薬理と治療

Abstract

Objectives A randomized double︱blind placebo︱controlled trial was performed to examine the effects of oral supplementation with fish︱derived collagen peptide on human skin damage induced by ultraviolet irradiation. Methods Before and after ingestion of 5 g of collagen peptide or placebo for 4 weeks, ultraviolet irradiation at 1.5 minimal erythema dose was applied to the back skin of Japanese adult males aged 20︱59 years with skin photo typeⅡ or Ⅲ. Erythema（a＊value）and melanin （Mexameter value）were measured on days 1（irradiation day）, 4, and 8. The water content of the stratum corneum and trans︱epidermal water loss were determined on days 1, 4, 8, 11, and 15. Results Erythema increased evidently on day 4 and decreased on day 8, while melanin increased slightly on day 4 and evidently on day 8. No significant differences were observed between the collagen peptide group and the placebo group for erythema and melanin before or after ingestion. However, when a stratified statistical analysis was performed for subjects older than 30 years of age, significant suppression of erythema was detected on day 4 in the collagen peptide group after ingestion for 4 weeks. No significant changes were detected for the water content and trans︱epidermal water loss. No adverse side effects attributable to collagen peptide ingestion were observed. Conclusions The present results suggest that supplemental ingestion of fish︱derived collagen peptide has beneficial effects on human skin for suppressing erythema induced by ultraviolet irradiation, particularly in older subjects above 30 years of age.