— A tablet of aspirin a day could "keep mortality at bay", according to a large new study of women.
Nearly 80,000 women were involved in the study, which found that those who took aspirin daily had a 25% lower risk of death during the study period than their counterparts who did not take the drug. However, doctors caution that other large studies have not shown this benefit from aspirin and that further research is needed to clarify its health effect.
Andrew Chan at Harvard Medical School in Boston, Massachusetts, US, and colleagues analysed information collected from 79,439 women enrolled in a nurses' health study. Every two years, since 1980, women in the study provided details about their medication use. Chan's team analysed the data collected until 2004, by which time around 9500 of the women in the trial had died from various causes.
The analysis revealed that women who used aspirin had a 25% lower risk of death from all causes than those who did not take the medication. Aspirin-takers also had a 38% lower risk of death from heart disease and a 12% lower risk of death from cancer.
Aspirin disrupts the blood clotting response in the body, and might subsequently reduce the chance of a dangerous clot forming in the heart or brain. Doctors say this appears to be how the drug prevents against heart attack and stroke. They add that the medication seems to have an anti-inflammatory effect, and that this could be why it might cut the risk of cancer.
Chan believes that aspirin might benefit specific groups of women, such as those with a history of heart disease in their family.
Physicians are quick to add, however, that aspirin can cause serious side effects, including stomach ulcers. "Aspirin use risks gastrointestinal bleeding at any dose," says Chan.
But John Baron at the Dartmouth Medical School in Hanover, New Hampshire, US stresses that whether or not aspirin can "keep mortality at bay" remains unclear. He notes that earlier studies such as the Women's Health Study involving 40,000 participants have not found that aspirin reduces the risk of death from heart disease or from any other cause.
Baron points out volunteers in the Women's Health Study were randomly assigned to take either aspirin or a placebo pill over the course of 11 years. By comparison, Chan's team simply observed the reported medication use of subjects in the Nurses' Health Study.
This key difference could explain how the two large studies reach conflicting conclusions. He suggests that the women in the Nurses' Health Study who decided themselves to take aspirin might simply be more health-conscious.
Journal reference: Archives of Internal Medicine (vol 167, p 562)