Healthy lifestyle and the risk of stroke in women
Background: Healthy lifestyle has been associated with decreased risk of coronary heart disease. In contrast, little is known about its association with stroke risk. Methods: This is a prospective cohort study among 37 636 women 45 years or older participating in the Women's Health Study. Stroke was self-reported and confirmed by means of medical record review. We considered the following self-reported lifestyle factors: smoking, alcohol consumption, exercise, body mass index, and diet. The health index was calculated from these variables by assigning scores from 0 to 4 to the respective variable categories, with a higher score indicating healthier behavior. Healthy behavior was defined as never smoking, alcohol consumption between 4 and 10.5 drinks per week, exercise 4 or more times per week, body mass index (calculated as weight in kilograms divided by the square of height in meters) less than 22, and a diet high in cereal fiber, folate, and omega-3 fatty acids, with a high ratio of polyunsaturated to saturated fat, and low in trans fat and glycemic load. Results: During 10 years of follow-up, 450 strokes (356 ischemic, 90 hemorrhagic, and 4 undefined) were confirmed. Compared with participants with 0 to 4 health index points (4.3%), women with 17 to 20 health index points (4.7%) had multivariable-adjusted hazard ratios (95% confidence interval) of 0.45 (0.24-0.83; P<.001 for trend) for total stroke, 0.29 (0.14-0.63; P<.001 for trend) for ischemic stroke, and 1.27 (0.37-4.29; P=.62 for trend) for hemorrhagic stroke. Conclusions: In this large prospective cohort of apparently healthy women, a healthy lifestyle consisting of abstinence from smoking, low body mass index, moderate alcohol consumption, regular exercise, and healthy diet was associated with a significantly reduced risk of total and ischemic stroke but not of hemorrhagic stroke. Our findings underscore the importance of healthy behaviors in the prevention of stroke.