Multivitamins may slow aging at the cellular level, study finds

A two-year study of nearly 1,000 older adults suggests that taking a daily multivitamin could slow some markers of biological aging—though the effect is modest, roughly equivalent to four months of cellular aging prevention over two years.

The research, published in Nature Medicine, measured biological age through "epigenetic clocks"—patterns of chemical changes to DNA that accumulate over time and influence how genes function. Unlike chronological age (how many birthdays you've had), biological age reflects the actual state of your body at the cellular level. The theory is simple: if you can slow how fast your cells age, you might extend the years you spend in good health rather than managing age-related diseases.

Researchers at Mass General Brigham divided 958 healthy participants (average age 70) into four groups: some took a daily multivitamin with cocoa extract, others got a multivitamin with placebo, cocoa extract with placebo, or two placebos. Blood samples taken at the start and after one and two years showed that multivitamin takers experienced slower biological aging on two of five epigenetic clocks—particularly those linked to mortality risk. The cocoa extract alone had no effect.

The slowdown was most noticeable in people who showed faster biological aging at the study's start, suggesting those with existing nutritional gaps may have benefited most. This hints at something important: multivitamins might work as a nutritional safety net for people with deficiencies, not as a universal anti-aging tool.

What This Actually Means

Here's where the caution matters. Four months of cellular aging prevention over two years is real, but it's not transformative. Dr Howard Sesso, the study's senior author, was explicit: "We do not know for sure who benefits, and how." Experts from Columbia University stressed the effects were very small. Dr Marco Di Antonio from Imperial College London made the practical point: "I do not think that people should start taking multivitamins daily necessarily, but these results demonstrate that having a healthy diet and lifestyle will have an effect on your biological age."

That's the key tension in this research. The study showed multivitamins can influence aging at the molecular level—that's genuinely interesting. But it also highlighted what multivitamins cannot do: they cannot override poor sleep, sedentary habits, or a diet heavy in processed food. Di Antonio was direct about this: "Taking multivitamins daily will be pointless if there is not a healthy lifestyle associated with it."

The findings also sit awkwardly alongside a large study from last year showing that daily multivitamins did not help people live longer and might actually increase early death risk. Sesso's previous work, however, has found associations between multivitamins and better cognition, lower lung cancer risk, and fewer cataracts—suggesting the picture is more complicated than any single study can capture.

Dr Pilar Guallar Castillón from the Autonomous University of Madrid took the most skeptical stance: "My personal advice is to stop taking multivitamins... Eat a healthy, varied diet rich in fruit and vegetables and do not waste your money on nutritional supplements."

The honest takeaway is this: if you already eat well and exercise, a multivitamin probably won't transform your aging trajectory. If you have nutritional gaps—which some older adults do—a multivitamin might offer modest cellular benefits worth exploring with your doctor. But the supplement is not a substitute for the fundamentals: sleep, movement, real food, and social connection remain the actual levers of aging.