We’ve all seen the headlines about sex, food and rock-and-roll “lighting up” the same brain regions as drugs. The latest? “Tanning Bed Users’ Brains Like Addicts’,” claims the UPI, citing a new study.
I don’t mean to pick on the authors of the research, which was just published in the journal Addiction Biology. Bryan Adinoff of the University of Texas Southwestern Medical Center and his colleagues examined seven frequent users of tanning beds in a bed that either exposed them to ultraviolet (UV) light, which is what causes skin to tan, or to light that was filtered to block those rays.
In the “real” artificial sunlight condition — but not in the filtered light — the tanners’ brains showed activation of regions associated with pleasure and reward.
That’s a useful thing to study. It’s especially important in light of the fact that there are 120,000 cases of melanoma, an often deadly form of skin cancer, per year in the U.S. People who spend more than 50 hours a year in tanning beds triple their risk for the disease; getting just one blistering sunburn during childhood or adolescence doubles melanoma risk.
Many of us clearly take risks to enjoy tanning, which is one potential sign of addiction. But saying that tanning is “addictive” because the reward areas of people’s brains light up in response to UV light is a little like saying we like sugar because it tastes sweet. It’s a tautology. Anything that you perceive as enjoyable will activate the pleasure regions: if it didn’t, it couldn’t be experienced as pleasant.
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Further, it’s no secret that sunlight is rewarding. If it weren’t, happy temperaments wouldn’t be called “sunny” and people would stop lying out in the sun when their doctors warn them about cancer risks. Cats wouldn’t look so happy splayed out in warm spots.
It makes biological sense for UV light to feel good. It raises levels of vitamin D levels (which may even reduce the risk of some cancers). Before fire was tamed and artificial light was invented, humans needed to be active during the daytime in order to survive — that might also contribute to the light–happiness connection.
NEXT: “Enjoyment doesn’t mean addiction”
So it could certainly be helpful to learn how the feeling of UV light on the skin produces pleasure. The new research may help elucidate that: it shows, for example, that UV light is essential to sunning pleasure, since UV-filtered light did not produce the same brain responses.
However, simply demonstrating that a person’s reward areas light up doesn’t show that she’s an addict. For one thing, most people find food, sex and alcohol fun — and their brains’ pleasure regions light up as evidence — but they never become addicted to any of those things. Enjoyment doesn’t equal addiction.
Incidentally, neither does craving — by itself. A person’s brain may show a response indicating desire, but that doesn’t mean that urge is uncontrollable or that the person’s ability to make choices is impaired.
Addiction is much more complicated. We do a disservice both to the understanding of the brain and to our decisions regarding drug treatment and policy when we think about it so simplistically.
Neither pleasure nor desire is sufficient to define addiction, and brain scans typically don’t offer more information than that. Until we look what leads a small proportion of people — who tend to be unhappy, stressed, mentally ill or unemployed — to persist in unhealthy behavior despite negative consequences, or, in other words, addiction, we won’t make real progress.
Tanning may become an addiction for some people — but research like this can’t prove it.