Collagen, Diet, and Lifestyle Disorders: Interactions Across Metabolic, Cardiovascular, Skin, Joint, and Gut Health

Collagen is a central structural component of the extracellular matrix and, beyond its mechanical
role, is increasingly studied as a diet-responsive modulator of tissue repair, inflammation, and
metabolic homeostasis. Concurrently, collagen supplements have become widely consumed for
cosmetic outcomes (skin, hair, nails), musculoskeletal health, and, more recently, as adjuncts in
lifestyle-related disorders such as obesity, diabetes, and cardiovascular disease. This review
synthesizes contemporary evidence on (i) collagen biology relevant to lifestyle disorders, (ii)
dietary strategies that support endogenous collagen maintenance, and (iii) clinical and preclinical
findings on collagen supplementation for metabolic, cardiovascular, dermal, joint, and gut
outcomes. A structured literature mapping approach prioritized randomized controlled trials,
systematic reviews/meta-analyses, and mechanistic studies published through 2025. Overall,
collagen peptides show consistent, modest benefits for skin hydration and elasticity and variable
benefits for body composition and cardiometabolic risk markers; effects on glycemic endpoints
remain less consistent. Biological plausibility is supported by evidence that bioactive collagenderived peptides are absorbed and may influence extracellular matrix remodeling, immune
signaling, and gut microbiota. However, heterogeneity in collagen source (marine vs
bovine/porcine), molecular weight, dosing, outcome definitions, and trial duration limits
generalizability. Future work should emphasize product standardization, long-term safety,
comparative effectiveness versus dietary optimization, and mechanistic human studies
integrating biomarkers and microbiome profiling.