Effects of oral monosodium (L)-glutamate on insulin secretion and glucose tolerance in healthy volunteers

Aims To investigate the effects of glutamate on insulin secretion and glucose tolerance in humans. Methods Monosodium (L)-glutamate (10 g) was given orally in a double-blind placebo-controlled cross-over study to 18 healthy volunteers, aged 19-28 years, with an oral (75 g) glucose load. Results The 75 min insulin response (AUC(0,75 min)), up to t(max) of glutamate kinetics, was significantly correlated with the AUC(0,75 min) of glutamate concentrations (r=0.485, P=0.049). Glucose tolerance was not affected. Conclusions Oral (L)-glutamate enhances glucose-induced insulin secretion in healthy volunteers in a concentration-dependent manner.