Popping a multivitamin could reduce your biological age by a few months — but don't rush to the drugstore just yet

• A new study showed that older adults on a multivitamin slowed their rate of biological aging.
• The study is a first step toward answering what, if anything, multivitamins may do to improve aging.
• It's hoped that, one day, doctors will be able to tailor supplement "stacks" to a person's biological age.

We've all done it: popped a multivitamin and thought "will this actually do anything?"

For decades, the answer you'd typically get from health experts was a big shrug, because of a lack of solid evidence that multivitamins have a meaningful, measurable impact on our overall health or our odds of living a longer, healthier life.

A study published Monday in Nature Medicine suggests that, for older adults, we might be getting closer to an affirmative nod that multivitamins do something, after it showed a daily pill slowed their aging clocks by about four months.

Experts say the finding is interesting, but the effect is very small and it's premature to change your own supplement stack.

"This doesn't mean that everyone should go out and start taking a multivitamin," lead study author and supplement researcher Howard Sesso, an epidemiologist and associate professor of medicine at Harvard Medical School, told Business Insider. "Rather, this is starting to provide the connecting dots."

The study is part of a growing body of evidence suggesting older adults might derive some small, marginal benefits from taking multivitamins, especially if they're not getting enough nutrients in their diet. Another 2023 study published in the American Journal of Clinical Nutrition found that once-daily multivitamins helped improve people's scores on common memory tests, just a bit.

In the study, taking a once-daily multivitamin slowed down biological age clocks

The study, a large randomized control trial, followed 958 older adults (aged 70 on average: men over 60, women over 65). Half were asked to take a standard daily multivitamin for older adults for two years, while the others took a placebo pill. Those who reliably popped the multivitamin each day slowed down their biological aging by about four months over the course of the two years, when compared to their peers on the fake supplement.

The study was funded in part by the multivitamin maker Centrum — it provided the pills for the study cost-free to researchers — but the study was done at independent universities, and supported by federal grants from the National Institutes of Health. The study is more rigorous than most supplement trials out there.

The research team measured how the group aged using biological age clocks, also known as epigenetic clocks, including two called GrimAge and PhenoAge. They use a person's blood or spit to measure DNA methylation, the changes in how our genes are expressed as we age. The clocks are designed to predict how well we are aging overall, instead of giving a snapshot of health in one area of the body, like a blood pressure reading, cholesterol level, or pulse check would do.

The study found that the faster someone was aging, according to the clocks, the more that taking supplements seemed to help slow the pace, suggesting the multivitamins might be more beneficial for older adults already lacking in nutrients or in poorer health.

Sesso said there could be something about the "interconnectivity" of the different vitamins and minerals in a daily multivitamin "that might be working together in ways that we just don't fully appreciate."

However, the study couldn't show that the changes to biological age might make us feel better as we age, or determine how soon we'll die.

"It might turn out that what this is actually measuring is not really improved healthspan, but something else," the aging researcher Daniel Belsky, an associate professor of epidemiology at Columbia University, who was not involved in the study, told Business Insider. "Lots of things could cause variation in the epigenetic clocks that are not the biology of aging."

After all, biological age clocks have shown accelerated aging in people undergoing surgery, and pregnant women, but those changes are temporary, and likely not meaningful indications of a person's longevity.

Data on younger adults is lacking when it comes to supplements

If the evidence that multivitamins can help older adults maintain their health by providing the essential nutrients becomes stronger, then it may become more common for doctors to recommend them to older adults.

Already, some doctors and scientists, including Sesso, have told Business Insider they have switched to taking multivitamins as a result of new research. Specifically, Sesso was impressed by a separate, decades-long study funded by the National Institutes of Health that showed men over 50 may reduce their risk of cancer and developing cataracts, just slightly, by popping a once-daily multivitamin tablet. So, when he turned 50, he started taking one.

"That's all I take," he said, cautioning against taking unnecessary supplements. "The scientific rigor overall for dietary supplements is not as good as it should be. And yet the public continues to take these willingly without knowledge of really what any benefits or even harms might be."

Sesso tends to prioritize getting nutrients the old-fashioned way, through eating nutritious foods, plus incorporating other habits science shows can boost longevity, like staying active, and connecting to friends.

"I am a firm believer in diet, lifestyle and just healthy living, as best I can," he said.

The future of medicine could be informed by biological age tests that tell us which pills to take when

The hope is, Belsky said, that as our understanding of what's moving the needle on the "biological age" clocks develops, in a few years doctors could use it to help inform who gets supplements and when, tailoring people's stacks to their biology.

"It's looking good," he said. "Answers are coming, they're coming soon. They're just not here yet."