Multivitamin may slow biological aging clock
The Discovery That Started With A Failed Heart Trial
In 2015, researchers at Brigham and Women’s Hospital in Massachusetts launched a massive clinical trial. [1] They recruited more than 21,000 people over the age of 60. The goal was simple: test whether a daily cocktail of multivitamins and cocoa extract could prevent heart disease and cancer.
The trial was called COSMOS — Cocoa Supplement and Multivitamin Outcomes Study. Researchers led by JoAnn Manson, who heads preventative medicine at Brigham and Women’s Hospital, gave one group a multivitamin plus cocoa extract. Cocoa contains flavonoid compounds, which some studies had suggested might protect against age-related conditions. Other groups received only a multivitamin, only cocoa extract, or a placebo.
The principal goal failed. The multivitamin and cocoa cocktail did not reduce the risk of cardiovascular disease or cancer. But the researchers found something unexpected in the data. A subgroup of 958 participants had their biological age measured at the start of the trial and again two years later. Those who took the daily multivitamin aged, on average, more slowly than those who did not. The cocoa extract had no effect.
The effect was modest — a month or two over two years. But over longer periods, Manson told the New Scientist podcast ‘Change Your Mind,’ that difference could really add up. The discovery was accidental. The trial was designed to test for disease prevention, not aging. Yet it produced one of the strongest signals yet that a simple multivitamin might slow the biological clock.
Why Biological Age Is The Only Measurement That Works
Biological age is not the same as chronological age. Chronological age is simply the number of years since birth. Biological age is an estimate of how old the body appears at a cellular or molecular level. It attempts to measure the actual wear and tear on tissues, organs, and systems.
Measuring biological age is difficult. The most common method uses epigenetic clocks — patterns of chemical markers on DNA that change with age. These markers, called methylation groups, attach to DNA and influence which genes are active. Researchers have found that the pattern of these markers changes predictably over time, allowing them to estimate biological age from a blood sample.
The COSMOS trial used this method to measure biological age in the 958-participant subgroup. The multivitamin group showed slower epigenetic ageing compared to the placebo group. But the researchers were cautious. Biological age measurements are notoriously unreliable, Manson told the podcast. The finding did not show any meaningful change in the health of participants. Slowing down biological ageing does not necessarily correspond to an increase in healthspan — the years of life spent in good health.
A separate study from the University of Zurich in Switzerland added weight to the idea. [2] Last year, a team including researchers at the university published a study on omega-3 fatty acid supplementation in people aged 70 to 91. The traditional verdict on omega-3 supplements has been that they are not worth taking unless the diet is deficient in oily fish, flaxseed, chia seeds, or walnuts. The Zurich research challenged that.
Over three years, people who took the omega-3 supplement aged biologically three months less, on average, than those who took a placebo. Adding vitamin D and strength training increased the benefit to four months. But again, the researchers found no meaningful change in health outcomes. The measurement showed a signal, but the signal did not translate into fewer diseases, better mobility, or longer life.
The Constraint That Keeps The Pharmacy Door Closed
The evidence for anti-ageing supplements remains weak. In a book published earlier this year called “Supplements and Drugs for Healthy Longevity,” an expert panel led by biogerontologist Suresh Rattan at Aarhus University in Denmark rated the evidence for more than 250 compounds with supposed anti-ageing effects. These ranged from vitamins and minerals to plant extracts, traditional medicines, probiotics, and hormone supplements.
None of them met the highest standard of evidence, which Rattan defines as “solid, reproducible and trustworthy.” A few reached a secondary level, but on the whole, the authors recommend obtaining these compounds from food. The book concludes: “At present using one or more nutritional and other supplements… is mostly an act of faith and hope,” rather than being based on strong scientific evidence-based data.
The problem is measurement. Aging unfolds over decades. Most supplement trials last only weeks or months. Researchers cannot wait 30 years to see if a supplement extends lifespan. So they use biological age as a proxy. But biological age is a contested estimate. It does not directly measure healthspan. A person can have a younger biological age but still develop cancer, heart disease, or dementia.
Manson herself pointed out a possible explanation for her findings. The participants in her study may have been deficient in one or more vitamins. The multivitamin supplement merely corrected for that deficiency. The effect would then be a return to normal function, not a slowing of ageing itself. This is not the same as extending the human lifespan.
Daniel Belsky and Calen Ryan at Columbia University in New York wrote in response to the multivitamin study: ‘Evidence that simple multi-vitamin supplementation can slow aging, even slightly, would have substantial implications, including for public health guidelines.’ But they also acknowledged that the evidence is not yet there. The measurement technology is not precise enough to distinguish between a true anti-aging effect and a correction of deficiency. Until that changes, the pharmacy door remains closed.