Trial for the Development of Bio-Functional Foods to Prevent Diabetes and Dementia Using a High-Pressure Treatment

Type-2 diabetes and Alzheimer’s disease are very serious diseases and the former has been suggested to be one of the causes of the latter. Low glycemic index foods inhibit rapid increases in blood glucose and insulin secretion after meals. In this study, we investigated the palatability of boiled rice and inhibition of an abrupt increase in blood glucose level (BGL) and amyloid β peptide production after eating blend of ordinary brown rice, “Koshihikari” and anthocyanin-rich black-rice, “Okunomurasaki” unpolished rice cooked after a high-pressure treatment (HPT KO). “Okunomurasaki” showed a high antioxidant capacity and high inhibitory activity against β-secretase even after HPT and cooking. A randomized, single-blind, crossover-designed study was conducted using 15 subjects with a normal BGL. BGLs at 90 and 120 min after ingesting the cooked HPT KO were significantly lower than that for cooked Koshihikari polished rice (p < 0.05). Furthermore, the increase in the amyloid β40 peptide in the blood 120 min after eating HPT KO tended to be lower than that of cooked Koshihikari polished rice. It would be necessary to conduct a long-term test using the present HPTKO in terms of inhibitory activity against the abrupt increase of BGL and amyloid β peptide production for the probability to prevent type-2 diabetes and Alzheimer’s disease.