The sun is addicting

All content is checked by medical journalists.

MunichThere is plenty of sunshine on nice summer days. Even though we know very well that sunbathing increases the risk of skin cancer. Sun rays seem to be downright addicting. Researchers have now found evidence that this is indeed the case: UV radiation may act like a drug.

David Fisher and his team at Massachusetts General Hospital exposed shaved mice to moderate UV radiation five days a week. The dose was roughly equivalent to 20 to 30 minutes of lunchtime sunbathing in Florida. The experiment ran for a total of six weeks. The researchers examined the rodents' blood at regular intervals.

The sun promotes happiness hormones

The result: in the sun mice, the level of the "happiness hormone" endorphin rose after just one week. This was shown by a comparison with control mice that had not been irradiated with UV light. Endorphins relieve pain by acting on the opioid receptors - similar to heroin or morphine. Anyone who has a lot of it in the cycle feels happy. If the animals were given a drug that blocks the endorphin effect on the opioid receptors, they reacted with typical withdrawal symptoms such as tremors or chattering teeth.

Dangerous addiction

"It's amazing that we're programmed to become addicted to something as dangerous as solar radiation," says Fisher. Perhaps this is because we can synthesize vitamin D with the help of sunlight. This vitamin plays a role in building bones, for example. Nevertheless, Fisher recommends protecting yourself from too much sun: through clothing, sunscreen and avoiding the strong midday sun. (away)

Source: Fisher D. et al .: Skin b-Endorphin Mediates Addiction to UV Light, Cell, June 19, 2014.

Tags:  unfulfilled wish to have children magazine menopause