Assessing the Postprandial Glycemic Response to Japonica Rice (Oryza sativa L. cv. Koshihikari) with a Small Amount of Lysolecithin and Canola Oil in Japanese Adult Men : a Double-blind, Placebo-controlled, Crossover Study

Abstract: A double-blind, placebo-controlled, crossover trial was performed to analyze the effects of a small amount of lysolecithin and canola oil on blood glucose levels after consuming japonica rice. Overall, 17 Japanese adult men were assigned to consume 150 g of normally cooked japonica rice (placebo group) and 150 g of japonica rice cooked with 18 mg of lysolecithin and 1.8 g of canola oil (treatment group); these lipids were added as emulsified formulation (EMF) for stability and uniformity. Subsequently, blood samples were collected before and 30, 45, 60, 90, and 120 min after consuming test foods. There was no significant difference in blood glucose, insulin, and triglyceride levels between the groups. However, a stratified analysis of 11 subjects with body mass index (BMI) >- 22 revealed that blood glucose levels were significantly lower after 30 min in the treatment group than in the placebo group (p = 0.041). Through in vitro digestibility test, the rice sample of the treatment group was observed to release significantly less glucose within 20 min than that in the placebo group rice. These results suggest that the combination of a small amount of lysolecithin and canola oil modulated the increase in postprandial blood glucose levels induced by the intake of cooked japonica rice in adult men with BMI >- 22. This clinical trial was registered with the University Hospital Medical Information Network (UMIN) Center, (UMIN000045744; registered on 15/10/2021).