An Antioxidant Cocktail May Prove to Be Heart Unhealthy
Aug. 9, 2001 -- It's pop quiz time. True or false: antioxidants such as vitamins E and C, beta-carotene, and selenium can protect against heart disease.
If you answered true, you're not alone. Most Americans -- and many American doctors -- believe that antioxidants are very effective at preventing heart disease but new data suggest that it is time to re-examine that belief.
Moreover, some heart experts say that taking antioxidants in combination with cholesterol-lowering drugs can actually be hazardous.
The latest disappointing finding on antioxidants comes from a study of more than 150 people with heart disease. Researchers randomized patients to the standard cholesterol-lowering drug therapy with simvastatin and niacin, the drugs plus an antioxidant cocktail, antioxidants alone, or placebo. The antioxidant cocktail contained vitamins E and C, beta-carotene, and selenium.
Adding an antioxidant chaser to the drug therapy appeared to work against the effect of the cholesterol-lowering drugs. Taken alone the drug combination simvastatin and niacin increased HDL, the so-called good cholesterol by 25%, but when antioxidants were added HDL increased by only 18%.
What is even more disturbing was the effect on a component of HDL that does the most good in reducing the risk for heart disease. Simvastatin and niacin increased this component an average of 42% but adding antioxidants to the drugs resulted in no increase in the beneficial component.
"Antioxidants appear to impair the benefits of cholesterol-lowering drugs and the antioxidants do this in a very specific way," says Marian C. Cheung, PhD, author of the study, which is published in Atherosclerosis, Thrombosis, and Vascular Biology: Journal of the American Heart Association."
Lewis H. Kuller, MD, PhD, professor and chairman of the department of epidemiology at the University of Pittsburgh School of Public Health, tells WebMD that the new findings "are consistent with other clinical trials that have found vitamin E to have no benefit in primary prevention."
In an editorial that accompanies the study by Cheung, Kuller wrote "antioxidant combinations above the recommended daily allowances should not be recommended for prevention or treatment of cardiovascular disease." He says, too, that doctors should warn patients that combining antioxidants with cholesterol-lowering drugs could be hazardous.
Kuller says that antioxidants are popular because "people like to have magic bullets and doctors are like everybody else in that they often believe it is easier to swallow a pill." He says that instead of chasing miracle vitamin combinations, doctors and patients should concentrate their efforts on "effective and proven" methods to prevent and treat heart disease. "That is where the emphasis should be."
Cheung, who is an assistant professor at the School of Medicine at the University of Washington in Seattle, tells WebMD that she and her colleagues were very surprised by the findings. "The antioxidant theory is very popular and we had no idea that we would find [such] an effect," she says.
But Cheung adds that she is unwilling to make a general recommendation based on this study alone. "I think it is too soon to say what should be done about antioxidants," she says.