Effects of the Dietary Approach to Stop Hypertension (DASH) diet on cardiovascular risk factors: a systematic review and meta-analysis

The Dietary Approach to Stop Hypertension (DASH) is recommended to lower blood pressure (BP), but its effects on cardiometabolic biomarkers are unclear. A systematic review and meta-analysis of randomised controlled trials (RCT) was conducted to determine the effects of the DASH diet on cardiovascular risk factors. Medline, Embase and Scopus databases were searched from inception to December 2013. Inclusion criteria were as follows: (1) DASH diet; (2) RCT; (3) risk factors including systolic and diastolic BP and glucose, HDL, LDL, TAG and total cholesterol concentrations; (4) control group. Random-effects models were used to determine the pooled effect sizes. Meta-regression analyses were carried out to examine the association between effect sizes, baseline values of the risk factors, BMI, age, quality of trials, salt intake and study duration. A total of twenty articles reporting data for 1917 participants were included in the meta-analysis. The duration of interventions ranged from 2 to 24 weeks. The DASH diet was found to result in significant decreases in systolic BP ( - 5·2 mmHg, 95% CI - 7·0, - 3·4; P< 0·001) and diastolic BP ( - 2·6 mmHg, 95% CI - 3·5, - 1·7; P< 0·001) and in the concentrations of total cholesterol ( - 0·20 mmol/l, 95% CI - 0·31, - 0·10; P< 0·001) and LDL ( - 0·10 mmol/l, 95% CI - 0·20, - 0·01; P= 0·03). Changes in both systolic and diastolic BP were greater in participants with higher baseline BP or BMI. These changes predicted a reduction of approximately 13% in the 10-year Framingham risk score for CVD. The DASH diet improved cardiovascular risk factors and appeared to have greater beneficial effects in subjects with an increased cardiometabolic risk. The DASH diet is an effective nutritional strategy to prevent CVD.