Discussion
obesity, metabolic syndrome, type 2 diabetes mellitus)Our study
OBESITY, METABOLIC SYNDROME
The present results demonstrated that an acute intake of a strawberry beverage increased serum vitamin C and folate levels and enhanced the antioxidant capacity of LDL in healthy young women. There was no significant difference in the glycemic response between the placebo and strawberry beverage consumptions. This is one of the few studies that have investigated the effect of an acute intake of a food product that is rich in folate and/or vitamin C on postprandial changes in their serum levels.Several clinical studies have indicated a great variation in the bioavailability of food folate (ranging from 30 to 98 % compared with chemical-based folic acid products)Our present analyses also revealed that the ingestion of the strawberry beverage significantly extended the lag phase of LDL oxidation. This acute effect against LDL oxidation might be due to the antioxidant properties of the phytonutrients of strawberry. Another study showed that the LDL oxidation in response to a high-fat meal was attenuated after 6 weeks of the daily consumption of a strawberry beverageOur earlier study demonstrated that an acute intake of green tea catechins at a dose of 1 g total catechin (of which most [>99 %] was the gallated type) resulted in increases in the levels of LDL catechins and prolonged the lag time of LDL oxidation in healthy adultsWe also observed that the subjects’ serum concentrations of glucose reached a peak at 0⋅5 h after the ingestion of either the strawberry or placebo beverage. There was no significant difference in peak blood glucose levels between the placebo and strawberry ingestions. The consumption of 16 g of glucose and 16 g of fructose from the strawberry beverage caused slight increases in blood glucose and insulin at 0⋅5 h, and the values then quickly returned to baseline levels, which was similar to the placebo beverage. It has been reported that dietary supplementation with strawberries improved postprandial insulin responses, blunting postprandial insulin and glucose responses in both metabolically healthy and unhealthy subjects (e.g. subjects with obesity, metabolic syndrome or type 2 diabetes mellitus)Our study has several limitations. First, individual genetic diversity such as single nucleotide polymorphisms of methylenetetrahydrofolate reductase were not taken into account. Second, we measured postprandial changes in serum vitamin C and folate levels, but not changes in polyphenolic compounds. Third, the antioxidant capacity of LDL was evaluated only by the In conclusion, a single intake of a strawberry beverage increased serum vitamin C and folate levels and enhanced the antioxidant capacity of LDL, and this can be expected to contribute to the health of women of childbearing age.