July 15, 2008

How Much Sunshine is Too Much?

California and Florida may vie for the title "sunshine state," but Colorado has the distinction of getting a lot more sunshine overall and thanks to its higher average altitude, a lot less atmosphere to shield its residents.

Colorado trails other states in skin cancer rates but the three main types, basal cell carcinoma, squamous cell carcinoma and melanoma, still afflict many here, ranging between 17.6 and 23.6 people per 100,000 in 2004, according to the U.S. Centers for Disease Control and Prevention. That puts Colorado in the same range as California, Wyoming and Kansas among Western states.

The debate over just how healthy or dangerous the sun is -- and ultraviolet radiation in general that many people absorb artificially -- has been going on for a long time. Walk into a dermatologist's office and you're likely to see a poster proclaiming, "A healthy tan is the first sign of skin cancer. Ironic, isn't it?"

To make it even more worrisome, this week, a new report claimed that most sunscreens don't even offer the protection people think they do. And in March, when people started thinking they needed a head start on their summer complexions, the Indoor Tanning Association ran a full-page ad in The New York Times criticizing dermatologists and the makers of sunscreens.

The industry association claimed that doctors and sunscreen makers were in collusion, trying to scare people. The association went on to cite the benefits of sunlight and vitamin D, and its members point to studies they say advocate tanning, including by artificial methods to prevent disease.

They denied what they said were charges by dermatologists that tanning beds caused melanoma. The industry may be quibbling there, because it's really two other types of skin cancer they say are more likely to develop.

The CDC itself says that the risk of basal cell carcinoma is 1.5 times greater from tanning beds than from sun exposure 2.5 times for squamous cell cancer. The National Institutes of Health have warned people not to use them for the same reason.

Basal cell carcinoma is what causes many people in their 50s and older to spend a few days with Band-Aids on their noses and ears when doctors have had to remove lesions. The most common of skin cancers, they can in some cases become serious and spread beyond the epidermis, the top layer of skin.

Squamous cell cancer is less common but a lot more serious because it's more likely to spread. It usually takes a deeper surgical procedure to remove.

Melanoma is the worst kind of skin cancer and the American Cancer Society projects it will cause 8,420 deaths this year.

The Colorado Department of Public Health and Environment warns that men in the state stand a 1 in 33 chance of getting the sometimes deadly form of skin cancer in their lifetime and women 1 in 62.

Skin cancer death rates for women are generally lower, because more men tend to have outside jobs and women pay more attention to the early signs of skin cancer.

Bedside manner

Dr. Sharon Kessler, a Pueblo dermatologist, explains that melanoma prevention has to start early because there's evidence that people who suffer serious sunburns when they're young have a greater likelihood of developing melanoma later.

Kessler also is no fan of indoor tanning beds and warns her patients against using them, often meeting with resistance.

She discounts the health benefits of ultraviolet radiation claimed by the tanning industry, saying that most people get plenty of sunlight without going out of their way to absorb it. For proof of that, she said, people should look at their arms and notice how much darker their left arms get during the summer even if they drive with their car windows up and the air conditioner on.

"At 5,000 feet, even with sunscreen on, you get plenty of vitamin D," she said. "I've never seen a case of rickets," she adds with a laugh.

But Kessler doesn't doubt that tanning makes people feel good. Studies have indicated that it releases endorphins and that pleasurable experience is what keeps people going back to the salons for more, or spending more time lying out in the sun.

She recalls a patient who had developed skin cancer and how upset the woman became.

"I naively thought she was upset about having cancer," Kessler said.

It turned out the woman was mad because she was told not to use tanning beds again. A few days later she came back and apologized for her reaction.

Another time, a mother called and said her 12-year-old daughter had won a dozen free sessions at a tanning salon. "I just about fell over," Kessler said. She said she convinced the woman not to accept the prize.

Kessler acknowledges that even she uses ultraviolet A radiation, the stuff that tanning beds use, for therapeutic reasons. It's effective on psoriasis and eczema because it's a very powerful immunity suppressant. That's one of the reasons it's tied to cancers, she adds, because it interferes with the body's immune system. She also said she would not use the treatment on children because of the possibility of permanent damage and points out that the radiation doctors use is a much lower dose than a tanning bed's.

While children need to be protected from too much ultraviolet exposure, older people also are increasingly at risk. Many of the drugs prescribed for baby boomers to treat high blood pressure and cholesterol carry warnings about sunlight sensitivity that the medicines can cause.

The best protection, she said, is avoiding tanning beds and staying out of the sun at mid-day. That's especially true for fair-skinned people, she said, explaining that people with Irish and Scottish ancestors are more likely to develop skin cancer than even other Europeans. Because natural melanin is a protection, most Hispanics are much less likely to have skin cancer and African Americans even less.

"You just have to embrace your pastiness," she said.

And even sunscreens may not offer adequate protection from the most dangerous rays of the sun, she adds. She recommends hats and long sleeves with thick fabric for the best protection.

That was driven home this week by a study reported by Environmental Working Group. The nonprofit research group looked at 952 sunscreens and found only one in five actually offered protection from the sun while some included chemicals that could be absorbed by the body.

The study also criticized the Food and Drug Administration for failing to rein in advertising claims and not issuing its own 30-year-old report on the effectiveness of sunscreens.