When we are exposed to UV radiation from the sun or tanning beds, it causes major structural and functional deterioration of the skin.
There are three types of UV rays—UVA, UVB and UVC, each with different wavelengths and damaging effects. UVA rays, commonly called aging rays, are long wave rays that reach deep into the dermis of the skin and cause permanent damage, leading to skin aging and potentially skin cancer. UVB rays are called burning rays; they primarily cause sunburn as well other skin damage that leads to premature aging and potentially cancer. While UVC rays have been coined cancer-causing rays, many sources indicate that UVC rays do not reach our skin, and aren’t believed to be a concern.
Both UVA and UVB rays accelerate the aging process by breaking down and reducing the proteins in our skin. They destroy collagen, causing collagen fibers to decrease, collapse, become elongated and fragmented. Plus, production of new collagen is reduced. This collagen breakdown causes lines and wrinkles and volume loss that contribute to sagging. UV rays also cause elastin to become shortened, cut off or disappear, causing skin to lose its ability to snap back. This is what causes the loose, sagging skin seen with sun damage, technically called elastosis.
Dermal vessels are comprised of collagen and elastin, when UV rays break down these vital constituents, this damages and reduces dermal vessels leading to dilated capillaries and impaired skin nutrition. UV rays damage the epidermis, which causes it to thicken while the deeper layer (the dermis) remains thin.
If UVA continues to penetrate the skin, it produces highly reactive oxygen species that reach the cell that produces pigment or melanin (melanocyte), causing it to oxidize and develop a tan. Once all the melanin has oxidized, the protective cap over the DNA is no longer present. The reactive oxygen species damage the DNA, and there is overall reduction of DNA in the skin. This activates the P53 gene, which determines whether the cell should be repaired or destroyed, resulting in the formation of sunburn or apoptotic cells. Skin cancer results from faulty DNA repair in cells that probably should have undergone apoptosis (programmed cell death).
With sunburns, there is an influx of enzymes that break down collagen, elastin and other components of the skin. Elastase destroys elastin, collagenase destroys collagen and hyaluronidase dehydrates matrix-moisture. Cyclooxygenase triggers prostaglandins, which are responsible for causing inflammation. Following sun exposure, apply Pevonia’s After Sun Soothing Gel, which contains sodium palmitoyl proline (amino acid), water-lily extract and green tea that help safeguard the skin’s vital components.
UV rays create superoxide free radicals that attack skin cells, causing free radical damage. This results in inflammation and sets into motion a number of processes, which cause skin to lose its youthful vitality.
Sun damage impedes the skin’s ability to repair itself. UV damage causes improper repair of UV induced damage, which over time contributes to signs of aging and possibly precancerous skin changes.
Genetics or heredity play a significant role in sun damage. Skin produces pigment (melanin) to protect itself from the sun’s damaging rays, which then gives skin more resistance to sunburn and cumulative damage. Sun damage is less evident in those who naturally have more melanin or pigment in their skin. Unfortunately, those with fair skin suffer greater sun damage due to a natural lack of protective pigment, which causes more vulnerable to damaging UV rays. However, no one is immune to the sun’s ravages
as overexposure to UV rays cause this protective mechanism to go awry, even in those with more pigment.
News Just In: HEV light, light that makes the sky blue is shown to cause free radicals to form on the skin too, building oxidative damage that hastens aging; one more reason to choose sunscreens with antioxidants like Pevonia’s Hydrating Sunscreen SPF 30. For information on how to correct sun damage see The Best Ingredients + Products to Treat Sun Damage.