Définition
Collagen is the most abundant protein in the body — the structural scaffold of skin, tendons, ligaments, cartilage, and bone. Collagen synthesis declines 1% per year after age 25, accelerates sharply with estrogen decline, and can be meaningfully supported through diet, specific supplementation, and skin protection.
There are over 28 types of collagen, but Types I, II, and III account for the vast majority in human tissue. Type I collagen forms the fibrous matrix of skin, bone, tendon, and organs. Type II is predominant in cartilage. Type III forms elastic fibers in skin and blood vessels.
Collagen synthesis requires specific building blocks: glycine, proline, and hydroxyproline as the primary amino acids, vitamin C as an essential co-factor for the hydroxylation reactions, and zinc and copper as trace mineral catalysts. The collagen triple helix structure depends on adequate hydroxyproline, which explains why vitamin C deficiency (scurvy) produces connective tissue breakdown.
Collagen production peaks in the early 20s and declines thereafter. The decline accelerates dramatically with estrogen withdrawal — the skin loses 30% of its collagen in the first five years after menopause. UV radiation, smoking, high-glycemic diets (which generate AGEs that crosslink and stiffen collagen fibers), and cortisol excess also accelerate collagen degradation.
Hydrolyzed collagen peptides — collagen broken down into small dipeptides and tripeptides — are absorbed intact in the gut and have direct evidence for stimulating fibroblast collagen synthesis. Multiple RCTs show improvements in skin elasticity, dermal collagen density, and skin hydration with 2.5–10g daily over 8–12 weeks. The peptides appear to act as "damage signals" that stimulate fibroblasts to increase collagen production. Co-supplementation with vitamin C amplifies the effect.
Ava Longevity · Built on the Ava Method · MMXXV