(HealthDay News) -- Moderate to high levels of regular exercise may help slow lung function decline in smokers and lower their risk of developing chronic obstructive pulmonary disease (COPD), a Spanish study suggests.

Researchers publishing in the March issue of the American Journal of Respiratory and Critical Care Medicine examined the physical activity, smoking history and lung function of nearly 6,800 people over 11 years. None of them had COPD at the start of the trial, but 928 of the participants developed the lung disease during the study.

The researchers found that moderate to high levels of exercise among smokers in the study were associated with a 21 percent decline in potential new cases of COPD. They believe that regular exercise suppresses the production of inflammatory markers in the lungs caused by smoking.

It had been believed that quitting smoking and reducing occupational exposure to smoke were smokers' only options for slowing lung function decline. This study showed that exercise may provide another important option, the study authors said.

"The interaction between physical activity and smoking should be taken into account when projecting the future burden of this respiratory disease," researcher Dr. Judith Garcia-Aymerich, of the Center for Research in Environmental Epidemiology at the Institut Municipal d'Ivestigacio Medica in Barcelona, said in a prepared statement.

COPD, the fourth leading cause of death in the United States, results from chronic bronchitis and emphysema. Smoking is the primary cause of COPD.

More information

The American Academy of Family Physicians has more about COPD.

By Robert Preidt
SOURCE: American Thoracic Society, news release, March 1, 2007
Last Updated: February 2008
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