Collagen is the most abundant protein in the body. Its fiber-like structure is used to make connective tissue. Like the name implies, this type of tissue connects other tissues and is a major component of bone, skin, muscles, tendons, and cartilage. It helps to make tissues strong and resilient, able to withstand stretching.
In food, collagen is naturally found only in animal flesh like meat and fish that contain connective tissue. However, a variety of both animal and plant foods contain materials for collagen production in our own bodies.
Our bodies gradually make less collagen as we age, but collagen production drops most quickly due to excess sun exposure, smoking, excess alcohol, and lack of sleep and exercise. With aging, collagen in the deep skin layers changes from a tightly organized network of fibers to an unorganized maze. Environmental exposures can damage collagen fibers reducing their thickness and strength, leading to wrinkles on the skin’s surface.
Despite its abundance in our bodies, collagen has become a top-selling supplement purported to improve hair, skin, and nails—key components of the fountain of youth. The idea of popping a pill that doesn’t have side effects and may reverse the signs of aging is attractive to many. According to Google Trends, online searches for collagen have steadily increased since 2014.
Collagen first appeared as an ingredient in skin creams and serums. However, its effectiveness as a topical application was doubted even by dermatologists, as collagen is not naturally found on the skin’s surface but in the deeper layers. Collagen fibers are too large to permeate the skin’s outer layers, and research has not supported that shorter chains of collagen, called peptides, are more successful at this feat.
Oral collagen supplements in the form of pills, powders, and certain foods are believed to be more effectively absorbed by the body and have skyrocketed in popularity among consumers. They may be sold as collagen peptides or hydrolyzed collagen, which are broken-down forms of collagen that are more easily absorbed. Collagen supplements contain amino acids, the building blocks of protein, and some may also contain additional nutrients related to healthy skin and hair like vitamin C, biotin, or zinc.