Free Newsletters - Space News - Defense Alert - Environment Report - Energy Monitor
by Staff Writers
Boston MA (SPX) Jun 20, 2014
Sun lovers eagerly flock to the beach every summer, despite widespread awareness of the risk of skin cancer. A study published June 19th by Cell Press in the journal Cell reveals that chronic exposure to ultraviolet (UV) radiation causes the release of feel-good hormones called endorphins, which act through the same pathway as heroin and related drugs, leading to physical dependence, tolerance, and addiction-like behavior in rodents.
The findings could explain why people have an instinctive desire to be in the sun, despite its known health risks.
"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," says senior study author David Fisher of Massachusetts General Hospital and Harvard Medical School. "Our findings suggest that the decision to protect our skin or the skin of our children may require more of a conscious effort rather than a passive preference."
Skin cancer is the most common form of cancer in the United States, and UV-seeking behavior is a major risk factor. Many UV seekers meet clinical criteria for a substance-related disorder, but the mechanisms underlying such an addiction have been unclear.
One potential clue is that UV exposure stimulates the production of endorphins, which relieve pain by activating opioid receptors through the same pathway activated by prescription painkillers, morphine, and heroin.
In the new study, Fisher and his team examined whether this pathway could underlie UV addiction. They exposed shaved mice to UV light for 6 weeks and found that endorphin levels in the bloodstream increased within 1 week. After the 6 week period ended, treatment with an opioid-blocking drug caused withdrawal symptoms, including shaking, tremors, and teeth chattering, in mice that had been exposed to UV light.
As a result, these mice avoided locations where they had been given the drug, suggesting that chronic UV exposure produces physical dependence and addiction-like behavior.
"It's surprising that we're genetically programmed to become addicted to something as dangerous as UV radiation, which is probably the most common carcinogen in the world," Fisher says.
"We suspect that the explanation involves UV's contribution to vitamin D synthesis in the skin. However, in the current time, there are much safer and more reliable sources of vitamin D that do not come with carcinogenic risk, so there is real health value in avoiding sunlight as a source of vitamin D."
Massachusetts General Hospital
All About Human Beings and How We Got To Be Here
|The content herein, unless otherwise known to be public domain, are Copyright 1995-2014 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement All images and articles appearing on Space Media Network have been edited or digitally altered in some way. Any requests to remove copyright material will be acted upon in a timely and appropriate manner. Any attempt to extort money from Space Media Network will be ignored and reported to Australian Law Enforcement Agencies as a potential case of financial fraud involving the use of a telephonic carriage device or postal service.|