Prior or Concomitant Drinking of Vegetable Juice with a Meal Attenuates Postprandial Blood Glucose Elevation in Healthy Young Adults

Abstract

Controlling postprandial blood glucose levels can prevent and improve lifestyle-related diseases. We aimed to evaluate the effects of a commercially available vegetable juice, which is a convenient alternative to vegetables, on postprandial glucose elevation. In test 1, we confirmed the appropriate timing to consume the vegetable juice (200 mL), and demonstrated that postprandial glucose elevation was attenuated by drinking the vegetable juice with or before the experimental meal. The change in maximum concentration (ΔCmax) of blood glucose was the lowest when the vegetable juice was consumed at 30 min before the meal. In test 2, we confirmed the necessary ingestion volumes of vegetable juice (range: 68.5 - 274 mL) for attenuating the response to 50 g of carbohydrates. After drinking 200 mL of vegetable juice, the ΔCmax and incremental area under the curve values for blood glucose were significantly lower than those for after drinking the same volume of water (p < 0.05). However, a greater volume of vegetable juice did not provide an additive effect. Our results suggest that approximately 200 mL of vegetable juice at 30 min before meals is the most effective method for using vegetable juice to suppress postprandial blood glucose elevation. Stimulation of insulin secretion due to the pre-meal vegetable juice intake may contribute to this effect, although further studies are needed to identify the detailed mechanism for the attenuation.