2020 年 7 巻 2 号 p. 174-180
Objective: Persistence of postprandial hyperglycemia causes elevation of glycative stress. The purpose of this study was to examine the suppressing effect of lemon juice on postprandial hyperglycemia when ingesting cooked rice, thereby, the changes in blood glucose (BG) levels were compared and verified, based on an intake of cooked rice alone as a standard, when lemon juice was ingested before cooked rice. Methods: Subjects were 12 healthy males and females aged 20 to 30 years old who participated in a briefing session held in advance and provided written consent. The changes in BG level were verified between three test foods as follows: when the cooked rice was ingested alone (A), 15 g of lemon juice was ingested before the rice (B), and 30 g of lemon juice was ingested before the rice (C). Lemon juice was ingested after diluting it with 150 mL of water. FreeStyle Libre Pro was used for the test, and the measured glucose concentration in the interstitial fluid was taken as the BG level. The BG levels evaluated were collected before ingesting the test food (0 min), 15, 30, 45, 60, 90, and 120 min after the start of the test. The results were evaluated by the BG level, the maximum BG change (ΔCmax) and the incremental area under the curve of BG (iAUC). Bonferroni multiple test was performed for statistical analysis. Results: There were no adverse events and no subject met the exclusion criteria for analysis, therefore, all 12 subjects were included in the efficacy analysis. The blood glucose change (ΔBG) increased until 45 min after the start of the A to C intake test, and decreased until 120 min thereafter. After 30 min, ΔBG of test food C tended to be lower than that of A and B (p < 0.1). The highest value was shown 45 min after ingestion of the test foods A to C, when ΔBG was significantly lower in C than in A (p < 0.05). ΔCmax was 20.3% lower in C than in A (p < 0.05). iAUC in C tended to be 24.8% lower than that of A (p < 0.1). Conclusion: This study showed that a diet that ingest lemon juice prior to rice suppressed postprandial hyperglycemia that was observed when 30 g of lemon juice was taken. A dietary habit of ingesting a beverage containing lemon juice before meals may reduce glycative stress by suppressing postprandial hyperglycemia, and may contribute to the prevention of aging and disease progression.