Effect of cacao polyphenol-rich chocolate on postprandial glycemia, insulin, and incretin secretion in healthy participants

OBJECTIVES There is substantial interest in using dark chocolate to prevent postprandial hyperglycemia. We investigated the effects of cacao polyphenol-rich chocolate on postprandial glycemic and insulinemic responses and whether cacao polyphenol-rich chocolate increases glucagon-like peptide-1 (GLP-1) secretion. METHODS In a stratified, randomized, crossover study, 48 healthy participants ingested either water (W) or cacao polyphenol-rich chocolate plus water (C) 15 min before a 50 g oral glucose tolerance test (OGTT). Pre- and postprandial concentrations of blood glucose, insulin, free fatty acid, glucagon, and GLP-1 were evaluated. RESULTS Peak plasma glucose concentrations did not differ significantly between groups W and C; however, plasma glucose concentrations at 120 min in group C were significantly lower than those in group W (P < .01). Postprandial serum insulin and plasma GLP-1 concentrations and incremental serum insulin and plasma GLP-1 area under the curve (AUC)-15-180 min for group C were significantly higher than those for group W (P < .05). When comparing the changes after the OGTT, the incremental plasma glucose AUC0-180 min for group C was significantly lower than that for group W (P < .05), but the incremental serum insulin and plasma GLP-1 AUC0-180 min did not differ significantly between groups W and C. CONCLUSIONS This study indicated that the intake of cacao polyphenol-rich chocolate before a 50 g OGTT could enhance early insulin and GLP-1 secretion in healthy participants, and illustrates the potential of cacao polyphenol-rich chocolate in managing postprandial glucose excursions.