Regular Multivitamin Use Associated With Slower Aging in Older Adults: Study

A new study suggests that taking a daily multivitamin may help slow biological aging in older adults. Researchers from Mass General Brigham analyzed data from a large clinical trial and found that regular multivitamin use over two years was associated with a modest but measurable reduction in the pace of aging. The findings were published in Nature Medicine.

Biological age refers to how quickly the body’s cells and tissues age, which may differ from a person’s chronological age. To evaluate this process, scientists often use epigenetic clocks, which track changes in DNA methylation—small chemical modifications that influence how genes are expressed. These changes accumulate over time and can help estimate a person’s biological aging rate.

The research used data from the COcoa Supplement Multivitamin Outcomes Study (COSMOS), a large randomized clinical trial involving older adults. For this analysis, researchers examined DNA methylation data from blood samples of 958 healthy participants, whose average age was about 70 years. Participants were randomly assigned to receive either a daily multivitamin, cocoa extract, both, or a placebo.

Scientists assessed five different epigenetic clocks at the beginning of the study and again after one and two years. Compared with the placebo group, participants taking a daily multivitamin showed slower biological aging across all five clocks. Two of these clocks are known to strongly predict mortality risk. Overall, the effect was equivalent to approximately four months less biological aging over the two years.

The benefits were particularly noticeable among individuals who had a higher biological age than their chronological age at the start of the study. Researchers say further studies are needed to determine whether this slowing of biological aging leads to measurable health benefits, such as improved cognition or reduced risk of conditions like cancer and cataracts.

REFERENCE: Li, S., et al. (2026). Effects of daily multivitamin–multimineral and cocoa extract supplementation on epigenetic aging clocks in the COSMOS randomized clinical trial. Nature Medicine. DOI: 10.1038/s41591-026-04239-3. https://www.nature.com/articles/s41591-026-04239-3