A new analysis that looked at 277 clinical trials involving nearly 1 million people has revealed that most nutritional supplements and dietary interventions cannot prevent death and cardiovascular disease.
Supplements, Longer Life, And Heart Health
In a new study, Erin D. Michos, associate professor of medicine at the Johns Hopkins University School of Medicine, and colleagues reported that most calcium alone, iron, selenium, multivitamins, vitamin A, vitamin B6, vitamin C, vitamin E, and vitamin D alone are not associated with longer life or protection from heart disease.
Supplements that combine calcium and vitamin D may in fact cause harm by increasing risk for stroke. The researchers found that potential health benefits were only linked to low-salt diet, omega-3 fatty acid supplements, and folic acid supplements.
"Reduced salt intake, omega-3 LC-PUFA use, and folate supplementation could reduce risk for some cardiovascular outcomes in adults. Combined calcium plus vitamin D might increase risk for stroke," Michos and colleagues wrote in their study, which was published in the Annals of Internal Medicine on July 8.
Other earlier studies also failed to prove the health benefits of taking dietary supplements. Some of these studies even suggest these supplements may even cause harm.
A 2016 study from the Johns Hopkins University, for instance, found that people who take calcium pills tend to have higher risk for plaque in the arteries than people who did not take them.
In a 2018 study, vitamin D also failed to live to its hype of providing protection against the bone-thinning disease osteoporosis. Researchers found that taking vitamin D supplements could not prevent fractures and falls. The supplements do not have also have significant effects on bone density.
More Than Half Of Americans Take Supplements Daily
Despite these scientific findings, dietary supplements remain a multibillion dollar industry. Surveys conducted by the U.S. Centers for Disease Control and Prevention revealed that 52 percent of Americans take at least one vitamin or other dietary/nutritional supplement every day.
"The panacea or magic bullet that people keep searching for in dietary supplements isn't there," Michos said. "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."