Addicted to the Sun
Summer is officially upon us. The season of warm weather, lots of outdoor activities, and for many, time spent at the beach or pool. While it's definitely great to be enjoying ourselves outside rather than sitting inside only getting up from the television to get a snack, there is our ultraviolet light exposure to consider. And if you are someone who loves basking in the sun long beyond what is required to produce your daily dose of vitamin D, then the dangers of too much exposure just might outweigh the desire to tan. So why do so many people still insist on summer sunbathing? Based on the results of new research, it may be due to an actual addiction to the sun's effect on our bodies.
The study, which was conducted at Massachusetts General Hospital and Harvard Medical School in Boston, found that exposure to UV rays may trigger the production of endorphins, causing the same euphoria that certain drugs do and potentially resulting in a similar type of physical addiction.1 Rather than using human subjects, the scientists performed the experiment on shaved mice. For a six-week period, the mice received regular, low-dose exposure to UV light. One week into the trial, blood samples were taken to assess the level of endorphins--which are chemicals released in the body that can promote positive feelings and diminish pain--and they had risen among the mice.
Endorphins affect specific receptors in the brain, and these are the very same areas that opioid-based drugs such as heroin and the prescription painkillers morphine, oxycodone, and hydrocodone, among others, home in on. So it would appear that UV exposure might switch on the exact type of chemical reaction as these highly addictive substances. To determine whether that was the case, the researchers evaluated the mice for certain traits common in opioid signaling. Much like a human addict, the mice were found to develop a numbing to sensory stimulation. Even more, the scientists then provided the mice with an opiate-blocking medication, and the sensory numbing disappeared.
In addition, after the mice were given the opioid blocker, they began to exhibit withdrawal symptoms like those of an addict who isn't getting a fix. The mice were shaking, experiencing tremors, and their teeth were chattering, all of which are associated with a physical addiction that is not being satisfied. The researchers also reported that the mice sought to avoid the conditions that produced the withdrawal symptoms, and instead attempted to satisfy their addiction, in this case by seeking out the UV light.
While these findings are very interesting, it is difficult to know just how well they might translate to humans. If UV exposure can affect an addiction center in the brain, it would certainly go a long way toward explaining why some people choose to sunbathe until their skin is red and blistered or dry and leathery. It might even help explain how some of us choose to use tanning beds despite evidence, such as a 2010 study at the University of Minnesota in Minneapolis, that their regular use can increase the risk of developing melanoma.2 But mice clearly are not humans, so these outcomes can only be considered preliminary at best.
What's more, the amount of UV exposure the average sun worshipper takes in is tough to quantify. For the study's purposes, the scientists assessed the levels of exposure the mice received to be equivalent to a person with fair skin, yet a capability to tan, spending 20 to 30 minutes in the natural midday sun in Florida in the summertime. Obviously, the UV rays the mice were exposed to were pretty strong if they were similar to midday summer sun exposure in the sunshine state. But gauging their effect on a human is different, and people themselves vary so widely on how much they will tan or burn and their tolerance to time in the sun. Plus, the researchers don't seem to offer any explanation as to why only some people seem to become addicted to sunbathing while others are completely unaffected.
At any rate, there's really little proof to back you up if you try to claim it was your sun addiction that caused you to spend the whole day baking at the beach. Get your sunlight in small doses, opt for morning and afternoon sun rather than midday sun, and cover up and wear a hat if you know you will be outside for a long period of time, even if there is cloud cover. Outdoor activities can be a great boost to a healthy lifestyle, just protect yourself well and get out early or late in the day when the sun is not at its strongest.
In the meantime, now that a study has equated sunbathing to addiction, how long will it be before we see sunbathing rehab clinics opening in Malibu and Palm Springs--with the celebrities lining up to check in?
- 1. Kwan, Nicole. "UV exposure may cause drug-like addiction." Fox News. 19 June 2014. Accessed 22 June 2014. http://www.foxnews.com/health/2014/06/19/uv-exposure-may-cause-drug-like-addiction
- 2. Lazovich, D.; et al. "Indoor tanning and risk of melanoma: a case-control study in a highly exposed population." Cancer Epidemiology, Biomarkers and Prevention. June 2010. Accessed 24 June 2014. http://www.ncbi.nlm.nih.gov/pubmed/20507845