Multivitamin myth: Study shows no benefit to long-term health, longevity

ROCKVILLE, Md. — For decades, multivitamins have been a staple in medicine cabinets across America. Nearly one in three adults pops these colorful pills daily, hoping to fill nutritional gaps and boost their overall health. But do these supplements actually help us live longer? A new study suggests the answer is no.

Researchers from the National Cancer Institute have conducted one of the largest and longest investigations into multivitamin use and mortality to date. Their findings, published in JAMA Network Open, challenge the widespread belief that a daily multivitamin is a simple way to improve health and longevity. While many people take multivitamins hoping to prevent chronic diseases and live longer, researchers didn't find evidence to back up those beliefs.

The study followed over 390,000 generally healthy American adults for more than 20 years. Participants came from diverse backgrounds and regions across the country. By comparing multivitamin users to non-users over this extended period, the researchers aimed to uncover any potential long-term benefits or risks.

What they found was surprising: regular multivitamin use was not associated with a lower risk of death from any cause. In fact, daily users had a slightly higher mortality risk in some analyses, though the difference was small.

This lack of benefit held true across various subgroups, including men and women, different age ranges, and people with varying diet quality and health behaviors. The researchers also looked at specific causes of death, like heart disease and cancer, but still found no advantage for multivitamin users.

These findings may come as a shock to the millions of Americans who faithfully take their daily multivitamin. The supplement industry has long promoted these products as an “insurance policy” for good health. However, nutrition experts have increasingly questioned whether synthetic vitamins in a pill can replicate the complex mix of nutrients found in whole foods.

So why do so many people believe in the power of multivitamins? Part of it may be clever marketing. But there's also a psychological appeal to the idea of a simple pill that can optimize our health. Unfortunately, human biology is rarely that straightforward.

This doesn't mean all supplements are useless. Certain groups, like pregnant women or older adults with limited diets, may still benefit from specific vitamin supplementation as recommended by their doctor. But for the average healthy adult, this study suggests that a daily multivitamin is unlikely to be the key to a longer life.

“We did not find evidence to support improved longevity among healthy adults who regularly take multivitamins,” the authors write in their paper. “However, we cannot preclude the possibility that daily multivitamin use may be associated with other health outcomes related to aging.”

Instead, scientists emphasize that proven lifestyle factors like eating a healthy diet rich in fruits and vegetables, exercising regularly, not smoking, and maintaining a healthy weight are far more important for longevity. These habits provide a complex array of nutrients and health benefits that can't be easily replicated in pill form.

As we learn more about nutrition and longevity, it's becoming clear that there are no quick fixes or magic bullets. Good health comes from consistent, healthy choices over a lifetime – not from a handful of vitamins each morning.

Methodology

The researchers combined data from three large, long-running health studies in the U.S. They looked at information from over 390,000 adults who were generally healthy at the start. Participants reported whether they took multivitamins and how often. The researchers then tracked who died over the next 20+ years using national death records. They compared death rates between multivitamin users and non-users, while accounting for other factors that could affect lifespan (like age, smoking, diet quality, etc.).

Results

After following participants for more than two decades, the researchers found that people who took multivitamins daily were not less likely to die than those who didn't take them. This was true for death from any cause, as well as for specific causes like heart disease and cancer. In some analyses, daily multivitamin users had a slightly higher risk of dying, but the difference was small (about 4%).

Limitations

While this study was large and long-term, it wasn't a randomized controlled trial (the gold standard in medical research). People chose whether to take multivitamins, so there could be other differences between users and non-users that affected the results. The study also relied on people accurately reporting their supplement use, which isn't always perfect. Additionally, the composition of multivitamins can vary, and the study couldn't account for every possible formulation.

Key Takeaways

1. For generally healthy adults, taking a daily multivitamin doesn't appear to help you live longer.
2. The study found no benefit for multivitamin use in preventing death from major causes like heart disease and cancer.
3. These findings held true across different groups, regardless of age, sex, or overall diet quality.
4. The researchers emphasize that eating a healthy diet, exercising, not smoking, and maintaining a healthy weight are much more important for longevity than taking a multivitamin.
5. Some groups (like pregnant women) may still benefit from specific vitamin supplements as recommended by their doctor, but for most adults, getting nutrients from a balanced diet is likely sufficient.
6. This study challenges the common belief that multivitamins are a simple way to improve health and prevent chronic diseases.