Both collagen and melanin play a protective role in healthy skin. Melanin absorbs harmful ultraviolet light and protects the skin from photo damage. Skin collagen molecules connect to each other and form a matrix, which includes other molecules, thus creating the skin organ. It provides protection against disease and injury. The thicker the skin and the more melanin, the better the protective barrier against the effects of aging.
Melanin is a class of biological pigments important as photo-protectors of skin. Pigment cells named melanocytes produce melanins in the outer skin layer. All melanocytes produce melanin, but cells in darker-skinned people produce more per cell. The two melanins produced by human skin include black-brown, eumelanin, and yellow-red, pheomelanin. Each melanin has separate biological properties. Also, women produce 3 to 4 percent less melanin in their skin than men.
Before global migration, most humans with the darkest skin lived closest to the equator. Melanin absorbs ultraviolet light, thus protecting humans from harmful UV radiation. UV radiation damages skin cells and promotes melanoma, cancer of the skin. European Americans have a 10 times higher risk of melanoma than African Americans. Even though melanin is protective, complete shielding would be harmful, because shortwave UV radiation needs to penetrate the skin to produce vitamin D. Approximately 90 percent of vitamin D is synthesized in the skin.
About one quarter of the human body is collagen. Collagen composes the majority of proteins in tendons, ligaments, cartilage, bone and skin. In skin it is present in the dermis, the inner layer of skin. Collagen fibers support the skin’s mechanical strength and texture. Because it has a mechanical function, collagen is subject to wear and tear. The quantity and quality of skin collagen plays a major role in appearance.
Numerous factors cause collagen damage. Some damaging factors include: sun, smoking, pollution and injury. These destroy cells and collagen molecules. Thus, injured skin cells fail to synthesize new collagen molecules to replace damaged collagen fibers. Additionally, genetics play a role in collagen destruction. It influences chronological aging, hormone depletion and immune suppression, all affecting collagen formation. In such instances, the ratio of collagen formation to collagen breakdown is reversed, and collagen is broken down faster than it can be made.
Because both melanin and collagen protect skin from damage, supporting their function is imperative. Sufficient amounts of vitamin C promote efficient collagen synthesis, so it is a key ingredient for skin. Low-dose estrogen prevents thinning skin in post-menopausal women, and sun blocking products inhibit UV exposure beyond melanin’s protective ability. Also, dietary intake of carotenoids from fruits and vegetables protects skin from the sun’s damaging rays.
- Dr. Dennis O'Neil, PhD; Anthropology; San Marcos, California
- Journal of Human Evolution: The Evolution of Human Skin Coloration
- Medical News Today: Skin Collagen Production Stimulated By Estradiol Application
- American Journal of Pathology: Decreased Collagen Production in Chronologically Aged Skin