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 AUC_{0-180 min} for group C was significantly lower than that for group W (P < .05), but the incremental serum insulin and plasma GLP-1 AUC_{0-180 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.