“Our findings suggest that low-dose aspirin may have beneficial effects on asthma,” says study co-author Dr. Tobias Kurth, an assistant professor of medicine and an associate epidemiologist in the division of aging at Brigham and Women’s Hospital in Boston. But, Kurth adds, it’s too soon to recommend that anyone start using daily aspirin solely for asthma prevention. As many as 20 million Americans have asthma, according to the American Academy of Allergy, Asthma and Immunology. Despite advances in treatment, about 5,000 people die due to asthma every year in the United States. The incidence of asthma has been rising in recent years, coincident with a drop in the use of aspirin as people have switched to other over-the-counter pain relievers. Kurth and his colleagues reviewed data from the Physicians’ Health Study, which began in 1982. They included data from 22,071 male physicians between the ages of 40 and 84. The physicians were randomly assigned to receive either a daily dose of 325 milligrams of aspirin or a placebo. The original aim of the research was to study aspirin’s role in heart-disease prevention. During the 5-year study period, 113 new cases of asthma were diagnosed in the 11,037-member aspirin group, compared with 145 in the placebo group. This represented a 22% decrease in the risk of developing asthma for those taking low-dose aspirin. Kurth says the researchers weren’t able to study the reasons why aspirin might have this preventive effect against asthma, but theorized that aspirin’s anti-inflammatory effects might play a role. He did caution, however, that for some people who already have asthma, aspirin can be an irritant that can actually trigger asthma symptoms. “This is a complex issue and is more of a study for the research community,” says Kurth. The question for researchers now, he says, is “for those at risk of getting asthma, should they be treated with aspirin or not?” More from Prevention: Your Guide To Adult Asthma