Vegetable juice preload ameliorates postprandial blood glucose concentration in healthy women : A randomized cross-over trial

Abstract

Background and Objectives: The aim of this study was to evaluate the acute effect of drinking vegetable juice 20 min before carbohydrate on postprandial blood glucose concentrations in young healthy women. Method: In this randomized controlled cross-over study, 24 women (age 21.3 ±0.6 years, HbA1c 5.4 ±0.2 %, mean ± SD) consumed either 200 g of vegetable juice, vegetable (150 g of tomato and 40 g of broccoli), or water at 20 min before consuming 200 g of boiled white rice for 3 separate days. The blood glucose concentrations were measured by self-monitoring blood glucose pre- and post-breakfast at -20, 0, 15, 30, 45, 60, 120, and 180 min. The glycemic parameters were compared among 3 days. Results: The incremental glucose peak at 45 min (vegetable juice 48.3 ± 4.1, vegetable 47.4 ± 3.3 vs. water 66.8 ± 4.3 mg/dl, respectively, both p < 0.01, mean ± SEM) and large amplitude of glycemic excursion (LAGE; vegetable juice 57.1 ± 3.1, vegetable 58.3 ± 3.6 vs. water 78.3 ± 4.3 mg/dl, respectively, both p < 0.05) in consuming vegetable juice and vegetable at 20 min before carbohydrate intake were all significantly lower than those of water. There was no significant difference between glycemic parameters of vegetable juice and vegetable. Conclusions: Drinking vegetable juice 20 min before carbohydrate ameliorates the postprandial blood glucose concentrations as well as vegetable preload, despite total amounts of energy and carbohydrate of vegetable juice or vegetable are higher than those of water.