60-Second Health

Tanning Mice Get Physically Addicted

Mice regularly exposed to UV light produced feel-good endorphins and behaved like addicts. If humans do, too, it could explain why we seek sun, despite damage. Dina Fine Maron reports


You may love to soak up the sun—or the UV rays at the tanning salon. But are you actually addicted?
A study finds that mice regularly exposed to UV produced the feel-good opioid β-endorphin, and behaved like addicts.
What’s more, when they were given a drug that blocked the opioid effects, they went through the rodent equivalent of withdrawal: shaky paws and chattering teeth. The study is in the journal Cell. [Gillian L. Fell et al, Skin β-Endorphin Mediates Addiction to UV Light] (To hear an interview with study author David E. Fisher, go to the Cell Web site.)
The mice were exposed to UV light roughly on par with a fair-skinned human soaking up a half-hour of Florida midday sun, five days a week for a month-and-a-half. But it took just one week for the endorphin levels to zoom.
Mice are normally nocturnal and, of course, covered by fur. But the research team says that the apparent physical reward for UV exposure suggests it’s worth exploring if a similar chemical reaction may be spurring humans to keep running to the beach or tanning bed.
They also say it’s likely sunblock would protect against these UV-induced addictive behaviors. Yet another reason to slather on the sunscreen.
—Dina Fine Maron
[The above text is a transcript of this podcast.]

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