The Medical Minute: The myth of the healthy tan

June 03, 2004

By John Messmer, M.D.
Penn State Milton S. Hershey Medical Center

Summer is almost here. Memorial Day is the beginning of sun season for many Americans with trips to the beach, rounds of golf, swimming, backyard activities and much more. If you are hoping to get a little color this summer, think again. The lighter skinned among us are developing skin cancer at an increasing rate. There is no such thing as a "healthy tan."

Sunlight contains powerful radiation. The light we see -- visible light -- warms us and provides energy for plant growth. It's what we don't see that causes harm -- the sun's ultraviolet or UV rays.

There are three forms of UV. Fortunately, the earth's atmosphere blocks the most damaging element, called UVC. But the other two forms, UVB and UVA, reach beyond the clouds and ozone. UVB penetrates our skin, damaging the DNA in our cells. If the DNA is not repaired properly, cancer, particularly malignant melanoma, can develop. UVA (the kind used in tanning beds) does not penetrate as deeply as UVB so it doesn't burn, but it affects the DNA as UVB can and does cause basal cell and squamous carcinomas. These two cancers, while not as aggressive as melanoma, can be invasive and disfiguring. Although UVA does contribute to the production of vitamin D, we need only 10 minutes exposure three times a week.

Although it is preventable, the Environmental Protection Agency notes that one in five Americans will develop skin cancer. The incidence of melanoma, the most serious form, has doubled since 1969. Each sunburn increases the risk of melanoma, particularly burns in childhood.

UVA and UVB also cause wrinkles and rough spots -- noncancerous changes called photo aging -- by damaging the supporting proteins in our skin. Color becomes uneven and the skin gets rough. The price of today's tan is premature aging of the skin. Many of the sun worshippers of 30 years ago are spending a small fortune on skin rejuvenation treatments and plastic surgery to look as young as the small number of their peers who never tanned or burned.

It's not just light skinned individuals who are at risk. Although darker skin is somewhat protective, it is a misunderstanding to think that getting a tan will protect the skin from the sun since damage occurs while getting the tan in the first place. Photo aging still occurs and skin cancer is often more advanced when diagnosed in darker-skinned individuals.

We receive a large portion of our lifetime sun exposure by age 18. Parents should be vigilant in protecting their children from the sun, but sun protection is beneficial even for adults. Limiting exposure to the sun's damaging rays is the best method of prevention.

UV light is most intense between 10 a.m. and 4 p.m. Don't be comforted by clouds as most of the UV passes through them. Cool days still provide damaging UV exposure. Check your local paper or http://www.epa.gov/sunwise/uvindex.html for the UV index for the day. The higher the number from 1-11+, the more protection you'll need.

If you use sun block -- and you should -- you're probably familiar with the initials spf -- short for sun protective factor, a rating of protection against sunburn. The spf says how many times longer one can stay in the sun before being burned compared to having no protection. Someone who burns after 30 minutes unprotected should be able to avoid a burn with an SPF 15 for 15 x 30 minutes or seven and a half hours. A sunscreen with SPF 15 blocks 93 percent of the damaging UV rays. The 7 percent that passes can still cause skin aging and contribute to skin cancer. To maximize safety, one should use at least an SPF of 15 (spf 45 blocks about 98 percent of UV) plus clothing and head covering when spending time outside.

For best protection, apply sunblock to dry skin before going out to give it time to penetrate into the skin for a protective barrier. OK, so you put on two coats of a 45 SPF sunblock and you have your 100 percent UV blocking sunglasses, so you're good to go for a day at the beach, right? Not necessarily -- moisture washes away even waterproof sunblock so reapply it every two hours or so. Even then, try to stay in shade, for example, under an umbrella, and use a wide brimmed hat for protection of the top of the head and ears. Remember to protect your lips with sun blocking lip balm.

Whether you are at the beach, a ballpark, a picnic or in your own backyard, the object of sun protection is to reduce your risk of burning and cancer from the sun exposure you cannot avoid. Since there is no safe tan, no one should intentionally stay in direct sunlight even with sunblock. As the CDC says, "If you're tanned, you're toast."

The best advice for outdoor activity is to cover your skin with clothing that does not let light through and wear sunblock on exposed surfaces. This is critical for children and highly recommended for adults. With a few precautions you can enjoy the summer sun without burns, cancer, cataracts or the telltale signs of premature aging.

(Media Contacts)

Last Updated March 19, 2009