Millions of Americans take large doses of antioxidant vitamins, such as C and E, hoping to ward off everything from cancer to heart disease. But a new study in the Journal of the American Heart Association shows that taking antioxidants with cholesterol-lowering statin drugs like Zocor may reduce the effectiveness of the those drugs.
In a study of 153 patients with coronary artery disease, those who took Zocor and the vitamin niacin had a 25% increase in HDL--or "good" cholesterol--over 1 year. But those who added a daily antioxidant cocktail to the mix, consisting of 1,000 milligrams of vitamin C, 800 milligrams of vitamin E, 25 milligrams of beta carotene, and 100 micrograms of selenium, showed just an 18% increase in good cholesterol. That is 7% less than with the statin-niacin combination alone.
Patients who took the antioxidants by themselves, with no statins, showed no change in overall HDL but a 22% decrease in HDL2, the portion of good cholesterol considered the most protective.
"I don't recommend the routine use of antioxidants in patients with heart disease and now there's some new information that makes us take pause--that they may be doing harm," says cardiologist Dr. Holly Andersen of Weill Cornell Medical Center.
The latest study is the first to show a negative interaction between statins and vitamin therapy, but of nine clinical trials involving 140,000 people on antioxidants alone, eight trials have shown no cardiac benefit and some have indicated an increased cancer risk, despite the common belief that antioxidants are protective.
Lipid specialist Dr Henry Ginsberg of Columbia Presbyterian Medical Center says patients like to romanticize the benefits of vitamins instead of separating hype from fact.
"They're afraid to take drugs that have been proven in trial to be beneficial because there are potential side effects," he says. "Well, all drugs have side effects, but there are probably side effects to herbs and antioxidants and vitamins in large amounts, but no one knows because they have not been tested."
Doctors say it's okay to take a multivitamin since most multivitamins contain only a small amount of antioxidants. The best way to prevent heart disease is eating a diet rich in fruits and vegetables and exercising regularly. It's not always easy, but it works.
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