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Can a daily multivitamin improve your memory?

<p><a href="https://theconversation.com/profiles/jacques-raubenheimer-1144463">Jacques Raubenheimer</a>, <em><a href="https://theconversation.com/institutions/university-of-sydney-841">University of Sydney</a></em></p> <p><em><a href="https://theconversation.com/au/topics/research-check-25155">Research Checks</a> interrogate newly published studies and how they’re reported in the media. The analysis is undertaken by one or more academics not involved with the study, and reviewed by another, to make sure it’s accurate.</em></p> <hr /> <p>Don’t we all want to do what we can to reduce the impact of age-related decline on our memory?</p> <p>A new study suggests a daily multivitamin and mineral supplement is a simple and inexpensive way to help older adults slow the decline in some aspects of memory function.</p> <p>The <a href="https://ajcn.nutrition.org/article/S0002-9165(23)48904-6/fulltext">new study</a>, which comes from a <a href="https://www.clinicaltrials.gov/ct2/show/NCT02422745?term=NCT02422745&amp;draw=2&amp;rank=1">long-running clinical trial</a>, shows there may be a small benefit of taking a daily multivitamin and mineral supplement for one type of cognitive task (immediate word recall) among well-functioning elderly white people. At least in the short term.</p> <p>But that doesn’t mean we should all rush out and buy multivitamins. The results of the study don’t apply to the whole population, or to all types of memory function. Nor does the study show long-term benefits.</p> <h2>How was the study conducted?</h2> <p>The overarching COSMOS study is a well-designed double-blind randomised control trial. This means participants were randomly allocated to receive the intervention (a daily multivitamin and mineral supplement) or a placebo (dummy tablet), but neither the participants nor the researchers knew which one they were taking.</p> <p>This type of study is considered the <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5654877/">gold standard</a> and allows researchers to compare various outcomes.</p> <p>Participants (3,562) were older than 64 for women, and 59 for men, with no history of heart attack, invasive cancer, stroke or serious illness. They couldn’t use multivitamins or minerals (or <a href="https://www.pnas.org/doi/10.1073/pnas.2216932120">cocoa extract</a> which they also tested) during the trial.</p> <p>Participants completed a <a href="https://www.clinicaltrials.gov/ct2/show/NCT04582617?term=NCT04582617&amp;draw=2&amp;rank=1">battery of online cognitive tests</a> at the start of the study (known as baseline), then yearly for three years, of which only three were reported in this paper:</p> <ul> <li> <p>ModRey, measuring immediate recall. Participants were shown “a list of 20 words, one at a time, for three seconds each,” and then had to type the list from memory</p> </li> <li> <p>ModBent, measuring object recognition. Participants were given 20 prompts with a shape and then had to select the correct match from a pair of similar prompts. After this, they were prompted with 40 shapes in turn, and had to indicate whether each was included in the original 20 or not</p> </li> <li> <p>Flanker, measuring “executive control”. Participants had to select a coloured block that corresponded to an arrow in a matrix of arrows, which could have the same (or different) colour to the surrounding arrows, and the same (or different) direction as the prompt block.</p> </li> </ul> <h2>What did the researchers find?</h2> <p>Of all the tests the researchers performed, only immediate recall (ModRey) at one year showed a significant effect, meaning the result is unlikely to just be a result of chance.</p> <p>At two and three years, the effect was no longer significant (meaning it could be down to chance).</p> <p>However they added an “overall estimate” by averaging the results from all three years to arrive at another significant effect.</p> <p>All the effect sizes reported are very small. The largest effect is for the participants’ immediate recall at one year, which was 0.07 – a value that is <a href="https://academic.oup.com/jpepsy/article/34/9/917/939415">generally considered very small without justification</a>.</p> <p>Also of note is that both the multivitamin and placebo groups had higher immediate word recall scores at one year (compared to baseline), although the multivitamin group’s increase was significantly larger.</p> <p><a href="https://www.pnas.org/doi/epdf/10.1073/pnas.2216932120">In the researchers’ prior study</a>, the increase in word recall scores was described as a “typical learning (practice) effect”. This means they attributed the higher scores at one year to familiarisation with the test.</p> <p>For some reason, this “learning effect” was not discussed in the current paper, where the treatment group showed a significantly larger increase compared to those who were given the placebo.</p> <h2>What are the limitations of the study?</h2> <p>The team used a suitable statistical analysis. However, it did not adjust for demographic characteristics such as age, gender, race, and level of education.</p> <p>The authors detail their study’s major limitation well: it is not very generalisable, as it used “mostly white participants” who had to be very computer literate, and, one could argue, would be quite well-functioning cognitively.</p> <figure class="align-center "><figcaption></figcaption>Another unmentioned limitation is the advanced age of their sample, meaning long-term results for younger people can’t be assessed.</figure> <p>Additionally, the baseline diet score for their sample was abysmal. The researchers say participants’ diet scores “were consistent with <a href="https://jamanetwork.com/journals/jamainternalmedicine/fullarticle/1899558">averages from the US population</a>” but the cited study noted “the overall dietary quality… [was] poor.”</p> <p>And they didn’t measure changes in diet over the three years, which could impact the results.</p> <h2>How should we interpret the results?</h2> <p>The poor dietary quality of the sample raises the question: can a better diet be the simple fix, rather than multivitamin and mineral supplements?</p> <p>Even for the effect they observed, which micronutrient from the supplement was the contributing factor?</p> <p>The researchers speculate about vitamins B12 and D. But you can find research on cognitive function for any arbitrarily chosen <a href="https://www.centrum.com/content/dam/cf-consumer-healthcare/bp-wellness-centrum/en_US/pdf/lbl-00000775-web-ready-centrum-silver-adults-tablets-(versio.pdf">ingredient</a>, including <a href="https://scholar.google.com/scholar?hl=en&amp;as_sdt=0%2C5&amp;q=selenium+cognitive+function">selenium</a>, which can be <a href="https://www.sciencedirect.com/science/article/pii/S0048969720378608">toxic at high levels</a>.</p> <h2>So should I take a multivitamin?</h2> <p><a href="https://newsinhealth.nih.gov/2013/08/should-you-take-dietary-supplements">Health authorities advise</a> daily multivitamin use isn’t necessary, as you can get all the nutrients you need by eating a wide variety of healthy foods. However, supplementation may be appropriate to meet any specific nutrient gaps an individual has.</p> <p>Using a good quality multivitamin at the recommended dose shouldn’t do any harm, but at best, this study shows well-functioning elderly white people might show some additional benefit in one type of cognitive task from using a multivitamin supplement.</p> <p>The case for most of the rest of the population, and the long-term benefit for younger people, can’t be made.</p> <hr /> <h2>Blind peer review</h2> <p><strong>Clare Collins writes:</strong></p> <p>I agree with the reviewer’s assessment, which is a comprehensive critique of the study. The key result was a small effect size from taking a daily multivitamin and mineral (or “multinutrient”) supplement on memory recall at one year (but not later time points) and is equivalent to a training effect where you get better at taking a test the more times you do it.</p> <p>It’s also worth noting the study authors received support and funding from commercial companies to undertake the study.</p> <p>While the study authors state they don’t believe background diet quality impacted the results, they didn’t comprehensively assess this. They used a brief <a href="https://pubmed.ncbi.nlm.nih.gov/22513989/">diet quality assessment score</a> only at baseline. Participants may have changed their eating habits during the study, which could then impact the results.</p> <p>Given all participants reported low diet quality scores, an important question is whether giving participants the knowledge, skills and resources to eat more healthily would have a bigger impact on cognition than taking supplements. <img style="border: none !important; box-shadow: none !important; margin: 0 !important; max-height: 1px !important; max-width: 1px !important; min-height: 1px !important; min-width: 1px !important; opacity: 0 !important; outline: none !important; padding: 0 !important;" src="https://counter.theconversation.com/content/208114/count.gif?distributor=republish-lightbox-basic" alt="The Conversation" width="1" height="1" /></p> <p><em>Image credit: Shutterstock</em></p> <p><em><a href="https://theconversation.com/profiles/jacques-raubenheimer-1144463">Jacques Raubenheimer</a>, Senior Research Fellow, Biostatistics, <a href="https://theconversation.com/institutions/university-of-sydney-841">University of Sydney</a></em></p> <p><em>This article is republished from <a href="https://theconversation.com">The Conversation</a> under a Creative Commons license. Read the <a href="https://theconversation.com/can-a-daily-multivitamin-improve-your-memory-208114">original article</a>.</em></p>

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The hidden dangers of multivitamins and our heart health

<p>As the vitamin industry continues to boom as it promises that supplements can prevent various health issues, more and more studies are exposing these claims.</p> <p>Now, a new study has focused on getting to the bottom of a popular myth – whether multivitamins can prevent heart attack, strokes and other cardiovascular death.</p> <p>The <span style="text-decoration: underline;"><a href="http://www.uab.edu/news/health/item/9587-study-multivitamins-do-not-prevent-strokes-heart-attacks-or-cardiovascular-disease-deaths" target="_blank"><strong>study</strong></a>,</span> by researchers at the University of Alabama at Birmingham, analysed data on 2000 people over 12 years and found that supplements made no impact on heart health.</p> <p>Lead author, Joonseok Kim, said supplements could be detrimental as people who took multivitamins felt they were improving their health, so made little other effort.</p> <p>"It is immensely difficult to convince the public that multivitamin and mineral supplements don't prevent cardiovascular diseases – especially when there is a strong preconception and commercial profits at stake," Dr Kim told the<em> <a href="http://www.dailymail.co.uk/health/article-5938775/Stop-relying-multivitamins-supplements-heart-health-study-finds.html" target="_blank"><strong><span style="text-decoration: underline;">Daily Mail</span></strong></a>.</em></p> <p>"People tend to prefer a quick and easy solution, such as taking a pill, rather than the more effortful method to prevent cardiovascular disease. </p> <p>"It is easy to believe that taking [multivitamin] supplements can fill the nutritional gap that people may have, and improve cardiovascular health. Despite this strong popular belief, the cardiovascular benefit of these supplements has never been proven by population-based scientific studies. </p> <p>"I hope our study will get people to discuss the use of multivitamin supplements with their physicians, and reallocate their resources to something that is proven to work, like fruit and vegetable intake and exercise."</p> <p>The researchers analysed 18 studies that were published by the American Heart Association journal <em>Circulation</em>.</p> <p>After looking at the data, they found there was no benefit to heart health after taking vitamins.</p> <p>"We meticulously evaluated the body of scientific evidence," said Dr Kim, assistant professor of cardiology in the Department of Medicine. </p> <p>"We found no clinical benefit of multivitamin and mineral use to prevent heart attacks, strokes or cardiovascular death."      </p> <p>Dr Kim has called for people to protect their heart health by using measures that have been proven to reduce risk.</p> <p>"Although multivitamin and mineral supplements taken in moderation rarely cause direct harm, we urge people to protect their heart health by understanding their individual risk for heart disease and stroke and working with a healthcare provider to create a plan that uses proven measures to reduce risk," Dr Kim said. </p> <p>"These include a heart-healthy diet, exercise, tobacco cessation, controlling blood pressure and unhealthy cholesterol levels, and when needed, medical treatment."</p> <p>Chief medical officer for prevention from the American Heart Association, Eduardo Sanchez, said the study was a vital wakeup call.</p> <p>"Eat a healthy diet for a healthy heart and a long, healthy life," Dr Sanchez said. </p> <p>"There's just no substitute for a balanced, nutritious diet with more fruits and vegetables that limits excess calories, saturated fat, trans fat, sodium, sugar and dietary cholesterol."</p>

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