ERIN ANDERSEN / Lincoln Journal Star | Posted: Saturday, June 25, 2005 7:00 pm
For years we have slathered ourselves in sunscreens with ratings of SP 15 or more, finally accepting the advice of doctors that full exposure to the sun could cause skin cancer.
Now comes new preliminary research touting the benefits of sun sans sunscreen, sun hats and sun-shielding attire for fighting some types of cancer, including some skin cancers.
So is the sun good for you?
Or bad?
In truth, the answer is both.
Which is all quite confusing.
And that concerns Lincoln dermatologist Dr. David Bigler, who has seen the incidence of skin cancer particularly the very deadly melanoma increase dramatically during his 20 years in dermatology practice.
"Melanoma is rapidly on the increase," Bigler said. "I am seeing it in people younger than I ever thought I would. It is not an old person's disease."
"The good news is that the death rate is not rising anywhere near the rate of diagnosis," he said. "The implication is we are getting to it earlier and treating it better."
And that's why Bigler is so concerned about these studies not because he questions their veracity, but because he worries how average sun-loving, tan-seeking people will interpret these findings.
Each year, nearly one million Americans are diagnosed with skin cancer 44,000 of those will have melanoma, the most serious form of skin cancer. About 7,300 of those people will die from it, according to the American Academy of Dermatology.
Doctors know that the sun is not all bad it has long been used to treat some skin diseases.
But overexposure and too much exposure over a lifetime is unhealthy.
It causes wrinkles, freckles and skin texture changes. It can dilate blood cells.
And it causes skin cancer more than 90 percent of all skin cancers occur on sun-exposed skin, according to the academy.
So how is it that a study published in the Journal of the National Cancer Institute earlier this year found practically the opposite that sunlight exposure can help victims of melanoma survive the disease yet at the same time cause the disease?
And a second study indicates that exposure to sunlight may reduce the risk of getting certain cancers of the lymph glands such as non-Hodgkin's lymphoma.
"It's totally counterintuitive and we're trying to investigate it," Marianne Berwick, who led the study, told the Associated Press earlier this year.
Berwick, of the department of internal medicine at the University of New Mexico, told the AP that the result of her study of 528 melanoma victims over a five-year period found that increased sun exposure led to increased survival rates. Berwick is now conducting a second study of 3,700 melanoma patients worldwide.
According to her study results, sunburn is one of the factors associated with melanoma survival and at the same time sunburn is considered one of the primary causes of melanoma.
Doctors find these results curious and intriguing.
But sun worshippers and people who have long believed a good tan makes them look healthy may foolishly think it gives them full license to bake and burn without threat.
The sun is still dangerous, Bigler said.
"A tan is actually the skin's response to injury," he said.
"And there are those who have to get a serious amount of injury to get a little tan," Bigler said, referring to fair-skinned people who burn easily and have trouble tanning. "To get a little bit of tan, they are getting a huge amount of injury."
People fail to realize that it is not a one-time sunburn or a few tan summers that do the damage. It's a lifetime of accumulation, from those rides in your baby stroller to those teenage summers spent soaking up rays at the pool to winter vacations skiing in the mountains.
The more sun exposure without the protection of sunscreens, the greater the risk of contracting some form of skin cancer, Bigler said.
The sun does have its health benefits, however.
Sunlight absorbed through the skin helps produce Vitamin D, which is needed to build strong bones. New research finds that Vitamin D helps regulate cell division, thereby helping stop unneeded cell growth (which is what cancer is). And so doctors are investigating whether it is actually the Vitamin D that is helping patients with melanoma and lymph node cancers fight off the disease.
But for the most part, healthy people can get all the Vitamin D they need from less risky methods than the sun, Bigler said. In the U.S., people can get their daily dose of Vitamin D simply by drinking a glass of Vitamin D fortified milk, eating foods rich in the vitamin or taking a multivitamin pill, he said.
Even when wearing sunscreen, the average person receives enough incidental ultraviolet (UV) exposure through daily activities to achieve recommended vitamin D levels, said Dr. Clay Cockerell, president of the American Academy of Dermatology.
"People should not increase their exposure to either natural or artificial UV light, because there is a high risk of developing skin cancer from repeated exposure," he said.
Others agree that people must not forsake caution in the sun.
"Sunlight, particularly ultraviolet radiation, is a very well established human carcinogen. Nothing in these papers (studies) should in any way detract from this message," Kathleen M. Egan of Vanderbilt University Medical Center told the Associated Press.
Translation: Keep wearing the sunscreen.
Reach Erin Andersen at 473-7217 or eandersen@journalstar.com.
Sun safety tips
* Use sunscreens rated SPF 15 or higher. Apply it to all exposed skins, including the lips. Wear sunscreen even on cloudy days.
* Reapply sunscreen frequently.
* Avoid unnecessary sun exposure, especially between 10 a.m. and 4 p.m., the peak hours for harmful ultraviolet radiation.
* Wear protective, tightly-woven clothing.
* Sit in the shade whenever possible.
* Wear a broad-brimmed hat and UV-protective sunglasses.
* Stay away from artificial tanning devices. If you want a tan, use a tanning cream or liquid.
* Examine your skin, head to toe, at least once every three months.
Sources: American Academy of Dermatology and The Skin Cancer Foundation