For frequent tanners, the tanning bed may offer more than a bronzed skin. The ultraviolet (UV) radiation used in indoor tanning may actually raise their mood and make them feel relaxed, new research suggests.

“Tanning isn’t just about pigment change in the skin,” according to Dr. Steven R. Feldman of Wake Forest University School of Medicine in Winston-Salem, North Carolina, who led the study.

“UV radiation has complex effects, among them an effect on mood, at least in frequent tanners,” Feldman said. “For some people it seems to become almost like an addiction.”

Not everybody is susceptible to this effect. “I think that the people who tan four to six times before the prom or a cruise don’t have the same response,” Feldman said. “Like a lot of other things, tanning is bad when done to excess.”

Although exposure to ultraviolet radiation has been linked to skin cancer, sunless tanning has become more and more popular in the U.S., according to the researchers’ report in the Journal of the American Academy of Dermatology. While some people use tanning beds only occasionally, at least 10 percent of indoor tanners use tanning beds for more than 20 hours a year.

Most research on the motivations of frequent tanners has focused on their desire to improve their appearance, but Feldman and his colleagues suspected that some people may tan because it makes them feel relaxed.

To examine what lures frequent tanners to tanning beds, the researchers studied 14 people - all women except one man - who used tanning beds 8 to 15 times a month.

During tanning sessions on Mondays and Wednesdays, participants spent part of the time in a normal tanning bed and part of the time in a tanning bed that did not emit any UV radiation. The beds were equipped with special filters that made them appear indistinguishable.

On Fridays, participants were offered the chance to use the tanning bed of their choice - either one bed for the whole session or a combination of the two.

Although the tanning beds looked identical, frequent tanners were not fooled. Out of the 12 people who chose to tan on Fridays, all but one selected the UV-emitting bed for the entire session.

What’s more, tanners felt more relaxed and less tense after using a UV tanning bed than they did after using a dummy tanning bed.

How UV radiation relaxes people is a bit of a mystery. One possibility, according to the report, is that it may trigger skin to produce substances called endorphins that are associated with pleasure. Whether endorphins are involved remains uncertain, however, because the researchers did not measure endorphin levels before and after UV exposure.

SOURCE: Journal of the American Academy of Dermatology, July 2004.