Ageing is defined by many processes.
Up to this moment, more than 300 theories of ageing have been put forward. In the recent years, the role of glycation and advanced glycation end products (AGEs) has been increasingly discussed in connection with skin ageing, and the potential of anti-AGE strategies has received high interest from pharmaceutical companies for the development of novel anti-ageing cosmeceutical compounds.
What is glycation?
Glycation was first diagnosed in diabetic patients as leading to the accumulation of advanced glycation end (AGE) products in different tissues and organs, such as blood vessels and retina. AGE products have been associated with end stage renal disease, atherosclerosis and other health-threatening conditions. Obviously, the skin is not an exception. AGEs products have been discovered both in dermis and in the deep layers of epidermis, in the skin of young people as well as older people. Apparently, in older people's skin the presence of AGEs is more marked, because their natural degradation declines with age.
Glycation is a specific reaction between sugars (mainly glucose and fructose) and proteins, lipids or nucleic acids. Glycation transforms bonded proteins and other agents into dysfunctional molecules: collagen will become less flexible, forming a triple helix structure, and what's worse, this new helix is very difficult to destroy or replace by new functional molecules. The lack of skin elasticity caused by transformed collagen quickly becomes irreversible.
Glycated molecules and glycation products (AGEs) increase the risk of the skin's photodamage, and ultraviolet radiation, in its turn, stimulates glycation, launching a vicious cycle. The risk of glycation is further increased in smokers leading to premature wrinkles, uneven complexion and loss of elasticity. Recently a link between glycation and eating habits has been established: sugar-rich diets play a crucial role in the increase of glycation, as do products with high contents of AGEs: barbecued meat, toasted bread, dark-coloured soft drinks, donuts. Sorry to bring this news, but apparently frying, roasting and grilling food apparently is not the best way to go if you desire to look younger.
The good news is, that healthy eating can reduce the amount of AGEs in the body. Healthy “anti-glycation” diet has to be low in monosaccharides (glucose AND fructose) and water-based cooking — boiling or steaming — is preferable. Some aromatic herbs and spices are supposedly able to reduce the endogenous production of AGEs: oregano, clove, ginger, cinnamon and garlic are your friends. Furthermore, since glycation is accelerated by free radical activity, the intake of antioxidants can inhibit the production of AGEs. The most effective is probably alpha-lipoic acid, but carnitine, resveratrol and flavonoids can also do you good, as well as zinc and manganese.
Research has been conducted on the inhibitors of glycation with promising results. For example, aspirin taken orally blocks glycation effectively enough. Unfortunately, not many ingredients are equally effective if applied topically. Antioxidants such as vitamin C and E, green tea extract, resveratrol and some others can be called anti-glycation agents because antioxidant activity helps reduce the formation of AGEs. However, antioxidants don't have a direct “unbinding” effect on the damaged structural proteins in the epidermis and dermis. A more or less “direct” anti-glycation effect following topical application is shown by coenzyme Q-10 and pentapeptide-34 trifluoroacetate, the latter enhancing the skin’s ability to produce coenzyme Q-10. Anti-glycation runner-ups are lactobionic and maltobionic acid, carnosic acid, gluconolactone, aminoguanidine and alisin (rarely used in cosmetics), blueberry and pomegranate extracts and a universal skin booster, vitamin B3 or niacinamide.
The signs of glycation (stiffness, discolouration, loss of elasticity and barrier function, wrinkles and dull complexion) can appear as early as at 30–35, especially in smokers and suntan lovers. So if this kind of thing bothers you, it is best to begin preemptive measures early.
