Taking regular vitamin E supplements probably won't protect you from cancer or heart disease, according to this week's issue of the Journal of the American Medical Association (Vol. 293, No. 11: 1338-1347). In fact, high doses appear to actually raise the risk of heart failure, researchers reported.

The study isn't the first to find no overall cancer or heart benefits from vitamin E, but some experts say it may be the last word on the subject.

In an editorial published with the study, University of Washington professors B. Greg Brown, MD, PhD, and John Crowley, PhD, say the work "effectively closes the door" on the idea that vitamin E will be of major benefit in preventing cancer or heart disease.

Brown is a professor in the division of cardiology at the university's medical school. Crowley is a professor of biostatistics at the university's School of Public Health and Community Medicine and a member of the department of cancer research and biostatistics at Fred Hutchinson Cancer Research Center, in Seattle.

The new research, they said, will give patients a definitive answer to questions about vitamin E:

"In nearly 68,000 patients studied to date, there is no compelling evidence that higher doses of vitamin E reduce cardiovascular risk or cancer," they wrote. "You may hear that vitamin E is a 'natural,' yet effective way to prevent heart disease or cancer, but this has proven to be a false hope."

The study, known as HOPE-TOO, followed nearly 4,000 people 55 and older for more than seven years. The participants were all at high risk of heart disease because of diabetes, circulation problems, or other factors. They were assigned to take either 400 IU (international units) of vitamin E or a dummy pill.

The researchers examined overall cancer cases and deaths and found no significant differences between the two groups.

Then they looked at specific cancers that previous studies suggested might be helped by vitamin E: prostate, lung, oral, colorectal, breast, and melanoma. Even for these cancers, no significant difference was seen between the groups.

When the researchers examined heart disease, they found no differences between the groups for heart attacks, stroke, unstable angina, and several other types of heart problems. However, people on vitamin E were more likely to develop heart failure.

No other study of vitamin E has looked at heart failure; the researchers suggest reviews of previous research be done to look for similar links.

Despite the disappointing results of this study for cancer and heart disease overall, Brown and Crowley note that vitamin E hasn't been ruled out completely as a helpful substance for some very specific conditions, including certain cancers.

The ongoing SELECT trial, for instance, will help answer whether vitamin E and selenium can protect men against prostate cancer.

Vitamin E may also help people with age-related macular degeneration, a condition that can cause blindness, and with a specific type of kidney problem.

Nevertheless, they said, patients shouldn't ignore other, proven methods of preventing disease in favor of vitamin E.