Influence of Ultra-High Hydrostatic Pressurizing Brown Rice on Cognitive Functions and Mental Health of Elderly Japanese Individuals: A 2-Year Randomized and Controlled Trial

: Brown rice contains many ingredients that might protect against cognitive decline and Alzheimer's disease. However, brown rice is very hard, difficult to cook, and is poorly digested; thus, it is difficult to eat long-term. To solve these problems, ultra-high hydrostatic pressurizing brown rice (UHHPBR) was prepared. We investigated the effects of dietary UHHPBR administration for 24 mo on cognitive function and mental health in the elderly. Healthy elderly participants (n=52) were randomized into UHHPBR and polished white rice (WR) groups. The UHHPBR group consumed 100 g of UHHPBR per day for 24 mo and the WR group consumed white rice. At baseline, and after 12 and 24 mo, cognitive functions were assessed using the Revised Hasegawa's Dementia Scale, Mini-Mental State Examination, Frontal Assessment Battery (FAB), and the Cognitive Assessment for Dementia, iPad version (CADi). Mental health condition was also assessed using the Apathy Scale and the Zung Self-Rating Depression Scale, and serum biochemical parameters were determined. From baseline to month 24, the mean change in the FAB-sub item 1 scores was higher in the UHHPBR group compared to the WR group. Furthermore, apathy scores decreased, as well as the time required to answer all questions of the CADi, and plasma epinephrine levels increased. These results indicate that a 2-y oral consumption of UHHPBR increases information processing speed (as a measure of cognitive function) and improves apathy in the elderly, suggesting a protective effect of UHHPBR administration against age-related decline in brain cognition and motivation.