Heading to the beach for the first official weekend of summer? You might want to make a note of a new study showing exactly how tanning can be addicting. Scientists from Harvard Medical School and Massachusetts General Hospital found that repeated sun exposure produces endorphins in the body, much the same way as heroin does.
The researchers took mice and shaved their little backs, exposing them to sunlight for just half an hour a day for six weeks. The rodents' blood had elevated levels of edorphins and when administered an opiod blocker, the poor critters showed signs of withdrawal like tremors and jitteriness.
Think it's only furballs affected? A 2010 study showed that one in three people using tanning salons also fit the criteria for addiction. "People who may have no intention of using any drugs may just think they're going out to enjoy a great day outdoors and may be becoming addicted and exposing themselves and their children to UV in a fashion which could elevate their risk of developing skin cancer," says David Fisher, M.D., one of the researchers on the study.
"It sounds like a cruel joke to be addicted the most ubiquitous carcinogen in the world," Fisher says. He theorizes that the reason human beings may have this pleasurable response to the sun is because it could have given us an evolutionary advantage, helping us to get adequate vitamin D which we need for everything from healthy teeth to strong immune systems. While some scientists are skeptical that tanning really qualifies as an addiction, like drugs or alcohol, it's long been known that too much sun leads to cancer so it's best to play it safe whether or not you feel "addicted" or not.
The American Cancer society recommends doing the "shadow test": If you go outside and your shadow is shorter than you are, you need to take measures to protect yourself. Their motto is "Slip! Slap! Slop! Wrap!" to remind you to slip on a shirt, slap on a hat, slop on some broad-spectrum sunscreen, and wrap sunglasses around your face.