What leads to the loss of collagen?
Age: As we age, the natural decrease in collagen production is a part of human physiology. In our 20s, we start to lose about 1% of collagen every year. By our 30s, this process accelerates and its effects on the skin become more apparent. This is because as we age, collagen fibers become more fragile and brittle, as can be observed by changes in the structure and integrity of the extracellular matrix. Additionally, aging reduces the body's ability to produce new collagen. (Fisher GJ, et al. Collagen fragmentation promotes oxidative stress and elevates matrix metalloproteinase-1 in fibroblasts in aged human skin. Am J Pathol. 2009;174(1):101-14.)
Sun UV exposure: The damage of UV to skin collagen is gradual and accumulative, and long-term exposure leads to skin aging, resulting in wrinkles and laxity. When the skin is exposed to UV, it produces excess free radicals, which can destroy the collagen in the skin, leading to skin aging. Additionally, UV can stimulate skin cells to produce matrix metalloproteinases (MMPs), enzymes that can break down collagen and elastin, causing the skin to lose elasticity. (Krutmann, J. et al. Photoaging of human skin. Photodermatol Photoimmunol Photomed. 2004 Aug;20(4):175-83.)
Smoking: Smoking can destroy collagen in various ways. First, the chemicals in tobacco can directly damage skin cells, including those that produce collagen. Second, smoking causes the microcapillaries that carry blood to the skin to constrict, reducing the skin's ability to get oxygen and nutrients, thus affecting collagen production. Studies have found that the skin collagen content of smokers is significantly lower than that of non-smokers. (Morita A. Tobacco smoke causes premature skin aging. J Dermatol Sci. 2007 Dec;48(3):169-75.)
Glycation: Inside the body, sugar molecules can bind to proteins (like collagen) through a process called glycation, forming so-called Advanced Glycation End products (AGEs). AGEs can destroy the structure and function of collagen, making it stiff and brittle. A long-term high-sugar diet accelerates this process, leading to faster skin aging. In a 2010 article in the Journal of Dermatological Science, researchers found that AGEs can accelerate the breakdown of collagen by stimulating the production of matrix metalloproteinases. (Pageon H. Reaction of glycation and human skin: the effects on the skin and its components, reconstructed skin as a model. Pathol Biol (Paris). 2010 Jun;58(3):226-31.)
