The science behind why you are obsessed with getting a tan

A little bit of fun in the sun is a great way to cultivate a nice tan and soak up some extra vitamin D. Of course, just like with so much else in life, moderation is key. Stay out in the sun too long and you’ll find yourself with a nasty case of sunburn soon enough. Additionally, prolonged and excessive sun exposure over long periods is linked to an increased risk of skin cancer.

Still, many people just can’t seem to stop themselves from lounging in the sun day in and day out. This type of “sun-seeking behavior” has always been considered nothing more than a personal preference, but now a new study finds it may actually be linked to one’s genes.

Researchers from King’s College London have discovered five genes usually associated with addiction, behavioral tendencies, personality traits, and brain functions that appear to also be connected to sun-seeking behavior. So, in light of these findings, it appears some people may be genetically predisposed toward a tanning “addiction.”

The study’s authors believe their findings could prove incredibly useful in the construction of future skin cancer awareness campaigns.

“Our results suggest that tackling excessive sun exposure or use of tanning beds might be more challenging than expected, as it is influenced by genetic factors. It is important for the public to be aware of this predisposition, as it could make people more mindful of their behavior and the potential harms of excessive sun exposure,” comments senior study author Dr. Mario Falchi from King’s College London, in a press release.

An incredibly large dataset was used for this project. To start, researchers analyzed an extensive collection of health data on 2,500 pairs of twins. For each person, that information included typical sun-seeking behavior habits, as well as genetics.

Among pairs of twins, identical twins were much more likely to display similar or exact sun-seeking habits in comparison to non-identical, or fraternal, twins. Identical twins share the same genes, while non-identical twins only share about half of the same genes. So, this was the research team’s first clue that genes indeed play a role in tanning behaviors.

Then, an even larger dataset consisting of 260,000 people was assessed. That process led to the discovery of the five aforementioned genes linked to sun-seeking habits and behavior. A few of those genes have already been linked to risk-taking and addiction-associated behaviors, like cigarette use, alcoholism, and even sexual promiscuity.

“It is clear that we see individuals who have very unhealthy sun behaviour and are fully aware of it. They will continue to expose themselves excessively even if they have clear skin cancer risk factors. Our research shows that genes regulating addiction and other risky behavior are important and may explain some of the reticence in changing behaviors in the sun,” explains study collaborator Dr. Veronique Bataille, a consultant dermatologist from King’s College London.

In conclusion, the study’s authors are hopeful that their findings will help lead to more robust and useful ways to educate the public on the dangers of excessive sun exposure. Just the knowledge that they may be genetically inclined toward unhealthy sun-seeking habits may be enough to curtail many from visiting their local beach or tanning salon for the third day in a row.

The full study can be found here, published in the Journal of Investigative Dermatology.