Continuous astaxanthin intake reduces oxidative stress and reverses age-related morphological changes of residual skin surface components in middle-aged volunteers

Oxidative stress accelerates skin aging, and dietary supplementation with antioxidants may alleviate it. Morphological analysis of the residual skin surface components (RSSCs) allows detecting age-related changes in corneocyte desquamation, microbial presence, and lipid droplet size. We hypothesized that continuous ingestion of carotenoid antioxidant astaxanthin (4 mg/d) for 4 weeks could influence RSCC morphology and evaluated RSSC samples taken from middle-aged subjects before and after this dietary intervention. The study included 31 volunteers (17 men and 14 women) over the age of 40. RSSC samples were collected from the surface of the facial skin at the beginning (day 0) and end (day 29) of the study. In addition, blood samples were taken on days 0, 15, and 29 for measuring plasma levels of malondialdehyde that allowed assessing systemic oxidative stress. The results demonstrated that plasma malondialdehyde consistently decreased during astaxanthin consumption (by 11.2% on day 15 and by 21.7% on day 29). The analysis of RSSC samples has revealed significantly decreased levels of corneocyte desquamation (P=.0075) and microbial presence (P=.0367) at the end of the study. These phenomena as well as a significant (P=.0214) increase in lipid droplet size were more strongly manifested among obese (body mass index >30 kg/m2) subjects. All described RSSC changes correspond to a shift toward characteristics of skin associated with a younger age. The results confirm our hypothesis by demonstrating that continuous astaxanthin consumption produces a strong antioxidant effect resulting in facial skin rejuvenation which is especially pronounced in obese subjects.