The Effect of Non-Oil Seed Legume Intake on Blood Pressure: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.

Abstract

Hypertension is a primary modifiable risk factor for CVD, whereby even small reductions in blood pressure (BP) can decrease risk for CVD events. Modification of dietary patterns is an established, nonpharmacologic approach for the prevention and management of hypertension. Legumes are a prevailing component of dietary patterns associated with lower BP in observational research, but there is a need to understand the effects of legume consumption on BP. This study aimed to synthesize evidence from randomized controlled trials (RCTs) for the effects of non-oil seed legume consumption on systolic blood pressure (SBP) and diastolic blood pressure (DBP) (PROSPERO registration: CRD42021237732). We searched CINAHL, Cochrane, Medline, and PubMed scientific databases from inception through November 2022. A random-effects meta-analysis was conducted to assess the mean differences (MDs) for each outcome variable between legume-based and comparator diets. This review included 16 RCTs and 1092 participants. Studies ranged in duration (4-52 wk), participant age (17-75 y), and weekly legume dose (450-3150 g) in whole or powdered form. No significant overall effect between legume consumption and BP amelioration was observed in the meta-analysis (SBP-MD: -1.06 mm Hg; 95% CI: -2.57, 0.4410 mm Hg; I2 = 45%; DBP-MD: -0.48 mm Hg; 95% CI: -1.06, 0.10 mm Hg; I2 = 0%). The certainty of evidence was determined as low for SBP and DBP. Significant subgroup differences in SBP were found when studies were grouped according to participant BMI, with SBP reduction found for participants with overweight/obese BMI (MD -2.79 mm Hg, 95% CI: -4.68, -0.90 mm Hg). There is a need for large, high-quality trials to clearly define the benefits and mechanisms of legume consumption in BP management. Consideration of the relevance in individuals with obesity, overweight, and hypertension may also be warranted. This trial was registered at PROSPERO as CRD42021237732.