Multivitamins are the most common dietary supplement in the U.S. People take these pills (or gummies, indeed) for a variety of health reasons, but the science on what multivitamins may do for your health is mixed, and none of them are approved by the U.S. Food and Drug Administration. But intriguingly, a new study suggests that taking a daily multivitamin could slow biological aging.
In a randomized clinical trial involving 958 adults aged 60 or older, researchers found that taking a multivitamin-multimineral supplement for two years modestly slowed two molecular signals for aging in the body known as “epigenetic clocks.” Chemical changes on DNA called DNA methylation in specific parts of the genome can help estimate a person’s biological age. In the people who took the supplement, the clocks’ rate of increase slowed by around 1.5 to two months per year compared with the clocks of those who took a placebo. The findings were published Monday in Nature Medicine.
The results are “encouraging,” the researchers write in the paper, adding that more research is needed to understand how multivitamins effect biological aging.
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Experts who were not involved in the new study urged caution. While the researchers saw an effect with two epigenetic clocks called PCPhenoAge and PCGrimAge, three other epigenetic clocks included in the study showed no statistically significant change to their speed.
“The multivitamin produced small favorable changes in two epigenetic aging markers, but not across all the clocks that were measured,” says José Ordovás, a professor of nutrition and genetics at Tufts University, who was not involved with the study. “That makes the finding interesting, but it is still far from showing that multivitamins broadly slow aging or improve longevity.”
One of the study’s strengths is that the researchers carefully matched the characteristics of people in the vitamin group to those in the placebo group, says Zachary Clayton, an assistant professor of medicine at the University of Colorado Anschutz, who was also not involved with the research. “However, the magnitude of the observed differences was modest, and their clinical significance remains uncertain,” he says.
The study doesn’t take a person’s exact diet or physical activity during the two-year period into account, and those factors can’t be ruled out as having an effect on biological aging, he adds.
Still, in nutrition science, randomized clinical trials of this kind are rare. They aren’t generally required to sell supplements like multivitamins, even if the makers claim specific health benefits. Additional trials, the authors note, “are needed to confirm these findings and determine the role of [multivitamins] in extending healthy aging not only among older adults, but also across the lifespan.”