Rice bran triterpenoids improve postprandial hyperglycemia in healthy male adults: a randomized, double-blind, placebo-controlled study

• Published in: Food & nutrition research 2018-10, Vol.62, p.1-7
• Main Authors: Misawa, Koichi, Jokura, Hiroko, Shimotoyodome, Akira
• Format: Article
• Language: English
• Subjects: Acute effects; Adults; Alcohol; Alcohols; Antifungal agents; Biomarkers; Blood; Blood glucose; Blood pressure; Cardiovascular disease; Diabetes; Diabetes mellitus; Dietary fiber; Dietary supplements; Double-blind studies; Food; GIP; GLP-1; Glucagon; Glucagon-like peptide 1; Glucose; Hyperglycemia; Hypotheses; Insulin; Insulin resistance; Metabolism; Mortality; Oils & fats; Olive oil; Original; Peptides; Randomization; Rice; Rice bran; Sterols; Triterpenoids
• ISSN: 1654-661X; 1654-661X
• DOI: 10.29219/fnr.v62.1412

Compared to white rice, brown rice induces a lower glycemic response in healthy and diabetic humans. This effect is partly attributed to the higher amounts of water- or oil-soluble bran components and dietary fiber in brown rice. We hypothesized that dietary supplementation with oil-soluble rice bran triterpenoids (RBTs; triterpene alcohol and sterol prepared from rice bran) might reduce the incidence of postprandial hyperglycemia in healthy humans. We examined the acute effects of a single RBT-supplemented meal on the postprandial blood glucose responses of healthy male adults in a double-blind, randomized, placebo-controlled, crossover trial. Nineteen subjects consumed a test meal containing either placebo- or RBT-supplemented olive oil. Blood biomarkers were evaluated in a fasting state and up to 240 min postprandially. Compared to the placebo-supplemented meal, the RBT-supplemented meal significantly suppressed the increase in postprandial blood glucose level. A subclass analysis revealed that RBT-supplemented oil significantly reduced blood glucose increases in subjects with higher postprandial blood glucose elevations. Postprandial increases in blood insulin, glucose-dependent insulinotropic peptide (GIP), and glucagon-like peptide-1 (GLP-1) levels did not differ between the groups. These results suggest that RBT consumption improves postprandial hyperglycemia in healthy humans, especially those with higher postprandial glucose increases.