| dc.description.abstract | Introduction: Skin aging has become a recurring concern even for younger people, mainly owing to increased life expectancy. Appearance is important in aspects such as social attractiveness and health. In this context, the use of nutricosmetics as supplements has increased in recent years. Moreover, numerous scientific studies have shown the benefits of hydrolyzed collagen supplementation in improving the signs of skin aging. Objective: The objective of this study was to summarize the evidence on the effects of hydrolyzed collagen supplementation on human skin through a systematic review followed by a meta-analysis of clinical trials focusing on the process of skin aging. Methods: A literature
search was conducted in the Medline, Embase, Cochrane, LILACS (Latin American and Caribbean Health Sciences Literature), and Journal of Negative Results in BioMedicine databases for articles published in English, Spanish, and Portuguese, with no restrictions on publication date. Eligible studies were randomized, double-blind, and controlled trials that evaluated oral supplementation with hydrolyzed collagen as an intervention and reported at least one of the following outcomes: skin wrinkles, hydration, elasticity, and firmness. Results: After retrieving articles from the databases, 19 studies were selected, with a total of 1,125 participants aged between 20 and 70 years (95% women). In the meta-analysis, a grouped analysis of studies showed favorable results of hydrolyzed collagen supplementation compared with placebo in terms of skin hydration, elasticity, and wrinkles. The findings of improved hydration and elasticity were also confirmed in the subgroup meta-analysis. Conclusion: On the basis of results obtained from the studies, ingestion of hydrolyzed collagen for 90 days is effective in reducing skin aging, as it reduces wrinkles and improves skin elasticity and hydration. Supplements rich in
prolylhydroxyproline and hydroxyprolylglycine peptides are effective in reducing wrinkles and improving skin elasticity after 4 weeks of use. Hydrolyzed collagen is a safe food supplement, as evidenced by the absence of adverse effects in all analyzed studies. | en |
