Sugar attaches to proteins; a process called glycation, and the proteins collagen and elastin become linked. Whereas protein strands normally slide over to one another, become attached to the glucose and cannot move about freely.
Perhaps the worst consequence of glycation is linking, which is the formation of chemical bridges between proteins and other large molecules. A material undergoes linking usually becomes harder, less elastic and has the tendency to become brittle and fragile. In an ageing skin, glycation causes the loss of resiliency (bounce back) and feeling of adhesion (hardening) under the skin and stiffening joints.
AGE’s exert their harmful effects on two levels; most obviously, they physically impair protein, DNA and lipids, altering their chemical properties. They also act as cellular signals, triggering a cascade of destructive event when they attach to their cellular binding sites. A sagging and inflexible skin is a result of this process; aggravating the appearance of ageing in addition it can have a detrimental effect on microcirculatory system of the skin.