While sunlight may be necessary and desirable for numerous living things, it can also be harmful — particularly to our skin. Skin that has been exposed to the sun, whether from tanning or excessive outdoor exposure, ages prematurely.
According to the National Institutes of Health’s News In Health, sunlight makes its way to Earth as both visible and invisible rays, also called waves. Long waves, such as radio waves, are harmless to people.
But the shorter waves that come in the form of ultraviolet light, can be harmful. The longest of these UV rays are called UVA rays. The shorter ones are UVB rays.
Too much exposure to UVB rays can cause sunburn. UVA rays travel more deeply into the skin than UVB rays, but they both can adversely affect skin’s health.
The skin’s outer layer has cells that contain the pigment called melanin. Melanin is a chemical that allows the skin to get darker. It’s the stuff behind your tan. Melanin’s job is to protect the skin from the sun’s UV rays.
Most people know that the UV rays can lead to sunburn, but may not realize that over time, they may reduce skin’s elasticity and cause that premature aging.
Here’s one of the reasons behind that. UVA and UVB radiation actually changes how our skin cells make chemicals.
Think of it this way — tanned skin is the result of the overproduction of melanin. Again, this is how the skin naturally protects itself against damage. Chronic or excessive sun exposure can cause skin cells producing melanin to mutate and divide uncontrollably, resulting in patchy or irregular skin pigmentation.
Scientific studies have reported that repeated UV radiation exposure breaks down collagen and impairs the synthesis of new collagen. Collagen is the main component of our connective tissue. Without the skin's supportive connective tissue, it loses its flexibility and strength.
On top of that, when skin is repeatedly exposed to sunlight, it loses its ability to repair itself.
Over time, UV radiation damage can take a toll on your skin. It may become thick and leathery, and develop more lines and wrinkles.
A recent study, reported in the medical journal Clinical Cosmetic and Investigational Dermatology, found that UV rays accounted for 80 percent of skin aging, including wrinkles. As part of the study, dermatologists examined the faces of 298 women, aged 30 to 78.
Their results showed that the effects of UV exposure only increases with age. Noticeable differences were seen in skin-texture quality and wrinkles after age 50. Those who had excessive sun exposure looked older than their actual age.
Sources:
Dobson, Roger. "Blame the Sun for Your Visible Wrinkles: UV Rays Account for 80 per Cent of Skin Ageing." Mail Online. Associated Newspapers, 19 Oct. 2013. Web. 8 July 2015.
http://www.dailymail.co.uk/health/article-2467385/Suns-UV-rays-account-80-cent-skin-wrinkles-ageing.html
Dr. Khanna, Manish. "The Number One Cause of Skin Aging." The Huffington Post. Web. 8 July 2015.
http://www.huffingtonpost.ca/dr-manish-khanna/dermatology-aging-skin_b_2697274.html
"NIH News in Health." NIH News in Health RSS. Web. 8 July 2015.
http://newsinhealth.nih.gov/issue/Jul2014/Feature1
"Sun's Effect on Skin - Anatomy Video: MedlinePlus Medical Encyclopedia." U.S National Library of Medicine. U.S. National Library of Medicine. Web. 8 July 2015.
http://www.nlm.nih.gov/medlineplus/ency/anatomyvideos/000125.htm
Reviewed July 10, 2015
by Michele Blacksberg RN
Edited by Jody Smith