Unexpected results from a phase 3 trial exploring the effect of multivitamins and cognition have now been published.
Results from a phase 3 study show that daily use of multivitamins, but not cocoa, is linked to a significantly slower rate of age-related cognitive decline.
Initially presented last November during the 14th edition of the clinical trials on Alzheimer’s disease (CTAD) and reported by Medscape Medical News at this time, this is the first large-scale, long-term randomized controlled trial to examine the effects of cocoa extract and multivitamins on global cognition. The primary focus of the trial was cocoa extract, which previous studies have shown may preserve cognitive function. Analysis of the effect of multivitamins was a secondary outcome.
Showing vitamins, but not cocoa, was beneficial, exactly the opposite of what the researchers expected. Still, the findings offer an exciting new direction for future studies, said lead researcher Laura D. Baker, PhD, professor of gerontology and geriatric medicine at Wake Forest School of Medicine, Winston-Salem, North Carolina. Medscape Medical News.
“This study pointed us to a pathway for possible cognitive protection,” Baker said. “Without this study, we would never have looked down this path.”
The full results have been published online today in Alzheimer’s and dementia.
The COSMOS-Spirit The study is a sub-study of a larger parent trial called COSMOS. He studied the effects of cocoa extract and a standard mineral multivitamin (MVM) on cardiovascular and cancer outcomes in over 21,000 elderly participants.
In COSMOS-Mind, researchers tested whether daily intake of cocoa extract versus a placebo and a mineral multivitamin versus a placebo improved cognition in older adults.
More than 2200 participants aged 65 and over were enrolled and followed for 3 years. They conducted phone tests at baseline and annually to assess memory and other cognitive abilities.
Results showed that cocoa extract had no effect on global cognition compared to placebo (mean z-score, 0.03; P = 0.28). However, daily multivitamin use showed significant benefits on global cognition compared to placebo (z mean, 0.07, P = 0.007).
The beneficial effect was most pronounced in participants with a history of cardiovascular disease (no history 0.06 versus history 0.14; P = .01).
The researchers found similar protective effects for memory and executive function.
Baker suggested that a possible explanation for the positive effects of multivitamins could be the increase in essential micronutrients and minerals they provide.
“With nutrient-deficient diets and a high prevalence of cardiovascular disease, diabetes, and other medical comorbidities that we know impact the bioavailability of these nutrients, we may be dealing with older people which are below optimum in terms of their essential micronutrients and minerals,” she says.
“Even suboptimal levels of essential micronutrients and minerals can have significant consequences for brain health,” she added.
More research needed
As intriguing as the results are, more work is needed before the findings can have an impact on nutritional advice, according to Maria C. Carrillo, PhD, chief scientific officer of the Alzheimer’s Association.
“While the Alzheimer’s Association is encouraged by these findings, we are not prepared to recommend widespread use of a multivitamin supplement to reduce the risk of cognitive decline in older adults,” Carrillo said in a statement.
“For now, and until there is more data, people should talk with their healthcare providers about the benefits and risks of all dietary supplements, including multivitamins,” a- she added.
Baker agreed, noting that the study was not designed to measure multivitamin use as a primary outcome. Additionally, nearly 90% of participants were non-Hispanic white, which is not representative of the overall demographics of the population.
The researchers are now designing another, larger trial that would include a more diverse group of participants. It will specifically aim to learn more about how and why multivitamins seem to offer a protective effect on cognition, Baker noted.
The study was funded by the National Institute on Aging of the National Institutes of Health. Baker and Carrillo do not report any relevant financial relationship.
Alzheimer’s dementia. Published online September 14, 2022. Full Text
Kelli Whitlock Burton is a reporter for Medscape Medical News covering psychiatry and neurology.