Objective　A randomized, double-blind, placebo-controlled crossover study with non-diabetic individuals was conducted to investigate the suppressive effect of acacia polyphenol （AP）supplement on postprandial blood glucose elevation.
Methods　The changes in the blood glucose and insulin levels in thirteen individuals were monitored over a period of 120 min after taking either 120 mg of proanthocyanidins（ 250 mg of AP） or a placebo before consuming 200 g of cooked rice.
Results　The results showed a significant difference between those who had taken the AP and the placebo with respect to the change in blood glucose level over the time period from 0 min to 60 min after the rice consumption. Both the blood glucose IAUC and insulin IAUC were significantly lower in the group who had been given AP. These results demonstrated that the AP supplement reduced the absorption of carbohydrates and limited the rise of the blood glucose in humans after eating and hence AP may be able to be used in the control of blood glucose in humans suffering from diabetes.
Conclusions　This study demonstrates that the AP supplement decreases glucose absorption and limits the blood glucose elevation in humans after eating; it also prevents the rapid secretion of insulin. These effects of an AP supplement are beneficial for blood glucose control.