Effectiveness of the DASH diet versus alternative dietary interventions for hypertension management: A systematic review and meta-analysis.

Abstract

BACKGROUND: The Dietary Approaches to Stop Hypertension (DASH) diet is widely recommended for blood pressure control; however, its comparative effectiveness relative to other structured dietary interventions remains uncertain. OBJECTIVE: To evaluate the comparative effectiveness of the DASH diet versus alternative dietary interventions on blood pressure and cardiometabolic outcomes in adults. METHODS: A systematic review and meta-analysis of randomized controlled trials was conducted in accordance with PRISMA guidelines. Multiple databases were searched from inception to February 2026. Eligible studies included adults with elevated blood pressure or hypertension comparing the DASH diet with other dietary interventions or usual care. Continuous outcomes were pooled using random-effects models and expressed as mean differences (MD) or standardized mean differences (SMD). Risk of bias was assessed using the Cochrane RoB 2 tool, and certainty of evidence was evaluated using the GRADE approach. RESULTS: A total of 22 randomized controlled trials were included in the qualitative synthesis, of which 10 were included in the meta-analysis. The DASH diet did not demonstrate a statistically significant advantage over comparator diets in reducing systolic blood pressure (MD = 1.30; 95% CI: -1.54 to 4.14) or diastolic blood pressure (MD = 0.21; 95% CI: -3.72 to 4.14), with substantial heterogeneity observed across studies. Significant effects were identified for selected cardiometabolic outcomes, including reductions in urinary sodium excretion (MD = -32.89; 95% CI: -62.76 to -3.01), LDL cholesterol (MD = -8.59; 95% CI: -14.64 to -2.54), and glycated hemoglobin (HbA1c) (MD = -0.49; 95% CI: -0.52 to -0.46), as well as an increase in urinary potassium excretion (MD = 11.76; 95% CI: 4.08 to 19.44). The certainty of evidence ranged from moderate to very low across outcomes. CONCLUSIONS: The DASH diet was not superior to other dietary interventions in reducing blood pressure; however, it demonstrated consistent benefits in selected cardiometabolic parameters. Given the overall low certainty of evidence and substantial heterogeneity, these findings should be interpreted cautiously. Future research should focus on well-designed trials with standardized outcomes and longer follow-up to clarify comparative effectiveness.