薬理と治療

Abstract

Recent study has demonstrated that dietary supplementation of soy peptides, composed primarily of di- and tri-peptides(Hinute, Fuji Oil Co. Ltd), improved age-associated cognitive decline, such as delayed memory and immediate memory. Furthermore, soy peptide intake increased the levels of certain neuroactive amino acids in the adult mouse brain. In this study, we evaluated the effects of soy peptide supplementation on higher brain function in healthy young volunteers. A randomized, double-blind, placebo-controlled study was performed in 41 healthy male subjects aged between 20 and 22(soy peptide group:n=21, placebo group:n=20). Neuropsychological tests were performed at baseline and after 2-week supplementation of 8 g/day soy peptide or placebo. The task performance accuracy assessed by the Uchida-Kraepelin test was significantly higher in the soy peptide group than in placebo group. The recognition memory test for words showed significant improvement in the recognition memory performances of new items in the soy peptide group. Subjective evaluation by the visual analogue scale also demonstrated that soy peptide supplementation reduced fatigue and stress after the neuropsychological tests. These results suggest that soy peptide dietary supplementation could help reduce fatigue and stress and improve task-solving ability.