Study details and key findings

To evaluate the impact of daily multivitamins on cognitive aging and memory, the researchers tracked 3,562 older adults. One group of participants received a placebo, and the other took a Centrum Silver multivitamin every day for three years.

Each participant took online tests to evaluate their memory. They were given lists of related and unrelated words and asked to remember as many as they could. According to Aubrey, "[l]ist-learning tests assess a person's ability to store and retrieve information."

After one year, the participants who took a daily multivitamin showed improvements in their ability to recall words. Compared to the placebo group, they remembered around a quarter more words, equating to a few additional words.

"We estimate that the effect of the multivitamin intervention improved memory performance above placebo by the equivalent of 3.1 years of age-related memory change," the authors wrote.

Commentary

JoAnn Manson, study author and chief of the division of preventive medicine at Brigham and Women's Hospital, acknowledged "a clear signal for benefit in slowing age-related memory loss and cognitive decline" in the study. She also noted that this is not the first study to demonstrate the benefits of multivitamins.

In a  study  published last year in  Alzheimer's & Dementia, participants who took a daily multivitamin had better overall performance on global cognitive function when taking tests that measured story recall, verbal fluency, digit ordering, and executive function.

Jeffrey Linder, chief of general internal medicine at Northwestern University Feinberg School of Medicine, who was not involved in the study, said the study findings were "intriguing," but noted that the overall effect found in the study was relatively small. "It seems like a pretty modest difference," Linder said.

In addition, Linder noted that the multivitamins did not influence other areas of cognition evaluated in the study, including executive function.

According to Manson, deficiencies in vital nutrients may also impact memory loss or accelerate cognitive decline. "Our bodies and brains require many nutrients for optimal health and efficiency," Aubrey writes.

Taking a multivitamin may help an individual prevent a deficiency if they are not receiving essential nutrients from their diet, Manson added.

"It's important to highlight that a multivitamin will never be a substitute for a healthy diet," Manson said. "But it may be a complementary approach or strategy for maintaining cognitive health among older adults."

Linder said he will continue to tell his patients that they likely won't see a significant benefit from a multivitamin if they eat a healthy diet. "If you're taking too much of a particular supplement and your body doesn't need it, you're just peeing it out," he said.

"Eating a diet that has plenty of fruits and vegetables is associated with longevity and better function and better quality of life," Linder said. To protect cognitive function, "the current thinking is that all of the stuff that's good for your heart is also good for your brain," he noted.

When Linder discusses healthy aging with his patients, he emphasizes good sleep habits, physical activity, and a healthy diet. "My big concern with all of the focus that people have on vitamins is that it's distracting them from things that actually will help them stay healthy," Linder said.

"If someone is taking a multivitamin, I'm not going to tell them to stop," said R. Sean Morrison, a geriatrician at Mount Sinai Health System. However, Morrison said he will not encourage multivitamin use to protect against memory loss, claiming that the effects measured in the studies are not very convincing.

"I don't think it's the magic bullet that people are looking for," Morrison said. (Aubrey, "Shots," NPR, 5/26; Yeung et al., American Journal of Clinical Nutrition, 5/24)

While nutrition studies pose a unique set of challenges, experts say there is a growing body of compelling evidence that suggests certain diets may benefit an aging brain. Writing for the  New York Times, Amelia Nierenberg explains the connection between diet and brain health. Read the full story below.