Effect of Ayunohikari, a Sugary Rice, on Postprandial Blood Glucose Concentration and Insulin Response in Humans

Abstract

Ayunohikari, a type of sugary rice, has an inhibitory effect on digestion compared with other rice cultivars due to its resistant structure. The present study investigated the effects of Ayunohikari on postprandial blood glucose concentration and insulin response in comparison with a standard rice, Koshihikari. A randomized single-blind crossover-designed study was conducted using eight healthy male subjects (age 39.0±1.7 y, body mass index 23.3±0.6 kg/m², fasting blood glucose concentration 96.4±2.1 mg/dL). Postprandial blood glucose and serum insulin concentrations were observed at ∼240 min after ingestion of Ayunohikari or Koshihikari cooked rice containing 55 g of carbohydrate. The incremental area under the curve of the blood glucose concentration for 240 min after ingestion of Ayunohikari was 17.5% (non-significantly) lower than that after ingestion of Koshihikari (p=0.07). The incremental area under the curve of the serum insulin concentration for 240 min after ingestion of Ayunohikari was 41.3% (significantly) lower than that after ingestion of Koshihikari (p<0.01). Our finding suggest that Ayunohikari is a useful rice strain for primary prevention of diabetes.