A bit of aspirin every other day can help women keep asthma away, according to a study.
Previous research has shown the same benefit for men, but this study, published in the British journal Thorax, is the first to demonstrate that aspirin reduces the risk of asthma in women as well.
The findings are based on a massive survey of nearly 40 000 US female healthcare professionals, 45 and older, over 10 years.
Half the participants, who had no serious illness or allergy when the study began, took 100 milligrammes of aspirin every two days, while the other half took a look-alike placebo.
In the placebo group, 963 new cases of asthma were diagnosed, but 872 new cases - 10 percent fewer - were reported among the women taking aspirin.
Aspirin - which in its classic form comes in 325 milligramme tablets - reduced the risk of asthma irrespective of age, menopausal status, exercise levels or smoking.
But it had no impact in clinically obese women.
Previous research in male doctors showed that aspirin cut the chances of asthma by 22 percent, though the doses taken were more than three times higher.
Asthma is a chronic disease that causes inflammation and swelling of the inside of the airways leading to the lungs, reducing the flow of air.
According to World Health Organisation estimates, 300 million people suffer from asthma around the world, and 255 000 people - mainly in poorer countries - died from the disease in 2005.
Among people who have already been diagnosed with asthma, aspirin can worsen symptoms in around one in 10 cases, say the authors.