Scientific research has come a long way in the past few years in helping us understand how sun rays damage the skin and what we can do to protect ourselves from this damage. A new study recently published in the Proceedings of the National Academy of Sciences by John D. Simon, a Duke University biophysicist, throws new light on just how the sun affects our skin. Researchers have long known that sunlight can cause the skin to sag, wrinkle, and turn leathery. But experts said the Simon study is the first to show why this happens and just how UVA rays bring it about.
The Simon study has revealed that UVA radiation, whether from the sun or artificial sources, is absorbed by urocanic acid, a natural molecule made by the outermost skin cells. This radiation chemically changes urocanic acid and causes it to create within the cells a type of oxygen-free radical, a highly active molecule that can be damaging to cells. Simon said this oxygen radical “degrades collagen and elastin, which are the major molecules that make up the skin. This process accelerates photoaging of the skin.”
By degrading collagen and elastin, he said, “you decrease the elasticity of the skin. It makes you look older than you might be.”
The new study underscores the importance of using a lotion that blocks both types of ultraviolet radiation – UVA and UVB. At present, most sunscreens focus on protecting against UVB while doing little to protect against UVA. However, there are a few currently available which block both types. Look for one that contains zinc oxide.
Used in conjunction with a 10% glycolic acid preparation, the damage caused to our skin by the harmful rays of the sun can be greatly reduced. The glycolic acid helps the body repair the damage; the sunscreen helps prevent further damage from occurring.
