Millions of Americans use dietary supplements and a variety of diets to protect their heart health. But a large new analysis found that there was strikingly little proof from rigorous studies that supplements and some widely recommended diets have the power to prevent heart disease.
The new research, published in the Annals of Internal Medicine, reviewed data from hundreds of clinical trials involving almost a million people and found that only a few of 16 popular supplements and just one of the eight diets evaluated had any noticeable effect on cardiovascular outcomes.
Folic acid, reduced salt diets and omega-3 fatty acids, the kind found in fish oil, showed some benefits. But the evidence was fairly weak. And at least one showed evidence of harm: Taking calcium with vitamin D increased the risk of stroke, possibly because it increases blood clotting and hardening of the arteries.
The findings are likely to elicit controversy and continued debate. But the researchers said one clear message from their analysis was that the more than half of Americans who use dietary supplements should be wary of claims that multivitamins and other supplements will improve their heart health.
“People who are taking these supplements for the sake of improving their cardiovascular health are wasting their money,” said Dr. Safi U. Khan, an assistant professor at West Virginia University School of Medicine and the lead author of the new study.
The findings regarding supplements dovetail with the conclusions of a report by the United States Preventive Services Task Force, an influential group of health experts that reviewed vitamin and mineral supplements in 2013 and found little proof that they promote cardiovascular health. “This has been shown very consistently,” Dr. Khan said.
Read the full story in The New York Times.