Daily Multivitamin May Slow Biological Aging, Study Finds

The quest to not just add years to our lives, but life to those years, may have a surprisingly simple component: a daily multivitamin. New research suggests that regular multivitamin use may subtly sluggish the pace of biological aging, particularly in individuals who already show signs of aging faster than their chronological age would suggest.

The findings, published March 9, 2026, in Nature Medicine, stem from an analysis of data collected during the COcoa Supplement and Multivitamin Outcomes Study (COSMOS), a large randomized clinical trial. Researchers at Mass General Brigham, in collaboration with Harvard, evaluated the effects of a daily multivitamin on five distinct measures of biological aging over a two-year period. The study revealed a slowing of aging equivalent to roughly four months compared to those taking a placebo. Read the full study in Nature Medicine.

Understanding Biological Age vs. Chronological Age

It’s important to distinguish between how old we are and how old our bodies act. Chronological age is simply the number of years lived. Biological age, however, reflects the state of our cells and tissues – how quickly they’re aging at a molecular level. This can vary significantly from person to person, and is a stronger predictor of healthspan and longevity than chronological age alone. “There is a lot of interest today in identifying ways to not just live longer, but to live better,” explained 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.”

Researchers assess biological age using what are known as epigenetic clocks. These clocks don’t gaze at the DNA sequence itself, but rather at chemical modifications to DNA – specifically, a process called DNA methylation. DNA methylation patterns change naturally with age, influencing which genes are turned on or off. By analyzing these patterns, scientists can estimate a person’s biological age and track the rate at which it’s changing. Harvard Gazette provides further details on epigenetic clocks.

COSMOS Trial Design and Findings

The COSMOS trial involved 958 healthy participants with an average age of 70. Participants were randomly assigned to one of four groups: daily cocoa extract plus a multivitamin, cocoa extract plus a placebo, a multivitamin plus a placebo, or two placebos. Blood samples were collected at the beginning of the study, and again after one and two years. Researchers then analyzed changes in five different epigenetic clocks.

The results showed that those taking a multivitamin experienced slower biological aging across all five clocks compared to the placebo group. Notably, the effect was more pronounced in individuals who started the trial with a biological age higher than their chronological age – meaning their bodies were aging faster than expected. Two of the epigenetic clocks, specifically those known to be strong predictors of mortality risk, showed statistically significant slowing in the multivitamin group.

What Does This Mean for Your Health?

While the four-month slowing of biological aging may seem modest, researchers emphasize its potential significance. It suggests that a relatively simple and accessible intervention – taking a daily multivitamin – could have a measurable impact on the aging process. However, it’s crucial to understand the limitations of the study. This research doesn’t prove that multivitamins will extend lifespan or prevent age-related diseases. It simply indicates a change in biological markers associated with aging.

the study focused on a specific population – relatively healthy older adults. It’s unclear whether the same effects would be observed in younger individuals or those with pre-existing health conditions. The researchers also acknowledge that the observed changes in epigenetic clocks are just one piece of the puzzle. More research is needed to determine how these changes translate into real-world health outcomes, such as improved cognitive function, reduced risk of chronic diseases, or increased physical vitality.

Beyond Epigenetic Clocks: Cognitive Benefits and Ongoing Research

This isn’t the first time the COSMOS trial has yielded promising results regarding multivitamins. A study published in January 2024 found that daily multivitamin supplementation was associated with improved memory and slower cognitive decline in older adults. Mass General Brigham details the cognitive benefits of multivitamins. This adds to the growing body of evidence suggesting that multivitamins may play a role in maintaining cognitive health as we age.

Researchers are now planning follow-up studies to determine whether the slowing of biological aging observed in the COSMOS trial persists after the trial ends. They also intend to investigate the potential links between the effects of multivitamins on biological aging and other benefits observed in the trial, such as improved cognition and lower rates of cancer, and cataracts.

The Public Health Perspective: Accessible Interventions

The appeal of this research lies in the accessibility of the intervention. Unlike many anti-aging strategies that are expensive or require significant lifestyle changes, a daily multivitamin is relatively inexpensive and easy to incorporate into one’s routine. As Sesso notes, “A lot of people take a multivitamin without necessarily knowing any benefits from taking it, so the more One can learn about its potential health benefits, the better.”

However, it’s important to emphasize that a multivitamin is not a magic bullet. A healthy lifestyle – including a balanced diet, regular exercise, adequate sleep, and stress management – remains the cornerstone of healthy aging. This research simply suggests that a multivitamin may be a helpful addition to a comprehensive approach to wellness.

Looking Ahead: Continued COSMOS Analysis

The COSMOS team is continuing to analyze the wealth of biomarker data collected during the trial. This ongoing research promises to provide further insights into the complex interplay between nutrition, aging, and health outcomes. The ultimate goal is to identify accessible, safe, and effective interventions that can help people live longer, healthier lives.