Hydrolyzed collagen protein (HCP, also known as gelatin) is the chief structural protein that makes up connective tissues in the body (skin, hones, cartilage, tendons, and ligaments). Hydrolyzed collagen is simply a modified form of the protein that has been broken down into smaller pieces by enzymes. The hydrolysis process disrupts the ability of collagen to form a gel and thus makes the protein easier to incorporate into dietary products and may ease the digestion and absorption of the amino acids by the intestine. HCP is often used as a general protein source in bodybuilding products because it is relatively inexpensive, but the use of HCP as a protein for muscle building is flawed because of the incomplete nature of the amino acid profile in gelatin. Because of the high composition of amino acids found in collagen protein, HCP has most recently been used to promote joint health, nourish cartilage and bones, and help athletes recover from exercise and sports-related injuries.
As a joint support supplement, HCP is typically much less expensive compared with other popular joint supplements such as glucosamine and chondroitin, but the level and quality of the scientific evidence is also not nearly as strong. It may be, however, that because HCP and glucosamine/chondroitin products target different pails of the cartilage [structure (collagen and proteoglycans, respectively)], one ingredient or the other may work better for some people. Several products have recently been developed to include combinations of ingredients designed to work on different parts of the connective tissue matrix simultaneously.
HCP is not generally considered as good a source of "high-quality" protein as meat, poultry, fish, and concentrated or isolated protein powders comprised of soy, egg, or milk/whey proteins. On the one hand, HCP is a "poor" protein source because it is low in the sulfur-containing amino acids, such as cysteine and methionine. On the other hand, HCP is the richest dietary source of the primary amino acids that make up the collagen molecule glycine, praline, hydroxy pro line, lysine, and hydroxylysine. As a concentrated source of these collagen amino acids, HCP is thought to help nourish the collagen-containing tissues throughout the body tissues such as cartilage, bones, tendons and ligaments.
HCP has been widely used in Europe as a dietary supplement and an alternative treatment for arthritis and osteoporosis. In several small German and Czech studies, dosages of 7-10 g/day of HCP for 1-3 months have been shown to decrease the pain and stiffness associated with arthritis (Adam et al., 1976, 1980; Beuker and Rosenfeld, 1995; Brown etal., 1998). In some studies, HCP was as effective as oral painkillers such as acetaminophen/paracetamol (Tylenol) (Deal and Moskow-itz, 1999). In other studies, subjects were able to decrease or discontinue their use of analgesic medications while consuming HCP (Moskowitz, 2000). The only large multicenter study of HCP supplementation found no statistically significant differences for the total study group (all sites in the United States, Great Britain, and Germany) in total mean pain score, but a significant advantage of HCP over a placebo was found at the German sites (Moskowitz, 2000).
Although proponents of HCP consumption claim that it "rebuilds" cartilage, such claims are merely speculation (though probably correct) based on the body of scientific data showing pain reduction. At least one small German study has proved a suppression of bone breakdown in osteoporotic women (Adam et al., 1996). In addition, animal studies have demonstrated that orally administered HCP is better absorbed and incorporated into connective tissues than a comparable amount of labeled proline (Oesser et al., 1999), giving hope 10 athletes who routinely use HCP as a method for recovering from intense exercise training or sports injuries.
Aside from the possibility of mild gastrointestinal upset with large doses (up to 10 g/dose), no serious adverse effects are known to exist for consumption of hydrolyzed collagen protein. Clinical studies suggest that at least 7-10 g/day over the course of 30-90 days is needed for reduction of pain in patients with moderate osteoarthritis. Athletes wishing to supplement with HCP as a dietary source of connective tissue building blocks may or may not be able to use a lower dose, but it is unknown whether lower doses would be as effective or if higher doses might even be more effective or work faster.