The rate of glucose and the duration of elevated blood glucose levels induce many hormonal and metabolic changes that may affect health or disease parameters. Experimental evidences show that protein fraction of Leguminosae may modulate glucose metabolism, with positive effects on diabetes and heart disease prevention. The aim of this study was to investigate the effect on postprandial glucose response of acute administration of a standardized bean isolate protein (BEANBLOCK, Indena S.p.A., Milano, Italy) employed as supplement in a mixed Mediterranean balanced meal (40% of daily energy intake with 60% carbohydrates, 25% fat and 15% protein).

Twelve healthy subjects (BMI: 21.4±1.4 kg/m2, age: 22.5±2.0 years) received a standardized meal (40% of their energy expenditure, 999±143Kcal), consisting of a sandwich (ham, tomato, oil) with 100mg of BEANBLOCK or placebo in a randomized, cross-over and double-blind design. Venous blood samples were taken fasting and at 10,20,30,45,60,120 and 180 minutes after the meal consumption and analyzed for serum glucose, insulin and C-peptide.

With respect placebo, BEANBLOCK induced: a lower glucose increase at 30 minutes (p= 0.04), a lower insulin increase at 45 minutes (p= 0.04) and between 45 and 90 minutes (p=0.01), a lower C-peptide response between 30 and 90 minutes (p=0.03).

BEANBLOCK employed as supplement in a mixed Mediterranean balanced meal positively affected glucose metabolism. The achievement of a lower postprandial glucose response by a lower insulin response suggests the use of this supplement in subjects with absolute or partial lack of insulin secretion.