Can Multivitamins Slow Cognitive Decline By Two Years? Here’s What Experts Say

By | April 9th, 2024

Scientists analyzed data from a clinical trial of multivitamins, suggesting it can drastically slow cognitive decline. Experts say the study is sound, but some of the conclusions drawn by the authors overstep the findings.

The vitamins and minerals we get via the foods we eat play essential roles in our overall brain health. So, could an over-the-counter multivitamin supplement provide a cognitive boost? 

In a recent study published in the American Journal of Clinical Nutrition, scientists found that people who took a daily multivitamin — developed by the pharmaceutical company Haleon  — over two years performed a bit better on memory and cognitive tests than participants who received a placebo. The authors said the effect was “equivalent to reducing cognitive aging by two years.”

Dr. Pieter Cohen, a doctor at Cambridge Health Alliance, and several other experts, say the study is well-designed, but don’t rush out to the pharmacy’s supplements aisle just yet: Here’s why the science is still out on the link between daily multivitamins and cognitive health.

What exactly did the study find?

The multivitamin study looked at a subset of 573 participants over 60 who were randomized to take either a placebo or multivitamin daily for two years. 

The participants received a cognitive test at baseline and after two years. Even though both groups showed an improvement in cognition, the multivitamin group did a little better on memory and cognitive tests than the placebo group. The study also combined data from two previous trials of the same multivitamin, strengthening their findings.  

When comparing the cognitive decline in the multivitamin group to general test scores from the population, the authors said that the multivitamin slowed cognitive aging by two years. Cohen told Being Patient that “this comparison doesn’t hold much water.” The effects are minimal when compared to the placebo group in the study instead.

Dr. Hussein Yassine, an associate professor of neurology at the Keck School of Medicine at the University of Southern California told the Seattle Times that claiming the multivitamin could slow cognitive aging by two years “is really a stretch” and called the analysis the research authors used “misleading.”

The study was originally designed to test whether a daily cocoa extract or multivitamin would benefit cardiovascular health. Since the study was originally designed to test another question, it is hard to interpret the results of this substudy.

“This is more supportive evidence that there might be something there that’s worth studying in the future, but it also could just be a quirk of the data,” Cohen said. “ It wasn’t the main purpose of the original studies and they found this effect on the side.”

Should you take a daily multivitamin?

While experts agree the study is well-designed, and the results are interesting, it doesn’t mean everyone should rush to the supermarket and buy multivitamins. 

Mary Butler, an associate professor at the University of Minnesota who studies the effects of interventions like supplements in dementia thought the study was interesting but didn’t ultimately turn the tide on supplement research. “I would put it in the realm of promising, but I wouldn’t go to the bank with it,” she told The Seattle Times. 

Even though scientists have numerous run clinical trials on brain-boosting supplements, there is still no solid evidence that they provide a benefit for the average person and some evidence that they might cause harm. Of the few studies that show some benefit, many were only a few weeks or months in duration — too short to tell. 

Experts in this field agree: Despite these numerous clinical trials, there isn’t any strong evidence that the average person needs a multivitamin. A 2018 study reviewed the existing evidence for multivitamin use to prevent cognitive decline, finding no evidence that they reduce cognitive decline. However, this may be due to the small number of studies conducted on the topic. 

There is also some evidence that multivitamins might cause harm. The Iowa Women’s Health Study, which looked at 38,722 healthy older women, found that the women taking a multivitamin had a slightly higher mortality rate than those who didn’t. Scientists point out that the majority of healthy people receive enough minerals and nutrients from their diet already, and anything extra is just excreted through urine.

“I’m not convinced that there’s adequate evidence to support the idea that I could recommend a multivitamin to my patients with the expectation that we’ll have any actual real world benefit,” Cohen said. “There’s some interesting sort of results from these studies, but they’re not ready for primetime yet.”

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4 thoughts on “Can Multivitamins Slow Cognitive Decline By Two Years? Here’s What Experts Say

  1. I’ll continue to take my daily vitamins and other supplements that seem reasonable to me. Scientists’ studies vs. medical doctors. The medical field doesn’t have a great record-ie. eggs are bad/eggs are good; cut all cholesterol from your diet/no-the brain needs cholesterol/oh there is good and bad cholesterol/dietary cholesterol doesn’t affect blood cholesterol; all fat is bad/no there are good fats; etc. There’s NO PROOF yet of what does or does not CAUSE Alzheimer’s. The medical profession is known to take DECADES to change their minds and practices even WHEN they have indisputable proof that they’ve been using bad info. I am an RN, I respect a lot of doctors – just not those that put others down to make themselves look like they know it all-ie. those in the above article.

  2. I’ve tried to tell my Dr, I think I have Alzheimer’s. I’ve told her several times I’ve the past few years. They give me a verbally test & then tell me I’m ok. My memory has gotten a lot worse. I know other family & friends have noticed it as well. What can I do to find out for sure.

    1. Carol, it is so important that you advocate for yourself! If you feel something is off with your memory, it is also important to remember that are also a lot of treatable and sometimes even reversible causes of cognitive impairment — https://www.beingpatient.com/deep-dive-mild-cognitive-impairment-mci/, These can then give way to dementia, but some just require medical treatment. This is part of the reason why a doctor that takes your concerns seriously is so important. Is there a way to get a second opinion? Follow your instincts and fight for yourself. Thanks for being here and thanks for reading.

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