Food-derived collagen peptides: safety, metabolism, and anti-skin-aging effects

Collagen peptides (CPs) are a hot topic in the nutrition and health industries. This review summarizes their safety, metabolism, and anti-skin-aging effects, and addresses outstanding issues to guide further applications and research. CPs are safe, but the risks of excessive intake, harmful elements, and pathogenic agents should still be considered. Following gastrointestinal digestion, they are absorbed by the intestinal mucosa, pass through the liver, and enter the peripheral blood, where 25 types of hydroxyproline-containing peptides have been identified. These accumulate in the skin, improving its condition by alleviating oxidative stress, inhibiting inflammatory reaction, regulating cell behavior, and maintaining extracellular matrix homeostasis. However, questions remain concerning appropriate intake, evaluation methods, contrary findings, bioactive molecules, signaling pathways, and interactions with dietary components.