Effect of Dietary Pulses on Blood Pressure: A Systematic Review and Meta-analysis of Controlled Feeding Trials

BACKGROUND: Current guidelines recommend diet and lifestyle modifications for primary prevention and treatment of hypertension, but do not encourage dietary pulses specifically for lowering blood pressure (BP). To quantify the effect of dietary pulse interventions on BP and provide evidence for their inclusion in dietary guidelines, a systematic review and meta-analysis of controlled feeding trials was conducted. METHODS: MEDLINE, EMBASE, Cochrane Library, and CINAHL were each searched from inception through 5 May 2013. Human trials ≥3 weeks that reported data for systolic, diastolic, and/or mean arterial BPs were included. Two reviewers independently extracted data and assessed methodological quality and risk of bias of included studies. Effect estimates were pooled using random effects models, and reported as mean differences (MD) with 95% confidence intervals (CIs). Heterogeneity was assessed (χ(2) test) and quantified (I(2)). RESULTS: Eight isocaloric trials (n = 554 participants with and without hypertension) were included in the analysis. Dietary pulses, exchanged isocalorically for other foods, significantly lowered systolic (MD = -2.25 mm Hg (95% CI, -4.22 to -0.28), P = 0.03) and mean arterial BP (MD = -0.75 mm Hg (95% CI, -1.44 to -0.06), P = 0.03), and diastolic BP non-significantly (MD = -0.71 mm Hg (95% CI, -1.74 to 0.31), P = 0.17). Heterogeneity was significant for all outcomes. CONCLUSIONS: Dietary pulses significantly lowered BP in people with and without hypertension. Higher-quality large-scale trials are needed to support these findings. CLINICAL TRIAL REGISTRATION: NCT01594567.