A slow and presently irreversible process takes place inside your body, day in and day out: vital proteins are gummed and shackled into obstructive and sometimes toxic compounds by sugars and related chemicals from food. These byproducts of your metabolism are called advanced glycation end products, or AGEs, and are one root cause of aging. Year after year, this biochemical junk builds up; some forms accumulate faster than they can be broken down, and others your body is incapable of removing. Eventually, the levels of AGEs rise to the point of degrading the biological systems your life depends upon. Here is an informative review paper on how this all comes to pass:
Protein glycation is a slow natural process involving the chemical modification of the reactive amino and guanidine functions in amino acids by sugars and carbohydrates-derived reactive carbonyls. Its deleterious consequences are obvious in the case of long-lived proteins in aged people and are exacerbated by the high blood concentration of sugars in diabetic patients. The non-enzymatic glycation of proteins occurs through a wide range of concurrent processes comprising condensation, rearrangement, fragmentation, and oxidation reactions. Using a few well established intermediates such as Schiff base, Amadori product and reactive a-dicarbonyls as milestones and the results of in vitro glycation investigations, an overall detailed mechanistic analysis of protein glycation is presented for the first time. The pathways leading to several advanced glycation end products (AGEs) such as (carboxymethyl)lysine, pentosidine, and glucosepane are outlined, whereas other AGEs useful as potential biomarkers of glycation are only briefly mentioned. The current stage of the development of glycation inhibitors has been reviewed with an emphasis on their mechanism of action.
It is noteworthy that glycation in the body is comparatively well-understood at this time, and disappointing that so few initiatives are presently underway to develop the means of safely breaking down and removing AGEs before they rise to the level of causing damage.
The review above, for example, focuses on slowing the process of glycation; as for any therapy aimed only at slowing the processes of accumulated damage that cause aging, this will prove less valuable and effective than a therapy aimed at repair. Repair can be performed over and over again, and the underlying medical technology is not necessarily any harder to develop in the first place. This is a good specific example of a general problem in the approach taken by much of the mainstream at the present time.