Collagen

Figure 1: The Collagen triple helix.

Collagen is the main structural protein found in the body's various connective tissues. It is the most abundant protein in mammals, making up 25%-35% of the whole-body protein content. Collagen helps to make tissues strong and resilient and able to withstand stretching.

Collagen is made up of three amino acids glycine, proline, and hydroxyproline bound together to form a triple helix of elongated fibril known as a collagen helix. Within the body, it is mostly found in connective tissue such as cartilage, bones, tendons, ligaments, and skin. Collagen is also abundant in corneas, blood vessels, the gut, intervertebral discs, and the dentin in teeth.

Collagen comes in many types, and they can be classified into different groups depending on the structure they form. Regardless of type, every Collagen contains at least one triple helix. The five most common types of Collagen in the human body are:

• Type I: Collagen in the skin, tendon, vasculature, organs, and bone.
• Type II: Collagen in cartilage.
• Type III: Collagen in reticular fibers in soft tissues.
• Type IV: Collagen in the basal lamina (a layer which sits just under the epithelial skin cells).
• Type V: Collagen in cell surfaces, hair, and placenta.

Over 90% of Collagen in the human body are Type I.

Food Sources

Collagen is found in all animals and concentrated in parts such as skin and joints. Examples of Collagen-rich foods include:

• Chicken skin
• Pig knuckle
• Fish skin
• Bone broths

Collagen is produced naturally within the body from amino acids. As such, you can support Collagen growth by consuming foods that are high in protein such as poultry, fish, meat, beans, and eggs.

Vitamin C is necessary for Collagen synthesis. For its food sources, refer to the Codex entry for Vitamin C.

Taken as a Dietary Supplement

Collagen provides structural support to tissues and plays important roles in cellular processes, including tissue repair, immune response, cellular communication, and cellular migration (i.e. a process needed in tissue maintenance). As such, Collagen is typically taken to help with skin health (e.g. anti-aging), bone health (e.g. increase bone density), joint health (e.g. to manage joint pain, osteoarthritis), boost muscle mass, 

As people age, Collagen production decreases in efficiency and becomes more fragmented and loosely distributed. Along with the loss of another key structural protein called Elastin, these changes lead to signs of aging such as sagging skin and formation of wrinkles.

Lifestyle choices also affect Collagen formation within the body. For example, smoking is known to degrade collagen and cause skin aging, wrinkles, and loss of elasticity, while excessive drinking has also been shown to accelerate skin aging by reducing collagen production and damaging skin repair mechanisms.

Additionally, a diet high in added sugar and ultra-processed foods can lead to premature aging via a process called glycation, while excessive sun exposure degrades collagen production and accelerates premature skin aging.