Long-term low to moderate doses of aspirin beneficial for women

Women who take low to moderate doses of aspirin have a reduced risk of death from any cause, and especially heart disease related deaths, according to a report in the March 26 issue of Archives of Internal Medicine, one of the JAMA/Archives journals.

Some studies have provided evidence that aspirin may reduce the risk of heart disease and some types of cancer, the two leading causes of death in U.S. women, according to background information in the article. However, it is unclear whether aspirin reduces the risk of death overall for women.

Andrew T. Chan, M.D., M.P.H., Massachusetts General Hospital and Harvard Medical School, Boston, and colleagues examined the association between aspirin use and death in 79,439 women enrolled in the Nurses, Health Study, a large group of female nurses who have been followed since 1976. Beginning in 1980 and again every two years through 2004, the women were asked if they used aspirin regularly and if so, how many tablets they typically took per week. At the beginning of the study, the women had no history of cardiovascular disease or cancer.

A total of 45,305 women did not use aspirin; 29,132 took low to moderate doses (one to 14 standard 325-milligram tablets of aspirin per week); and 5,002 took more than 14 tablets per week. By June 1, 2004, 9,477 of the women had died, 1,991 of heart disease and 4,469 of cancer. Women who reported using aspirin currently had a 25 percent lower risk of death from any cause than women who never used aspirin regularly. The association was stronger for death from cardiovascular disease (women who used aspirin had a 38 percent lower risk) than for death from cancer (women who used aspirin had a 12 percent lower risk).

"Use of aspirin for one to five years was associated with significant reductions in cardiovascular mortality," the authors write. "In contrast, a significant reduction in risk of cancer deaths was not observed until after 10 years of aspirin use. The benefit associated with aspirin was confined to low and moderate doses and was significantly greater in older participants and those with more cardiac risk factors."

There are several mechanisms by which aspirin could reduce the risk of death, the authors note. "Aspirin therapy may influence cardiovascular disease and cancer through its effect on common pathogenic pathways such as inflammation, insulin resistance, oxidative stress [damage to the cells caused by oxygen exposure] and cyclooxygenase (COX) enzyme activity," also linked to inflammation, they write.

Because the study looked at women who made the decision themselves whether or not to take aspirin, as opposed to a clinical trial where women are randomly assigned to aspirin or a placebo, the results do not suggest that all women should take aspirin. "Nevertheless, these data support a need for continued investigation of the use of aspirin for chronic disease prevention," the authors conclude.