Collagen is the abundant structural component of human body, it comprises one-third of the total protein, accounts for three-quarters of the dry weight of skin, and is the most prevalent component of the extracellular matrix (ECM).
Collagen is protein molecules made up of amino acids. It provides structural support to the extracellular space of connective tissues. Due to its rigidity and resistance to stretching, it is the perfect matrix for skin, tendons, bones, and ligaments.
Collagen can be further divided into several groups depending on the type of structures they form. There are 28 various types of collagen that have been discovered, but by far, the most common are types I through IV, with type I comprising over 90% of the collagen in the human body.
Below is a list of types I to IV collagen and their functionalities for human body.
Types I Collagen
Type I collagen is the most common type of collagen found naturally in the body. It accounts for 90% of the body’s collagen stores and is found just below the surface of the skin in the dermis. Type I collagen can be found in most supplement types because of its wide range of potential benefits.
Type II Collagen
Type II collagen is found in both marine and chicken products. People with allergies to fish or chicken should consult their doctor before taking supplements containing type II collagen.
Current research on the efficacy of type II collagen is limited, but preliminary studies conducted on people with knee osteoarthritis found promising levels of pain reduction with the use of type II collagen in conjunction with acetaminophen.
Type II collagen is less tightly packed than type I collagen. This potentially indicates that the body could more easily break down and absorb collagen in this form. Other possible benefits may include healthy joint inflammation response, the rebuilding of damaged joint cartilage and increases in range of motion.
Type III Collagen
Type III collagen is the second most common type of collagen found naturally in the body. This type is different from the others because of its singular alpha chain. The other types of collagen have multiple alpha chains.
In conjunction with type I, type III collagen is thought to support gut, muscles, blood vessels and the uterus. Bovine products are the most common source of type III collagen.
While some studies show the body may utilize type III collagen to help fight inflammatory diseases, the body will use amino acids in whatever way it needs, putting the role supplements can play in this process in question. Taking a specific collagen supplement to target specific areas of the body will not necessarily be successful.
Type V Collagen
Type V collagen is found naturally in the eye, helping light pass through the cornea. This type of collagen works naturally with types I & III to create the framework for tissues and organs in the body. Type V collagen is also known to support bones, muscles, the liver and lungs.
Although scientists understand how the body uses its natural stores of type V collagen, more research is needed to determine whether the body can break down type V collagen supplements and use them to support these areas. Promising results of research on type V collagen supplements suggest possible benefits to eye health, cell membranes and the tissue found in the placenta.
Type IV collagen is the main collagen component of the basement membrane. It is a network-forming collagen that underlies epithelial and endothelial cells and functions as a barrier between tissue compartments. Type IV collagen has many binding partners and forms the backbone of the basement membrane. It holds important signaling potential as subdomains, such as tumstatin, are released when the protein is degraded by special proteases. Consequently, type IV collagen is both the most important structural collagen of the basement membrane and it entails key signaling potential, which is important for various physiological and pathological functions.