2010 年 7 巻 4 号 p. 18-25
Objective: Brewer’s yeast contains vitamins, minerals, amino acids and other nutrients, and has been reported to control intestinal function as well as to exert anti-ulceration, anti-tumor and anti-allergy effects. The present study evaluated the effects of oral treatment with dried brewer’s yeast tablets (study product) on skin in a single-blind placebo-controlled design in humans.
Methods: Thirty-two healthy volunteer women (37.0±4.8 years) were allocated as follows: Group E-30 (n=11) were treated with 30 tablets/day of the study product (containing 7,125mg/day of dried brewer’s yeast), Group E-9 (n=10) were given 9 tablets/day of the study product, and the control group (n=11) were given 30 placebo tablets/day. The treatment period was 8 weeks. Two patients prematurely discontinued the study (discontinuation rate: 5.9%) and were excluded from the analyses. The study product (Ebios Tablet®) was provided by Asahi Food & Healthcare Co., Ltd. Before and at 4 and 8 weeks after the study, subjective symptoms were evaluated using the Anti-Aging QOL Common Questionnaire (AAQol) and checking skin symptoms, skin images were analyzed with SK Info (SKI, Integral Co.) and Aphrodite-III (PSI), and skin color (CM-700d, Konica Minolta Sensing, Inc.) and elasticity (Cutometer MPA580, Courage & Khazaka electronic GmbH) were measured.
Results: In Group E-30, the AAQol physical symptom “cold skin” score was significantly improved at 8 weeks (p‹0.05). The skin symptoms “make-up runs easily” and “desiccated and gritty skin,” as well as the physical symptom “menstruation-related troubles” were improved in a significant and dose-dependent way from the control group (p‹0.01). On skin analysis, SKI demonstrated an increase in moisture content (15.4%, p=0.010), decrease in erythema (−18.3%, p‹0.001) and increase in elasticity (13.3%, p=0.003), while PSI revealed an increase in hydration (Total: 14.5%, T zone: 13.7%, U zone: 18.2%, p‹0.01) and decrease in pores (− 32.7%, p=0.022). Cutometer analysis showed a dose-dependent increase in skin elasticity, while analysis of skin color showed a decrease in hemoglobin (−9.5%, p=0.016), improved lightness (− 0.7%, p=0.045) and decrease in redness (−8.3%, p=0.013). During the study period, no serious adverse events were noted.
Conclusion: These results suggest that treatment with dried brewer’s yeast is useful in improving skin condition, e.g. moisture content and elasticity, and also QOL.