An analysis led by Mass General Brigham investigators found slower aging in older adults after two years of a daily multivitamin, with greater benefits for those who began the trial with accelerated biological age
How quickly our bodies age on a cellular level, our “biological age,” can differ from how old we actually are in years. Using data from a large randomized clinical trial of older adults, researchers at Mass General Brigham evaluated the effects of taking a daily multivitamin over the course of two years on five measures of biological aging and found a slowing equivalent to about four months of aging. The benefits were increased in those who were biologically older than their actual age at the start of the trial. Their results are published in Nature Medicine .
“There is a lot of interest today in identifying ways to not just live longer, but to live better,” said senior author Howard Sesso, ScD, MPH, associate director of the Division of Preventive Medicine in the Mass General Brigham Department of Medicine. “It was exciting to see benefits of a multivitamin linked with markers of biological aging. This study opens the door to learning more about accessible, safe interventions that contribute to healthier, higher-quality aging.”
Epigenetic clocks estimate biological aging based on tiny changes in our DNA. These clocks look at specific sites in our DNA that regulate gene expression (known as DNA methylation) and change naturally as we get older, helping track with mortality and the pace of aging. This study, which uses data from the well-established COcoa Supplement Multivitamins Outcomes Study (COSMOS), analyzed DNA methylation data from blood samples of 958 randomly selected healthy participants with an average chronological age of 70.
The study participants were randomized to take a daily cocoa extract and multivitamin; daily cocoa extract and placebo; placebo and multivitamin; or placebos only. Samples were analyzed for changes in five epigenetic clocks from the start of the trial and at the end of the first and second years. Compared to the placebo only group, people in the multivitamin group had slowing in all five epigenetic clocks, including statistically significant slowing seen in the two clocks that are predictive of mortality. The changes equated to about four months less biological aging over the course of two years. Additionally, people who were biologically older than their actual age at the start of the trial benefitted the most.
“We plan to do follow-up research to determine if the slowing of biological aging—observed through these five epigenetic clocks, and additional or new ones—persists after the trial ends,” said co-author and collaborator Yanbin Dong, MD, PhD, director of Georgia Prention Institute, Medical College of Georgia at Augusta Univeristy.
Further studies are also needed to determine how improvements in biological aging may explain reductions in clinical outcomes. The COSMOS team plans to investigate how the effects of a daily multivitamin on biological aging may extend to different outcomes they have seen evidence of benefits for, such as improvements in cognition and reductions in cancer and cataracts.
“A lot of people take a multivitamin without necessarily knowing any benefits from taking it, so the more we can learn about its potential health benefits, the better,” said Sesso. “Within COSMOS, we are fortunate and excited to build upon a rich resource of biomarker data to test how two interventions may improve biological aging and reduce age-related clinical outcomes.”
Authorship: In addition to Sesso, Mass General Brigham authors include Sidong Li, Rikuta Hamaya, Alexandre C. Pereira, Kerry L. Ivey, Pamela M. Rist, and JoAnn E. Manson. Additional authors include Haidong Zhu, and Brian H. Chen.
Disclosures: Manson and Sesso received investigator-initiated grants from Mars Edge, a segment of Mars Incorporated dedicated to nutrition research and products, for infrastructure support and donation of COSMOS study pills and packaging, and Pfizer Consumer Healthcare (now Haleon) for donation of COSMOS study pills (Centrum Silver and placebo) and packaging during the conduct of the study. Sesso additionally reported receiving investigator-initiated grants from Haleon, FOXO Technologies, Massachusetts Life Sciences Center, Pure Encapsulations, and American Pistachio Growers, and honoraria and/or travel for lectures from the Council for Responsible Nutrition, BASF, Haleon, and NIH during the conduct of the study. Rist has received in-kind support (specifically donations of study pills and packaging) from Mars Edge to be used in an NIH-funded, investigator-initiated trial (U01 AT012611). Chen was formerly an employee of FOXO Technologies, who provided in-kind donations to generate and pre-process the DNA methylation data. Charitable donations made possible by Sutter Health's California Pacific Medical Center Foundation provided salary support for Chen. Li received the EPI Early Career Travel Grant sponsored by the Council on Epidemiology and Prevention's Early Career Committee, American Heart Association.
Funding: This work is funded by the National Institutes of Health (HL157665). The COcoa Supplement and Multivitamin Outcomes Study (COSMOS) is supported by an investigator-initiated grant from Mars Edge, a segment of Mars dedicated to nutrition research and products, which included infrastructure support and the donation of study pills and packaging. Pfizer Consumer Healthcare (now Haleon) provided support through the partial provision of study pills (Centrum Silver and placebo) and packaging. COSMOS is also supported in part by grants AG050657, AG071611, and EY025623 from the National Institutes of Health, Bethesda, MD. Neither company had a role in the trial design or conduct, data collection, data analysis, or manuscript preparation or review. Additional investigator-initiated support for this work was also from investigator-initiated grants to HDS from both FOXO Technologies and Massachusetts Life Sciences Center. Charitable donations made possible by Sutter Health's California Pacific Medical Center Foundation provided salary support for Chen.
Paper cited: Li S et al. “Effect of Daily Multivitamin-Mineral and Cocoa Extract Supplementation on Epigenetic Clocks of Biological Aging: 2-Year Findings from the COSMOS Randomized Clinical Trial” Nature Medicine DOI: 10.1038/s41591-026-04239-3
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Nature Medicine
Randomized controlled/clinical trial
People
Effect of Daily Multivitamin-Mineral and Cocoa Extract Supplementation on Epigenetic Clocks of Biological Aging: 2-Year Findings from the COSMOS Randomized Clinical Trial
9-Mar-2026
Manson and Sesso received investigator-initiated grants from Mars Edge, a segment of Mars Incorporated dedicated to nutrition research and products, for infrastructure support and donation of COSMOS study pills and packaging, and Pfizer Consumer Healthcare (now Haleon) for donation of COSMOS study pills (Centrum Silver and placebo) and packaging during the conduct of the study. Sesso additionally reported receiving investigator-initiated grants from Haleon, FOXO Technologies, Massachusetts Life Sciences Center, Pure Encapsulations, and American Pistachio Growers, and honoraria and/or travel for lectures from the Council for Responsible Nutrition, BASF, Haleon, and NIH during the conduct of the study. Rist has received in-kind support (specifically donations of study pills and packaging) from Mars Edge to be used in an NIH-funded, investigator-initiated trial (U01 AT012611). Chen was formerly an employee of FOXO Technologies, who provided in-kind donations to generate and pre-process the DNA methylation data. Charitable donations made possible by Sutter Health's California Pacific Medical Center Foundation provided salary support for Chen. Li received the EPI Early Career Travel Grant sponsored by the Council on Epidemiology and Prevention's Early Career Committee, American Heart Association.