Today I’ll nail my colours to the mast: I’m not a fan of vitamin supplements. I think vitamins should be taken in foods.

But I may have to eat my words because a large study from US Universities Columbia and Harvard suggests that taking a daily multivitamin supplement can slow age-related memory decline.

“Cognitive aging is a top health concern for older adults, and this study suggests there may be a simple, inexpensive way to help older adults slow down memory decline,” says study leader Professor Adam M Brickman, of Columbia University.

Many older people take vitamins or dietary supplements believing they’re good for health. However, studies testing whether they improve memory and brain function have been mixed, and very few large-scale trials have been carried out.

In the current study, more than 3,500 adults over age 60 were given a daily multivitamin supplement or placebo for three years.

At the end of each year, participants did a series of online cognitive assessments at home to test memory as part of the COSMOS-Web study of Brigham & Women’s Hospital in collaboration with Harvard.

By the end of the first year, memory had improved in people taking a daily multivitamin, compared with those taking a placebo, and was equivalent to about three years of age-related memory decline.

It was sustained over a three-year study period and the benefit was more pronounced in people with heart disease.

“There is evidence that people with cardiovascular disease may have lower micronutrient levels that multivitamins may correct, but we don’t really know why the effect is stronger in this group,” says Prof Brickman.

The multivitamin supplement was linked to improvement in memory but it’s our overall nutrition that’s key for optimising brain health as we age.

“Our study shows that the aging brain may be more sensitive to nutrition than we realized, though it may not be so important to find out which specific nutrient helps slow age-related cognitive decline,” says Lok-Kin Yeung, PhD, first author, postdoctoral researcher in Columbia University.

JoAnn Manson of Brigham and Women’s Hospital adds: “The finding that a daily multivitamin improved memory in two separate cognition studies in the COSMOS randomized trial is remarkable, suggesting that multivitamin supplementation holds promise as a safe, accessible, and affordable approach to protecting cognitive health in older adults.”

But there’s a warning note from Prof Brickman, who adds: “Supplementation of any kind shouldn’t take the place of more holistic ways of getting the same micronutrients.

“Though multivitamins are generally safe, people should always consult a physician before taking them.”