薬理と治療

Abstract

Objectives The aim of this study was to evaluate the effect of food containing collagen hydrolysates, sphingomyelin, amino acids and glucosamine on skin conditions in healthy female subjects. Methods A randomized double-blind, placebo-control parallel-group study was conducted with 114 healthy female subjects ranging in age from 30 to 49 years old. Subjects ingested the active food including collagen hydrolysates, sphingomyelin, amino acids and glucosamine or the placebo food once a day for 8 weeks. Stratum corneum moisture content, transepidermal water loss（TEWL）, skin assessment by a dermatologist and subjective questionnaire were evaluated at 4 and 8 weeks-ingestion. The incidence of side effects was compared between two groups. Results Stratum corneum water content in the active food group was significantly improved after 4 and 8 weeks-ingestion compared with before-ingestion, however there was no significant difference in the placebo food group. The change of stratum corneum water content of 4 weeks-ingestion was trend to higher active food group compared to placebo food group. Between two groups, there was no significant difference in TEWL and skin assessment by dermatologist in 4 or 8 weeks-ingestion. In an additional analysis excluding subjects suspected of seasonal allergic rhinitis, the change of stratum corneum water content in 4 weeks-ingestion of active food group was significantly increased compared with placebo food group. No adverse effects were observed in both groups. Conclusion These results suggest that ingestion of the food containing collagen hydrolysates, sphingomyelin, amino acids and glucosamine for 4 weeks or more improve moisture content of stratum corneum in healthy female subjects.