薬理と治療

Abstract

Objective The aim of this study was to investigate the effect of intake of sweet beverage made from rice koji（amazake）on skin barrier functions in adult women. Methods We conducted a randomized, double-blind, placebo-controlled, parallel-group study with women subjects with moderately dry skin condition. Women subjects（64 persons aged from 20 to 64 years）were randomly allocated to 2 groups: placebo group（group P, n＝32）or amazake group（group A, n＝32）. They consumed 125 mL of amazake or placebo beverage daily for 8 weeks. After 4 and 8 weeks of the start of intake, measurements of stratum corneum hydration and trans-epidermal water loss（TEWL）on the left cheek and left upper arm as well as a self-assessed skin condition survey were conducted. The change from pretrial value were compared between the two groups（skin condition survey）. Results All of the subjects completed the study, whereas, 2 subjects in group A met the exclusion criteria for efficacy analysis. Thus, data for 62 subjects（n＝30 in group A and n＝32 in group P）were analyzed for efficacy. Since the results suggested an efficacy in elderly subjects with higher TEWL levels, a confirmatory analysis was performed on subjects（over 40 years old with their median cheek TEWL value≥14.7 g╱hm2（n＝12 in group P and n＝7 in group A）. The results revealed that TEWL in group A at week 4 was significantly lower（improved）compared to that in group P. No serious adverse event was observed during this study. Conclusions Intake of amazake is suggested to improve skin condition in women, especially in who aged over 40 and with moderate dry skin conditions.