Seventy percent of adults 71 years and older take a daily vitamin and about one-third of those folks make it a multivitamin pill. But is it a waste of money? Not according to a major new study led by researchers at Columbia University and Brigham and Women’s Hospital/Harvard. It found that taking a daily multivitamin can slow down age-related memory decline.

The study took place over three years and involved more than 3,500 adults 60 and older (mostly non-Hispanic and white) who took either a daily multivitamin or a placebo, an inactive substance (such as a sugar pill) or other intervention that looks the same as the drug or treatment being tested and is administered in the same way.

A daily multivitamin actually does improve memory — and the difference is significant.

At the end of each year, all the participants of the study took a series of online cognitive assessments in their homes. The tests were designed to measure the memory functions linked to the hippocampus. This area of the brain plays a major role in learning and memory and is usually affected by normal aging.

The good news that the study showed is that taking a daily multivitamin actually does improve memory — and the difference is significant. The researchers estimate that the improvement (which was sustained during the 3-year period) is equivalent to about three years of age-related memory decline.

The effect was even more pronounced in those with underlying cardiovascular disease.

The reason for this isn’t clear, but “There is evidence that people with cardiovascular disease may have lower micro-nutrient levels that multivitamins may correct, but we don’t really know right now why the effect is stronger in this group,” senior author, Adam M. Brickman, professor of neuropsychology at Columbia University Vagelos College of Physicians and Surgeons, said in a press release.

The study adds to growing evidence about the importance of nutrition in brain health. The study was not designed to determine whether there was a specific component of the multivitamin that improved memory, however.

The improvement was equivalent to about three years of age-related memory decline.

“Our study does show 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 to find out which specific nutrient age-related cognitive decline,” the first author of the study, Lok-Kim Yeung, a postdoctoral researcher in Columbia’s Taub Institute for Research on Alzheimer’s Disease and the Aging Brain, said.

Before you run out to buy a daily multivitamin, Brickman makes two additional points. 1) Supplementation of any kind should not take the place of eating a healthy well-balanced diet. 2) Although multivitamins are generally safe, it’s a good idea to always consult with one’s medical provider before taking them.

The study is published in the American Journal of Clinical Nutrition.