Glycation, a term from biochemistry, refers to the bonding of a sugar molecule to a protein or lipid (fat) molecule without any enzymatic regulation. Glycation may occur either inside the body (endogenous glycation) or outside the body (exogenous glycation). It can interfere with the functioning of biomolecules. Both forms of glycation are potentially harmful. Exogenous glycation comes from external sources - products that promote "caramelization" (chemical that produce darkening of meats and other products) are one type. Endogeneous glycation occurs as a reaction to simple sugars (glucose, fructose, and galactose) and have a relationship to the rise of disease processes such as those that lead to Alzheimer's disease, cancer, peripheral neuropathy (in which the myelin is attacked), and other sensory losses such as deafness.