Maintains Water Content in the Left Cheek Skin of Healthy Adults: A Randomized, Double-Blind, Placebo-Controlled, Parallel-Group, Comparative Trial.

PURPOSE

Improvement in water content and skin barrier function on human skin is believed to be induced by , a non-alcoholic beverage derived from rice fermented by (). In order to scientifically identify the effects of on human skin, we performed a randomized, double-blind, placebo-controlled, parallel-group comparative trial and quantified the content of glucosylceramide (GlcCer) which would be responsible for the effects.

PARTICIPANTS AND METHODS

Healthy adults concerned with their skin dryness were divided into (N = 30) or placebo group (N = 30). During this test, the test beverages were ingested at 118 g/day. Their water content and trans-epidermal water loss (TEWL) were measured at 0 week (baseline) and 8 weeks. The content of GlcCer in test beverages was quantified by HPLC-ELSD.

RESULTS

In comparison with the placebo group, the water content in the left cheek of individuals in the group was maintained for 8 weeks. In addition, changes in water content from the baseline to 8 weeks differed significantly between the (0.19) and placebo groups (-3.98). Unexpectedly, there was no significant difference in the TEWL between and placebo group. We analyzed GlcCer in both and placebo beverages, which were found to contain 1.35 ± 0.11 and 0.30 ± 0.07 mg/118 g, respectively. The amount of GlcCer in was approximately equal to the dosage of plant-derived GlcCer which has the ability to improve water content and TEWL in humans.

CONCLUSION

Present study has shown that intake of contributes to maintain the water content only on the left cheek. The content of GlcCer derived from was adequate for maintenance of the water content compared to previous reports. Therefore, it was concluded that GlcCer in acts as a functional ingredient.