The Protective Role of Astaxanthin for UV-Induced Skin Deterioration in Healthy People-A Randomized, Double-Blind, Placebo-Controlled Trial

Abstract

Skin is a major safeguard tissue in humans. Because biological barrier function is deteriorated by several kinds of stresses including exposure to ultra-violet (UV) rays, the protection and treatment of skin conditions by dietary supplements are important. We therefore evaluated the effects of dietary supplementation with an algal food-derived antioxidant, astaxanthin, on UV-induced skin deterioration. Twenty-three healthy Japanese participants were recruited to a 10-week double-blind placebo-controlled study. They were assigned to the astaxanthin group supplemented with a capsule containing 4 mg of astaxanthin or the placebo group. To assess the protective role of astaxanthin for UV-induced skin deterioration, we determined the minimal erythema dose (MED) and analyzed UV-induced changes of moisture and transepidermal water loss (TEWL) at baseline and after 9 weeks of supplementation. Subjective skin conditions were assessed by the visual analog scale. The astaxanthin group showed increased MED compared with placebo. In addition, the astaxanthin group had a reduced loss of skin moisture in the irradiated area compared with placebo. Subjective skin conditions for “improvement of rough skin” and “texture” in non-irradiated areas were significantly improved by astaxanthin. Astaxanthin seems protective against UV-induced skin deterioration and helps maintain healthy skin in healthy people.

Keywords: MED; UV; antioxidant; astaxanthin; moisture; skin; ultra-violet.

Figure 1

Flow diagram of participants.

Figure 2

Dietary supplementation with astaxanthin increases the minimal erythema dose. (a) Representative imaging of an irradiated area in the placebo group (left) and astaxanthin group (right) before and after supplementation; (b) Change in MED from baseline in the placebo group (black) and astaxanthin group (red). * p < 0.05 by Mann–Whitney U-test. Error bars indicate the standard deviation (SD).

Figure 3

Dietary supplementation with astaxanthin attenuates the decrease of moisture at the irradiated area. Change in moisture from baseline at the irradiated area 7 days after irradiation. The moisture levels at the irradiated area were normalized by those at the non-irradiated area. * p < 0.05 by unpaired t-test. Error bars indicate the SD.

Figure 4

Subjective skin conditions “improvement of rough skin” and “texture” are improved by dietary supplementation with astaxanthin. Change in VAS score for “improvement of rough skin” (a) and “texture” (b) from baseline at the non-irradiated area in the placebo group (black) and astaxanthin group (red). Positive and negative numbers indicate improvement and deterioration, respectively. * p < 0.05, ** p < 0.01 and *** p < 0.001 by unpaired t-test. Error bars indicate the SD.