Tanned skin looks good, but some people return to the tanning booth long after their skin has reached a healthy-looking hue. Obsession with tanning has been viewed as just another aesthetic preoccupation alongside wrinkle and hair removal, but new research has been piling up evidence that the ultraviolet radiation from tanning and natural sunlight may actually be chemically addictive.
As doctors began to suspect that UV was addictive, a trickle of studies made it past the gates of incredulity into the Journal of the American Academy of Dermatology. Last year, Dr. Sarah Zeller interviewed 1275 adolescents to see if their behavior fit the pattern for addiction. The difficulty that many subjects had quitting, which increased with the earliness of first tanning and the frequency of regular tanning, was consistent with addictive behavior. Dr. Steven Feldman, not content with hearing self-reports over the phone, tried to observe addictive behavior in the laboratory. With a blind experiment involving two seemingly-identical tanning booths, Dr. Feldman demonstrated that subjects consistently chose to enter the real UV booth. This means that people not only have the ability to subconsciously detect UV rays, but that they have a definite desire to absorb them. Subjects reported a deep feeling of relaxation only after tanning in the real UV booth.
The interview and experiment above established the presence of addict-like behavior, but they did not identify a mechanism for the development of this addiction. Dr. Feldman continued his search for the mechanism until he came to opioids, a pain reliever that works on the central nervous system and can be found in many narcotics. When frequent tanners were given opioid-blockers but still allowed to tan, they suffered withdrawal systems that infrequent tanners did not experience.
So the chemical culprit was revealed, but the search was not over, for no one understood how UV rays could transmute into opioids. That is were a recent study in Cell comes in. Dr. Ruato Cul found that Protein 53, sometimes called the "Guardian of the Genome," regulates both the UV-induced pigmentation change in tanning and the beta-endorphin type of opioid.
Dr. Cul's work does more than just complete the causation chain from sunshine to relaxation, it also impacts the debate on whether UV addiction is harmful. If this addiction damages health, then people must be made aware that a sense of well-being is leading them astray. However, consider that the "Guardian of the Genome" has been shown to protect against malignant tumors. It is logical to assume that the pleasure we get from sunshine is our body's way of assuring that we get enough UV rays to keep us healthy. It may be that what was once natural and healthy has become more dangerous as the ozone is depleted, but it is also possible that the positive effects of tanning, such as vitamin D production and p53 effects, still outweigh the risks. Don't cancel your vacation on the beach, but bring a few research journals as summer reading because this issue is not yet closed.
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