Many scientists agree that as much as 90% of the visible changes of aging skin can be caused by sun damage. Statistically, it is said that 50% of this damage occurs before the age of 18. Approximately 90% of all sun damage is unplanned, such as occurring while riding in a car or stopping outdoors to talk with a friend. Antioxidants help to battle free radical damage, which is a byproduct of normal skin function. This damage causes skin aging and thinning of the fat pad under the skin.