Birmingham, AL—Multivitamin, mineral tablets, and omega-3 products are among the most popular supplements on pharmacy shelves and elsewhere. Yet new studies suggest they do little to prevent heart disease, strokes, or death from cardiovascular disease.

One of the reports was a meta-analysis of 18 studies, which was published in Circulation: Cardiovascular Quality and Outcomes.

“We meticulously evaluated the body of scientific evidence,” explained lead author Joonseok Kim, MD, assistant professor of cardiology in the Department of Medicine at the University of Alabama at Birmingham. “We found no clinical benefit of multivitamin and mineral use to prevent heart attacks, strokes or cardiovascular death.”

The review included studies that had more than 2 million participants combined, with an average of 12 years of follow-up.

“It has been exceptionally difficult to convince people, including nutritional researchers, to acknowledge that multivitamin and mineral supplements don't prevent cardiovascular diseases,” Kim emphasized. “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 fruits and vegetables, exercising and avoiding tobacco.”

He noted, however, that the products rarely cause direct harm, although they might detract from proven techniques to reduce cardiovascular disease.

Recently, a new Cochrane systematic review combined the results of 79 randomized trials involving more than 100,000 participants determined that omega-3 supplements also have little or no effect on heart disease, stroke, or death.

Omega-3 fats have been promoted globally as a way to prevent heart disease by reducing blood pressure and/or cholesterol, according to the report.

Based on the meta-analysis, the risk of death from any cause was determined to be 8.8% in people who had increased their intake of omega-3 fats, compared with 9% in people in the control groups. Little difference also was found in relation to risk of cardiovascular events, coronary heart deaths, coronary heart disease events, stroke, or heart irregularities.

On the other hand, the review suggested long-chain omega-3 fats appeared to reduce some blood fats, triglycerides, and HDL cholesterol. The problem, according to study authors, is that while reducing triglycerides is likely to be protective of the heart, reducing HDL appears to have a contrary effect.

“We can be confident in the findings of this review which go against the popular belief that long-chain omega 3 supplements protect the heart,” said lead author Lee Hooper, PhD, of the University of East Anglia in the United Kingdom. “This large systematic review included information from many thousands of people over long periods. Despite all this information, we don't see protective effects.”

Hooper noted that the systematic review found moderate evidence that alpha-linolenic acid (ALA), which is found in rapeseed or canola oil and nuts, especially walnuts, might be slightly protective against some heart ailments. “However, the effect is very small, 143 people would need to increase their ALA intake to prevent one person developing arrhythmia. One thousand people would need to increase their ALA intake to prevent one person dying of coronary heart disease or experiencing a cardiovascular event. ALA is an essential fatty acid, an important part of a balanced diet, and increasing intakes may be slightly beneficial for prevention or treatment of cardiovascular disease,” she said.

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