Many folks pop a daily aspirin pill to reduce their risk of experiencing a heart or brain disaster. They do this with the blessings of their physicians and the medical establishment.

But results from a new trial found—contrary to popular opinion—that aspirin does not reduce the risk of heart attack and stroke for people with diabetes or peripheral arterial disease.

The study was conducted by Jill Belch, M.D., a professor of vascular medicine at the University of Dundee in Scotland. The report was published in the online issue of the British Medical Journal (BMJ).

In a HealthDay news report, Belch said aspirin is effective in reducing the risk of attacks for people who have already had a heart attack or stroke. But her study involved 1,276 people who had not yet suffered a heart attack or stroke. The patients were considered “high risk” because they had diabetes or peripheral arterial disease, which is partial blockage of leg arteries.

The findings showed that aspirin use was not effective in primary prevention of attacks in this group.

“The number of heart attacks and strokes was exactly the same over eight years for those taking aspirin and those taking placebo,” Belch said.

Both the American Heart Association and the Food and Drug Administration (FDA) recommend aspirin for people at high risk for heart disease due to diabetes and other conditions—but who have not had heart attacks or strokes.

William R. Hiatt, M.D., a professor of medicine at the University of Colorado in Denver, wrote in an accompanying editorial that the daily aspirin recommendations should probably be changed.

“Overall, if you do not have heart disease, the risk of bleeding outweighs any benefit you get from aspirin,” Hiatt said.

Hiatt served on an FDA advisory committee that reviewed Bayer’s 2003 request to include primary prevention in heart disease on aspirin labels. “We couldn’t support that request,” he said.