Multivitamins don't ward off heart disease, stroke

Millions of Americans take multivitamins as a quick fix for the nutrients missing from their diets. Some may think they’re good for heart and brain health. But the popular supplements don’t prevent heart disease or stroke, a new study shows.

The findings, the researchers said, will hopefully convince the estimated one-third of Americans who buy the products that a dietary supplement isn’t going to help them avoid a heart attack, stroke or other cardiovascular problems.

Dr. Joonseok Kim, a cardiologist and the study’s lead researcher, said it’s time to stop investing time and money in studying the relationship between multivitamins with minerals and heart disease and stroke because there’s strong evidence they don’t prevent the chronic diseases.

“One of the big problems with multivitamin use is that it could deviate the public from following the measures that are proven to be beneficial for cardiovascular health, including eating fruits and vegetables, and doing more exercise” said Kim, a researcher at the University of Alabama at Birmingham.

“People tend to prefer a quick and easy solution such as taking a pill [rather] than the more effortful method to prevent cardiovascular disease,” he said.

In the study, published Tuesday in Circulation: Cardiovascular Quality and Outcomes(link opens in new window), Kim and his colleagues evaluated 18 studies involving more than 2 million participants from the United States, Japan, France and other countries. In analyzing whether multivitamins helped prevent heart attacks, strokes, heart disease-related deaths and other cardiovascular events, the researchers found a clear theme: They didn’t.

Kim’s report comes on the heels of a June study (link opens in new window)that also found multivitamins had no protective effect against heart disease and stroke. Other research has found multivitamins have no influence on the risk of common cancers, cardiovascular disease or total mortality in postmenopausal women.

A strength of the new study is that it includes clinical trials, the findings of which are generally more reliable than population studies that rely heavily on data provided by participants, said Dr. Parag Joshi, a preventive cardiologist at UT Southwestern Medical Center in Dallas. The findings, he said, confirm those from “the best scientific evidence” that suggests multivitamins with minerals don’t prevent heart disease and stroke.

“There’s no magic bullet for replacing a healthy diet,” said Joshi, who was not involved in the new study.

For people who have vitamin deficiencies such as lack of vitamin D, which helps regulate blood pressure, they should find out what’s causing the problem and not rush to take supplements to fill a nutrient gap, Joshi said.

Joshi doesn’t counsel his patients to stop taking multivitamins. But he does dispel their perception that these vitamins help them live longer or better.

Kim hopes other doctors follow suit. Too many patients are still being given confusing messages about the benefits and harms of multivitamins, he said. And because dietary supplements aren’t regulated the same as drugs, they don’t have to be proven safe or effective before making their way to store shelves.

For now, Kim said the best he can hope for is that the findings resonate with the Americans who spend an estimated $5.7 billion a year on multivitamins because they mistakenly think they’re improving their health. Perhaps instead, he said, their money is best spent on tried and true products: “Fruits and vegetables are good for our heart.”

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