As the number of Americans living with Alzheimer’s grows, a new “exciting” study out of Mass General Brigham in Boston shows that taking a multivitamin could help prevent memory loss and slow down cognitive aging.

The researchers tested the effects of a daily multivitamin on cognitive changes in older adults, as part of the COSMOS trial (COcoa Supplement and Multivitamin Outcomes Study).

COSMOS is a large-scale trial testing cocoa extract and multivitamin supplements, run by researchers at Mass General Brigham. Two previous studies in COSMOS suggested that a daily multivitamin has a positive effect on cognition.

COSMOS researchers are now reporting the results of a third study in COSMOS — which focused on participants who took in-person assessments. The results showed a statistically significant benefit for memory and cognition among participants taking a daily multivitamin compared to the placebo.

The study suggests that taking a daily multivitamin may help prevent memory loss and slow cognitive aging in older adults.

“Cognitive decline is among the top health concerns for most older adults, and a daily supplement of multivitamins has the potential as an appealing and accessible approach to slow cognitive aging,” said first author Chirag Vyas, instructor in investigation at the Department of Psychiatry at Massachusetts General Hospital.

“The meta-analysis of three separate cognition studies provides strong and consistent evidence that taking a daily multivitamin, containing more than 20 essential micronutrients, helps prevent memory loss and slow down cognitive aging,” Vyas said.

The researchers for the study conducted in-person cognitive assessments among 573 participants in the subset of COSMOS known as COSMOS-Clinic.

The scientists found that there was a modest benefit from the multivitamin on global cognition over two years. There was a statistically significant benefit from the multivitamin for change in episodic memory, but not in executive function/attention.

The researchers estimated that the daily multivitamin slowed global cognitive aging by the equivalent of two years compared to the placebo.

“These findings will garner attention among many older adults who are, understandably, very interested in ways to preserve brain health, as they provide evidence for the role of a daily multivitamin in supporting better cognitive aging,” said Olivia Okereke, senior author of the report and director of Geriatric Psychiatry at MGH.

In 2020, an estimated 5.8 million Americans aged 65 years or older had Alzheimer’s disease. This number is projected to nearly triple to 14 million people by 2060, according to the CDC.

JoAnn Manson, co-author of the research report and chief of the Division of Preventive Medicine at Brigham and Women’s Hospital, said, “The finding that a daily multivitamin improved memory and slowed cognitive aging in three separate placebo-controlled studies in COSMOS is exciting and further supports the promise of multivitamins as a safe, accessible and affordable approach to protecting cognitive health in older adults.”