A study in the Cell journal says that routine sun exposure might get the brain addicted. It says that not only does tanning lead to browning of skin but also leads to the release of feel-good chemicals called endorphins which act like heroin and other opiates.

For a while now, scientists have suspected that exposure to UV radiation can become addictive. Previous studies have indicated that regular sun-tanners can tell the difference between UV light and non-UV lights, and it suggests that the cause might be the endorphis generated by UV-exposure.

A study by the Massachusetts General Hospital and Harvard Medical School reported that UV rays make a person want to bronze their bodies in the warm sun in the same way that food addicts can't stay away from dessert and drug addicts from their next drug. The study suggests that the most common type of cancer affecting 61,000 people in the U.S. in 2010, skin cancer, demands active measures to stop it in addition to stopping dangerous behaviour associated with it.

David Fisher, the study's senior author, said, "This information might serve as a valuable means of educating people to curb excessive sun exposure in order to limit skin cancer risk as well as accelerated skin aging that occurs with repeated sun exposure."

Fisher and his colleagues shaved mice and then exposed them to UV light for six weeks. The endorphin levels were noticed to have increased within a week. An opioid-blocking drug were given to them, after six weeks of trial. The team had speculated that the same receptors that were responsible for blocking pain with morphine and painkillers were involved in creating feelings of euphoria due to the UV rays. After they'd received the drug, the mice showed withdrawal symptoms like shaking, tremors and shaking.

Fisher said, "The addictive power of UV rays could explain why people feel compelled to leave themselves so exposed to cancer, despite knowing full well the behavior is dangerous. The desire to do is nearly instinctive. It's surprising that we're genetically programmed to become addicted to something as dangerous as UV radiation probably the most common carcinogen in the world."

Read more on Forbes and NBC News Web sites