When the sun is shining, many of us are unable to resist a trip to the beach to soak up the rays, despite recommendations that we should cover up to reduce the risk of skin cancer. And now, researchers have discovered why; ultraviolet radiation from the sun releases endorphins – “feel-good” hormones – that act like a drug, making exposure to sunlight addictive.

The research team, including senior author David Fisher of the Massachusetts General Hospital and Harvard Medical School in Boston, MA, recently published their findings in the journal Cell.

Skin cancer is the most common form of cancer in the US. According to the Skin Cancer Foundation, over 3.5 million skin cancers are diagnosed in more than 2 million people every year.

Approximately 90% of nonmelanoma skin cancers and 86% of melanoma skin cancers – the deadliest form of the disease – are caused by exposure to ultraviolet (UV) radiation from the sun and tanning beds or lamps.

To reduce the risk of skin cancer, public health experts recommend that people stay in the shade when the sun is at its strongest (usually around midday), wear clothing that covers arms and legs, wear a wide-brimmed hat and sunglasses, use sunscreen with a minimum sun protective factor (SPF) of 15 and avoid indoor tanning.

However, many of us tend to ignore these recommendations due to a desire to feel the sun on our skin.

According to Fisher and his colleagues, previous studies have indicated that many people who adopt UV-seeking behavior meet the clinical criteria for substance addiction. But Fisher notes that the mechanisms underlying UV addiction have been unclear.