Quitting smoking can reduce women's risk of strokes in as little as two years, regardless of age and past smoking history, according to a recent study by Harvard researchers.

The report, which appeared in last Week's Journal of the American Medical Association, is the first to define how soon stroke risk declines after quitting smoking.

Current smokers were found to be more than two-and-a-half times more likely to suffer a stroke than those who had never smoked. Researchers concluded that after quitting, smokers' additional risks disappeared within two to four years.

"A lot of studies up to now have been giving inconsistent answers in terms of how long it takes for the risk ofstroke to go away after quitting," said theprincipal author of the study, Dr. Ichiro Karachi,assistant professor of health and social behaviorat the School of Public Health.

"Until recently, a physician's advice to awoman quitting smoking is that it could take aslong as 15 years or as little as two years for thebenefits," Karachi said.

But Karachi stressed that despite "substantialbenefits from stopping [smoking]," the best advicestill remains not to start at all.

The report's data was drawn from the Brighamand Women Hospital Nurses' Health Study, a 17-yearold ongoing observation of 121,700 middle-agedfemale registered nurses. The study, the largestever involving former female smokers, asked nursesto describe their age, height, weight, smokinghistory, and other disease specifics.

Karachi said he plans to continue his studieson other diseases. "We're going to be examiningsimilar things in terms of heart attacks, coronaryheart disease, and heart disease," he said