Collagen is a protein that up about 25% of the protein in the human body. Collagen is important for the skin. Indeed, it is the principal structural protein holding the skin together. It is basically a fiber or, when fully mature, a mesh of fibers. Collagen is present in majority of organs, not just the skin. It occurs in different forms in different places.
Having a lot of collagen in your skin is not enough. Even having the right mix of the collagen types is not enough. It is also important that collagen be undamaged and properly deposited. The quantity and quality of your skin’s collagen has a major role in your appearance. In general the quality and quantity of collagen decreases with age.Collagen freshly deposited by young, healthy fibroblasts has a coherent and orderly structure. Although collagen is one of the fastest growing tissues, we do not know how it exactly depreciates with age. However, we do know that by the age of 60, all types of collagen are significantly below their youthful levels.
Aging of the skin is caused by factors such as sun exposure, environmental factors such as pollution, lack of sleep, smoking, drinking, gravity, repetitive facial expressions. When collagen is damaged by UV rays, free radicals, impaired glucose metabolism, smoking or other factors, its structure becomes distorted, leading to poor skin texture, wrinkles and other imperfections.
When skin becomes old skin loses its firmness and elasticity (elastic behaviour) because the collagen and elastin production has slowed down. The skin is much susceptible to damage. Skin cells do not regenerate as quickly as we age. Therefore, dead skin cells do not shed as quickly leading to rough dull looking skin.
As part of the aging processes, the number of pigment containing cells decreases and the remaining ones increase in size leading to skin blotchiness. The amount of fat under the skin also decreases causing hollow cheek and eye sockets. Loss of fat and connective tissue in the skin weakens the support system around blood vessels making them more susceptible to damage and subsequent bruising.
With age the bones also shrink a cirtain amount causing the support system to the skin to decrease.Blood vessels also become fragile with age that may cause diseases like bleeding under the skin(purpura). Blood vessels become more fragile with age and this causes purpura and bruising (bleeding under the skin) and cherry angiomas (small bright red raised bumps). Related to this are varicose veins (blue bulging veins in the legs). These are caused by degenerative blood vessels.
By far the greatest cause of premature aging is exposure to the sun. The sun can cause freckles, ages spots, spider veins or broken capillaries on the face (telangiectasis), rough and leathery skin, fine wrinkles, loose skin, irregular skin pigmentation, actinic keratoses (thick, warty, rough, reddish, growths), and skin cancer. fair-skinned people being more vulnerable than dark-skinned people