A massive new analysis published on 8 July in the Annals of Internal Medicine, which included findings from 277 randomised clinical trials using 24 different interventions (and a total of 992,129 subjects from around the world), has found almost all vitamin, mineral, and other dietary supplements, as well as most diets, to be useless in terms of protecting against heart disease and extending lifespan.
When it comes to heart disease and mortality, most supplements were found to be neutral, a few beneficial, and a few others even slightly detrimental.
“The panacea or magic bullet that people keep searching for in dietary supplements isn’t there,” said lead author Erin D. Michos, Associate Professor of Medicine at Johns Hopkins University School of Medicine. “People should focus on getting their nutrients from a heart-healthy diet, because the data increasingly show that the majority of healthy adults don’t need to take supplements.”
In the study, the majority of supplements, including multivitamins, selenium, vitamin A, vitamin B6, vitamin C, vitamin E, vitamin D alone, calcium alone, and iron showed no link to increased or decreased risk of death or heart health.
Low-salt diets were found to be associated with a 10% decrease in the risk of death in people with healthy blood pressure, and a 33% decrease in the risk of death from heart disease in people with high blood pressure, with evidence for both being classified as moderate.
The ever-popular omega-3 fatty acid supplements (usually taken in the form of fish oil) were found to provide an 8% reduction in heart attack risk, and a 7% reduction in coronary heart disease, although evidence for the link was ranked as low.
Folic acid was found to be moderately beneficial, yet the authors note that many of the studies with the most promising results were conducted in China, where cereals and grains aren‘t fortified with folic acid, which makes it questionable whether the same effect would apply elsewhere.
“Our analysis carries a simple message that although there may be some evidence that a few interventions have an impact on death and cardiovascular health, the vast majority of multivitamins, minerals and different types of diets had no measurable effect on survival or cardiovascular disease risk reduction,” concluded lead author Safi U. Khan, M.D., an Assistant Professor of Medicine at West Virginia University.