Effect of vegetable juice consumption prior to eating rice on postprandial blood glucose and insulin levels

Vegetable juice has been demonstrated to attenuate the elevation of postprandial blood glucose when consumed prior to meals. The present study aimed to investigate the effect of pre-meal consumption of vegetable juice on blood glucose and insulin levels. A total of 10 healthy volunteers aged 20–29 years ingested 200 ml of either water, a sugar solution with the same sugar composition as the vegetable juice or vegetable juice 30 min prior to consuming the cooked rice, and their blood glucose and insulin levels were measured. At the time of rice consumption and 15 min thereafter, blood glucose and plasma insulin levels tended to be lower in the vegetable juice intake group compared with those in the sugar solution intake group. However, there were no significant differences in the kinetic parameters (incremental area under the glucose curve and maximum change in glucose concentration) between these two groups. These results suggest that the sugars contained in vegetable juice account for the suppression of postprandial hyperglycemia.