Aspirin is not effective as a preventative measure for healthy people hoping to avoid heart attacks and strokes, according to a study published earlier this month in the Archives of Internal Medicine.

Examining nine trials with 102,621 people, researchers observed that taking aspirin did not result in a reduction in deaths from heart attack, stroke or cancer. In fact, taking aspirin as a primary prevention method when there is no history of heart attack or stroke increases the chances of internal bleeding by 30 percent. The study does not try to persuade those taking aspirin for proven cardiovascular disease to stop doing so, however. Official guidelines issued in 2005 by the Joint British Societies currently recommend 75 mg of aspirin a day for high-risk patients older than 50.