Plasma glucose and insulin reduction after consumption of breads varying in amylose content

Objective: Consumption of a meal high in amylose starch (70%) decreases peak insulin and glucose levels and area under the curve (AUC). The objective was to determine the amount of amylose necessary in a meal for the beneficial decrease in glucose or insulin to occur. Design: Twenty-five subjects, 13 men (averaging 88.1kg, 41y,and 27.9 body mass index) and 12 women (averaging 72.4kg, 41y and 27.1 body mass index) were given six tolerance tests in a Latin Square design: glucose alone (1g glucose/kg body weight) and five breads (1g carbohydrate/kg body weight) made with 70% amylose cornstarch, standard cornstarch (30% amylose), and blends of the two starches (40, 50 and 60% amylose starch). A standard menu was fed for 3 days. One subject withdrew from the study. Results: Glucose, insulin and glucagon response to the carbohydrate loads was similar in men and women. Peak glucose response was lowest after the breads containing 50-70% amylose starch. AUC was significantly higher after the glucose load than after all bread loads. The lowest AUCs occurred after the 60 and 70% amylose starch breads. Insulin response and AUC were significantly lower after the 60 and 70% amylose starch breads than after the glucose or the other breads. Conclusion: Results indicate that the amylose content of the starch used in the acute meal needs to be greater than 50% to significantly reduce plasma glucose and insulin in men and women.