Sun's rays addictive like heroin, claims new report
SUNSHINE acts like an addictive drug and has a similar effect on the body as heroin, scientists claim.
Ultraviolet (UV) rays from the sun stimulate the production of endorphins, "feel good" hormones that act on the same biological pathway as opioid drugs, research shows.
The study suggests that the desire to bake for hours on a beach involves more than topping up a tan.
It may appease our craving for a sunshine "fix", in much the same way as an addict satisfies a yearning for heroin or morphine.
Lead scientist Dr David Fisher, from Harvard Medical School in the US, 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 ageing that occurs with repeated sun exposure."
Experts had known that sun-seeking behaviour can fit the clinical criteria for a substance-related disorder. But what underlay this apparent "addiction" had been unknown until now.
Dr Fisher and his team investigated links between UV exposure and the opioid receptor pathway in "naked" laboratory mice.
After a week in the artificial sunshine, endorphin levels in the blood of shaved animals increased.
At the end of six weeks, the mice were given an opioid-blocking drug, naloxone.
Abruptly denied the drug-like effects of UV, they suffered an array of withdrawal symptoms, including shaking, tremors and teeth chattering.