Everyone knows smoking is a bad idea, but those who can't give it up may get a little protection from exercise, a study suggests. In a study of 42,000 older women tracked since 1986, researchers found that a physically active smoker had a 35% lower risk of lung cancer than a sedentary smoker.
One expert called that reduction trivial because smoking itself is so risky. And Dr. Kathryn Schmitz, the study's lead author, stressed that exercising does not give women a free pass to smoke. "The most important thing that smokers can do to reduce the risk of lung cancer is quit smoking," said Schmitz, an assistant professor at the University of Pennsylvania.
Those who quit smoking are 10 to 11 times less likely to develop lung cancer than those who smoke, she said.
In the study, published in this month's issue of Cancer Epidemiology Biomarkers & Prevention, the greatest benefits went to those who had quit smoking and also exercised.
Researchers suggest that improved pulmonary function reduces both the concentration of carcinogenic particles and the extent to which they are deposited in the lungs. Also, being more physically active could make smokers more aware of the damage they have caused their lungs -- leading them to smoke less or quit, Schmitz said.