Multivitamins may slow memory loss in older adults

Each study had “nonoverlapping” participants and used different methods, producing findings that varied slightly. But collectively they add to growing evidence that taking a daily multivitamin can have a significant impact on cognition among older people.

Cognitive decline is among the top health concerns for most older adults, said Chirag Vyas, an instructor in investigation in the psychiatry department at Massachusetts General Hospital and the most recent study’s first author. A daily supplement provides “an appealing and accessible approach” to slowing it, he said.

The studies are part of the COcoa Supplement and Multivitamin Outcomes Study (COSMOS), a larger body of research examining the health effects of certain dietary supplements; it is a collaboration of Massachusetts General Hospital, Brigham and Women’s Hospital, Columbia University and Wake Forest University.

The most recent study of 573 individuals found statistically significant improvements in short- and long-term memory — recalling a list of words provided to them during testing, for example — among those taking a multivitamin. But there was less benefit than in the first study for executive function tasks such as counting backward or timed naming of animals or vegetables, said JoAnn Manson, chief of Brigham’s division of preventive medicine and co-leader of the COSMOS study with Howard Sesso, associate director of the division.

The first study, which tested participants’ cognition through telephone interviews, showed a 1.8-year delay in memory loss and cognitive aging, whereas the second study, which involved web-based assessments, found that the multivitamin group showed an estimated 3.1 fewer years of memory loss compared with the placebo group. The third study showed a two-year delay in memory loss.

The first study showed a “significant” benefit in both memory and executive function, whereas the second study focused primarily on memory, not executive function, Manson said.

Many patients are worried about having Alzheimer’s, said Paul E. Schulz, professor of neurology and director of the Neurocognitive Disorders Center at the McGovern Medical School at UTHealth Houston. Often, though, it is aging-related normal cognitive decline, he said.

“Then people ask me: ‘I’m glad it’s not Alzheimer’s, but is there anything I can do about it?’” said Schulz, who was not involved in the research. “This study suggests the intriguing possibility that some degree of normal aging can be staved off by simple vitamin supplementation.”

‘Stunning’ results in multivitamin study

“The results are stunning and strong in their consistency,” said Manson, also a professor of medicine at Harvard Medical School. “Each study shows a slightly different result but, taken together, are a powerful indication of the overall benefits of multivitamins on memory and cognitive aging.”

The research — all randomized placebo-controlled clinical trials, considered the “gold standard” in methodology — studied 5,000 participants and lasted two to three years. The latest study and meta-analysis appeared Thursday in the American Journal of Clinical Nutrition.

The probability that these findings would occur by chance is less than 1 in 1,000, according to calculations in the meta-analysis, Manson said. This increases “the likelihood that these are real effects of the multivitamins,” she said.

All studies used a commonly available multivitamin — Centrum Silver for Adults (age 50+). But, though they haven’t been studied, “any high-quality multivitamin is likely to provide similar benefits,” Manson said.

“We have three separate studies, plus a combined analysis, that confirm the findings,” she said. “If this were an expensive drug, it would be aggressively marketed, even before there was evidence of long-term safety.” Multivitamins are over-the-counter and affordable, and “we already know they are safe when taken for many years,” she said.

The third study and the meta-analysis were funded by investigator-initiated grants from Mars Edge, the life sciences division of Mars Inc., and the National Institutes of Health. Multivitamin and placebo tablets and packaging were donated by the maker of Centrum Silver, Pfizer Consumer Healthcare (now Haleon), which did not provide funding, the researchers said.

Sesso additionally reported receiving investigator-initiated grants from Pure Encapsulations and Pfizer, and honoraria or travel for lectures from the Council for Responsible Nutrition, BASF, NIH and the American Society for Nutrition during the conduct of the study.

Healthy eating is important

The first two studies were racially and ethnically diverse because the interviews took place via telephone or online, while the third was less so because it involved in-person testing of participants confined to the Boston area — a study limitation the researchers acknowledged.

Differences in participants and methodology probably contributed to the variances in the results, Manson said.

“The vast majority of the participants were White, which doesn’t reflect the population of older adults as a whole,” said Christine Kistler, an associate professor of geriatrics at the University of Pittsburgh who was not involved in any of the studies. “I also wish the studies had been conducted over a longer time period.”

Kistler also said that “people may want to hedge their bets and take a multivitamin, since there is no harm, but I will stick to healthy eating, exercise and good sleep for now.”

Individuals could obtain essential vitamins and minerals necessary for brain health through healthy food, Manson said. But “many people have deficiencies in one or more important micronutrients important for cognitive function,” among them vitamins B12 and D, lutein and zinc, she said.

The Centrum product contains them. But “that doesn’t mean people should forsake healthy eating because they are taking multivitamins,” she said.

Multivitamins and minerals are already popular among Americans. More than 39 percent of those older than 60 take them, according to the Centers for Disease Control and Prevention.

“While this study doesn’t replace recommendations to eat a healthy diet, it strengthens previous findings, and remains the best evidence there is to take a multivitamin, at least for people age 60 and over,” said Donald Hensrud, a nutrition specialist at the Mayo Clinic, also not involved in the study.

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