薬理と治療

Abstract

Objective The purpose of the study was to evaluate the dose response effect of soy peptide supplementation on cognitive function in healthy middle-aged and elderly participants. Methods A randomized, double-blind, placebo-controlled study was conducted. A total of 60 healthy middle-aged and elderly participants （between the ages of 60-70 years）were randomly divided into the following groups: soy peptide group receiving a medium dose（4 g（seryltyrosine content: 9.89 mg）; n＝20）, soy peptide group receiving a low dose（2 g（seryltyrosine content: 4.95 mg）; n＝20）, or placebo group（n＝20）. Psychological tests were performed at baseline and 2 weeks after supplementation with the test foods. Results The performance of the soy peptide groups in the Uchida-Kraepelin test significantly improved. Soy peptide supplementation also had a dose-dependent effect on the performance of participants in the n-back task and recognition memory test. Soy peptide supplementation did not, however, influence the subjective evaluation of the visual analogue scale. Conclusions The current study suggests that daily supplementation with soy peptide improves cognitive abilities, including sustained concentration and attention, short-term memory, and long-term memory, of healthy middle-aged and elderly participants, in a dose -dependent manner（UMIN-CTR ID: UMIN000026779）.