Researchers from the University of Maryland School of Medicine interviewed 466 women who had had a stroke between the ages of 15 and 49, and were either smokers, non-smokers or former smokers. A comparison group consisted of 604 women of similar age, race, and ethnicity who had not had a stroke.
The study, which was published in Stroke: Journal of the American Heart Association, found that any smoking at all doubles the risk of stroke. Women who smoke one to 10 cigarettes a day increase their stroke risk 2.2 times. Those who smoke 40 or more cigarettes a day increase their risk 9.1 times, the study said.
The study also found that smoking raises the risk not only of stroke but also of heart disease by damaging blood vessels and making blood clots more likely. The risk declined as early as 30 days after a woman gave up smoking and returned to normal in about two years.
An estimated 21 percent of American women aged 18-44 are cigarette smokers, according to researchers.
