Let us talk about collagen. Collagen is one of the major components of extracellular matrix. Being a non-cellular component, extracellular matrix plays a role of scaffolding for the surroundings structures, providing skin strength, elasticity, and compressibility on the one hand. However, on the other hand, it maintains the basic physiological processes in the skin (homeostasis), for example, plays a role in the exchange function, involved in aging, would healing, repair and regeneration, and diseases.
Extracellular matrix is contained in the epidermis, particularly basement membrane and dermis, in both papillary and reticular layers. Apart from collagen, the other components of extracellular matrix are elastin, laminin, fibroblasts, fibronectin, glycosaminoglycans, including hyaluronic acid, proteoglycans. Besides, regulatory molecules, such as a number of cytokines and growth factors are represented in the extracellular matrix as well for the controlling of the normal metabolism of cells.
Collagen (from the Greek «kólla» - glue) is one of the common proteins in human body and is the main component of connective tissue. So, collagen may be found in the variety of internal organs, for example skin, lungs, blood vessels, bones, and cartilages. Among all 28 types of collagen, which are known, only several of them are in the skin, the most abundant are collagen I and III. All types of collagen are different in their localization, molecular structure, and functions. The common thing of all collagens is their triple helix structure with the amino acid glycine in every third position.
In the skin, collagen provide its structural integrity. Collagen structure changes with age due to intrinsic or chronoaging. The number of collagen fibers decrease, they become more compactly packed with the reducing their width and randomly oriented. Also, the synthesis of new collagen by fibroblasts diminish. All these alterations lead to the decrease of skin quality, its elasticity and cause superficial wrinkles formation and sagging. In addition, similar changes can be caused by the ultraviolet radiation, leading to the photoaging. In the result of the UV-radiation, free radicals in the skin oxidative damage collagen and elastin fibers, impact on skin vessels, epidermis. Opposite to chronoaging, photodamaged skin is characterized by the coarse wrinkles, dyspigmentation and presence of spider veins (telangiectasias).
Synthesis of collagen in the body begins with its precursor - procollagen - a protein, the main component of which is the amino acids glycine and proline. Then, the formation of a triple helix of collagen occurs in the presence of vitamin C. Vitamin C is found in large quantities in citrus fruits, rose hips, proline - in egg whites, dairy products, asparagus, and glycine - in protein products, gelatin. In addition, collagen itself can be found in animal products such as chicken or pork skin. However, no connection has been found between the consumption of these products and increasing of the collagen synthesis in the skin.
With regard to dietary supplements, which have now gained wide popularity, the collagen in these supplements can be of animal nature – bovine, egg; marine nature - fish, or vegetable origin. Most often, such collagen is hydrolyzed, that is, amino acids are already broken down into small chains for better absorption by the body. These amino acids are used for collagen synthesis, and also stimulate fibroblasts to synthesize collagen, elastin and hyaluronic acid. Bovine, fish and egg collagen are type I collagen, but fish collagen peptides are smaller, which improves their absorption in the body. Plant collagen is produced from yeast sources or bacteria such as Pichia pastoris.
How do these dietary supplements work? When taking a dietary supplement containing collagen, collagen is broken down into amino acids in the gastrointestinal tract, then they are redistributed to the necessary organs and tissues, and then a new protein is built. Of course, it is possible that some of the amino acids will be redistributed into the skin, but they can also be directed to other tissues, or they can simply be destroyed during the process of digestion. Consequently, the results of taking dietary supplements containing collagen and its effect on improving skin structure are controversial and a direct link is not fully established. In addition, it is important to think not only about building new collagen fibers, but also about preserving existing ones and taking into account the ability of ultraviolet radiation to destroy skin collagen. Therefore, it is necessary to use creams containing a sun protection factor (SPF) both in winter and in the summer, and also limit exposure to the sun during the hours of greatest solar activity.
Collagen is an essential component of various organs and tissues, in particular the skin. It has been proven that with age, the amount of collagen in the skin decreases, which is associated with various processes in the body. Despite the fact that there are currently a huge number of dietary supplements that contain collagen, the question of the benefits of such supplements and the improvement of skin quality when taking such supplements remains open.
Written by: Angela Kravchenko