The older women had spent a large portion of their lives out in the sun in Florida.

The researchers collected skin samples from the outer forearms and the buttocks of the women.

Obviously, the outer forearms get much more relative Sun exposure than the buttock area.

Their study was to determine how the skin ages differently when it is exposed a great deal to the Sun (as in the outer forearm area) and when it isn’t exposed to the Sun (as in the buttock area).

They found that enzymes called proteases break down collagen and elastin, which both gives elasticity to skin, and causes the skin to wrinkle.

Collagen is the main protein of connective tissue. Elastin is also a protein in connective tissue. It gives elasticity to tissue, allowing it to stretch and contract. When skin is pinched, elastin helps skin to return to its normal position.

When this happens, inflammation caused by the rays of the Sun causes other damage to the skin that prevents the skin from holding onto moisture, thus, making it much drier in texture and tone.

The Robinson team found that exposure to ultraviolet (UV) radiation from sunlight increases inflammation and speeds the aging process of the skin, including the formation for wrinkles.

This article was developed based on the article “Sun, inflammation speed aging of skin” in the Science News magazine of March 1, 2008.