Multivitamins and the Aging Clock: What a Two-Year Trial Revealed About the Pace of Biological Ageing
Inside the blood collection rooms of a large randomized clinical trial, researchers gathered samples at the start of the study and again after one and two years to measure DNA methylation changes. The trial tested daily multivitamins alongside a cocoa extract and enrolled 958 participants; its results suggest that multivitamins had a modest effect on some measures of biological ageing.
Do Multivitamins slow biological ageing?
Yes, the COSMOS randomized clinical trial found that daily multivitamin–multimineral supplementation modestly slowed the increase of two epigenetic clocks over two years. Specifically, the multivitamin group showed smaller yearly increases in PCGrimAge and PCPhenoAge compared with placebo, changes that the study quantified as a modest reduction in the rate of biological ageing. The trial used a daily multivitamin formulation (Centrum Silver) and measured five DNA methylation clocks: PCHannum, PCHorvath, PCPhenoAge, PCGrimAge and DunedinPACE.
What magnitude of change did the trial observe, and who showed the strongest effects?
The measured effect on two of the second‑generation epigenetic clocks was small but statistically significant. The between‑group yearly differences in change were quantified for PCGrimAge and PCPhenoAge. The trial also found that the multivitamin effect on PCGrimAge was larger among participants who began the study with accelerated biological ageing than among those with normal or decelerated biological ageing. The investigators noted that the overall slowdown equated to roughly four months less biological ageing over the two‑year period for the multivitamin group.
Did cocoa extract change the outcome?
No. The trial tested a cocoa extract providing 500 mg of cocoa flavanols per day, including 80 mg of (−)-epicatechin, and found no effect of the cocoa extract on any of the five epigenetic clocks tested. There was also no interaction between cocoa extract and the multivitamin intervention in affecting the DNA methylation measures.
How do the researchers and specialists interpret these findings?
Study authors emphasized caution about interpreting the results as proof of long‑term clinical benefit. The authors wrote that it is critical to determine the clinical relevance of these epigenetic changes. Dr Howard Sesso, an epidemiologist at Mass General Brigham department of medicine and senior author on the work, said the findings did not mean all older adults must take multivitamins. “There are no known risks for taking a multivitamin in our two large clinical trials. At the same time, we do not know for sure who benefits, and how, ” he said.
What are the social and public‑health angles, and what comes next?
The trial’s results raise questions about nutritional status, target populations, and the translation of modest molecular changes into meaningful health outcomes. The investigators noted that participants with faster biological ageing at baseline appeared to derive larger epigenetic benefit, suggesting nutritional deficits or baseline risk profiles might shape who responds. The study authors called for additional research to determine whether the observed epigenetic changes explain previously observed benefits of multivitamin supplementation for certain age‑related conditions and to establish clinical relevance.
Returning to the trial’s clinic rooms where blood samples were taken at baseline and at one and two years, the measurement of DNA methylation provided a new, molecular lens on a familiar question: can simple, daily interventions shift the pace of ageing? The COSMOS ancillary findings point to a modest answer for multivitamins and a null answer for the tested cocoa extract—results that invite further study rather than a definitive prescription for the public.
