Effects of low-dose Aloe sterol supplementation on skin moisture, collagen score and objective or subjective symptoms: 12-week, double-blind, randomized controlled trial

Abstract

Daily oral intake of 40 μg Aloe sterol was shown in a double-blind clinical trial to significantly increase skin barrier function, moisture and elasticity. Ultrasonographic results also suggested that the intake of Aloe sterol increases collagen content in the dermis. Here, we evaluate the effects of a much smaller dose of Aloe sterol, approximately half that used previously, on skin functions in more detail. This is a monocentric, double-blind, randomized, placebo-controlled, supplementation study of the effects of low-dose Aloe sterol on skin transepidermal water loss, hydration, collagen score, evaluation of objective or subjective symptoms, and safety after 12 weeks of daily intake. We randomly administrated either Aloe sterol or placebo to 122 healthy volunteers. Transepidermal water loss was significantly reduced and collagen score was increased in the Aloe sterol group compared with the placebo group at week 12. In the Aloe sterol group, there was significant improvement of objective skin condition (face erythema and pruritus of inner and outer arms) at week 12 compared with week 0, but not in the placebo group. Subjectively, there was significant improvement of visual analog scale of skin acne, fingernail brittleness and constipation in the Aloe sterol group. According to subgroup analysis, although not planned before the study initiation, subjects with dry skin in the Aloe sterol group had significantly increased skin hydration values at week 12 compared with the placebo group. Our results confirmed that even low-dose Aloe sterol ingestion improves skin moisture by promoting skin barrier function and dermal collagen production, which contributes to maintenance of healthy skin.

Keywords: adverse events; collagen; hydration; moisture; ultrasound.

Figure 1

Flow diagram of participants.

Figure 2

(a) The Δchanges in skin hydration and (b) transepidermal water loss (TEWL) during the treatment period. Data are expressed as means ± standard deviation. (Aloe sterol group, n = 60; placebo group, n = 58). *P < 0.05, versus values in placebo group. AU, arbitrary units.

Figure 3

Ultrasonography evaluations. (a) Ultrasound skin images of collagen content before and after 12 weeks of ingestion of Aloe sterol or placebo. Representative images of three subjects from each group are shown. (b) ΔChanges in the collagen scores before and after the ingestion. Data are expressed as means ± standard deviation (Aloe sterol group, n = 60; placebo group, n = 58). *P < 0.05, versus values in placebo group.

Figure 4

ΔChanges in the skin hydration of participants whose skin hydration was less than 27.4 arbitrary units (AU). Data are expressed as mean ± standard deviation (Aloe sterol group, n = 38; placebo group, n = 34). *P < 0.05, versus values in placebo group.