Study Raises Doubts About Vitamin E Supplements (Reuters)

CHICAGO (Reuters) - Daily vitamin E supplements do not prevent cancer, strokes or heart attacks in older people with vascular disease or diabetes, and may increase their risk of heart failure, a study said on Tuesday.

Millions of people take the supplements hoping for longer and healthier lives.

"In conjunction with its lack of efficacy, the potential for harm suggested by our findings strongly supports the view that vitamin E supplements should not be used in patients with vascular disease or diabetes mellitus," said the study from Canada's McMaster University and Hamilton Health Sciences Corp.

People in the study taking vitamin E were 40 percent more likely to be hospitalized for heart failure than those who were not taking it.

It adds to a growing body of evidence that suggests taking vitamins is not always a fast route to good health and can even be harmful.

In a study released in November 2004, doctors at Johns Hopkins University in Baltimore found that elderly people taking 200 international units or more of vitamin E a day died at a higher rate.

That research came from a review of 19 studies involving 136,000 mostly elderly patients in North America, Europe and China.

'CERTAINLY NOT THE FINAL WORD'

A group representing the supplement industry said it was important to note that the latest study involved only older people with a history of heart disease, stroke or diabetes.

"This is certainly not the final word on vitamin E and should not obscure the fact that for millions of healthy people vitamin E has many long-term benefits, including protecting against oxidative damage in body cells and reducing harmful inflammation," the Washington-based Council for Responsible Nutrition said.

The study's chief author, Dr. Eva Lonn, said: "In high risk people vitamin E does not prevent cardiovascular disease, namely heart attack and stroke, and it does not prevent cancer. Furthermore, we noticed an increased risk of heart failure, so there is a potential for harm in people receiving vitamin E."

The study was published in this week's Journal of the American Medical Association. It involved thousands of people age 55 and older with heart disease or diabetes, who were given 400 international units of vitamin E daily -- a standard dosage -- or a placebo.

The vitamin "had no clear impact on fatal and nonfatal cancers, major cardiovascular events or deaths," the study said.

But there was "an increase in the risk of heart failure, which is of concern. Although this adverse effect of vitamin E was unexpected and cannot be confirmed at this time by other trials, our data are internally consistent."

In an editorial commenting on the Canadian study and appearing in the same journal on Tuesday, experts at the University of Washington said the study "effectively closes the door on the prospect of a major protective effect of long-term exposure to this supplement, taken in moderately high dosage, against complications of atherosclerosis and overall cancer incidence."