Dietary Approaches to Stop Hypertension Diet and Incidence of Stroke : Results From 2 Prospective Cohorts

BACKGROUND AND PURPOSE: High adherence to the Dietary Approaches to Stop Hypertension (DASH) diet is associated with lower risk of hypertension, the major risk factor for stroke. We examined whether adherence to the DASH diet is inversely associated with the incidence of stroke. METHODS: The study population comprised 74 404 men and women (45-83 years of age), without stroke at baseline, from the Cohort of Swedish Men and the Swedish Mammography Cohort. Diet was assessed with a food-frequency questionnaire. A modified DASH diet score was created based on consumption of vegetables, fruits, legumes and nuts, whole grains, low-fat dairy, red meat and processed meat, and sweetened beverages. Stroke cases were identified through linkage to the Swedish National Patient and Cause of Death Registers. Relative risks and 95% confidence intervals were estimated using Cox proportional hazards regression model. RESULTS: During 882 727 person-years (mean, 11.9 years) of follow-up, 3896 ischemic strokes, 560 intracerebral hemorrhages, and 176 subarachnoid hemorrhages were ascertained. The modified DASH diet score was statistically significantly inversely associated with the risk of ischemic stroke (P for trend=0.002), with a multivariable relative risk of 0.86 (95% confidence interval, 0.78-0.94) for the highest versus the lowest quartile of the score. The modified DASH diet score was nonsignificantly inversely associated with intracerebral hemorrhage (corresponding relative risk=0.81; 95% confidence interval, 0.63-1.05) but was not associated with subarachnoid hemorrhage. CONCLUSIONS: These findings indicate that high adherence to the DASH diet is associated with a reduced risk of ischemic stroke. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifiers: NCT01127698 and NCT01127711 for the Swedish Mammography Cohort and the Cohort of Swedish Men, respectively