Background: Nutrition can influence skin health. Dark chocolate possesses health promoting properties, but its consumption can exacerbate acne vulgaris in young people. Objective: We evaluated effects of continuous dark chocolate intake on morphological characteristics of the residual skin surface components (RSSCs) collected from the facial skin of young and middle-aged men. Methods: RSSC samples were taken from 17 young and 16 middle-aged men before and after a four-week consumption period of dark chocolate (10g per day). Lipid droplet size, corneocyte desquamation, and microbial presence levels were measured in the collected RSSC. The project was registered as ISRCTN89815519 in the ISRCTN registry (https://www.isrctn.com/). Results: Chocolate consumption caused a significant increase in corneocyte desquamation only in the group of young men, whereas Gram-positive microorganism presence significantly increased in both the young and middle-aged men, though this effect was noticeably stronger in the young men. Conclusion: Dark chocolate consumption appears to affect the facial skin of young men by enhancing corneocyte desquamation and promoting bacterial colonization of the RSSC. These changes might potentially contribute to acne development.
Keywords: Acne vulgaris; corneocyte desquamation; dietary chocolate; facial epidermis; microbial presence.