Adding Lemon and n-3 PUFA-Rich Oil to Tomato Juice Preload to a Carbohydrate Meal Ameliorates Early Glycemic and Insulin Responses in Young Healthy Women: A Randomized Crossover Trial

Abstract

The aim was to evaluate the acute effect of drinking tomato juice preloaded with lemon and perilla oil 10 min before consuming carbohydrate on postprandial blood glucose, insulin, and lipids concentrations in young healthy women. In this randomized controlled crossover study, 21 women (age 21.1±0.6 y, HbA1c 5.2±0.2%, mean±SD) consumed either 200 g of tomato juice, tomato juice with 10 g of lemon juice and 5 g of perilla oil (n-3 PUFA-rich oil), or water 10 min before consuming 200 g of boiled white rice for 3 separate days. The energy and fat in tomato juice with lemon/n-3 PUFA-rich oil were higher (energy 402 kcal, fat 5.6 g) than tomato juice (354 kcal, 0.6 g) and water (315 kcal, 0.6 g). The blood parameters were measured at 0, 30, 60, and 120 min after carbohydrate consumption and compared among 3 d. The plasma glucose at 30 min in tomato juice with lemon/n-3 PUFA-rich oil was significantly lower than that of water (103.1±3.4 mg/dL vs. 127.8±4.0 mg/dL, p<0.001, mean±SE) and tended to be lower than that of tomato juice (113.9±4.9 mg/dL, p=0.078). The serum insulin at 30 min was also significantly lower in tomato juice with lemon/n-3 PUFA-rich oil than that of tomato juice (p<0.01). Adding lemon and n-3 PUFA-rich oil to tomato juice before carbohydrate meal can be practical method to lower early postprandial glucose and insulin responses in young healthy women.