The free radicals are in part due to the action of UV light on AGE (advanced glycation end products) such as Amadori products (a type of AGE) as a result of the reaction of DHA with the skin. AGEs are behind the damage to the skin that occurs with high blood sugar in diabetes where similar glycation occurs. Some of the damage from AGE is independent of UV light. A study showed glycation of a protein increases its free-radical production rate nearly fifty-fold.