In women over the age of 45, with no personal history of heart disease, 100 mg of aspirin taken daily prevented a relatively small number of heart attacks and even a smaller number of colorectal cancers. The risk of major gastrointestinal bleeding remained high.

In women over the age of 65, with no personal history of heart disease, the benefits of cardiovascular protection increased and incidence of colorectal cancers decreased, with 100 mg of aspirin, but at the expense of an even higher risk of bleeding.

The authors conclude that aspirin “is ineffective or harmful in the majority of women with regard to the combined risk of cardiovascular disease, cancer, and major gastrointestinal bleeding.” However, “selective treatment” in older women may be reasonable.

In most women, the benefits of regular aspirin use for primary prevention don’t outweigh the risks, a Heart study suggests.

Heart