Sun Damage and Your Skin

Katherine Farady, MD

Article by
Austin Dermatologist

Too much sun can be hazardous for your skin’s health and appearance. Sun damage (also called “photodamage”) accounts for 90% of the changes we associate with aging skin:  coarse wrinkles,  brown spots, loss of elasticity, leathery texture, dullness, roughness, sallowness, easy bruising/fragility, and the development of skin cancers. What about the other 10%?  That’s due to having too many birthdays!  

“Intrinsic aging” causes gradual thinning and fine lines. I will often tell patients to 
compare the skin on their rear ends to the skin on their faces. The difference is sun 
exposure! 
 
So how does the sun make our skin look like leather and develop cancer?    
Basically, sunlight is composed of two types of radiation: infrared (which is 
heat) and ultraviolet. There are two kinds of ultraviolet radiation that are harmful 
to our skin:  UVA and UVB.  They differ in their wavelengths: UVB is shorter and 
UVA is longer. Both can harm the skin by releasing molecules called “free 
radicals”; also known as “reactive oxygen species”. These molecules are highly 
unstable and can lead to the breakdown of collagen and elastin (which leads to 
wrinkles) and to the other changes mentioned above.
 
Ultraviolet radiation also damages cellular DNA, and over time, this can lead to the development of cancer. Now, our skin does have defense mechanisms to counteract this assault; we have natural antioxidants which neutralize the free radicals and cellular repair mechanisms in place to undo the damage. But the insults can frequently overwhelm our defenses (I should note that there are also other sources of free radical damage including smoking and pollution. One puff of a cigarette creates a trillion free radicals!).
 
What can we do to protect ourselves from all this radiation/free radical damage 
and try to repair our skin? First, obviously, is sun protection. This means 
avoidance of midday sun and use of  broad spectrum sunscreens. This is especially important for people with fair skin, as they do not have as much natural protection as darker skinned individuals. The small amounts of sun exposure we experience just going to and from work and running errands build up over time and cause most of the cumulative sun damage to our skin.
 
Broad-brimmed hats can protect the skin from direct sunlight, but remember that 50% of the sun’s rays can be reflected off of cement, sand, or water back onto your face. Windows and windshields screen only the UVB rays; the UVA rays come right through glass. Even when temperatures are cool, you can get significant sun exposure. Clouds offer little protection: 80% of the UV rays come right through.
 
Daily use of sunscreens is an excellent way to protect yourself from harmful UV radiation. There are hundreds of products on the market. Look for sunscreens with a sun protection factor (SPF) of at least 15 for everyday use. Products with higher SPF’s are also available. Many think that the additional protection of an SPF over 30 is minimal, but we feel that the higher protection factor helps make up for deficiencies of application. All sunscreens are good at blocking UVB, but the only sunscreens that adequately block UVA are those that contain titanium dioxide, zinc oxide, avobenzone (also known as Parasol 1789), or Mexoryl (also known as Ecamsule.) It is primarily UVA that causes skin aging, so be sure to use a sunscreen with at least one of these ingredients. Helioplex is a new ingredient that stabilizes chemical sunscreens and extends their protection to 4-5 hours. 
 
There are many sunscreens formulated for the face; these are less likely to feel greasy or clog pores. Many facial sunscreens contain moisturizing ingredients and can be used as an under makeup moisturizer. Sunscreens also come in waterproof formulations which are good for swimming and outdoor activities. Sunscreens should be applied to all exposed areas (face, neck, ears, tops of arms and hands) and ideally should be reapplied every few hours.
 
Don’t fall for the idea that tanning beds are safer than real sun. Tanning beds emit mostly UVA, the longer wavelength. We now know that UVA is not “safer” than UVB. Not only does UVA contribute to cancer, but it actually causes more aging changes than UVB!  Why pay for all this damage when you can get it for free?
 
There has recently been some controversy about vitamin D, the “sunshine vitamin.” Ultraviolet energy from the sun catalyzes the conversion of the vitamin D precursor in the skin to its active form. Vitamin D has been the subject of much research lately and has been shown to have many benefits to human health beyond bone metabolism. Many people are actually deficient in this vitamin, possibly due to use of sunscreens. Darker skinned individuals and those living in northern latitudes are most at risk for vitamin D deficiency. There are different estimates of how much sun exposure is required for adequate vitamin D production, from 10 minutes daily to 10-20 minutes twice weekly. It’s not clear that anyone knows the exact answer. In the meantime, it can’t hurt to take a vitamin D supplement. I recommend 1000 units of vitamin D3 daily, for adults. Some people take even higher doses. 
 
Beyond sunscreens, what’s next? If you are a smoker, please try to quit.  
Also, consider adding plenty of antioxidant containing foods to your diet, such as 
blueberries, brussel sprouts, broccoli, kale, red grapes, spinach, and strawberries. 
 
Antioxidant supplements such as Co-Q-10 in the form of Ubiquinol (100 mg per day) and alpha lipoic acid (100-200 mg per day) are worth considering. What about skin creams? There are thousands of skin care products on the market that claim to reverse the signs of photoaging. The best approach involves the use of retinoids and antioxidants.