Tan is artificial; threat is genuine

Experts fear salons are no safer than sun, but level of risk is unclear

10:09 PM CDT on Sunday, July 3, 2005

By LAURA BEIL / The Dallas Morning News

The tan you buy may be no safer than the one that comes for free.

Once hoped to offer a better way to brown, tanning salons now take as much heat from medical experts as the sun. The World Health Organization recently stated that artificial tanning "may provide the ideal setting for the development of malignant skin cancer" because users get periodic bursts of intense radiation. In addition, people in tanning beds often place their whole bodies under the ultraviolet light, leaving about twice the surface area exposed to direct rays.

Some doctors even suspect that tanning bed popularity may be one reason why younger people appear to be getting skin cancer with increasing frequency.

However, even in issuing its opinion, the health organization acknowledged that research so far has not provided consistent results.

"There are different arguments as to how much risk there actually is," said Dr. Martin Weinstock of Brown University. This month, Dr. Weinstock attended an international gathering of experts the World Health Organization invited to France to evaluate artificial tanning risks.

Difficult to study

One of the difficulties in studying tanning device hazards, scientists say, is that cancer patients who have spent time in tanning beds have also tended to love the sun, making it difficult to tease out whether their risk came from natural or artificial light. Cancer usually smolders for decades before it flares up on the skin, so most studies must rely on asking patients about sunning habits they had years before. And because cancers like melanoma are deadly but not among the most common malignancies, the studies up to now have been small.

One thing has not been in dispute. That lovely bronze is a response to radiation. "UV light clearly causes DNA damage," said Dr. Patrick Hwu, the chairman of melanoma medical oncology at the University of Texas-M.D. Anderson Cancer Center in Houston. If indoor tanning is doing its job by UV light, he said, "I think it's not safe."

But how unsafe is it?

To try to answer that question, researchers from the University of British Columbia recently pooled data from more than a dozen studies looking at the melanoma risk from artificial tanning. In a report published in March in the journal Cancer Epidemiology Biomarkers and Prevention, the Canadian scientists found that, overall, tanning bed use appeared to almost double the risk of melanoma. That would mean an American man's lifetime risk of melanoma, now about 1 in 50, would rise to about 2 in 50 with regular tanning bed use.

However, "it's not the kind of thing where you're going to have one message for the entire population," said Richard Gallagher of the British Columbia Cancer Agency, who led the research. Skin cancer is a much higher danger among the fair-skinned the very people most likely to use a tanning bed.

Risk factors

A person's risk of melanoma has been linked to the number of burns they have experienced in their youth. So, in theory, a tanning bed if it keeps a person from burning might appear to lower melanoma risk. Dr. Weinstock points out, however, that the burn itself may not be the harming factor. The sunburn could just be a warning signal that the person's skin is particularly sensitive to radiation.

The two other types of skin cancer, basal and squamous cell carcinoma, are more often associated with a person's total exposure to the sun. Research has suggested artificial tanning also increases the risk of those cancers. For example, one study from Dr. Weinstock and his colleagues of cancer patients in New Hampshire suggested that tanning devices more than doubled the risk of squamous cell carcinoma.

"The key question is," Dr. Weinstock said, "why do people go and get this exposure voluntarily? You can get your tan in a bottle if you really need a tan."

People seem to tolerate carcinogens when they are enjoyable and addictive, and some people who frequent tanning beds may feel a similar, though weaker, draw. Studies have suggested that ultraviolet light stimulates the release of endorphins, the body's own opiatelike compounds. Scientists from Wake Forest University School of Medicine in North Carolina have found that frequent tanners can distinguish a tanning bed with actual UV light from a sham bed simply by the way it makes them feel.

"UV light has a physiologic effect that drives people's behavior," said Wake Forest's Dr. Steven Feldman.

Yet despite the fact that doctors may be battling fashion and physiology, they remain resolute.

"We know we have a lot of work to do," said Dr. Clay Cockerell, a Dallas dermatologist who is also president of the American Academy of Dermatology. "You've got to make it cool to be safe. That's not easy to do."

A tan offers immediate reward, but cancer is a distant threat. "It usually takes about 20 years or so of skin damage to get skin cancer," Dr. Cockerell said. But by the time patients get to his office, he said, "they do usually regret it."

E-mail lbeil@dallasnews.com

Online at: http://www.dallasnews.com/s/dws/news/healthscience/stories/070405dnnatnutanning.6f87ff90.html