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 tmax 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.