Abstract
INTRODUCTION: Musculoskeletal discomfort is prevalent in primary care, with conditions such as osteoarthritis and osteoporosis being significant contributors. Collagen, particularly type I, is a major structural protein found in connective tissues. The supplementation of type I hydrolyzed collagen has been investigated for its potential benefits in musculoskeletal health. OBJECTIVE: This systematic review aims to evaluate the current literature on the effects of type I hydrolyzed collagen supplementation on bones, muscles, and joints. METHODS: A systematic search was conducted in August 2024 using four electronic databases - PubMed, Scopus, EMBASE, and CINAHL. The inclusion criteria were randomized controlled trials (RCTs) and systematic reviews evaluating oral supplementation with type I hydrolyzed collagen. Exclusion criteria were pre-clinical studies, experimental studies, studies not focusing on type I hydrolyzed collagen, studies with beauty-related endpoints, studies that combined collagen with other ingredients, and unblinded, nonrandomized, and uncontrolled trials. RESULTS: Out of 4,246 articles screened, 36 RCTs met the inclusion criteria. The study protocols varied in population, health conditions, and study duration. Studies focused on bone health faced limitations that prevent definitive conclusions about the effects of collagen supplementation. In contrast, studies on joint health reported beneficial outcomes, such as pain reduction, improvements in clinical parameters, increased physical mobility, and enhanced ankle function. The muscle health studies were inconsistent, with positive effects predominantly observed when supplementation was associated with physical exercise. CONCLUSION: Collagen supplementation demonstrates promising results. However, heterogeneity among studies limits the generalizability of findings. Future research should prioritize standardized protocols and consistent outcome measures.