A Primer on the Many Types of Collagen
Meredith Murray, ND
Collagen as an ingredient in supplement products is becoming more popular and has a variety of uses. Collagen is the most abundant protein of animal origin, making up almost 30% of the total protein in the human body. The main function of collagen is to support the structure of various organs and tissues throughout the body with its stable fibrils in the extracellular matrix and basement membranes.
The sources of the collagen used in supplements are always of animal origin – usually bovine or chicken, but we are also seeing more marine sources as well. This is something to discuss with vegan clients who are interested in a collagen product.
Gelatin is a form of collagen which has been used extensively in varying industries (pharmaceuticals, food and beverage, tissue engineering) because of its gelling property. The structure of collagen proteins are three polypeptide chains in the extracellular matrix which form a triple helix structure. When the chains/cross-linkages of collagen are broken down via partial heat-induced hydrolysis, gelatin forms. Gelatin is a combination of peptides and proteins.
Hydrolyzed collagen is another form of collagen that has been broken down into smaller peptides. As heat is what alters proteins such as collagen, recent ways to extract collagen from animal tissues have moved away from heat and more towards using proteases, an enzyme that breaks down proteins and peptides. The peptides from hydrolyzed-collagen (or collagen hydrolysate) are biologically active, but require digestion, processing or fermentation to liberate them from the parent protein.
The peptides are what have the physiologic functions in the body. The amino acid sequence of the peptides depends on the specific source of the protein and the method of production. Research has documented 27 types of collagen, but there are 3 main forms that are most abundant in the body. These are type I, II, and III collagen. Each form of collagen has a different make up of amino acids and a specific function within the body.
- Type I Collagen: Approximately 90% of the organic mass of bone in animal bodies is type I collagen which is crucial for tendons, ligaments, skin, interstitial tissues and the cornea. It offers both tensile strength for soft tissues and load bearing properties for bone.
- Type II Collagen: This is the main collagen found in cartilage. This is necessary for production and rebuilding of connective tissue throughout the body. This type of collagen has been studied for joint support in regards to flexibility and inflammation.
- Type III Collagen: Type III collagen is found primarily along with type I collagen containing tissues. It helps to create reticular fibers of the lung interstitial tissues, as well as liver, skin, spleen and blood vessels. Type III collagen is also abundant in elastic tissues.
As collagen production decreases with age, collagen supplements are often sought to help support upholding the level of collagen to be used for hair, skin, nails and other tissues. When taken orally, collagen is absorbed via the intestine, but will then circulate and exert positive actions on different areas of the body. A study showed that oral consumption of a collagen hydrolysate (Verisol®) resulted in a statistically significant increase in skin elasticity. Another study found that oral use of collagen peptides was supportive at improving joint discomfort2.
Collagen is another great example of a naturally created substance that can offer support when taken as a supplement if needed.
 Hashim P, Mohd Ridzwan MS, Bakar J, Mat Hashim D. Collagen in food and beverage industries. International Food Research Journal. 22(1):1-8. http://www.ifrj.upm.edu.my/22%20(01)%202015/(1).pdf.
 Gómez-Guillén M, Giménez B, López-Caballero M, Montero M. Functional and bioactive properties of collagen and gelatin from alternative sources: A review. Food Hydrocolloids. 2011;25(8):1813-1827. doi:10.1016/j.foodhyd.2011.02.007.
 Zdzieblik D, Oesser S, Gollhofer A, König D. Improvement of activity-related knee joint discomfort following supplementation of specific collagen peptides. Applied Physiology, Nutrition, and Metabolism. 2017;42(6):588-595. doi:10.1139/apnm-2016-0390.