Objective: To investigate the association between a low-risk lifestyle and risk of stroke.
Methods:The study population comprised 31,696 women, in the population-based SwedishMammography Cohort who at baseline had completed a questionnaire about diet and lifestyle and were free from cardiovascular disease and cancer. We defined a low-risk lifestyle as a healthy diet (top 50% of a Recommended Food Score), moderate alcohol consumption (5-15 g/d), never smoking, physically active (walking/bicycling $40 min/d and exercise $1 h/wk), and body mass index below 25 kg/m 2 . Stroke cases were identified from the Swedish National Patient Register and the Swedish Cause of Death Register. Stroke is a major cause of disability and mortality. Because the consequences of stroke are usually devastating and irreversible, primary prevention is of great importance. Hypertension is a strong and well-documented risk factor for stroke.1 Diet, alcohol consumption, smoking, physical activity, and adiposity can modify blood pressure and thus the risk of stroke.1,2 Few studies have examined the combined effect of a low-risk lifestyle on the incidence of stroke. [3][4][5][6] The objective of the present study was to examine the combined effect of multiple low-risk lifestyle factors (healthy diet, 7 moderate alcohol consumption, never smoking, physically active, and healthy body weight) on incidence of total stroke and stroke types in a population-based prospective cohort of Swedish women.METHODS Study population. For the present study, we used data from the Swedish Mammography Cohort, which has been described in detail previously. 8 Briefly, in the autumn of 1997, 39,227 women who resided in Uppsala and Västmanland counties, central Sweden, and were born between 1914 and 1948 completed a 350-item questionnaire concerning diet and lifestyle.Standard protocol approvals, registrations, and patient consents. The Regional Ethical Review Board at Karolinska Institutet in Stockholm, Sweden, approved this study. Return of the completed questionnaire was considered to imply informed consent.Assessment of lifestyle factors. At baseline in 1997, all participants of the Swedish Mammography Cohort completed a selfadministered questionnaire that solicited information on education, body weight, height, smoking, physical activity, use of aspirin, history of hypertension and diabetes, family history of myocardial infarction before the age of 60 years, alcohol consumption, and diet. Participants indicated how many minutes or hours per day they had walked/bicycled (almost never, ,20 min/d, 20-40 min/d,