Collagen is the most abundant protein in the skin and is found only in animal flesh like meat and fish that contain connective tissue. Collagen production in the body reduces with age, which may be influenced by external factors, including smoking, sun exposure, lack of sleep/exercise and alcohol consumption.

Limited data suggest that consuming collagen-dense foods can directly benefit skin or joint health. And thus, more research is needed to establish knowledge of collagen supplementations effects and physiologic mechanism.

Although human studies are lacking, some trials have shown that collagen supplements may improve skin hydration and elasticity. 

A review of sequencing surveys of healthy adults found the composition of microbial communities to be mainly dependent on the physiology of the skin site, with changes in the relative abundance of bacterial taxa associated with moist, dry and sebaceous environments. The reduced diversity of the skin microbiome in atopic dermatitis patients is due to a reduction in environmental biodiversity in the areas surrounding their homes. The patients must thus consume a rainbow of different colored foods every day, especially those rich in vitamins A, C and E. 

Another randomized, double-blind study by French researchers has shown that skin is prone to seasonal changes during the winter, particularly in exposed areas, and that oral micronutrient supplementation may prevent or even eliminate the negative effects of winter on the skin. It thus represents a safe treatment option with no serious side effects,

Source: Brunk D. Do collagen supplements benefit the skin? January 9, 2023. Available from: https://www.mdedge.com/dermatology/article/260516/aesthetic-dermatology/do-collagen-supplements-benefit-skin?reg=1icd%3Dlogin_success_email_match_norm