A large trial tested whether multivitamins and cocoa extract might be able to slow down cognitive aging. The result? Some strange and unexpected data.
For thousands of years, people have told myths about fountains, concoctions, and elixirs with incredible rejuvenating powers. The myth has persisted into modernity, the 21st-century version being that taking one pill can make you younger by radically changing your brain. Is there any truth to it?
Mounting evidence does show that different minerals and vitamins play important roles in brain health. But so far, scientists have yet to find a combination that can make people smarter or sharper — much less a way to administer that magic combo in pill form. That said, the link between certain foods, vitamins or nutrients and cognitive health is notoriously hard to prove, and while no vitamin study so far has shown conclusive proof of a benefit, many were only a few weeks or months in duration — too short to really understand any benefits over time.
Scientists aren’t giving up on the idea that there’s something there, however: Research shows the Mediterranean-style diet may reduce the risk of developing Alzheimer’s if consumed consistently, and many micronutrients and minerals that are central to that diet are also in multivitamin supplements. Meanwhile, cocoa extract contains molecules called flavanols that have anti-inflammatory properties with potential to improve brain health. So, in new study, published in Alzheimer’s & Dementia, one research team drilled down on two supplements in particular: cocoa extract, and a daily multivitamin, looking at whether taking these supplements could slow typical cognitive aging.
According to first author Laura Baker, a professor of gerontology and geriatric medicine at Wake Forest University, the results are promising: Cocoa extract didn’t appear to have any statistically significant impact on people’s cognition. The multivitamin, on the other hand, seemed to give people a slight cognitive boost compared to the placebo — and this was even more pronounced specifically in participants with a history of cardiovascular disease.
“Our main finding is that three years of daily supplementation with a commercially available multivitamin mineral improved cognition — global cognition — for older adults,” Baker told Being Patient. But don’t rush to the supplements aisle just yet: It’s a little more complicated than that.
The problem with the new multivitamins study
To test whether taking these dietary supplements daily — cocoa extracts or a multivitamin mineral — could improve cognition in healthy older adults age 65 and over, the research team looked at 2,262 participants split into several groups, comparing the effects of each supplement to a placebo. For three years, they made annual phone calls to study participants to perform a benchmark cognitive assessment and looked at the changes over time.
Here’s the twist: Even though it did appear the multivitamin made a difference in cognitive health, third-party researchers who looked at the results spotted a red flag. In the study results, both the groups who took the multivitamins and the control groups, who received placebos — or fake multivitamins that contained no nutrients at all — showed cognitive improvements over time, and that’s quite an unexpected change in an older population.
Pieter Cohen, a physician and researcher at Cambridge Health Alliance who studies the commercial supplements, found the results a bit confusing. None of the participants, even those in the placebo group, showed levels of cognitive decline that would be expected in an older population — and this makes the results a little too strange to then make the claim that multivitamins could slow cognitive decline.
“The most remarkable thing here is that they do a massive battery of cognitive tests to subjects that are over 65 years old, over a three- year period, and overall scores in the test go up,” Cohen told Being Patient of Baker’s team’s research. “That’s just not how cognition works in people when they’re 65. It’s either stable, a slight decline, or a slow, steady decline.”
When asked why this abnormality appeared in the data, Baker attributed the overall cognitive improvement to study participants remembering the test year to year, leading to improved scores on the test the next year, throwing off the results.
So, should you take multivitamins for cognitive health? Or hold out for the next clinical study?
Previous research on multivitamins provides some clues here, albeit confusing ones. A 2012 study looked at ten clinical trials and a total of 3000 participants found that multivitamins only benefited short-term memory and not global cognition. But only three of these trials lasted longer than a year.
A 2013 study of almost 6000 male physicians over the age of 65 found no benefits to cognitive health over 12 years. But this study might not be generalizable to everyone else, as physicians typically stay sharp for longer and are less likely to develop dementia than everyone else. A 2018 study reviewed the existing evidence for multivitamin use to prevent cognitive decline, finding no evidence that they reduce cognitive decline but this may be due to the small number of studies conducted on the topic.
Baker also agreed that while the results are potentially meaningful, there’s no reason to rush to the supermarket supplements aisle just yet — it will be necessary to further confirm the findings in a larger population.
“We feel like it is too early to make a widespread recommendation that everybody needs to go out and do this [use the multivitamin], it’s an expense,” Baker said. “Let us do this next study, with a more diverse, larger cohort, we’ll be able to look at this cardiovascular disease [and other biomarkers] much better.”