Pulse consumption improves indices of glycemic control in adults with and without type 2 diabetes: a systematic review and meta-analysis of acute and long-term randomized controlled trials

Purpose Findings from randomized controlled trials (RCTs) evaluating the effect of pulse intake on glycemic control are inconsistent and conclusive evidence is lacking. The aim of this study was to systematically review the impact of pulse consumption on post-prandial and long-term glycemic control in adults with and without type 2 diabetes (T2D). Methods Databases were searched for RCTs, reporting outcomes of post-prandial and long-term interventions with different pulse types on parameters of glycemic control in normoglycemic and T2D adults. Effect size (ES) was calculated using random effect model and meta-regression was conducted to assess the impact of various moderator variables such as pulse type, form, dose, and study duration on ES. Results From 3334 RCTs identified, 65 studies were eligible for inclusion involving 2102 individuals. In acute RCTs, pulse intake significantly reduced peak post-prandial glucose concentration in participants with T2D (ES - 2.90; 95%CI - 4.60, - 1.21; p <= 0.001; I-2 = 93%) and without T2D (ES - 1.38; 95%CI - 1.78, - 0.99; p <= 0.001; I-2 = 86%). Incorporating pulse consumption into long-term eating patterns significantly attenuated fasting glucose in normoglycemic adults (ES - 0.06; 95%CI - 0.12, 0.00; p <= 0.05; I-2 = 30%). Whereas, in T2D participants, pulse intake significantly lowered fasting glucose (ES - 0.54; 95%CI - 0.83, - 0.24; p <= 0.001; I-2 = 78%), glycated hemoglobin A1c (HbA(1c)) (ES - 0.17; 95%CI - 0.33, 0.00; p <= 0.05; I-2 = 78) and homeostatic model assessment of insulin resistance (HOMA-IR) (ES - 0.47; 95%CI - 1.25, - 0.31; p <= 0.05; I-2 = 79%). Conclusion Pulse consumption significantly reduced acute post-prandial glucose concentration > 1 mmol/L in normoglycemic adults and > 2.5 mmol/L in those with T2D, and improved a range of long-term glycemic control parameters in adults with and without T2D. PROSPERO registry number (CRD42019162322).