.org/10.3390/nu13072159">improvements of cognitive function with certain types of fibre</a>. </p>
<p>There are some gastrointestinal diseases, like Celiac disease, which are not typically associated with the benefits of dietary fibre. However, <a href="https://doi.org/10.1038/s41575-020-00375-4">there isn’t a consensus</a> to the specific type of fibre and dose that would be beneficial in treating most diseases.</p>
<h2>Not all fibre is good fibre</h2>
<p>Shockingly, not all fibre is good for you. Fibre is used as an umbrella term for indigestible plant polysaccharides, so there are many different types with varying fermentability, solubility and viscosity in the gut. </p>
<p>To make things more complex, <a href="https://doi.org/10.3389/fped.2020.620189">the source matters too</a>. Fibre from one plant isn’t the same as fibre from another plant. Additionally, the old proverb, “too much good is not good” rings true, where overconsumption of fibre supplements can cause symptoms such as constipation, bloating and gas. This is partly due to the differences in gut microbiomes that affect the ability to metabolize fibre to produce beneficial molecules like short-chain fatty acids. </p>
<p>In some cases, such as inflammatory bowel disease patients, lack of microbes with the capacity to digest fibre may allow intact fibres to <a href="https://doi.org/10.1053/j.gastro.2022.09.034">interact with intestinal cells directly and exert pro-inflammatory effects</a>. Recent evidence has even shown that excessively high consumption of soluble fibres, such as inulin, a common supplement, <a href="https://doi.org/10.1053/j.gastro.2023.10.012">can increase the risk of colon cancer development in an experimental animal model</a>.</p>
<h2>Part of a healthy diet</h2>
<p>Dietary fibre is an important part of a healthy diet that can promote both gut and overall health. Fibre helps you feel more satisfied after meals and helps to regulate your blood sugar and cholesterol. Do your best to consume fibre as part of your diet, and when needed, take only the dose of supplements as recommended. </p>
<p>Prebiotics promote the growth of gut microbes that can affect gut health and immunity in the context of many different diseases, although not all fibres are created equal. While fibre won’t cure illness, diet is a great addition to medicines and treatment strategies that can improve their efficacy.</p><img src="https://counter.theconversation.com/content/221384/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Mark Wulczynski 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>Fibre isn’t just associated with colon health; it’s associated with overall health and brain health through the gut-brain axis. But not all fibres are created equal.Mark Wulczynski, Medical Sciences PhD Candidate, McMaster UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1958102023-01-31T13:16:07Z2023-01-31T13:16:07ZMicrobes in your food can help or hinder your body’s defenses against cancer – how diet influences the conflict between cell ‘cooperators’ and ‘cheaters’<figure><img src="https://images.theconversation.com/files/506674/original/file-20230126-31491-80kf4u.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C1731%2C1731&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">You can change your gut microbiome composition by eating different foods.</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/bacteria-and-germs-on-food-royalty-free-image/596371624">wildpixel/iStock via Getty Images</a></span></figcaption></figure><p>The microbes living in your food can affect your risk of cancer. While some help your body fight cancer, others help tumors evolve and grow. </p>
<p>Gut microbes can influence your cancer risk by changing how your cells behave. Many cancer-protective microbes support normal, cooperative behavior of cells. Meanwhile, cancer-inducing microbes undermine cellular cooperation and increase your risk of cancer in the process. </p>
<p>We are <a href="https://scholar.google.com/citations?user=8abR970AAAAJ&hl=en">evolutionary</a> <a href="https://search.asu.edu/profile/2854856">biologists</a> who study how cooperation and conflict occur inside the human body, including the ways cancer can evolve to exploit the body. Our <a href="https://doi.org/10.1007/s13668-022-00420-5">systematic review</a> examines how diet and the microbiome affect the ways the cells in your body interact with each other and either increase or decrease your risk of cancer.</p>
<h2>Cancer is a breakdown of cell cooperation</h2>
<p>Every human body is a symphony of multicellular cooperation. <a href="https://www.scientificamerican.com/article/our-bodies-replace-billions-of-cells-every-day/">Thirty trillion cells</a> cooperate and coordinate with each other to make us viable multicellular organisms. </p>
<p>For multicellular cooperation to work, cells must engage in behaviors that <a href="https://doi.org/10.1111/eva.12303">serve the collective</a>. These include controlled cell division, proper cell death, resource sharing, division of labor and protection of the extracellular environment. Multicellular cooperation is what allows the body to function effectively. If genetic mutations interfere with these proper behaviors, they can lead to the breakdown of cellular cooperation and the emergence of cancer.</p>
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<figcaption><span class="caption">The food in your diet affects the composition of your gut microbiome.</span></figcaption>
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<p>Cancer cells can be thought of as <a href="https://press.princeton.edu/books/hardcover/9780691163840/the-cheating-cell">cellular cheaters</a> because they do not follow the rules of cooperative behavior. They mutate uncontrollably, evade cell death and take up excessive resources at the expense of the other cells. As these cheater cells replicate, cancer in the body begins to grow.</p>
<p>Cancer is fundamentally a problem of having multiple cells living together in one organism. As such, it has been around <a href="http://dx.doi.org/10.1098/rstb.2014.0219">since the origins of multicellular life</a>. This means that cancer suppression mechanisms have been evolving for hundreds of millions of years to help keep would-be cancer cells in check. Cells monitor themselves for mutations and induce cell death, also known as apoptosis, when necessary. Cells also monitor their neighbors for evidence of abnormal behavior, sending signals to aberrant cells to induce apoptosis. In addition, the body’s immune system monitors tissues for cancer cells to destroy them.</p>
<p>Cells that are able to evade detection, avoid apoptosis and replicate quickly have an evolutionary advantage within the body over cells that behave normally. This process within the body, called <a href="https://doi.org/10.1371/journal.pcbi.0020108">somatic evolution</a>, is what leads cancer cells to grow and make people sick.</p>
<h2>Microbes can help or hinder cell cooperation</h2>
<p>Microbes can affect cancer risk through changing the ways that the cells of the body interact with one another. </p>
<p>Some microbes can <a href="https://doi.org/10.1007/s13668-019-0257-2">protect against cancer</a> by helping maintain a healthy environment in the gut, reducing inflammation and DNA damage, and even by directly limiting tumor growth. Cancer-protective microbes like <em>Lactobacillus pentosus</em>, <em>Lactobacillus gasseri</em> and <em>Bifidobacterium bifidum</em> are found in the environment and different foods, and can live in the gut. These microbes <a href="https://doi.org/10.1007/s13668-022-00420-5">promote cooperation among cells</a> and limit the function of cheating cells by strengthening the body’s cancer defenses. <em>Lactobacillus acidophilus</em>, for example, increases the <a href="https://doi.org/10.1017/s0007114510000516">production of a protein called IL-12</a> that stimulates immune cells to act against tumors and suppress their growth.</p>
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<figcaption><span class="caption">Gut bacteria can influence the effectiveness of certain cancer treatments.</span></figcaption>
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<p>Other microbes can promote cancer by inducing mutations in healthy cells that make it more likely for cellular cheaters to emerge and outcompete cooperative cells. <a href="https://doi.org/10.1002/path.5047">Cancer-inducing microbes</a> such as <em>Enterococcus faecalis</em>, <em>Helicobacter pylori</em> and <em>Papillomavirus</em> are associated with increased tumor burden and cancer progression. They can release toxins that damage DNA, change gene expression and <a href="https://doi.org/10.1007/s13668-019-0257-2">increase the proliferation</a> of tumor cells. <a href="https://doi.org/10.1002/ijc.23484"><em>Helicobacter pylori</em></a>, for example, can induce cancer by secreting a protein called Tipα that can penetrate cells, alter their gene expression and drive gastric cancer.</p>
<h2>Healthy diet with cancer-protective microbes</h2>
<p>Because what you eat determines the amount of cancer-inducing and cancer-preventing microbes inside your body, we believe that the microbes we consume and cultivate are an important component of <a href="https://doi.org/10.1007/s13668-022-00420-5">a healthy diet</a>.</p>
<p>Beneficial microbes are typically found in <a href="https://doi.org/10.1002/ijc.31959">fermented</a> and plant-based diets, which include foods like vegetables, fruits, yogurt and whole grains. These foods have high nutritional value and contain microbes that increase the immune system’s ability to fight cancer and lower overall inflammation. <a href="https://doi.org/10.1093%2Fcdn%2Fnzy005">High-fiber foods are prebiotic</a> in the sense that they provide resources that help beneficial microbes thrive and subsequently provide benefits for their hosts. Many cancer-fighting microbes are abundantly present in fermented and high-fiber foods. </p>
<p>In contrast, harmful microbes can be found in highly-processed and meat-based diets. The Western diet, for example, contains an abundance of red and processed meats, fried food and high-sugar foods. It has been long known that meat-based diets are linked to higher cancer prevalence, and that red meat is a <a href="https://doi.org/10.2533/chimia.2018.718">carcinogen</a>. Studies have shown that meat-based diets are associated with cancer-inducing microbes including <a href="https://doi.org/10.1007/s13668-022-00420-5"><em>Fusobacteria</em> and <em>Peptostreptococcus</em></a> in both humans and other species.</p>
<p>Microbes can enhance or interfere with how the body’s cells cooperate to prevent cancer. We believe that purposefully cultivating a microbiome that promotes cooperation among our cells can help reduce cancer risk.</p><img src="https://counter.theconversation.com/content/195810/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Gissel Viridiana Marquez Alcaraz receives funding from the National Cancer Institute. </span></em></p><p class="fine-print"><em><span>Athena Aktipis receives funding from the National Cancer Institute and the John Templeton Foundation.</span></em></p>Cancer cells are ‘cheaters’ that do not cooperate with the rest of the body. Certain microbes in your diet can either protect against or promote tumor formation by influencing cell cooperation.Gissel Marquez Alcaraz, Ph.D. Student in Evolutionary Biology, Arizona State UniversityAthena Aktipis, Associate Professor of Psychology, Center for Evolution and Medicine, Arizona State UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1722112021-12-09T13:35:28Z2021-12-09T13:35:28ZColorful sweets may look tasty, but some researchers question whether synthetic dyes may pose health risks to your colon and rectum<figure><img src="https://images.theconversation.com/files/436174/original/file-20211207-27-1n10fff.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C2121%2C1412&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Early-onset colorectal cancer rates have been increasing since the 1990s.</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/homemade-christmas-gingerbread-cookies-royalty-free-image/878594696">kajakiki/E+ via Getty Images</a></span></figcaption></figure><p>Early-onset colorectal cancer incidence among the young, defined as those under age 50, has been <a href="https://dx.doi.org/10.1155%2F2019%2F9841295">rising globally</a> since the early 1990s. Rates for colon and rectal cancers are expected to <a href="https://doi.org/10.1001/jamasurg.2014.1756">increase by 90% and 124%</a>, respectively, by 2030.</p>
<p>One suspected reason behind this trend is <a href="https://doi.org/10.1017/S136898002000350X">increased global consumption</a> of a <a href="https://dx.doi.org/10.1053%2Fj.gastro.2017.02.015">Westernized diet</a> that consists heavily of red and processed meats, added sugar and refined grains. <a href="http://dx.doi.org/10.1136/bmjopen-2015-009892">Sixty percent of the Standard American Diet</a>, also known as “SAD,” is made up of ultra-processed food such as industrial baked sweets, soft drinks and processed meat. SAD is associated with an <a href="https://doi.org/10.1001/jamanetworkopen.2021.34308">increased risk of colorectal cancer</a>. </p>
<p>One aspect of ultra-processed foods I’m concerned about is how colorful they are. This characteristic is on full display in many delicious foods and treats present during the year-end holidays. However, many of the colors that make up candy canes, sugar cookies and even cranberry sauce and roast ham, are synthetic. And there’s some evidence that these artificial food dyes may trigger cancer-causing processes in the body.</p>
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<a href="https://images.theconversation.com/files/435965/original/file-20211206-23-18akuko.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Rainbow-colored gum drops in a glass bowl against a white background." src="https://images.theconversation.com/files/435965/original/file-20211206-23-18akuko.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/435965/original/file-20211206-23-18akuko.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=399&fit=crop&dpr=1 600w, https://images.theconversation.com/files/435965/original/file-20211206-23-18akuko.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=399&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/435965/original/file-20211206-23-18akuko.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=399&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/435965/original/file-20211206-23-18akuko.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=502&fit=crop&dpr=1 754w, https://images.theconversation.com/files/435965/original/file-20211206-23-18akuko.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=502&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/435965/original/file-20211206-23-18akuko.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=502&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">While artificial food coloring may look pretty, potential health risks require further study.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/rainbow-colored-candy-royalty-free-image/171363813">cmannphoto/E+ via Getty Images</a></span>
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<p>As the <a href="https://scholar.google.com/citations?user=zHSS6mQAAAAJ&hl=en">director of the Center for Colon Cancer Research</a> at the University of South Carolina, I have been studying the effects of these synthetic food dyes on colorectal cancer development. While research on the potential cancer risk of synthetic food dyes is only just starting, I believe that you may want to think twice before you reach for that colorful treat this holiday season. </p>
<h2>What are synthetic food dyes?</h2>
<p>The food industry uses synthetic dyes because they make food look better. The first food dyes were <a href="https://www.atlasobscura.com/articles/coal-tar-food-coloring-perkin">created from coal tar</a> in the late 1800s. Today, they are often synthesized from a chemical derived from petroleum called naphthalene to make a final product called an <a href="https://psiberg.com/azo-dyes-history-uses-synthesis/">azo dye</a>.</p>
<p>Food manufacturers prefer synthetic dyes over natural dyes like beet extract because they are <a href="https://www.washingtonpost.com/opinions/the-rainbow-of-food-dyes-in-our-grocery-aisles-has-a-dark-side/2011/03/21/AFyIwaYB_story.html">cheaper, brighter and last longer</a>. While manufacturers have developed hundreds of synthetic food dyes over the past century, the <a href="https://doi.org/10.1080/19440049.2016.1274431">majority of them are toxic</a>. Only nine are approved for use in food under U.S. <a href="https://www.fda.gov/industry/color-additive-inventories/summary-color-additives-use-united-states-foods-drugs-cosmetics-and-medical-devices#table1B">Food and Drug Administration</a> policy, and even fewer pass <a href="https://www.everydayhealth.com/diet-nutrition/why-are-some-food-additives-that-are-banned-in-europe-still-used-in-the-us/">European Union</a> regulations.</p>
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<figcaption><span class="caption">Food manufacturers in the U.S. started using synthetic dyes to standardize the coloring of their products as a marketing strategy.</span></figcaption>
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<h2>What drives colorectal cancer?</h2>
<p><a href="https://doi.org/10.1016/j.cell.2011.02.013">DNA damage</a> is the primary driver of colorectal cancer. When DNA damage occurs on cancer driver genes, it can result in a mutation that tells the cell to divide uncontrollably and turn cancerous.</p>
<p>Another driver of colorectal cancer is <a href="https://doi.org/10.2174/1871530320666200909092908">inflammation</a>. Inflammation occurs when the immune system sends out inflammatory cells to begin healing an injury or capture disease-causing pathogens. When this inflammation persists over time, it can harm otherwise healthy cells by releasing molecules called <a href="https://dx.doi.org/10.4103%2F0973-7847.70902">free radicals</a> that can damage DNA. Another type of molecule called <a href="https://dx.doi.org/10.3389%2Ffimmu.2018.01270">cytokines</a> can prolong inflammation and drive increased cell division and cancer development in the gut when there isn’t an injury to heal. </p>
<p>Long-term poor dietary habits can lead to a <a href="https://www.health.harvard.edu/staying-healthy/all-about-inflammation">simmering low-grade inflammation</a> that doesn’t produce noticeable symptoms, even while inflammatory molecules continue to damage otherwise healthy cells.</p>
<h2>Synthetic food dyes and cancer</h2>
<p>Although none of the FDA-approved synthetic food colors are classified as carcinogens, currently available research points to potential health risks I <a href="https://cspinet.org/resource/food-dyes-rainbow-risks">and others</a> find concerning.</p>
<p>For example, the bacteria in your gut can <a href="https://www.doi.org/10.2741/400">break down synthetic dyes</a> into molecules that are known to cause cancer. More research is needed on how the <a href="https://doi.org/10.1038/s41416-021-01467-x">microbiome</a> interacts with synthetic food coloring and potential cancer risk.</p>
<p>Studies have shown that artificial food dyes can <a href="https://doi.org/10.1089/dna.2010.1181">bind to the DNA</a> and <a href="https://doi.org/10.1016/j.compbiolchem.2015.04.006">proteins</a> inside cells. There is also some evidence that synthetic dyes can <a href="https://doi.org/10.1016/j.nut.2017.08.010">stimulate the body’s inflammatory machinery</a>. Both of these mechanisms may pose a problem for colon and rectal health.</p>
<p>Synthetic food dyes have been found to <a href="https://doi.org/10.2131/jts.35.547">damage DNA in rodents</a>. This is supported by unpublished data from my research team showing that Allura Red, or Red 40, and Tartrazine, or Yellow 5, can cause DNA damage in colon cancer cells with increased dosages and length of exposure in vitro in a controlled lab environment. Our results will need to be replicated in animal and human models before we can say that these dyes directly caused DNA damage, however.</p>
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<p>Finally, artificial food coloring may be of particular concern for children. It’s known that children are <a href="https://doi.org/10.1377/hlthaff.2011.0151">more vulnerable to environmental toxins</a> because their bodies are still developing. I and others believe that this concern may extend to <a href="https://oehha.ca.gov/risk-assessment/report/health-effects-assessment-potential-neurobehavioral-effects-synthetic-food">synthetic food dyes</a>, especially considering their prevalence in children’s food. A <a href="https://doi.org/10.1177/0009922816651621">2016 study</a> found that over 40% of food products marketed toward children in one major supermarket in North Carolina contained artificial food coloring. More research needs to be done to examine how repeated exposure to artificial food dyes may affect children.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/435966/original/file-20211206-17-zfqrkp.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Child eating a donut with blue frosting." src="https://images.theconversation.com/files/435966/original/file-20211206-17-zfqrkp.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/435966/original/file-20211206-17-zfqrkp.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/435966/original/file-20211206-17-zfqrkp.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/435966/original/file-20211206-17-zfqrkp.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/435966/original/file-20211206-17-zfqrkp.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/435966/original/file-20211206-17-zfqrkp.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/435966/original/file-20211206-17-zfqrkp.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Many foods marketed toward kids contain synthetic food coloring.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/enjoying-my-dessert-royalty-free-image/898216164">FluxFactory/E+ via Getty Images</a></span>
</figcaption>
</figure>
<h2>Lowering your risk of colorectal cancer</h2>
<p>A few treats during the holidays won’t cause colorectal cancer. But a long-term diet of processed foods might. While more research is needed on the link between synthetic food dyes and cancer, there are evidence-based steps you can take now to <a href="https://www.cancer.org/latest-news/six-ways-to-lower-your-risk-for-colon-cancer.html">reduce your risk of colorectal cancer</a>.</p>
<p>One way is to get screened for colon cancer. Another is to increase your physical activity. Finally, you can eat a <a href="https://doi.org/10.1002/ijc.31198">healthy</a> <a href="https://doi.org/10.1093/annonc/mdx171">diet</a> with more whole grains and produce and less alcohol and red and processed meat. Though this means eating fewer of the colorful, ultra-processed foods that may be plentiful during the holidays, your gut will thank you in the long run.</p>
<p>[<em>Get our best science, health and technology stories.</em> <a href="https://theconversation.com/us/newsletters/science-editors-picks-71/?utm_source=TCUS&utm_medium=inline-link&utm_campaign=newsletter-text&utm_content=science-best">Sign up for The Conversation’s science newsletter</a>.]</p><img src="https://counter.theconversation.com/content/172211/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Lorne J. Hofseth receives funding from the National Cancer Institute.</span></em></p>Sixty percent of the Standard American Diet consists of ultra-processed food, which isn’t great for colon health. Researchers are looking into whether artificial food colors play a role.Lorne J. Hofseth, Professor and Associate Dean for Research, College of Pharmacy, University of South CarolinaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1584512021-04-22T07:17:49Z2021-04-22T07:17:49ZClear evidence for a link between pro-inflammatory diets and 27 chronic diseases. Here’s how you can eat better<figure><img src="https://images.theconversation.com/files/396420/original/file-20210421-13-o33a3w.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C1000%2C667&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Shutterstock</span></span></figcaption></figure><p><a href="https://www.aihw.gov.au/reports/australias-health/chronic-conditions-and-multimorbidity">Almost half of all Australians</a> live with a chronic disease, which contribute to some <a href="https://www.aihw.gov.au/getmedia/8f7bd3d6-9e69-40c1-b7a8-40dca09a13bf/4_2-chronic-disease.pdf.aspx">90% of deaths</a>.</p>
<p>It’s no secret our diet can have a major impact on our health. But our new umbrella review, published <a href="https://academic.oup.com/advances/advance-article-abstract/doi/10.1093/advances/nmab037/6238545?redirectedFrom=fulltext">this week in Advances in Nutrition</a>, provides compelling evidence that pro-inflammatory diets increase the risk of 27 chronic diseases and premature death. An umbrella review is a review of multiple reviews, and is among the highest levels of evidence.</p>
<p>What’s more, reducing inflammation by eating better could cut our risk of developing certain chronic diseases. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/the-rise-of-ultra-processed-foods-and-why-theyre-really-bad-for-our-health-140537">The rise of ultra-processed foods and why they're really bad for our health</a>
</strong>
</em>
</p>
<hr>
<h2>Clear evidence</h2>
<p>A pro-inflammatory diet is one that, over the long-term, may lead to increased inflammation in the body. Such a diet often includes high amounts of commercially baked goods, fried foods and fatty meats, and at the same time is low in fruits, vegetables and other healthy foods. </p>
<p>We reviewed and pooled data from 15 meta-analyses, which is a type of study that summarises data from lots of individual studies. All up, we looked at 38 health outcomes from four million people from across the world. </p>
<p>We found strong evidence for a link between pro-inflammatory diets and heart attacks, premature death and certain cancers including bowel cancer, pancreatic cancer, respiratory cancers and oral cancers. There was also evidence pro-inflammatory diets were linked with depression.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/plant-rich-diets-may-help-prevent-depression-new-evidence-103898">Plant-rich diets may help prevent depression – new evidence</a>
</strong>
</em>
</p>
<hr>
<p>By bringing together data from populations all over the world, we were able to provide a comprehensive and reliable overview of the research to date. We also looked at the strength of the evidence of studies and found that for most outcomes, evidence was limited, highlighting the need for more research. </p>
<p>Because of the type of study we did, we were unable to determine cause and effect, so we can’t conclusively say pro-inflammatory diets <em>cause</em> these chronic diseases yet. But we found clear evidence a pro-inflammatory diet is linked with <em>an increased risk</em> of developing certain chronic diseases and premature death.</p>
<figure class="align-center ">
<img alt="Fried crumbed veal with chips" src="https://images.theconversation.com/files/396422/original/file-20210421-15-17uz7s9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/396422/original/file-20210421-15-17uz7s9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/396422/original/file-20210421-15-17uz7s9.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/396422/original/file-20210421-15-17uz7s9.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/396422/original/file-20210421-15-17uz7s9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/396422/original/file-20210421-15-17uz7s9.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/396422/original/file-20210421-15-17uz7s9.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Dietary patterns that contain lots of calorie-dense, ultra-processed foods can contribute to inflammation and increase your risk of certain chronic diseases.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<h2>But what is inflammation, and what role does our diet play?</h2>
<p>Inflammation is part of our body’s natural defence processes. It’s our immune system’s response to an irritant, be that an infection or injury, and is often a welcome sign our body is working to protect us. For example, swelling when you roll your ankle delivers resources to help repair the damage. </p>
<p>But when inflammation can’t be turned off, this process may start to work against us. </p>
<p>Persistent low levels of inflammation (known as chronic inflammation) can be problematic and is linked to premature death and conditions including coronary heart disease and <a href="https://bmcmedicine.biomedcentral.com/articles/10.1186/1741-7015-11-200">depression</a>, to name a few. </p>
<p>We can detect whether chronic inflammation exists by a simple blood test that looks at levels of inflammatory markers in the blood. Our diet is one factor that influences levels of these inflammatory markers, among many.</p>
<p>Take the “Western diet”, for example, which consists of calorie-dense, <a href="https://onlinelibrary.wiley.com/doi/abs/10.1111/obr.13146">ultra-processed foods</a> and is low in fruits, vegetables and other plant-foods. This type of dietary pattern has been linked to <a href="https://pubmed.ncbi.nlm.nih.gov/15447916/">higher levels of inflammation</a>.</p>
<p>Conversely, healthy dietary patterns have been linked to <a href="https://pubmed.ncbi.nlm.nih.gov/15234425/">lower inflammatory markers</a>. This includes the <a href="https://theconversation.com/what-is-the-mediterranean-diet-and-why-is-it-good-for-you-12656">Mediterranean diet</a>, which is high in fruits, vegetables, legumes, olive oil and oily fish, and low in ultra-processed, refined foods. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/mediterranean-diet-increases-gut-bacteria-linked-to-healthy-ageing-in-older-adults-131928">Mediterranean diet increases gut bacteria linked to healthy ageing in older adults</a>
</strong>
</em>
</p>
<hr>
<p>The potential for diets to be pro- or anti-inflammatory can be measured using a tool known as the Dietary Inflammatory Index. </p>
<p>The index takes into account a number of nutrients, compounds, and foods that have been identified in research as having either anti- or pro-inflammatory properties.</p>
<h2>Using foods to fight inflammation</h2>
<p>Despite promising marketing claims you might see online, there’s no magic supplement or superfood to combat all our inflammation woes.</p>
<p>Instead, you should focus on improving your overall diet quality, rather than on a single food or nutrient. This is because many nutrients and foods interact with one another and can work together to improve inflammation.</p>
<figure class="align-center ">
<img alt="Two pieces of salmon with lemon wedge" src="https://images.theconversation.com/files/396421/original/file-20210421-19-nk461d.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/396421/original/file-20210421-19-nk461d.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=397&fit=crop&dpr=1 600w, https://images.theconversation.com/files/396421/original/file-20210421-19-nk461d.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=397&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/396421/original/file-20210421-19-nk461d.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=397&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/396421/original/file-20210421-19-nk461d.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=499&fit=crop&dpr=1 754w, https://images.theconversation.com/files/396421/original/file-20210421-19-nk461d.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=499&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/396421/original/file-20210421-19-nk461d.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=499&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">A Mediterranean diet full of oily fish, fruit, vegetables and legumes has been linked with lower levels of inflammation.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<p>As for what to eat?</p>
<ol>
<li><p>Load up your plate with a wide variety of plant foods such as fruits, vegetables, wholegrains and legumes, like chickpeas and lentils. These foods are high in anti-inflammatory nutrients, such as fibre and a range of vitamins. They also contain unique “phytochemicals”, such as polyphenols which are plant compounds that have potential antioxidant and <a href="https://pubmed.ncbi.nlm.nih.gov/31583990/">anti-inflammatory effects</a></p></li>
<li><p>Flavour your food liberally with herbs and spices, and sip on tea and coffee regularly. These are also great sources of polyphenols </p></li>
<li><p>Enjoy oily fish regularly, such as salmon, sardines and mackerel, which are rich in anti-inflammatory omega-3 fatty acids</p></li>
<li><p>Reduce your intake of foods that may fuel inflammation. These include foods high in trans and saturated fats, found in commercially baked goods, fried foods and fatty meats.</p></li>
</ol>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/phytonutrients-can-boost-your-health-here-are-4-and-where-to-find-them-including-in-your-next-cup-of-coffee-132100">Phytonutrients can boost your health. Here are 4 and where to find them (including in your next cup of coffee)</a>
</strong>
</em>
</p>
<hr>
<p>Given almost half of us live with a chronic disease, and many more are likely at risk, adopting an anti-inflammatory diet could be very beneficial for your health, and may help you live longer too.</p><img src="https://counter.theconversation.com/content/158451/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Meghan Hockey receives funding from Rotary Health Australia and Deakin University. </span></em></p><p class="fine-print"><em><span>Wolfgang Marx is currently funded by an Alfred Deakin Postdoctoral Research Fellowship and a Multiple Sclerosis Research Australia early-career fellowship. Wolfgang has previously received funding from the NHMRC, Clifford Craig Foundation, Cancer Council Queensland and university grants/fellowships from La Trobe University, Deakin University, University of Queensland, and Bond University, received industry funding and has attended events funded by Cobram Estate Pty. Ltd, received travel funding from Nutrition Society of Australia, received consultancy funding from Nutrition Research Australia, and has received speakers honoraria from The Cancer Council Queensland and the Princess Alexandra Research Foundation. The Food & Mood Centre has received Grant/Research support from Fernwood Foundation, Wilson Foundation, the A2 Milk Company, and Be Fit Foods</span></em></p>Our research provides clear evidence pro-inflammatory diets are linked to poor health, including heart attacks, bowel cancer and depression.Meghan Hockey, PhD Candidate, Accredited Practising Dietitian, Deakin UniversityWolfgang Marx, Postdoctoral research fellow, Deakin UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/581492016-04-25T20:14:27Z2016-04-25T20:14:27ZHigh fat and sugar diets stop us from feeling full<figure><img src="https://images.theconversation.com/files/119427/original/image-20160420-25595-1dog1oc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Eating a typical Western diet high in fat and sugar is bad for our memory, including remembering whether or not we're full.</span> <span class="attribution"><span class="source">from www.shutterstock.com.au</span></span></figcaption></figure><p>When we eat a meal, we take for granted that we should feel full afterwards. But eating a diet high in sugar and fat makes it harder for our body to tell if we are full or not.</p>
<p>The typical diet in Western societies consists of highly processed, highly palatable foods, with lots of saturated fat and refined sugar. Examples of specific foods include red meat, vegetable oils, ice cream, sweetened yoghurts, cakes, cereal, biscuits and soft drinks. </p>
<p>These foods are so commonly consumed in developed nations it has become known as the “Western diet”. We know this sort of diet is high calories and therefore tends to make us gain weight. But <a href="http://www.ncbi.nlm.nih.gov/pubmed/22023100">new research</a> suggests this diet might also impair our ability to stop eating when we’re full, which would be another reason it would make us put on weight.</p>
<h2>Gut-brain signals</h2>
<p>When you eat a meal, the body releases hormones to tell your brain you are full. These hormones send messages to specific areas of the brain, which are involved in the decision to either stop eating or continue eating. One important area of the brain that receives these messages is the hippocampus.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/119429/original/image-20160420-25597-1jjdz99.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/119429/original/image-20160420-25597-1jjdz99.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/119429/original/image-20160420-25597-1jjdz99.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/119429/original/image-20160420-25597-1jjdz99.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/119429/original/image-20160420-25597-1jjdz99.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/119429/original/image-20160420-25597-1jjdz99.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/119429/original/image-20160420-25597-1jjdz99.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/119429/original/image-20160420-25597-1jjdz99.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The hippocampus.</span>
<span class="attribution"><span class="source">from www.shutterstock.com</span></span>
</figcaption>
</figure>
<p>The hippocampus is involved in memory. People whose hippocampus has been removed are densely amnesic – they are unable to form new memories. But <a href="http://www.ncbi.nlm.nih.gov/pubmed/22023100">our</a> research suggests another important function of the hippocampus is receiving messages from the gut about internal states such as hunger. </p>
<p>Humans with severe damage to their hippocampus will <a href="http://www.ncbi.nlm.nih.gov/pubmed/3843537">always say they are hungry</a>, regardless of whether they have just eaten or not. They will eat a full meal, and then only a few minutes later eat an entire second meal. So the hippocampus is very important in telling the body we’re full and don’t need to eat any more.</p>
<p>Rats and mice fed a Western diet have <a href="http://www.ncbi.nlm.nih.gov/pubmed/20413889">damage to the hippocampus</a>. In our lab, we wanted to know whether eating a Western diet damages the hippocampus in humans too. To test this hypothesis, we looked at memory ability, and the ability to detect signals to indicate fullness.</p>
<h2>Our research</h2>
<p>Our <a href="http://www.ncbi.nlm.nih.gov/pubmed/22023100">first study</a> compared two groups of people: those who eat a Western diet, and those with a diet low in saturated fat and refined sugar - a healthy diet. Both groups were matched for age, sex and body mass index.</p>
<p>Both groups were given a range of snacks, followed by some tests of memory ability and then they ate lunch. They were asked to rate how hungry they were before and after the meals, and asked to recall how much they ate during the snack and lunch meals.</p>
<p>Compared to the healthy diet group, the Western diet group had poorer scores on memory tasks, had poorer memory for what they had eaten during the snack period, showed reduced feelings of fullness for the same amount of food eaten, and ate more during the lunch period.</p>
<p>This is the first evidence in otherwise healthy, normal-weight humans that eating a Western diet could be damaging the hippocampus and causing poorer memory ability and reduced sensitivity to feelings of fullness after eating. Because they couldn’t accurately remember what they ate during the snack period, and because they had less sensitivity to feelings of fullness, it is not surprising they ate more during the lunch period.</p>
<p>In a <a href="http://www.ncbi.nlm.nih.gov/pubmed/25449390">second study</a>, we showed the same effect seems to happen with thirst. When participants were made thirsty by feeding them salty chips, the Western diet group didn’t feel as thirsty, but needed to drink more water to quench their thirst. This suggests the Western diet was impairing their brain’s ability to receive messages from the gut.</p>
<h2>What this means for you</h2>
<p>It’s not just the calories in a Western diet making us overweight. The diet itself makes us less sensitive to feelings of fullness, causing us to eat more.</p>
<p>But there is some good news. Individuals in the healthy diet group were more sensitive to their internal signals of fullness and thirst. This provides hope that, after taking the initial first step of eating a healthy diet, it might become easier to eat according to your body’s hunger signals and to continue making better dietary choices.</p>
<p>Importantly, these findings were in healthy young adults. This means even if you’re young and of a healthy body weight, you should consider the impact of the food you’re eating on your brain. This information could be a great motivating force to get people to eat a healthy diet and perhaps reduce rates of obesity.</p>
<h2>What can we do about it?</h2>
<p>Various nutrients have been shown to improve hippocampal dependent memory, and protect against the effects of ageing on the brain.</p>
<p><strong>Omega-3 fatty acids</strong></p>
<p>These are often referred to as a “good fat”. Omega 3 fatty acids include acids critical for brain function. They’re found in fish, avocado and flaxseed.</p>
<p><strong>Antioxidant foods</strong></p>
<p>When cells produce energy, they produce reactive oxygen species which cause damage to the cell. The body can counteract these harmful effects through antioxidants. Various micronutrients have antioxidant properties:</p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/119431/original/image-20160420-25625-1w0361k.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/119431/original/image-20160420-25625-1w0361k.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/119431/original/image-20160420-25625-1w0361k.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/119431/original/image-20160420-25625-1w0361k.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/119431/original/image-20160420-25625-1w0361k.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/119431/original/image-20160420-25625-1w0361k.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/119431/original/image-20160420-25625-1w0361k.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/119431/original/image-20160420-25625-1w0361k.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Antioxidants protect cells from harmful effects.</span>
<span class="attribution"><span class="source">from www.shutterstock.com</span></span>
</figcaption>
</figure>
<p><strong>Polyphenols</strong></p>
<p>These micronutrients are found in fruits and vegetables (especially dark berries), as well as coffee, tea, red wine, chocolate and soy. Polyphenols have an antioxidant effect and can also reduce inflammation in the brain. Improved brain function after consuming cocoa has been shown in both young and old adults.</p>
<p><strong>Curcumin</strong></p>
<p>This is a component of turmeric, the spice that gives the yellow colour to a lot of curries. It has been shown to promote brain health through its antioxidant and anti-inflammatory properties. It is speculated the high intake of curcumin in India might explain why there is such a low incidence of Alzheimer’s disease in that country.</p>
<p><strong>Vitamin E</strong></p>
<p>Vitamin E has antioxidant properties and has been shown to improve neurological function with age. It is found in nuts, green leafy vegetables, wheatgerm and vegetable oils such as sunflower and grapeseed.</p>
<p><strong>Folate</strong></p>
<p>Also known as folic acid, folate is found in spinach, oranges and yeast. It is required for optimal brain function, and supplementation with folate has been shown to reduce the risk of cognitive decline with age.</p><img src="https://counter.theconversation.com/content/58149/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Heather Francis 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>When we eat a meal, we take for granted that we should feel full afterwards. But eating a diet high in sugar and fat makes it harder for our body to tell if we are full or not.Heather Francis, Postdoctoral Researcher & Clinical Neuropsychologist, Macquarie UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/383782015-03-06T05:17:30Z2015-03-06T05:17:30ZMore than one good reason for eating mainly plant foods<figure><img src="https://images.theconversation.com/files/74021/original/image-20150306-3295-y1h5wo.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Advice to favour plant-based foods and reduce meat intake should now be considered part of healthy dietary advice given by doctors and nutritionists.</span> <span class="attribution"><a class="source" href="https://www.flickr.com/photos/marc0047/6118947057">Marc Phu/Flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc-sa/4.0/">CC BY-NC-SA</a></span></figcaption></figure><p>Meat contains some important nutrients, but it’s not essential for a healthy diet. Many people, especially men in Western countries are, on average, eating too much of it. Despite vested interests that wish to maintain this status quo, which prevails in most Western countries, there are very good reasons to curb your meat consumption. </p>
<p>A large body of evidence suggests vegetarians enjoy lower rates of <a href="http://ajcn.nutrition.org/content/early/2013/01/30/ajcn.112.044073.abstract">cardiovascular disease</a>, <a href="http://www.ncbi.nlm.nih.gov/pubmed/23779232">type 2 diabetes</a> and <a href="http://archinte.jamanetwork.com/article.aspx?articleid=1832195">hypertension</a>. <a href="http://archinte.jamanetwork.com/article.aspx?articleid=1710093">A 2013 study</a> of over 70,000 individuals in the United States found a 12% reduction in premature death for vegetarians and studies of healthy long-lived populations all show modest consumption of red meats.</p>
<p>Clearly, advice to favour plant-based foods and reduce meat intake should now be considered part of healthy dietary advice given by doctors and nutritionists. Especially because myths that a vegetarian diet leads to inadequate levels or iron or protein have been <a href="https://www.mja.com.au/open/2012/1/2">dispelled</a>. But a recent report by a <a href="http://www.health.gov/dietaryguidelines/committee/">US nutrition advisory committee</a> that suggests exactly this has come under fire. </p>
<h2>Under attack</h2>
<p>The scientific report of the 2015 <a href="http://www.health.gov/dietaryguidelines/committee/">dietary guidelines advisory committee</a> will form the basis of the latest <a href="http://www.health.gov/dietaryguidelines/2015.asp">US dietary guidelines</a>, which will aim to curtail the growing national prevalence of lifestyle diseases. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/74023/original/image-20150306-3314-1g8z1un.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/74023/original/image-20150306-3314-1g8z1un.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/74023/original/image-20150306-3314-1g8z1un.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/74023/original/image-20150306-3314-1g8z1un.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/74023/original/image-20150306-3314-1g8z1un.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/74023/original/image-20150306-3314-1g8z1un.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/74023/original/image-20150306-3314-1g8z1un.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Meat contains some important nutrients, but it’s not essential for a healthy diet.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/anotherpintplease/8673600976">Mike/Flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc-sa/4.0/">CC BY-NC-SA</a></span>
</figcaption>
</figure>
<p>Half of American adults have one or more preventable chronic diseases and over two-thirds of the adult population and one-third of children are overweight or obese. (Australians are not far behind with over 60% of adults and 25% of children overweight or obese.)</p>
<p>The US report has been in the news for its recommendations to scrap restrictions on eggs and the advice to limit red meat as well as refined grains and sugary foods and drinks.</p>
<p>Australian dietary guidelines have never restricted eggs, but the most recent set, <a href="https://www.nhmrc.gov.au/guidelines-publications/n55">released in 2013</a>, made similar recommendations about avoiding large quantities of red meat – especially for men. Indeed, our guidelines have emphasised the need for more plant foods, including vegetables, legumes, nuts, seeds and grains (as wholegrains rather than refined grain products) since the first set was released in 1981. </p>
<p>But the US committee has faced quite strident criticism from the <a href="https://www.meatinstitute.org/">North American Meat Institute</a> and other meat industry groups for its focus on diet’s impact on human health and the environment. The report states: </p>
<blockquote>
<p>The major findings regarding sustainable diets were that a diet higher in plant-based foods, such as vegetables, fruits, whole grains, legumes, nuts and seeds, and lower in calories and animal-based foods is more health promoting and is associated with less environmental impact than is the current US diet.</p>
</blockquote>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/74022/original/image-20150306-3295-llvmw7.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/74022/original/image-20150306-3295-llvmw7.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=297&fit=crop&dpr=1 600w, https://images.theconversation.com/files/74022/original/image-20150306-3295-llvmw7.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=297&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/74022/original/image-20150306-3295-llvmw7.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=297&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/74022/original/image-20150306-3295-llvmw7.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=373&fit=crop&dpr=1 754w, https://images.theconversation.com/files/74022/original/image-20150306-3295-llvmw7.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=373&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/74022/original/image-20150306-3295-llvmw7.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=373&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Greenhouse gas emissions from the livestock sector, mostly methane and nitrous oxide, are estimated to account for 14.5% of the global total.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/usdagov/16109646769">U.S. Department of Agriculture/Flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<h2>Meat and the environment</h2>
<p>According to the report, following its suggestions would lead to:</p>
<blockquote>
<p>lower greenhouse gas emissions and more favorable land, water and energy use than are current US dietary patterns.</p>
</blockquote>
<p>It’s not alone is highlighting the impact of meat consumption on climate change. Greenhouse gas emissions from the livestock sector, mostly methane and nitrous oxide, are estimated to <a href="http://www.fao.org/docrep/018/i3437e/i3437e.pdf">account for 14.5%</a> of the global total. This is more than direct emissions from the transport sector.</p>
<p><a href="http://www.chathamhouse.org/publication/livestock-%E2%80%93-climate-change%E2%80%99s-forgotten-sector-global-public-opinion-meat-and-dairy">And a report</a> from UK think tank Chatham House released late last year recognises modification of meat consumption as one of the strategies to reduce the extent of climate change.</p>
<p>But many people enjoy eating meat and don’t wish to adopt a vegetarian diet. For them, the good news is modest meat intake is compatible with both health and environmental benefits. Having at least some main meals with less meat and more legumes, nuts, seeds and vegetables will be good for not only your health, but also the environment.</p><img src="https://counter.theconversation.com/content/38378/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>The authors do not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.</span></em></p>The high meat intake in Western countries is not only bad for waistlines but also for the environment.Malcolm Forbes, Research Associate, Centre for Research Excellence in Chronic Disease Prevention and Care, James Cook UniversityRosemary Stanton, Nutritionist & Visiting Fellow, UNSW SydneyLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/350642015-01-20T11:04:15Z2015-01-20T11:04:15ZFat and sugar-heavy diet harms your brain – and makes you keep on eating<figure><img src="https://images.theconversation.com/files/69337/original/image-20150119-2710-i9f6pl.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">A Western diet may be negatively affecting your brain not just your belly.</span> <span class="attribution"><a class="source" href="https://www.flickr.com/photos/fengschwing/3907244654">Jams</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc-sa/4.0/">CC BY-NC-SA</a></span></figcaption></figure><p>Do you eat only when you’re actually hungry? Many of us eat even when our bodies don’t need food. Just the thought of food entices us to eat. We think about food when we see other people eating, when we pass a favorite fast-food restaurant, when we see a scrumptious snack near the check-out at a convenience store. In addition, we’re the targets of sophisticated advertising techniques designed to keep thoughts of food and the pleasures of eating almost constantly in our minds.</p>
<p>Obviously, overeating unhealthy foods can lead to overweight. But looking beyond direct effects on expanding waistlines, our lab studies how mental functioning is related to diet. We’ve found a troubling link between a fat-rich diet common in the West and brain-related ailments that can actually impair our ability to avoid overeating.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/69338/original/image-20150119-2735-1q2i06i.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/69338/original/image-20150119-2735-1q2i06i.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/69338/original/image-20150119-2735-1q2i06i.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/69338/original/image-20150119-2735-1q2i06i.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/69338/original/image-20150119-2735-1q2i06i.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/69338/original/image-20150119-2735-1q2i06i.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/69338/original/image-20150119-2735-1q2i06i.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/69338/original/image-20150119-2735-1q2i06i.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Messages to eat are all around us.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/thomashawk/5051022322">Thomas Hawk</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc/4.0/">CC BY-NC</a></span>
</figcaption>
</figure>
<h2>Fatter and fatter</h2>
<p>Many scientists believe that <a href="http://dx.doi.org/10.1016/S0140-6736(11)60813-1">societal factors</a>, such as advertising, have combined to create an environment in which the temptations to eat have overwhelmed our body’s natural biological ability to control what and how much we consume. The result is that in the United States, two-thirds of adults, and more than one third of children and adolescents, are now <a href="http://dx.doi.org/10.1001/jama.2009.2014">overweight or obese</a>. This trend is spreading to other countries <a href="http://dx.doi.org/10.1038/nrendo.2012.199">all over the world</a>. Even worse, <a href="http://dx.doi.org/10.1186/1471-2458-9-88">diseases</a> that are associated with excess body weight – such as diabetes, high blood pressure and heart problems – are also becoming more prevalent.</p>
<p>At the core of the problem is the fact that many of the foods we can’t seem to resist are unhealthy. Some of the most attractive and popular foods in our current environment contain high amounts of saturated fats – high levels are found in red meats and dairy products like ice cream and butter. This type of diet is consumed by so many people in the US and other western societies that it is often called the “western diet.” No wonder obesity has become such a problem.</p>
<h2>Beyond bellies to brains</h2>
<p>Over the past several years, many scientists have reported that consuming a western diet and gaining excess body weight may have harmful effects on the brains of both human and nonhuman animals. For example, some research suggests that middle-aged adults who are overweight and obese are at greater risk for developing <a href="http://dx.doi.org/10.1016/j.biopsych.2009.02.013">Alzheimer’s disease</a> and <a href="http://dx.doi.org/10.1212/01.wnl.0000306313.89165.ef">other types</a> of late-life cognitive <a href="http://dx.doi.org/10.3233/JAD-2011-110917">dementias</a> compared to people of normal weight. The results of other studies suggest that even <a href="http://dx.doi.org/10.3945/ajcn.113.079624">children</a> as young as seven years of age may suffer certain types of <a href="http://dx.doi.org/10.1016/j.jpeds.2014.10.008">memory impairments</a> as a consequence of consuming too much of a western diet and accumulating too much body fat.</p>
<p>Much information about the nature of the effects of western diets on the brain comes from studies with rats and mice. <a href="http://dx.doi.org/10.1016/j.neuroscience.2013.08.044">Research in our lab</a> and <a href="http://dx.doi.org/10.2174/138161208784705496">elsewhere</a> has repeatedly shown that feeding rats a diet with levels of <a href="http://dx.doi.org/10.3233/JAD-2010-091414">saturated fat and sugar</a> much like those in the human western diet <a href="http://dx.doi.org/10.1016/j.physbeh.2010.12.003">weakens the blood-brain barrier</a> (BBB). The BBB is a system of cells and membranes that form tight junctions to prevent harmful agents that circulate in the bloodstream from entering the brain. Feeding rats a western-style diet weakens those tight junctions and thereby allows potentially harmful substances to pass into the brain.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/69435/original/image-20150119-14500-17tsg3c.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/69435/original/image-20150119-14500-17tsg3c.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/69435/original/image-20150119-14500-17tsg3c.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/69435/original/image-20150119-14500-17tsg3c.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/69435/original/image-20150119-14500-17tsg3c.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/69435/original/image-20150119-14500-17tsg3c.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/69435/original/image-20150119-14500-17tsg3c.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/69435/original/image-20150119-14500-17tsg3c.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Healthy tight junctions keep substances in the bloodstream from diffusing into the brain.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/gudanowski/2229615568">Chrejsa</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc-sa/4.0/">CC BY-NC-SA</a></span>
</figcaption>
</figure>
<p>To determine which areas of the brain are most vulnerable to the ill-effects of a leaky BBB, we infuse a small amount of dye into the bloodstream of a rat and measure areas of the brain where the dye accumulates. In overweight rats fed a western-style diet, the dye appears to collect preferentially in the hippocampus, a brain structure involved with important learning and memory functions. As an apparent response to the accumulation of such intruding substances, the hippocampus becomes inflamed and its electrochemical activity changes. Rats that suffer these consequences also show deficits in their ability to use certain types of information processed by the hippocampus.</p>
<h2>A vicious cycle</h2>
<p>Do these deficits have anything to do with our ability to resist eating high-fat and sugary foods? We think they do. One type of information that is processed by the hippocampus takes the form of internal physiological signals about one’s need for food. Rats and people who have sustained <a href="http://dx.doi.org/10.1037/0735-7044.99.6.1031">damage</a> to their hippocampus appear to have difficulty <a href="http://dx.doi.org/10.1037/a0018402">using those internal signals</a> to tell whether or not they’ve had <a href="http://dx.doi.org/10.1037/a0025998">enough to eat or drink</a>. In the presence of powerful cues in the environment that entice you to eat, a reduced ability to use information from your body that tells you that you don’t need food can lead to overeating.</p>
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<p>The result could be a vicious cycle in which eating a western diet produces <a href="http://dx.doi.org/10.1016/j.coph.2007.10.008">hippocampal dysfunction</a> which weakens the ability to <a href="http://dx.doi.org/10.1016/j.nlm.2013.07.014">use internal cues</a> to counter eating elicited by cues in the environment. This could lead to progressively more eating of western diet based on progressively greater deterioration of hippocampal function. As the hippocampus becomes more and more impaired, the severity and scope of learning and memory deficits would also increase. The result could be not only obesity but also more serious cognitive decline.</p>
<p>How to break this feedback loop is an important research question. Maybe the answer will be to find ways to protect and strengthen the BBB against the bad effects of western diet. Maybe it will be in finding ways to make the western diet less damaging. But until other answers are found, the only protection we have is knowing that an excessive intake of a western diet may harm both our physical and mental well-being.</p><img src="https://counter.theconversation.com/content/35064/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Terry Davidson receives funding from the National Institutes of Child Health and Development (NIH)</span></em></p><p class="fine-print"><em><span>Camille Sample 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>Do you eat only when you’re actually hungry? Many of us eat even when our bodies don’t need food. Just the thought of food entices us to eat. We think about food when we see other people eating, when we…Terry Davidson, Director of the Center for Behavioral Neuroscience and Professor of Psychology, American UniversityCamille Sample, PhD Student in Behavioral and Neural Homeostasis, American UniversityLicensed as Creative Commons – attribution, no derivatives.