Reported August 13, 2007

Taking vitamins C and E and beta carotene supplements does not seem to reduce the risk of heart attacks or heart-related death among women at high risk for heart disease, finds a study in Archives of Internal Medicine.

Diets high in fruit and vegetables have been associated with lower rates of heart disease and stroke. It's thought that the antioxidants they contain prevent harm to cells caused by exposure to oxygen, which may contribute to cardiovascular disease.

"Antioxidants scavenge free radicals and limit the damage they can cause," the authors write.

So researchers set out to find out whether taking antioxidant supplements would lower heart disease risks.

Nancy R. Cook of Brigham & Women's Hospital and Harvard Medical School in Boston, and colleagues followed 8,171 women 40 years or older (average age 60.6), from 1995 to 2005. The women, who either had a history of cardiovascular disease or three or more risk factors, were randomly assigned to take:

* 500 milligrams of ascorbic acid (vitamin C) or placebo every day;
* 600 IU (international units) of vitamin E or placebo every other day;
* 50 milligrams of beta carotene or placebo every other day.

During the average study period of 9.4 years, 1,450 women had one or more cardiovascular events, including 274 heart attacks, 298 strokes, 889 bypass surgeries or angioplasties and 395 cardiovascular deaths (out of a total 995 deaths).

The researchers found no benefit in preventing heart disease, heart attacks, or heart surgeries from the supplements, either alone or in combination. But they did note fewer strokes among those taking both vitamin C and vitamin E.

At the same time, the researchers found no harm in taking the supplements, except for a small increase in reports of upset stomach among those taking beta carotene.

The authors conclude: "While additional research into combinations of agents, particularly for stroke, may be of interest, widespread use of these individual agents for cardiovascular protection does not appear warranted."

A meta-analysis of almost 70 studies, published in JAMA earlier this year, found that beta carotene, vitamin A, and vitamin E do not reduce mortality and may actually be harmful when taken in large amounts.

Source : CTV.ca News Staff