Background: The Dietary Approach to Stop Hypertension (DASH) is recommended to lower blood pressure (BP) but effects on cardiovascular risk factors are unclear. We conducted a systematic review and meta-analysis of randomised controlled trials (RCTs) to test the effects of the DASH diet on cardiovascular risk factors.
Methods and Results: Medline, EMBASE, and Scopus databases were searched from inception to December 2013. Inclusion criteria were: 1)DASH diet; 2)RCTs; 3)risk factors including systolic and diastolic BP, glucose, high-density lipoproteins (HDL), low-density lipoproteins (LDL), triglycerides and total cholesterol; and 4)control group. Random-effects models were used to determine the pooled effect sizes. Meta-regression analysis examined the associations between the effect size and baseline values of the cardiovascular risk factors, body mass index (BMI), age, quality of trials and study duration.
Results: Twenty articles reporting data for 1,917 participants were included in the meta-analysis. Intervention duration ranged from 2 to 24 weeks. The DASH diet produced significant decreases in systolic (−4·5mmHg, 95%CI = −5·7 −3·2, p < 0·001, Figure 1) and diastolic BP (−2·5mmHg, 95%CI = −3·3 −1·7, p < 0·001) and concentrations of total cholesterol (−7·6 mg/dL, 95%CI = −12·5 −2·8, p = 0·002), LDL (−4·9 mg/dL, 95%CI = −8·9 −0·8, p = 0·01) and glucose (−3·0 mg/dL, 95%CI = −5·5 −0·6, p = 0·01). Changes in both systolic and diastolic BP were greater in participants with higher baseline BP or BMI. These changes in cardiovascular risk factors predicted ~12% reduction in 10-year risk Framingham risk score for cardiovascular diseases (Figure 1).
Fig. 1. Forest-plots of randomized clinical trials investigating the effects of DASH dietary interventions on systolic pressure (BP, left panel) and predicted percent change in 10-year probability of developing a cardiovascular event as a consequence of changes in systolic blood pressure, total cholesterol and HDL from the meta-analysis data (right panel).
Conclusions: The DASH diet improved cardiovascular risk factors and appeared to have greater benefits in subjects at higher cardio-metabolic risk. The DASH diet is an effective nutritional strategy to lower cardiovascular risk.
