The effect of dietary patterns on estimated coronary heart disease risk results from the Dietary Approaches to Stop Hypertension (DASH) trial

Background: The Dietary Approaches to Stop Hypertension (DASH) diet is recommended in the 2005 US Dietary Guidelines. To understand the potential benefits of DASH on coronary heart disease (CHD), we applied the Framingham risk equations to calculate 10-year risk of developing CHD using data from the DASH trial. Methods and Results: In the DASH trial, 459 individuals with prehypertension or stage-1 hypertension not taking antihypertensive medication were randomly assigned to 1 of 3 diets: control, fruits and vegetables (F/V), or DASH (rich in fruits, vegetables, low-fat dairy, and reduced in fats and cholesterol). Weight was held constant. Estimated 10-year CHD risk was the primary outcome of this secondary analysis. Among 436 participants with complete data, mean (SD) age was 44.7 (10.7) years, 51% were male, and 60% were African-American. Median 10-year CHD risk was 0.98% at baseline and decreased in all groups. Compared with control, the relative risk ratio comparing 8-week with baseline 10-year CHD risk was 0.93 (95% confidence interval, 0.85 to 1.02; P=0.12) for F/V and 0.82 (95% confidence interval, 0.75 to 0.90; P<0.001) for DASH. Comparing DASH with F/V, the relative risk ratio was 0.89 (95% confidence interval, 0.81 to 0.97; P=0.012). With the exception of an interaction between dietary pattern and race suggesting a greater risk reduction in blacks than whites (P for interaction=0.038), results were similar across subgroups. Conclusions: Compared with control and F/V, the DASH diet reduced estimated 10-year CHD risk by 18% and 11%, respectively. In addition to reducing blood pressure, the DASH diet should substantially reduce the risk of CHD. Clinical Trial Registration: URL: http://clinicaltrials.gov. Unique identifier: NCT00000544.