Effects of dietary intake of Colla corii asini on skin parameters and appearance: Results of a 12-week randomized, controlled, open-labeled trial

Abstract

BackgroundAs a traditional Chinese medicine, the Colla corii asini (CCA), obtained from the skin of Equus animus L, has been used to nourish blood in China for more than 2000 years. The beneficial role of CCA supplementation in beauty has been reported in different case studies; however, research supporting these claims remains sparse. ObjectivesTo conduct a 12-week randomized, controlled, open-labeled, blinded assessment trial to clinically evaluate the effects of CCA on hydration, complexion, wrinkles, and elasticity of human skin. MethodsParticipants (n=90) were randomly assigned to receive either no supplement or 6 g of CCA once daily for 12 weeks. Parameters evaluating skin hydration, complexion, wrinkles, and elasticity were assessed at baseline and after 4, 8, and 12 weeks of treatment. Results and ConclusionsCompared with the control group, skin-hydration values were significantly higher in the CCA group after 8 and 12 weeks (P=0.002, P=0.007, respectively). After 12 weeks, in the CCA group, the melanin index was significantly decreased compared with the control group (P=0.013). In terms of the safety of CCA, none of the participants presented adverse symptoms related to the CCA during the study period. These results suggest that CCA is an effective supplement for the improvement of skin hydration and to brighten skin color.