Dietary supplements don’t extend life and might actually shorten it if taken at high levels, researchers reported Monday in the Annals of Internal Medicine. While certain nutrients may contribute to a longer life, they need to come from a food source, the study found.
At a time when more celebrities, social media influencers and wellness websites sell concoctions of vitamins, the new findings join a growing body of evidence that supplements don’t help most people. A 2018 study from the University of Birmingham had found multivitamins and mineral supplements didn’t protect against heart disease.
“Based on the totality of evidence, it’s becoming more and more clear that the regular use of dietary supplements is not beneficial in reducing the risk of mortality among the general population in the U.S.,” said study coauthor Dr. Fang Fang Zhang, an associate professor at the Friedman School of Nutrition Science and Policy at Tufts University. “But, we need more research to look at long-term use of supplements. It would also be worth exploring whether supplements might be helpful among those who have nutritional deficiencies.”
With more than half of U.S. adults using dietary supplements, Zhang and her colleagues explored their effects, as well as the impact of nutrients found in foods, with data from 27,725 adults participating in the National Health and Nutrition Examination Survey. All participants were 20 or older when they signed on to be part of the NHANES.
The participants included in Zhang’s study all had filled out a 24-hour food questionnaire twice. In addition, during a household interview, they answered whether they had used any dietary supplements in the previous 30 days. Those who said they had used supplements were asked for details, including how often they took the products.
More than half of the study participants reported using dietary supplements in the previous 30 days and 38.3 percent reported using multivitamin and mineral supplements.
Intriguingly, supplement users were more likely than others to have higher levels of education and family income, eat a healthy diet and be physically active. Those factors are “already known to reduce mortality,” Zhang said.
During the median follow-up of six years, 3,613 of the study participants died. That number included 945 cardiovascular deaths and 805 cancer deaths.