tag:theconversation.com,2011:/ca/topics/hdl-cholesterol-26406/articlesHDL cholesterol – The Conversation2023-09-15T00:56:34Ztag:theconversation.com,2011:article/2117482023-09-15T00:56:34Z2023-09-15T00:56:34ZHow can I lower my cholesterol? Do supplements work? How about psyllium or probiotics?<figure><img src="https://images.theconversation.com/files/545897/original/file-20230901-17-zovk4b.jpg?ixlib=rb-1.1.0&rect=2%2C0%2C1908%2C1279&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.pexels.com/photo/white-ceramic-bowls-with-supplements-7615572/">Nataliya Vaitkevich/Pexels</a></span></figcaption></figure><p>Your GP says you have high cholesterol. You’ve six months to work on your diet to see if that’ll bring down your levels, then you’ll review your options. </p>
<p>Could taking supplements over this time help?</p>
<p>You can’t rely on supplements alone to control your cholesterol. But there’s some good evidence that taking particular supplements, while also eating a healthy diet, can make a difference.</p>
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Read more:
<a href="https://theconversation.com/got-high-cholesterol-here-are-five-foods-to-eat-and-avoid-63941">Got high cholesterol? Here are five foods to eat and avoid</a>
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<h2>Why are we so worried about cholesterol?</h2>
<p>There are two main types of cholesterol, both affecting your risk of heart disease and stroke. Both types are carried in the bloodstream inside molecules called lipoproteins.</p>
<p><strong>Low-density lipoprotein or LDL cholesterol</strong></p>
<p>This is often called “bad” cholesterol. This lipoprotein carries cholesterol from the liver to cells throughout the body. High levels of LDL cholesterol in the blood can lead to the <a href="https://www.ahajournals.org/doi/full/10.1161/JAHA.118.011433">build-up of plaque</a> in arteries, which leads to an <em>increased</em> risk of heart disease and stroke. </p>
<p><strong>High-density lipoprotein or HDL cholesterol</strong></p>
<p>This is often called “good” cholesterol. This lipoprotein helps remove excess cholesterol from the bloodstream and transports it back to the liver for processing and excretion. Higher levels of HDL cholesterol are <a href="https://www.ahajournals.org/doi/full/10.1161/CIRCRESAHA.119.312617">linked to</a> a <em>reduced</em> risk of heart disease and stroke. </p>
<p>Diet can play a key role in reducing blood cholesterol levels, especially LDL (“bad”) cholesterol. Healthy dietary choices are <a href="https://theconversation.com/got-high-cholesterol-here-are-five-foods-to-eat-and-avoid-63941">well recognised</a>. These include a focus on eating more unsaturated (“healthy”) fat (such as from olive oil or avocado), and eating less saturated (“unhealthy”) fat (such as animal fats) and trans fats (found in some shop-bought biscuits, pies and pizza bases).</p>
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<a href="https://images.theconversation.com/files/546536/original/file-20230905-26-5plf10.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Cut avocado, glass of olive oil, green herbs and cut lemon on timber background" src="https://images.theconversation.com/files/546536/original/file-20230905-26-5plf10.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/546536/original/file-20230905-26-5plf10.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/546536/original/file-20230905-26-5plf10.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/546536/original/file-20230905-26-5plf10.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/546536/original/file-20230905-26-5plf10.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/546536/original/file-20230905-26-5plf10.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/546536/original/file-20230905-26-5plf10.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">You can find unsaturated fat in foods such as olive oil and avocado.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/food-background-fresh-organic-avocado-lime-253287091">Shutterstock</a></span>
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Read more:
<a href="https://theconversation.com/health-check-whats-healthier-butter-or-margarine-19777">Health Check: what's healthier, butter or margarine?</a>
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<h2>Fibre is your friend</h2>
<p>An additional way to significantly reduce your total cholesterol and LDL cholesterol levels through diet is by eating more <a href="https://theconversation.com/fiber-is-your-bodys-natural-guide-to-weight-management-rather-than-cutting-carbs-out-of-your-diet-eat-them-in-their-original-fiber-packaging-instead-205159">soluble fibre</a>.</p>
<p>This is a type of fibre that dissolves in water to form a gel-like substance in your gut. The gel can bind to cholesterol molecules preventing them from being absorbed into the bloodstream and allows them to be eliminated from the body through your faeces. </p>
<p>You can find soluble fibre in whole foods such as fruits, vegetables, oats, barley, beans and lentils.</p>
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<em>
<strong>
Read more:
<a href="https://theconversation.com/fiber-is-your-bodys-natural-guide-to-weight-management-rather-than-cutting-carbs-out-of-your-diet-eat-them-in-their-original-fiber-packaging-instead-205159">Fiber is your body's natural guide to weight management – rather than cutting carbs out of your diet, eat them in their original fiber packaging instead</a>
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<h2>Fibre supplements, such as psyllium</h2>
<p>There are also many fibre supplements and food-based products on the market that may help lower cholesterol. These include:</p>
<ul>
<li><p><strong>natural soluble fibres</strong>, such as inulin (for example, Benefiber) or psyllium (for example, Metamucil) or beta-glucan (for example, in ground oats)</p></li>
<li><p><strong>synthetic soluble fibres</strong>, such as polydextrose (for example, STA-LITE), wheat dextrin (also found in Benefiber) or methylcellulose (such as Citrucel)</p></li>
<li><p><strong>natural insoluble fibres</strong>, which bulk out your faeces, such as flax seeds.</p></li>
</ul>
<p>Most of these supplements come as fibres you add to food or dissolve in water or drinks. </p>
<p>Psyllium is the fibre supplement with the strongest evidence to support its use in improving cholesterol levels. It’s been <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5413815/">studied</a> in at least 24 high-quality randomised controlled trials.</p>
<p>These trials show consuming about 10g of psyllium a day (1 tablespoon), as part of a healthy diet, <a href="https://www.sciencedirect.com/science/article/pii/S0002916523070107#:%7E:text=Conclusions%3A,mild%2Dto%2Dmoderate%20hypercholesterolemia.">can significantly lower</a> total cholesterol levels by 4% and LDL cholesterol levels by 7%.</p>
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<a href="https://images.theconversation.com/files/545910/original/file-20230901-20-orbx53.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Person stirring in psyllium into glass of water, bowl of psyllium next to glass" src="https://images.theconversation.com/files/545910/original/file-20230901-20-orbx53.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/545910/original/file-20230901-20-orbx53.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/545910/original/file-20230901-20-orbx53.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/545910/original/file-20230901-20-orbx53.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/545910/original/file-20230901-20-orbx53.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/545910/original/file-20230901-20-orbx53.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/545910/original/file-20230901-20-orbx53.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">You can mix psyllium fibre into a drink or add it to your food.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/woman-adds-spoon-psyllium-fiber-mix-2031428417">Shutterstock</a></span>
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<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/health-check-are-you-eating-the-right-sorts-of-fibre-20089">Health Check: are you eating the right sorts of fibre?</a>
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<h2>Probiotics</h2>
<p>Other cholesterol-lowering supplements, such as probiotics, are not based on fibre. Probiotics are thought to help lower cholesterol levels via a <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3352670/">number of mechanisms</a>. These include helping to incorporate cholesterol into cells, and adjusting the microbiome of the gut to favour elimination of cholesterol via the faeces.</p>
<p>Using probiotics to reduce cholesterol is an upcoming area of interest and the <a href="https://www.sciencedirect.com/science/article/abs/pii/S089990071500461X">research</a> is promising. </p>
<p>In a <a href="https://pubmed.ncbi.nlm.nih.gov/29384846/">2018 study</a>, researchers pooled results from 32 studies and analysed them altogether in a type of study known as a meta-analysis. The people who took probiotics reduced their total cholesterol level by 13%.</p>
<p><a href="https://www.tandfonline.com/doi/full/10.3109/07853890.2015.1071872">Other</a> <a href="https://link.springer.com/article/10.1007/s11906-020-01080-y">systematic reviews</a> support these findings.</p>
<p>Most of these studies use probiotics containing <em>Lactobacillus acidophilus</em> and <em>Bifidobacterium lactis</em>, which come in capsules or powders and are consumed daily.</p>
<p>Ultimately, probiotics could be worth a try. However, the effects will likely vary according to the probiotic strains used, whether you take the probiotic each day as indicated, as well as your health status and your diet.</p>
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<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/health-check-should-healthy-people-take-probiotic-supplements-95861">Health Check: should healthy people take probiotic supplements?</a>
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</em>
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<h2>Red yeast rice</h2>
<p><a href="https://www.nccih.nih.gov/health/red-yeast-rice">Red yeast rice</a> is another non-fibre supplement that has gained attention for lowering cholesterol. It is often used in Asia and some European countries as a complementary therapy. It comes in capsule form and is thought to mimic the role of the cholesterol-lowering medications known as statins.</p>
<p>A <a href="https://www.frontiersin.org/articles/10.3389/fphar.2021.819482/full">2022 systematic review</a> analysed data from 15 randomised controlled trials. It found taking red yeast rice supplements (200-4,800mg a day) was more effective for lowering blood fats known as triglycerides but less effective at lowering total cholesterol compared with statins.</p>
<p>However, these trials don’t tell us if red yeast rice works and is safe in the long term. The authors also said only one study in the review was registered in a major <a href="https://www.clinicaltrials.gov">database</a> of clinical trials. So we don’t know if the evidence base was complete or biased to only publish studies with positive results.</p>
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<a href="https://images.theconversation.com/files/546589/original/file-20230906-23-a4o8yh.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Red yeast rice capsules" src="https://images.theconversation.com/files/546589/original/file-20230906-23-a4o8yh.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/546589/original/file-20230906-23-a4o8yh.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=274&fit=crop&dpr=1 600w, https://images.theconversation.com/files/546589/original/file-20230906-23-a4o8yh.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=274&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/546589/original/file-20230906-23-a4o8yh.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=274&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/546589/original/file-20230906-23-a4o8yh.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=344&fit=crop&dpr=1 754w, https://images.theconversation.com/files/546589/original/file-20230906-23-a4o8yh.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=344&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/546589/original/file-20230906-23-a4o8yh.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=344&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">Red yeast rice is often used in Asia and some European countries to lower cholesterol.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/red-yeast-rice-supplement-capsules-on-1625852824">Shutterstock</a></span>
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<h2>Diet and supplements may not be enough</h2>
<p>Always speak to your GP and dietitian about your plan to take supplements to lower your cholesterol.</p>
<p>But remember, dietary changes alone – with or without supplements – might not be enough to lower your cholesterol levels sufficiently. You still need to quit smoking, reduce stress, exercise regularly and get enough sleep. Genetics can also play a role.</p>
<p>Even then, depending on your cholesterol levels and other risk factors, you may still be recommended cholesterol-lowering medications, such as <a href="https://jamanetwork.com/journals/jama/fullarticle/2795522">statins</a>. Your GP will discuss your options at your six-month review.</p><img src="https://counter.theconversation.com/content/211748/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Lauren Ball works for The University of Queensland and receives funding from the National Health and Medical Research Council, Queensland Health, Mater Misericordia and the Royal Australian College of General Practitioners. She is a Director of Dietitians Australia, a Director of the Darling Downs and West Moreton Primary Health Network and an Associate Member of the Australian Academy of Health and Medical Sciences.</span></em></p><p class="fine-print"><em><span>Emily Burch works for Southern Cross University.</span></em></p>If you try supplements, you still need to eat a healthy diet, exercise, reduce your stress, quit smoking and get enough sleep. Even then, they may still not be enough.Lauren Ball, Professor of Community Health and Wellbeing, The University of QueenslandEmily Burch, Dietitian, Researcher & Lecturer, Southern Cross UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1271542019-12-05T16:02:06Z2019-12-05T16:02:06ZLimited eating times could be a new way to fight obesity and diabetes<figure><img src="https://images.theconversation.com/files/304824/original/file-20191202-67028-7oi1vv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Time limits on eating may help to keep diabetics' blood glucose in check.
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/glucometer-ripe-fruits-shape-clock-time-1557461105">ratmaner/Shutterstock.com</a></span></figcaption></figure><p>People with obesity, high blood sugar, high blood pressure or high cholesterol are often advised to eat less and move more, but <a href="https://www.cell.com/cell-metabolism/fulltext/S1550-4131(19)30611-4">our new research suggests</a> there is now another simple tool to fight off these diseases: restricting your eating time to a daily 10-hour window.</p>
<p><a href="Http://doi.org/10.1016/j.cmet.2014.11.001">Studies done</a> <a href="Http://doi.org/10.1016/j.cmet.2012.04.019">in mice</a> and <a href="http://doi.org/10.1038/s41467-019-10563-9">fruit</a> <a href="https://doi.org/10.1126/science.1256682">flies</a> <a href="http://doi.org/10.1186/s12967-016-1044-0">suggest</a> that limiting when animals eat to a daily window of 10 hours can prevent, or even reverse, <a href="https://www.cdc.gov/pcd/issues/2017/16_0287.htm">metabolic diseases that affect millions in the U.S.</a> </p>
<p>We are scientists - <a href="https://panda.salk.edu">a cell biologist</a> and a <a href="https://profiles.ucsd.edu/pam.taub#narrative">cardiologist</a> - and are exploring the effects of the timing of nutrition on health. Results from flies and mice led us and others to test the idea of time-restricted eating in healthy people. <a href="https://doi.org/10.1016/j.cmet.2015.09.005">Studies lasting more than a year</a> showed that <a href="https://doi.org/10.1139/apnm-2018-0389">TRE was safe among healthy individuals</a>. Next, we tested time-restricted eating in patients with conditions known collectively as <a href="https://www.mayoclinic.org/diseases-conditions/metabolic-syndrome/symptoms-causes/syc-20351916">metabolic syndrome</a>. We were curious to see if this approach, which had a profound impact on obese and diabetic lab rats, can help millions of patients who suffer from early signs of diabetes, high blood pressure and unhealthy blood cholesterol. </p>
<h2>A leap from prevention to treatment</h2>
<p>It’s not easy to count calories or figure out how much fat, carbohydrates and protein are in every meal. That’s why using <a href="https://doi.org/10.1017/jns.2018.13">TRE provides</a> <a href="https://doi.org/10.1016/j.cmet.2015.09.005">a new strategy for fighting</a> <a href="http://doi.org/10.1002/oby.22449">obesity and</a> <a href="http://doi.org/10.1017/S0007114513001359">metabolic diseases</a> that affect millions of people worldwide. Several studies had suggested that TRE is a lifestyle choice that healthy people can adopt and that can <a href="http://doi.org/10.1016/j.cmet.2018.04.010">reduce their risk</a> for future metabolic diseases. </p>
<p>However, TRE is rarely tested on people already diagnosed with metabolic diseases. Furthermore, the vast majority of patients with metabolic diseases are often on medication, and it was not clear whether it was safe for these patients to go through daily fasting of more than 12 hours – as many experiments require – or whether TRE will offer any benefits in addition to those from their medications. </p>
<p>In a unique collaboration between our basic science and clinical science laboratories, we tested whether restricting eating to a 10-hour window improved the health of people with metabolic syndrome who were also taking medications that lower blood pressure and cholesterol to manage their disease.</p>
<p><a href="http://doi.org/10.1161/CIRCULATIONAHA.109.192644">We recruited patients</a> from UC San Diego clinics who met at least <a href="http://doi.org/10.1016/j.jacc.2015.06.1328">three out of five criteria</a> for <a href="https://www.nhlbi.nih.gov/health-topics/metabolic-syndrome">metabolic syndrome</a>: obesity, high blood sugar, high blood pressure, high level of bad cholesterol and low level of good cholesterol. The patients used a <a href="https://doi.org/10.1016/j.cmet.2015.09.005">research app called myCircadianClock</a>, developed in our lab, to log every calorie they consumed for two weeks. This helped us to find patients who were more likely to spread their eating out over the span of 14 hours or more and might benefit from 10-hour TRE. </p>
<p>We monitored their physical activity and sleep using a watch worn on the wrist. As some patients with bad blood glucose control may experience low blood glucose at night, we also placed a continuous glucose monitor on their arm to measure blood glucose every few minutes for two weeks. </p>
<p>Nineteen patients qualified for the study. Most of them had already tried standard lifestyle interventions of reducing calories and doing more physical activity. As part of this study, the only change they had to follow was to self-select a window of 10 hours that best suited their work-family life to eat and drink all of their calories, say from 9 a.m. to 7 p.m. Drinking water and taking medications outside this window were allowed. For the next 12 weeks they used the <a href="https://mycircadianclock.org/">myCircadianClock</a> app, and for the last two weeks of the study they also had the continuous glucose monitor and activity monitor. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/304982/original/file-20191203-66994-1n414zk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/304982/original/file-20191203-66994-1n414zk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/304982/original/file-20191203-66994-1n414zk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=629&fit=crop&dpr=1 600w, https://images.theconversation.com/files/304982/original/file-20191203-66994-1n414zk.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=629&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/304982/original/file-20191203-66994-1n414zk.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=629&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/304982/original/file-20191203-66994-1n414zk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=790&fit=crop&dpr=1 754w, https://images.theconversation.com/files/304982/original/file-20191203-66994-1n414zk.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=790&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/304982/original/file-20191203-66994-1n414zk.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=790&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">Tens of millions of people in the U.S. have symptoms of metabolic syndrome.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-vector/metabolic-syndrome-signs-symptoms-apple-pear-315847109">Designua/Shuttersock.com</a></span>
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<h2>Timing is the medicine</h2>
<p>After 12 weeks, the volunteers returned to the clinic for a thorough medical examination and blood tests. We compared their final results with those from their initial visit. <a href="https://www.cell.com/cell-metabolism/fulltext/S1550-4131(19)30611-4">The results, which we published in Cell Metabolism</a>, were pleasantly surprising. We found most of them lost a modest amount of body weight, particularly fat from their abdominal region. Those who had high blood glucose levels when fasting also reduced these blood sugar levels. Similarly, most patients further reduced their blood pressure and LDL cholesterol. All of these benefits happened without any change in physical activity. </p>
<p>Reducing the time window of eating also had several inadvertent benefits. On average, patients reduced their daily caloric intake by a modest 8%. However, statistical analyses did not find strong association between calorie reduction and health improvement. <a href="http://doi.org/10.1016/j.cmet.2018.04.010">Similar benefits of TRE on blood pressure and blood glucose</a> control were also found among healthy adults who did not change caloric intake. </p>
<p>Nearly two-thirds of patients also reported restful sleep at night and less hunger at bedtime – similar to what was reported in other TRE studies on <a href="https://doi.org/10.1016/j.cmet.2015.09.005">relatively healthier cohorts</a>. While restricting <a href="http://doi.org/10.1016/j.cmet.2018.04.010">all eating to just a six-hour window</a> was hard for participants and caused several adverse effects, patients reported they could easily adapt to eating within a 10-hour span. Although it was not necessary after completion of the study, nearly 70% of our patients continued with the TRE for at least a year. As their health improved, many of them reported having reduced their medication or stopped some medication. </p>
<p>Despite the success of this study, time-restricted eating is not currently a standard recommendation from doctors to their patients who have metabolic syndrome. This study was a small feasibility study; more rigorous randomized control trials and multiple location trials are necessary next steps. Toward that goal, we have started a <a href="https://clinicaltrials.gov/ct2/show/NCT04057339?term=Pam+taub&draw=2&rank=2">larger study</a> on metabolic syndrome patients. </p>
<p>Although we did not see any of our patients go through dangerously low levels of glucose during overnight fasting, it is important that time-restricted eating be practiced under medical supervision. As TRE can improve metabolic regulation, it is also necessary that a physician pays close attention to the health of the patient and adjusts medications accordingly. </p>
<p>We are cautiously hopeful that time-restricted eating can be a simple, yet powerful approach to treating people with metabolic diseases. </p>
<p>[ <em>Deep knowledge, daily.</em> <a href="https://theconversation.com/us/newsletters?utm_source=TCUS&utm_medium=inline-link&utm_campaign=newsletter-text&utm_content=deepknowledge">Sign up for The Conversation’s newsletter</a>. ]</p><img src="https://counter.theconversation.com/content/127154/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Satchin Panda receives funding from the National Institute of Health, Department of Defense, Federal Emergency Management Agency, Helmsley Charitable trust, Robertwood Johnson Foundation, and Glenn Foundation for Medical Research. He is the author of the book "The Circadian Code" for which he receives author royalty. Satchin Panda is a founding member of the Center for Circadian Biology at UC San Diego. </span></em></p><p class="fine-print"><em><span>Pam Taub receives funding from NIDDK, American Heart Association, Department of Defense. </span></em></p>What if you could treat obesity, diabetes and high blood pressure just by limiting when you eat and drink all your calories? New research says it might work.Satchin Panda, Professor of Regulatory Biology at the Salk Institute for Biological Studies, Adjunct Professor of Cell and Developmental Biology at UCSD, University of California, San DiegoPam Taub, Associate Professor of Medicine, University of California, San DiegoLicensed 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/841402018-01-26T11:00:56Z2018-01-26T11:00:56ZThe simple cholesterol test that says if you need statins — and why doctors in UK aren’t using it<figure><img src="https://images.theconversation.com/files/203398/original/file-20180125-107971-1egjzch.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/medical-equipment-blood-test-tube-laboratory-537711568">Shuttertstock</a></span></figcaption></figure><p>Heart disease stubbornly remains one of the biggest killers in the UK, where there are <a href="https://www.bhf.org.uk/about-us/press-centre/facts-and-figures">7m people</a> living with the condition. During the past 60 years, the management of cholesterol has become an important weapon in the fight against this – and drugs called statins are often used in treatment. </p>
<p>But as <a href="http://bjsm.bmj.com/content/early/2018/01/16/bjsports-2017-098497">a new review highlights</a>, statins can often cause crippling side-effects – and may actually result in more harm than good. Writing in the British Journal of Sports Medicine, Australian science reporter Maryanne Demasi claims that doctors and patients are being misled about the true benefits and harms of these drugs. She also suggests that raw data on their efficacy and safety are being kept secret and have not been subjected to scrutiny by other scientists. </p>
<p>But despite <a href="https://www.nice.org.uk/Media/Default/News/NICE-statin-letter.pdf">concerns about patients taking them unnecessarily</a>, the use of statins is so widespread that they are now the <a href="https://www.bhf.org.uk/heart-health/treatments/statins">most prescribed drug in the UK</a>. There have even been <a href="http://www.bmj.com/content/358/bmj.j3674.long">recent calls</a> for all males over 65 and females over 75 to be prescribed them. If this were to happen it would mean they were used by almost 12m people across the country. </p>
<p>One of the key diagnostic tests to decide if a person should be put on statins is often a <a href="http://heartuk.org.uk/health-and-high-cholesterol/cholesterol-tests---know-your-number?gclid=EAIaIQobChMIm--zrPfy2AIVCLftCh3A5QQOEAAYASAAEgIrePD_BwE">blood cholesterol test</a>. If the results show raised levels, the patient will generally be thought of as being at an increased risk of cardiovascular disease and prescribed statins. But there is <a href="http://www.onlinecjc.ca/article/S0828-282X(16)30732-2/pdf">mounting evidence</a> which shows this test alone is insufficient in its predictive power. </p>
<h2>Cholesterol explained</h2>
<p>To make sense of this it helps to understand how cholesterol is transported around our bodies. A simple analogy may be to think of how boats move cargo around waterways. But rather than rivers and canals, our bodies have a network of arteries and capillaries, with “lipoprotein” particles which act like minuscule vessels, constantly shuttling cholesterol back and forth.</p>
<p>These particles exist in a variety of distinct types, with perhaps the most well known being low density lipoproteins (LDL) and high density lipoproteins (HDL). LDL particles are commonly referred to as “bad cholesterol” as they ship cholesterol to the arterial wall where it can potentially form a plaque. Whereas HDL is often known as “good cholesterol” as it removes cholesterol from arteries. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/203404/original/file-20180125-107946-g7aif9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/203404/original/file-20180125-107946-g7aif9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=343&fit=crop&dpr=1 600w, https://images.theconversation.com/files/203404/original/file-20180125-107946-g7aif9.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=343&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/203404/original/file-20180125-107946-g7aif9.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=343&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/203404/original/file-20180125-107946-g7aif9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=431&fit=crop&dpr=1 754w, https://images.theconversation.com/files/203404/original/file-20180125-107946-g7aif9.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=431&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/203404/original/file-20180125-107946-g7aif9.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=431&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">A clogged artery with platelets and cholesterol plaque.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-illustration/clogged-artery-platelets-cholesterol-plaque-concept-259675388">Shutterstock</a></span>
</figcaption>
</figure>
<p>Despite these simplistic explanations it is important to realise that when doctors test for LDL they are actually observing the amount of cholesterol stored on board the boat (or particle), rather than looking at the actual vessel itself. This seemingly minor detail is where problems can arise. </p>
<p>Although conventional wisdom holds that there is a positive relationship between the cholesterol on board LDL particles and cardiovascular risk, we have known for some time through <a href="https://www.ncbi.nlm.nih.gov/pubmed/16467234">large-scale</a> <a href="https://www.ncbi.nlm.nih.gov/pubmed/7050440?dopt=Abstract">studies</a> that this is not always the case. </p>
<p>In reality some people with high LDL cholesterol may actually be at a low risk of heart disease and are therefore potentially treated unnecessarily. And in the same way, some individuals with low LDL cholesterol levels can be at an extremely high risk – yet remain untreated due to a lack of diagnosis. The number of people who fall into these categories is substantial – <a href="http://www.lipidjournal.com/article/S1933-2874(11)00027-4/fulltext">studies suggest</a> up to 20% may be affected. </p>
<p>To address these issues, doctors have now been told to use “non-HDL” cholesterol as a determinant of cardiovascular risk. This encompasses all cholesterol stored in lipoproteins which contribute towards cardiovascular disease, except for HDL. </p>
<p>But although this has been shown to be a better predictor, <a href="http://circoutcomes.ahajournals.org/content/4/3/337.long">problems remain</a>. This is mainly because non-HDL is also determined from the cholesterol content of particles, rather than by measuring the particles themselves. </p>
<h2>The test</h2>
<p>Returning to our earlier analogy, if an enemy armada was approaching at sea, surely it would be better to gauge the threat by counting the number of boats, rather than trying to determine the amount of cargo contained on board. Remarkably, we can do something similar with our lipoproteins.</p>
<p>Attached to each LDL particle is a single molecule of a protein called apolipoprotein B100 (ApoB). And by determining how much ApoB is in the blood we can “count” exactly how many LDL particles are present. </p>
<p>Determining LDL in this way is better than measuring the cholesterol stored inside, because ApoB <a href="http://circoutcomes.ahajournals.org/content/4/3/337.long">has been shown</a> to be a superior predictor of cardiovascular disease than measuring both LDL cholesterol and non-HDL cholesterol.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/203406/original/file-20180125-107963-qpv52x.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/203406/original/file-20180125-107963-qpv52x.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=360&fit=crop&dpr=1 600w, https://images.theconversation.com/files/203406/original/file-20180125-107963-qpv52x.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=360&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/203406/original/file-20180125-107963-qpv52x.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=360&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/203406/original/file-20180125-107963-qpv52x.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=452&fit=crop&dpr=1 754w, https://images.theconversation.com/files/203406/original/file-20180125-107963-qpv52x.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=452&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/203406/original/file-20180125-107963-qpv52x.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=452&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Experts have raised concerns that those using statins see next to no benefit.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/download/confirm/479441023?src=q3FyiDbRkQYEYm4eG6dMJQ-1-87&size=huge_jpg">Shutterstock</a></span>
</figcaption>
</figure>
<p>But despite this, tests for ApoB aren’t routinely used – partly because of the cost. An ApoB test is more expensive than using non-HDL alone – which can be quickly and cheaply calculated using data derived from routine lipid checks. </p>
<p>Many doctors may also be simply unaware of the importance of ApoB – despite countries such as Canada incorporating ApoB testing into their <a href="http://www.onlinecjc.ca/article/S0828-282X(16)30732-2/pdf">guidelines</a>. The UK, for example, has been reluctant to make such recommendations. All of which further perpetuates the hesitance of health care professionals to incorporate the measure into their assessments. </p>
<p>But this is highly shortsighted, given the scale of the burden that cardiovascular disease places upon the NHS – and the mass prescription of statins and their widely documented side-effects.</p>
<p>Perhaps then, it is time to ask if the current diagnostic method for blood cholesterol really is the best option.</p><img src="https://counter.theconversation.com/content/84140/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Richard Webb 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>Current cholesterol tests in the UK are outdated and are putting lives at risk.Richard Webb, Postdoctoral Researcher in Nutritional Science, Liverpool John Moores UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/876492017-12-22T09:38:54Z2017-12-22T09:38:54ZA Christmas spice that may help reduce your blood cholesterol<figure><img src="https://images.theconversation.com/files/199950/original/file-20171219-5004-15z7dy2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/cinnamon-sticks-powder-on-wood-646377511?src=m6k9k1_KIML4wrw0mJKgAA-1-1">amphaiwan/Shutterstock.com</a></span></figcaption></figure><p>Cinnamon is a popular spice at Christmas time, used to flavour everything from mulled wine to pumpkin pie. And, unlike many Christmas foods, this one might actually be good for you. </p>
<p>Cinnamon, the bark of a small evergreen tree, has been used as a medicine for centuries, if not millennia. It is widely used in traditional Chinese medicine for treating, among other things, <a href="https://www.philadelphia-acupuncture.com/cinnamon-chinese-herbal-medicine/">acute traumatic pain and “weak digestion”</a>. In Ayurvedic medicine it is used to treat <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4210501/">arthritis, diarrhoea and menstrual irregularities</a>.</p>
<p>In Western medicine, it has been known for decades that cinnamon contains biologically active substances (polyphenals) that act in a similar manner to insulin. As a result, it has been proposed that the spice might be beneficial for diabetics. However, a systematic review of the evidence, <a href="https://www.ncbi.nlm.nih.gov/pubmed/17909085">published in Diabetes Care</a> in 2008, didn’t support using cinnamon for glucose control in patients with type 1 or type 2 diabetes. </p>
<h2>Effect on blood cholesterol</h2>
<p>Recent studies, though, suggest that cinnamon might be useful in lowering blood cholesterol levels. Raised cholesterol is a huge public health problem as it increases the risks of heart disease and stroke. The <a href="http://www.who.int/gho/ncd/risk_factors/cholesterol_text/en/">World Health Organisation</a> estimates that 2.6m deaths – 4.5% of all deaths, worldwide – are related to high cholesterol. </p>
<p>A recent <a href="https://www.ncbi.nlm.nih.gov/pubmed/28887086">review</a> of 13 randomised controlled trials investigated whether there was a link between cinnamon supplementation and blood lipid concentrations. There were 750 participants in total – most of them were diabetic. They each took one to six grams of cinnamon powder daily, up to four months. </p>
<p>The authors of the review found that cinnamon supplementation significantly reduced blood triglycerides and total cholesterol levels, but it had no effect on levels of low-density lipoprotein (LDL) cholesterol and high-density lipoprotein (HDL) cholesterol levels, separately. However, when one of the studies was removed in a “sensitivity analysis”, cinnamon supplementation was found to be significantly associated with an elevation in HDL cholesterol, so-called good cholesterol. </p>
<p>Another <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5469078/">recent study</a> compared supplementation with cinnamon versus a placebo (a capsule containing flour) on 116 Asian Indians with metabolic syndrome. The researchers found that those in the experimental group (the ones who received three grams of cinnamon for 16 weeks) had significant reductions in total cholesterol, LDL cholesterol and triglycerides, compared with the control group (placebo). The experimental group also showed a significant increase in HDL (good) cholesterol. </p>
<p>So, in summary, the best available evidence shows that cinnamon may be able to reduce blood lipids in people with diabetes or metabolic syndrome. Unfortunately, there isn’t enough data to demonstrate benefits in non-diabetic people, specifically those with high cholesterol.</p>
<h2>But is it safe?</h2>
<p>Cinnamon is considered <a href="https://nccih.nih.gov/health/cinnamon">safe</a> for most people, when used in small amounts. However, the spice contains a compound, called coumarin, that can cause or worsen liver disease. (Coumarin is also chemically related to the blood-thinning drug, warfarin.)</p>
<p>Of the two common types of cinnamon: cassia cinnamon (Indonesian, Vietnamese, Chinese) and so-called true cinnamon (Ceylon cinnamon), true cinnamon has much lower levels of coumarin (0.04%) compared with cassia cinnamon (4-8%).</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/199952/original/file-20171219-4965-ro6r2f.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/199952/original/file-20171219-4965-ro6r2f.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/199952/original/file-20171219-4965-ro6r2f.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/199952/original/file-20171219-4965-ro6r2f.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/199952/original/file-20171219-4965-ro6r2f.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/199952/original/file-20171219-4965-ro6r2f.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/199952/original/file-20171219-4965-ro6r2f.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">Ceylon cinnamon (Cinnamomum zeylanicum) has naturally lower levels of coumarin.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/new-fresh-red-colored-leaves-on-547903093?src=4N0nGGGdzDB1YOS8Sx-rlw-1-0">Artush/Shutterstock.com</a></span>
</figcaption>
</figure>
<p>The European Food Safety Authority’s recommended tolerable daily intake of <a href="https://www.ncbi.nlm.nih.gov/pubmed/20024932">coumarin</a>
is 0.1 mg per kilogram of body weight. However, no long-term experimental studies have established the safety of cinnamon supplementation, nor of taking cinnamon with statins. </p>
<p>If you want to lower your total or LDL cholesterol levels, there are known effective, safe ways of doing so. These include losing weight, being physically active and eating a balanced, varied diet that is low in saturated and trans fats.</p><img src="https://counter.theconversation.com/content/87649/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Preethy D'Souza 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>Studies show that cinnamon can lower blood lipids in people with diabetes or metabolic syndrome.Preethy D'Souza, Research Associate, Social Science Research Unit (SSRU), Department of Social Science (DSS), UCL Institute of Education, UCLLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/831652017-09-05T11:04:50Z2017-09-05T11:04:50ZDoes ‘good cholesterol’ really deserve its name?<figure><img src="https://images.theconversation.com/files/184691/original/file-20170905-13729-hfpovu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/download/confirm/564636238?src=WG9XbHcObK9I0ZOggdGvIA-1-15&size=medium_jpg">Elena11/Shutterstock</a></span></figcaption></figure><p>People with extremely high levels of so-called “good cholesterol” have a 65% higher mortality rate than people with normal levels, according to a new <a href="https://academic.oup.com/eurheartj/article/38/32/2478/3608700/Extreme-high-high-density-lipoprotein-cholesterol">Danish study</a>. Does this mean that good cholesterol has gone from hero to villain? Can we still consider good cholesterol to be good?</p>
<p>Cholesterol, it seems, is never far from the news. Scientific studies frequently report that cholesterol, and the drugs that control cholesterol such as statins, are implicated in many diseases beyond heart disease, from <a href="http://www.alzheimers.net/2013-09-20/high-cholesterol-and-alzheimers/">Alzheimer’s disease</a> to <a href="http://www.aston.ac.uk/news/releases/2017/august/study-suggests-statins-linked-to-lower-rates-of-breast-cancer/">cancer</a>. Cholesterol is essential for life, and is found throughout the body. It is a waxy substance made in the the liver but is also found in some foods, including <a href="https://heartuk.org.uk/cholesterol-and-diet/low-cholesterol-diets-and-foods/dietary-cholesterol">full-cream dairy and animal fats</a>. </p>
<p>Cholesterol can’t travel through the blood on its own as it doesn’t dissolve in the watery blood plasma. In order to travel in the blood, cholesterol combines with proteins to form lipoproteins. There are two main types of lipoproteins, <a href="https://www.bhf.org.uk/heart-health/risk-factors/high-cholesterol">low-density lipoproteins (LDL) and high-density lipoproteins (HDL)</a>. LDL is commonly referred to as “bad cholesterol” because it delivers cholesterol from the liver to the other cells in the body. HDL is known as “good cholesterol” as it does the reverse, carrying cholesterol back to the liver to be broken down. </p>
<p>Changes to the levels of cholesterol in the blood can lead to a build up of fatty material in the walls of arteries, increasing the risk of <a href="https://www.ncbi.nlm.nih.gov/books/NBK343489/">stroke or heart attack</a>. This risk is known to be particularly high if a person has a <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2747394/">high ratio of LDL to HDL</a>. Effectively, <a href="http://www.webmd.com/cholesterol-management/guide/hdl-cholesterol-the-good-cholesterol#1">high HDL levels reduce heart disease risk, whereas low levels increase it</a>. New evidence, however, suggests that this might not always be the case.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/184692/original/file-20170905-13718-1405bi9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/184692/original/file-20170905-13718-1405bi9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/184692/original/file-20170905-13718-1405bi9.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/184692/original/file-20170905-13718-1405bi9.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/184692/original/file-20170905-13718-1405bi9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/184692/original/file-20170905-13718-1405bi9.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/184692/original/file-20170905-13718-1405bi9.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">High-density lipoproteins (HDL) carries cholesterol to the liver.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-illustration/highdensity-lipoproteins-hdl-one-five-major-564979207?src=j_TGnZ03hJ8FTHGKSUPAFw-1-6">ibreakstock/Shutterstock</a></span>
</figcaption>
</figure>
<h2>U-shaped risk</h2>
<p>In the new Danish study, over 116,000 Danish men and women were pooled together from two large study cohorts. Participants had a blood sample taken at the start of the study, where their cholesterol was measured. They were then followed up for a number of years – in some cases, for as long as 23 years. </p>
<p>During the follow-up period, over 10,000 participants died. When the researchers analysed the data, they found something very interesting. The relationship between HDL levels and mortality was U-shaped. This means that people with either extremely high or low concentrations of HDL had an increased risk of death. This means that those people with the highest levels of HDL were more likely to die than those with normal levels of HDL, and about as likely as those with the very lowest levels of HDL. </p>
<p>There were some noticeable differences between men and women, with the ideal HDL level in men being around 25% lower than in women.</p>
<p>The researchers might have anticipated that low levels of HDL would be a risk factor for an early death, but evidence that the highest levels of HDL carry a similar risk is very interesting. So what do these findings mean for the rest us? </p>
<h2>A genetic cause?</h2>
<p>No study is perfect, and although this study was very large it relied on a single blood sample at the point of recruitment, and was limited to white people of Danish descent. This means that any changes in HDL level that may have occurred throughout the study were not taken into account, and that the findings may not be applicable to more ethnically mixed populations. </p>
<p>Very few people actually have <a href="https://www.ncbi.nlm.nih.gov/pubmed/24627418"><em>very</em> high HDL levels</a>, and in this study only 216 men and 218 women out of 116,000 showed the highest concentrations of HDL, so the number of people affected in real terms may be low, even if the relative risk is high. </p>
<p>The study does, however, give us an opportunity to consider what we really know about HDL. Although consistent observational evidence of the relationship between HDL and heart disease risk exists, the relationship <a href="http://www.bmj.com/content/349/bmj.g4379">doesn’t appear to be causal</a> as boosting HDL levels (but not to ultra-high levels) using drugs doesn’t decrease the risk of heart disease or early death. </p>
<p>It is possible that a genetic mutation is the root cause of extremely high HDL, which is why these cases are so rare. As <a href="https://www.ncbi.nlm.nih.gov/pubmed/27160732">HDL has subtypes</a>, it is also possible that one or more of these subtypes are key in preventing heart disease, but more research is needed to confirm this.</p>
<p>Doctors should take note of this study and consider that if they see cases of extremely high levels of HDL in their patients it may be worth monitoring. It is, however, unlikely that many people reading this article will have HDL levels high enough to cause them, or their doctor, to worry. In general, it is still a good idea to assume that good cholesterol is good for your heart.</p><img src="https://counter.theconversation.com/content/83165/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>James Brown does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Having very high levels of HDL is associated with increased mortality. But that doesn’t mean it’s not ‘good cholesterol’.James Brown, Senior Lecturer in Biology and Biomedical Science, Aston UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/766982017-05-08T19:46:03Z2017-05-08T19:46:03ZViewpoints: is saturated fat really the killer it’s made out to be?<figure><img src="https://images.theconversation.com/files/167121/original/file-20170428-15112-137ejx9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">A controversial editorial has questioned whether saturated fats really clog up your arteries and put you at risk of heart disease. But can it really overturn decades of research?</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/download/confirm/99621002?src=jxTPXTYXmpHsEfNjNB44hA-2-42&size=medium_jpg">from www.shutterstock.com</a></span></figcaption></figure><p>A recent editorial in the <a href="http://bjsm.bmj.com/content/early/2017/03/31/bjsports-2016-097285">British Journal of Sports Medicine</a> dismissed the widely held belief that a diet rich in saturated fats increases our risk of heart disease as “just plain wrong”.</p>
<p>The authors concluded we have been concentrating on reducing one type of fat in our diet when instead we should be promoting a <a href="https://theconversation.com/what-is-the-mediterranean-diet-and-why-is-it-good-for-you-12656">Mediterranean diet</a>, exercise and reducing stress to reduce our chances of heart disease.</p>
<p>So, is saturated fat really the killer it’s made out to be. Or, as the editorial suggests, have we really got it all wrong?</p>
<hr>
<h2>The case for saturated fat’s role in heart disease</h2>
<p><strong>David Sullivan, Clinical Associate Professor, University of Sydney</strong></p>
<p>According to evidence collected over more than five decades, the level of saturated fat in our diet is one of the most powerful environmental risk factors for the inflammatory process in the artery wall that leads to <a href="http://jamanetwork.com/journals/jamainternalmedicine/article-abstract/2530902">heart attack and stroke</a>. </p>
<p>Science and medicine have never suggested saturated fat <em>itself</em>, for instance from a diet rich in fatty meat or processed foods, blocks your arteries (vessels that carries blood from the heart to other organs).</p>
<p>What we know is eating too much saturated fat raises levels of blood cholesterol, in particular the type commonly called “bad” cholesterol, <a href="https://www.heartfoundation.org.au/your-heart/know-your-risks/blood-cholesterol">low-density lipoprotein cholesterol</a> or LDL.</p>
<p>LDL and related particles enter the artery wall where they are chemically modified, triggering a vicious cycle of inflammation and cholesterol accumulation. It is this cycle of inflammation and cholesterol accumulation that leads to heart disease and stroke.</p>
<p>That’s why doctors like to keep an eye on your blood cholesterol levels, as part of assessing your risk of heart disease.</p>
<p>But it’s not just LDL particles that contribute to the inflammatory process; other related particles do so too. So doctors look beyond simple measures of LDL cholesterol to measure your risk. It’s <a href="http://www.sciencedirect.com/science/article/pii/S1933287408002742">better</a> to start with your total level of blood cholesterol, then take away levels of so-called “good” cholesterol – the high-density lipoprotein or HDL cholesterol. This gives you an idea of the level of damaging particles (or non-HDL cholesterol).</p>
<p>If we understand that raised blood cholesterol levels (in particular, raised LDL) increase your risk of heart disease and stroke, then it stands to reason that reducing their levels might decrease your chances.</p>
<p>This is exactly what two <a href="http://www.nejm.org/doi/full/10.1056/NEJMoa1410489#t=article">recent</a> <a href="http://www.nejm.org/doi/full/10.1056/NEJMoa1615664#t=article">studies</a> showed. These provided the highest form of evidence in over 40,000 patients; they looked at how two cholesterol-lowering drugs significantly reduced cardiovascular events, like heart attacks and stroke.</p>
<p>Neither drug has anti-inflammatory effects. Instead, their success is attributed to reduced levels of harmful cholesterol-carrying particles, including LDL cholesterol.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/167125/original/file-20170428-15091-h7013r.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/167125/original/file-20170428-15091-h7013r.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/167125/original/file-20170428-15091-h7013r.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/167125/original/file-20170428-15091-h7013r.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/167125/original/file-20170428-15091-h7013r.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/167125/original/file-20170428-15091-h7013r.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/167125/original/file-20170428-15091-h7013r.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">In one study, participants swapped butter for polyunsaturated margarine as a way of reducing their saturated fat intake.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/download/confirm/514088740?src=Ju6y5EkxtXFJhD6TABFPOw-1-57&size=medium_jpg">from www.shutterstock.com</a></span>
</figcaption>
</figure>
<p>So, what role does diet play in all this? Two <a href="http://www.nejm.org/doi/full/10.1056/NEJMoa1200303#t=article">landmark</a> <a href="http://circ.ahajournals.org/content/103/13/1823">studies</a> in people who ate Mediterranean-style diets show what happens when you eat less saturated fat. Replacing saturated fat in the diet with foods containing healthier unsaturated fat, like the fats in nuts, extra virgin olive oil, polyunsaturated margarine – but not processed carbohydrates – reduced levels of heart attacks and premature death.</p>
<p>Downplaying the role of dietary saturated fat in heart disease prevents health care workers from managing cardiovascular risk using diet. Any recommendation to not be so focused on saturated fat will therefore increase population levels of blood cholesterol, increasing the need for statins and other cholesterol-lowering drugs.</p>
<hr>
<p><em><a href="https://theconversation.com/some-things-you-should-know-about-statins-and-heart-disease-19655">Some things you should know about statins and heart disease</a></em></p>
<hr>
<p>The implication, that one of the most thoroughly researched areas of medical science – that excess saturated fat puts you at risk of heart disease and stroke – is a hoax, misrepresents the evidence.</p>
<hr>
<h2>The case against labelling saturated fat ‘bad’</h2>
<p><strong>Yutang Wang, Senior Lecture at Federation University Australia</strong></p>
<p>Saturated fat (for instance high in fatty meat or full-fat dairy) is thought to clog the arteries and increase the risk of heart disease. But currently available evidence does not support these common beliefs.</p>
<p>First, let’s look at whether saturated fat really clogs the heart’s arteries leading to coronary <a href="https://www.nhlbi.nih.gov/health/health-topics/topics/atherosclerosis">atherosclerosis</a> (when plaque builds up inside your arteries, in time hardening and narrowing them). In a surprise finding, one study in women who had been through the menopause found a diet richer in saturated fat was linked with <a href="http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1270002">less, not more</a>, progression of coronary atherosclerosis.</p>
<p>Second, whether eating saturated fat increases your chances of dying from heart disease. When researchers combined the results from 41 research papers published from 1981 to 2014, eating saturated fat <a href="http://www.ncbi.nlm.nih.gov/pubmed/26268692">was not linked</a> with dying from heart related diseases, like heart attack, stroke or type 2 diabetes.</p>
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<p><em><a href="https://theconversation.com/health-check-are-saturated-fats-good-or-bad-21524">Health Check: are saturated fats good or bad?</a></em></p>
<hr>
<p>Many of us think saturated fat is bad for us because it increases levels of low-density lipoprotein cholesterol or LDL in our blood. But is LDL-cholesterol really that bad?</p>
<p>When researchers studied all the research papers written in English that investigated the effects of LDL-cholesterol on the deaths in people over 60, they had some surprising results. In most of the papers (representing 92% of participants), LDL-cholesterol was linked with a <a href="http://bmjopen.bmj.com/content/6/6/e010401">lower death rate, and there was no link</a> in the remaining 8% of participants.</p>
<p>It is not the level of LDL <em>itself</em> that predicts people’s risk of heart disease, but the ratio of total cholesterol and another type of cholesterol, high-density lipoprotein (HDL) cholesterol, that’s the key.</p>
<p>While LDL is largely responsible for delivering cholesterol to cells around the body, HDL cholesterol transports extra cholesterol back to the liver for recycling. So LDL and HDL work together to ensure cells in our body maintain the right levels of cholesterol.</p>
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<img alt="" src="https://images.theconversation.com/files/167307/original/file-20170501-12987-asrrpr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/167307/original/file-20170501-12987-asrrpr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/167307/original/file-20170501-12987-asrrpr.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/167307/original/file-20170501-12987-asrrpr.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/167307/original/file-20170501-12987-asrrpr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/167307/original/file-20170501-12987-asrrpr.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/167307/original/file-20170501-12987-asrrpr.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">Eating three eggs a day increased levels of HDL cholesterol in the short term.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/download/confirm/596694929?src=xlRooFpchhtbJK_CxPPEMw-1-0&size=medium_jpg">from www.shutterstock.com</a></span>
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<p>A higher ratio of total cholesterol against HDL-cholesterol is commonly associated with <a href="http://www.ncbi.nlm.nih.gov/pubmed/7944071">higher incidence</a> of heart disease because a higher ratio reflects that more cholesterol will be deposited into the blood vessel and less will be removed from it.</p>
<p>But when we eat saturated fat, both LDL and HDL cholesterol levels increase. So, eating normal amounts of saturated fat <em>will not</em> tip the balance. We need saturated fat in our diet to form the building blocks for the cells in our body and to help our cells communicate with each other.</p>
<p>The long-term effect of eating too much cholesterol on the ratio of total against HDL cholesterol is not clear. A short-term study <a href="https://www.ncbi.nlm.nih.gov/pubmed/18203890">suggests</a> eating moderately high levels of cholesterol may not be bad. Researchers found that eating three eggs a day (containing 640 mg cholesterol) for 12 weeks did not increase LDL-cholesterol. </p>
<p>Instead it significantly increased HDL-cholesterol by 20% compared to those who ate an egg substitute without cholesterol.</p>
<p>So, we may need to stop thinking about “bad” saturated fat and “bad” cholesterol. Rather, we should enjoy our meals containing moderate amounts of saturated fat and be physically active. That will be more effective in keeping us healthy.</p>
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<p><strong>David Sullivan:</strong></p>
<p>The author mentions the <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1270002/">study of progression of artery disease in women who have gone through the menopause</a>. This shows women with the highest saturated fat intake had the lowest LDL cholesterol levels (despite taking less lipid-lowering treatment). This might be explained, <a href="https://doi.org/10.1016/j.cell.2012.03.001">as some researchers suggest</a>, by genetic factors that allow some people to tolerate saturated fat better, leading to a lower LDL and a reduced risk of heart disease.</p>
<p>And rather than eating moderate amounts of saturated fat, as the author suggests, there is ample evidence for <a href="http://onlinelibrary.wiley.com/doi/10.1111/j.1365-2796.2012.02553.x/abstract">avoiding saturated and trans fats, replacing them</a> with healthier ones and <a href="https://www.heartfoundation.org.au/images/uploads/publications/CON-084.v3-HealthyEating-LR-secure.pdf">reserving saturated fats as treats</a>.</p>
<p>We also differ in our opinions of the best marker of heart-disease risk that your doctor might consider when analysing blood test results.</p>
<p>Use of the total cholesterol to HDL ratio, as the author proposes, has declined because levels of HDL cholesterol itself may not be a marker of <a href="https://academic.oup.com/jcem/article-lookup/doi/10.1210/jc.2011-1846">heart disease protection</a>. And raising HDL <a href="https://www.ncbi.nlm.nih.gov/pubmed/28099220">has not reduced the risk</a> of heart disease. Instead, non-HDL cholesterol has been introduced as a superior measure to LDL, as I have mentioned.</p>
<p>Finally, there’s confusion over how the terms cholesterol and saturated fat are used. Saturated fat is chain-shaped and consumed in much greater amounts than the ring-like <a href="https://www.nhlbi.nih.gov/health/health-topics/topics/hbc">cholesterol</a>. And it’s saturated fat in the diet that’s the main determinant of cholesterol levels in the blood.</p>
<hr>
<p><strong>Yutang Wang:</strong></p>
<p>Despite decades of research on whether eating saturated fat increases our chances of dying from heart disease, the results are not consistent. Some show eating high <a href="http://jamanetwork.com/journals/jamainternalmedicine/article-abstract/2530902">saturated fat is bad</a>, whereas others <a href="http://www.ncbi.nlm.nih.gov/pubmed/26268692">do not</a>. </p>
<p>For instance, as recently as 2016, a study showed higher total saturated fat intake was linked to <a href="http://ajcn.nutrition.org/content/early/2016/01/20/ajcn.115.122671">lower levels of heart disease</a>. </p>
<p>Yes, LDL cholesterol can be chemically modified and involved in the inflammation process. However, this does not mean non-modified LDL cholesterol in the blood <a href="http://bmjopen.bmj.com/content/6/6/e010401">is bad</a>.</p>
<p>There is no doubt that cholesterol-lowering drugs <a href="http://www.nejm.org/doi/full/10.1056/NEJMoa1615664#t=article">can lower</a> your risk of a heart attack or stroke. These drugs can decrease LDL-cholesterol. However, the beneficial effect of cholesterol-lowering drugs may be largely because of the favourable change in the balance between total cholesterol and HDL-cholesterol, rather than lowering “harmful” LDL-cholesterol alone.</p><img src="https://counter.theconversation.com/content/76698/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>David Richmond Sullivan received funding to support diet studies involving chocolate, plant sterols and pork. </span></em></p><p class="fine-print"><em><span>Yutang Wang does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>We need to eat a healthy diet, do some exercise and avoid stress rather than blame saturated fat for heart disease, says a recent editorial. But does the evidence stack up?David Richmond Sullivan, Clinical Associate Professor, University of SydneyYutang Wang, Senior Lecturer, Federation University AustraliaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/574392016-04-07T13:04:36Z2016-04-07T13:04:36ZIt’s good to eat walnuts, but is it true that they prevent heart disease?<figure><img src="https://images.theconversation.com/files/117815/original/image-20160407-16275-11a8j7o.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Superfood or superhype?</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=walnuts&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=312880136">www.shutterstock.com</a></span></figcaption></figure><p>On a morning when much of the world’s media focused on the revelations from the <a href="https://theconversation.com/uk/topics/panama-papers">Panama Papers</a>, one British title chose to focus on a rather different story. “Walnuts prevent heart disease,” <a href="http://www.pressreader.com/uk/daily-express/20160405/281487865496369/textview">declared the Daily Express</a> in a huge, front-page headline. It might have had retirees rushing to buy them by the sackful. </p>
<p>So, pickled, chopped, on cakes or just eaten on their own, walnuts taste great. But what are the health benefits? And do they really prevent heart disease?</p>
<p>The excitement at the Express came from <a href="http://www.fasebj.org/content/30/1_Supplement/293.4.abstract">the abstract of a study</a> on walnuts and health ageing, presented recently at a conference in San Diego. It suggested that eating walnuts every day might help to lower LDL-cholesterol, a risk factor for heart disease. </p>
<p>Based on the conference abstract alone, it’s probably too early to make this sort of recommendation – the work hasn’t been formally peer-reviewed and published yet, and we don’t know enough about the details of the study design to know whether the results are reliable.</p>
<p>From the abstract, it appears that 707 healthy older people – recruited at a centre in Spain and one in the US – were divided into two groups. One group supplemented their diet with walnuts, while the other (control) group continued with their normal diet, but avoided nuts (it isn’t clear whether this group avoided all nuts or just walnuts). The participants in the walnut group aimed to eat enough walnuts to make up 15% of their energy intake. The researchers then measured changes in blood cholesterol, and also in body weight – since walnuts are highly calorific, those who supplemented their diet with walnuts might be expected to put on weight. </p>
<h2>Much too early to say</h2>
<p>The aim was to follow the groups for two years. However, the abstract presents data for only 514 participants, only one year into the study. Fifty-six people had dropped out of the study for various unspecified reasons, and a further 137 participants had not yet had the one-year assessment. We don’t know why the researchers didn’t wait to include these 137 participants. And we can’t predict whether the early results from this subgroup are representative of the whole group, or whether there was something different about them.</p>
<p>Also, details of how the participants were randomised into the two groups are not given, we don’t know whether the characteristics of the two groups were the same at the beginning of the trial, and we don’t know if the people who carried out the measurements were aware of who was allocated to each treatment. These are all possible <a href="http://media.wix.com/ugd/dded87_40b9ff0bf53840478331915a8ed8b2fb.pdf">sources of bias</a>. </p>
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<img alt="" src="https://images.theconversation.com/files/117841/original/image-20160407-16282-fodf4g.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/117841/original/image-20160407-16282-fodf4g.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=346&fit=crop&dpr=1 600w, https://images.theconversation.com/files/117841/original/image-20160407-16282-fodf4g.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=346&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/117841/original/image-20160407-16282-fodf4g.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=346&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/117841/original/image-20160407-16282-fodf4g.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=435&fit=crop&dpr=1 754w, https://images.theconversation.com/files/117841/original/image-20160407-16282-fodf4g.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=435&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/117841/original/image-20160407-16282-fodf4g.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=435&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">Best to wait for the actual paper.</span>
<span class="attribution"><a class="source" href="http://www.shutterstock.com/cat.mhtml?autocomplete_id=&language=en&lang=en&search_source=&safesearch=1&version=llv1&searchterm=medical%20conference%20&media_type=photos&media_type2=photos&searchtermx=&photographer_name=&people_gender=&people_age=&people_ethnicity=&people_number=&color=&page=1&inline=222906040">www.shutterstock.com</a></span>
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<p>Despite these reservations, the researchers did check that the walnut group had actually eaten more walnuts than the control group, by measuring the amount of a fatty acid called alpha-linolenic acid. This fatty acid is present in particularly high quantities in walnuts, but <a href="http://www.hsph.harvard.edu/nutritionsource/omega-3-fats/">not in many other foods</a>. Another strength of the study design was that it was based in two countries with different diets, so that the effect of adding walnuts to a Mediterranean or Western diet could be seen.</p>
<h2>Who funded the research?</h2>
<p>The source of funding for a research study is always worth looking at, in case the funders have vested interests in the results, and this study was supported by the <a href="http://www.fasebj.org/content/30/1_Supplement/293.4.abstract">California Walnut Commission</a>.</p>
<p>Of course, just because research is supported by industry doesn’t necessarily mean it’s biased, but care should be taken when looking at the findings of such research and how it’s presented and interpreted. Another study funded by the California Walnut Commission, published in BMJ Open Diabetes Research and Care in 2015, also looked at the <a href="http://drc.bmj.com/content/3/1/e000115.full">effect of eating walnuts</a> on LDL cholesterol. Participants were again randomised to groups that either included or avoided walnuts. </p>
<p>In the abstract of this published paper (often the only part picked up by the media) it was reported that the group who included walnuts in their diet showed a decrease in LDL cholesterol in the blood. This is true, but what the authors failed to mention in the abstract is that the control group – who excluded walnuts from their diet – also showed a decrease in LDL cholesterol, and there were no statistically significant differences between the walnut-included and walnut-excluded groups. So LDL cholesterol levels were lowered whether or not walnuts were consumed. </p>
<p>Only by reading the whole research paper carefully could this be picked up, and many readers don’t get further than the abstract.</p>
<h2>Should we be eating more nuts?</h2>
<p>In spite of doubts about premature reporting of the new study, the results are consistent with earlier research on nuts. An analysis of the pooled results of <a href="http://archinte.jamanetwork.com/article.aspx?articleid=415912">25 intervention studies</a> indicated that nut consumption is likely to lower blood cholesterol. The cholesterol lowering effect might be explained by the presence of plant sterols in nuts, which can <a href="https://www.bda.uk.com/foodfacts/PlantStanolsAndSterols.pdf">interfere with cholesterol absorption</a>. </p>
<p>Nuts are also rich in <a href="http://www.bbcgoodfood.com/howto/guide/health-benefits-nuts">B vitamins, antioxidants, minerals, fibre, omega-3 fatty acids and protein</a>. Including nuts in your diet may help to prevent many of the chronic diseases associated with ageing, with various studies indicating that they can <a href="http://ajcn.nutrition.org/content/100/1/256.long">prevent heart disease</a> <a href="http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0103376">improve blood sugar control</a> in people with diabetes and <a href="http://www.stopcancerfund.org/p-breast-cancer/can-a-handful-of-nuts-a-day-keep-cancer-away/">may prevent cancer</a>. </p>
<p>In spite of their high calorie count, most people don’t put on weight, and some even lose weight, when consuming nuts on a daily basis. This might be due to the satiating effect of fat and protein, or perhaps we can’t absorb all the fat as it’s tightly stored within cells and associated with fibre that can <a href="http://www.ncbi.nlm.nih.gov/pubmed/20199999">slow down its absorption</a>. </p>
<p>It’s too early to say whether we should trust the research presented in San Diego, but it is safe to say that nuts can be enjoyed as part of a healthy diet.</p><img src="https://counter.theconversation.com/content/57439/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Jennie Jackson 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>A study claims that getting 15% of your calorie intake from walnuts can help lower LDL (‘bad’) cholesterol – an expert takes a closer look at the results.Jennie Jackson, Lecturer in Human Nutrition and Dietetics, Glasgow Caledonian UniversityLicensed as Creative Commons – attribution, no derivatives.