Multivitamins and minerals have no benefit in preventing heart attacks, strokes or cardiovascular disease, an analysis of more than two million participants has found.
A multibillion dollar industry, the supplements are often marketed with a wide array of health-promoting claims.
But researchers from the University of Alabama, who followed more than two million people from 18 trials of nutritional supplements, saw no evidence they could lower heart disease deaths.
Instead, the study suggested that people may not be taking more effective lifestyle and dietary steps to improve their health because they are relying too much on supplements.
“It has been exceptionally difficult to convince people, including nutritional researchers, to acknowledge that multivitamin and mineral supplements don’t prevent cardiovascular diseases,” said the study’s lead author Dr Joonseok Kim, an assistant professor of cardiology in the department of medicine at the University of Alabama.
“I hope our study findings help decrease the hype around multivitamin and mineral supplements and encourage people to use proven methods to reduce their risk of cardiovascular diseases – such as eating more fruit and vegetables, exercising and avoiding tobacco.”
The nutritional supplement industry will be worth more than £200bn globally by 2024, Dr Kim writes in the study published in the American Heart Association (AHA) journal Circulation.
But these products in countries like the UK and US do not require approval on safety or effectiveness grounds.
While manufacturers are barred from making specific claims about their products’ ability to prevent, cure or treat disease, this does not extend to more general health claims.
Dr Kim added that examples of these types of supplements causing direct harm were “rare”, but that people could be neglecting lifestyle or medical interventions of proven benefit if they thought vitamins were an easier option.
“Eat a healthy diet for a healthy heart and a long healthy life,” said Dr Eduardo Sanchez, the AHA’s chief medical officer, who was not a part of this study. “There’s just no substitute for a balanced, nutritious diet with more fruits and vegetables that limits excess calories, saturated fat, trans fat, sodium, sugar and dietary cholesterol.”