If you spend hours in the sun despite knowing how dangerous it can be, you’re not alone.
Because a study suggests that sunbathing is addictive – and affects the brain in a way similar to heroin.
Harvard scientists claim exposure to sunlight prompts the body to produce endorphins, chemicals that ease pain and make us feel good.
They discovered that mice which were regularly exposed to sunlamps showed signs of addiction, and went into withdrawal when they were deprived of their fix.
The finding could help to explain why we find it hard to resist baking on the beach or lying on sunbeds when we know it increases our risk of developing skin cancer.
The disease claims more than 2,000 lives a year and the number of cases has risen seven-fold since sunshine package holidays took off in the 1960s.
The US researchers said: ‘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.’
However, British experts have questioned whether the findings, tested on mice, would apply to people.
The team, from Harvard Medical School, gave mice a daily dose of UV light for six weeks. The amount was equivalent to 20 to 30 minutes in the hot Florida sun at midday.
Within a week, the animals’ endorphin levels rose and they became less sensitive to pain. The mice were then given a drug that stops endorphins from working, and quickly developed symptoms of withdrawal such as trembling and chattering teeth. They also went out of their way to avoid the place where they had been given the drug.
Researcher Professor David Fisher described the effect of sunlight as ‘reminiscent of heroin’ but weaker.
He said: ‘This information might serve as a valuable means of educating people to curb excessive sun exposure.’
He added that the addiction may have evolved to ensure the body was getting enough vitamin D.
The ‘sunshine vitamin’ is manufactured when our skin is exposed to sunlight. It is credited with warding off Alzheimer’s, keeping the heart healthy, slowing prostate cancer and stopping multiple sclerosis from developing.
Unlike our ancestors, we now have the option of getting vitamin D from supplements, rather than the sun, Daily Mail informs.
