Despite many years of intense research on the cause of aging, it is still not fully understood, although general consensus is that chronic inflammation appears to be a major underlying factor. It is known that aging is a complex process that has both genetic and environmental components. It is also known that, in many cases, aging is not always systemic. The process of aging results in an increase of inflammatory cytokines, which are chemicals that are cell signals responsible for many of the degenerative diseases that are associated with aging.1 Rheumatoid arthritis is a classic chronic inflammatory disease associated with excess levels of cytokines that include tumor necrosis factor-alpha (TNF-a), interleukin-6 and NF-kappaB (NF-kB), which are known to cause or contribute to the inflammatory syndrome. In this article, the three known causes of chronic inflammatory disease associated with aging will be addressed, including NF-kB, oxidative damage and the effects of ultraviolet (UV) light on the skin.
NF-kB is a critical compound in body protection, and in the initiation of inflammation. When it is in excess or if it is stimulated by some pathological condition, it can produce both acute and chronic inflammation.2 One of the compounds that is capable of stimulating NF-kB production is known as an advanced glycation end product (AGE). Glycation is the binding of a protein molecule to a glucose molecule, or a fat molecule, resulting in the formation of abnormal protein structures. Many known age-related diseases, such as cataracts and neurological impairment, are at least partially attributable to glycation. These glycation end products contain reactive chemical groups that can combine with proteins and lipids, and cause insoluble complexes.3 These complexes, while biologically active, are physiologically abnormal and thus are capable of entering into cellular reactions that are related to the production of inflammatory components, particularly the cytokines. Foods that are cooked above 140°C will undergo glycation. Frying, baking, broiling and roasting all are done at temperatures in excess of 300°C.
One of the ways that the action of NF-kB can be avoided is to decrease the intake of AGE products. Although this may seem to be an extremely difficult change in the diet, it actually is not quite that bad. As of now, the safe amount of intake of glycation products is unknown. Consider that 100 g of roast chicken skin contains more than six million glycation units.