Tuesday, 1 August 2017

Re: Aloe Vera Sterol Supplement Improves Skin Elasticity in Men with Sunlight-exposed Skin

Aloe Vera (Aloe vera, Xanthorrhoeaceae) Skin Elasticity Sunlight-exposed Skin Date: 07-31-2017 HC# 011711-573 Tanaka M, Yamamoto Y, Misawa E, et al. Aloe sterol supplementation improves skin elasticity in Japanese men with sunlight-exposed skin: a 12-week double-blind, randomized controlled trial. Clin Cosmet Investig Dermatol. 2016;9:435-442. Skin aging is a result of exposure to extrinsic factors, such as chronic exposure to ultraviolet (UV) radiation, and internal physiological factors that occur over time. Studies have suggested that supplementation with aloe vera (Aloe vera, Xanthorrhoeaceae) sterols may improve skin moisture, skin elasticity, and collagen scores. The aim of this 12-week, randomized, double-blind, placebo-controlled study was to assess the effect of aloe vera sterol intake on the sunlight-exposed skin of Japanese men during the summer. This study took place in Japan from July 2015 to October 2015. A total of 48 healthy, adult Japanese men (age, 30-59 years), who spent 2-5 hours outside during the day, were randomly assigned to the placebo (n = 24) or aloe vera sterol (n = 24) group. Subjects were excluded if they regularly used cosmetics or cream on their arms (other than sunscreen), used cosmetics or consumed foods that adversely affected their skin, had skin disorders, or had a health problem that would interfere with the study. Each subject consumed either 5 tablets per day of powdered aloe vera gel, consisting of 40 µg of aloe sterols, or a placebo consisting of dextrin. Both the placebo and aloe tablets also contained equal amounts of citric acid, maltose, sour milk, cellulose, calcium phosphate, flavor, glycerin fatty acid, sugar ester, and food color. The article does not say if the researchers prepared the tablets or if they were prepared by a manufacturer. All subjects were instructed to expose the inner side of 1 forearm to sunlight outdoors every day for 2 to 5 hours. The inner side of the forearm from each subject was then examined at weeks 0, 4, 8, and 12 of the treatment period. The skin parameters assessed included skin color, hydration, and elasticity. All 48 subjects recruited for the study participated, although 1 was later excluded from the study analysis because of a compliance violation (1 in the aloe sterol group had "20% of intake rate" in the first 4 weeks, though what, exactly, was taken in was never specified). There were comparable baseline characteristics and no significant differences between the 2 groups. Furthermore, there were no significant adverse events reported from blood lipid or biochemical parameters assessed in the study (data were not shown). Compared to baseline values, there was a significant increase in melanin index values at 4, 8, and 12 weeks in the placebo group, and at 4 and 12 weeks in the aloe vera sterol group (P < 0.005). Similar results were found for b value (skin color balance between yellow and blue). There was a significant increase in b for all time points and groups relative to baseline values (P < 0.05). Also compared to baseline, a decrease in the L values (lightness, ranging from total black [L = 0] to total white [L = 100]) was observed in both groups, some significantly. Skin color values, lightness, and the melanin index were not significantly different between groups, nor were a values (skin color balance between red and green). A decrease in hydration was found for both groups at 8 and 12 weeks (data were not shown). Compared to baseline, skin elasticity values (R2, gross elasticity; R5, net elasticity; and R7, biological elasticity) were significantly higher at 12 weeks for both groups (P < 0.05). Overall, there was no significant difference between the 2 groups for the elasticity values. When separated into different age groups, however, it was found that those aged < 46 years in the aloe vera sterol group (n = 12) had a significantly higher change from baseline in their R5 and R7 values (0.057% ± 0.016% and 0.023% ± 0.010%, respectively) compared to the placebo group in the same age range (n = 11; 0.005% ± 0.017% and −0.011% ± 0.012%, respectively) at 8 weeks (R5, P = 0.0412 and R7, P = 0.0410). In this same age group, it was found that at 12 weeks, the change in R2 in the aloe vera sterol group (0.024% ± 0.009%) was significantly higher compared to baseline (P < 0.05), whereas the placebo group did not have a significant change in R2 (0.009% ± 0.008%) relative to baseline. The authors found that aloe vera supplementation significantly increased elasticity (R5 and R7) in UV-exposed men < 46 years of age. Similarly, a previous study by these authors revealed that a dietary supplement with the same aloe vera sterol dose increased collagen and skin hydration, as well as all 3 skin elasticity parameters, in women protected from sunlight by clothing.1 The authors suggest that the effects of aloe vera sterols may depend on age and gender. The authors go on to mention that one of the limitations of this study was the broad range in UV exposure time. Future trials should assess the effects of aloe vera sterols in men and women of different ages with consistent UV exposure. More information should also be provided about subjects' sunscreen use, and the mechanistic effects of aloe vera sterols. Six of the authors are employees in the Functional Food Ingredients Department of the Food Ingredients & Technology Institute at Morinaga Milk Industry Co., Ltd. (Zama, Kanagawa, Japan), a company that develops and produces functional food ingredients and products. —Laura M. Bystrom, PhD

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