Continuous Ingestion of Kale Containing Glucoraphanin Improves Skin Condition inHealthy Japanese Adults with Skin Dryness―A Randomized, Double—blind, Placebo—controlled,Parallel—group Study―

Objective Cruciferous kale has been reported to have various pharmacological functions. Our previous study indicated that kale containing glucoraphanin may have a positive effect on skin condition. Therefore, we further investigated the effects of daily kale ingestion on skin moisture content and transepidermal water loss（TEWL）. Methods In this 12-week, randomized, double-blind, placebo-controlled, parallel-group study, 70 healthy Japanese male and female subjects aged 30-59 years were randomly assigned to a kale group or a placebo group. Skin moisture content and TEWL were measured and visual evaluation was performed by a medical specialist to assess skin condition. Results Skin moisture content at the cheek was significantly increased at 6 weeks after starting ingestion in the kale group compared with the placebo group. TEWL in the kale group was significantly lower at 6 and 12 weeks than at baseline, but there were no significant differences between the groups. In a subgroup analysis of subjects aged 40 years or older, skin moisture content was significantly increased at 6 and 12 weeks in the kale group compared with the placebo group. Scores for visual evaluation of elasticity determined by a medical specialist were significantly improved in the kale group. There were no adverse clinical events due to ingestion of test samples during the study period. Conclusion These results suggest that daily intake of kale containing glucoraphanin can contribute to maintaining healthy skin condition through improvement of skin moisture content and skin barrier function. In particular, kale may be remarkably effective for age-related skin changes. （UMI30264）