With winter right around the corner, some of you might be thinking about taking a trip to your local tanning bed. But be warned, a study out this week finds these devices can be especially harmful to your skin, even beyond natural Sun exposure.

Scientists at Northwestern University and the University of California, San Francisco, examined the medical records of tanning bed users. These users not only had a higher risk of melanoma compared to non-users, they also tended to have more cancer and cancer-related mutations in parts of the body not typically touched by the Sun.

“To me, the evidence is clear. Tanning beds represent a uniquely dangerous exposure when it comes to skin cancer,” study researcher Alan Hunter Shain, a cancer biologist at UCSF, told Gizmodo.

A unique risk

UV (ultraviolet) radiation is the primary risk factor of skin cancer, including melanoma. And while most cases are tied to the UV exposure we get from the Sun, tanning beds pose a clear risk as well.

The tanning bed industry has long argued that these beds are no more dangerous to our skin than the Sun. Shain notes, however, that they can provide intense bouts of UV exposure at all times of the year and to any part of the body. Some of the authors had also noticed a rise of unusual skin cancer cases in their practice, such as relatively young people coming down with multiple melanomas—cases they suspected were linked to tanning beds.

To better quantify the risks of tanning beds, the researchers analyzed medical records data from around 3,000 tanning bed users and compared them to similar people matched in age with no such history. In a separate experiment, they genetically sequenced skin cells taken from tanning bed users and controls.

A graphic illustration of the unique melanoma and mutation risks seen in tanning bed users compared to non-users. © Gerami et al/Science Advances

Overall, 5.1% of people who used tanning beds were diagnosed with melanomas, compared to 2.1% of non-users. And even after the researchers adjusted for other factors like a family history of skin cancer, tanning bed use was still associated with a nearly threefold increase of melanoma. This added risk was dose-dependent, meaning that people who reported using tanning beds more had a greater likelihood of melanoma compared to others. And they were more likely to have melanomas in body parts rarely seen by the Sun, such as the buttocks and lower back.

The team’s genetic analysis also revealed some unusual and worrying patterns.

“In our study, we saw tanning bed users in their 30s and 40s with more mutations in their skin cells than people in their 70s and 80s from the general population,” Swain said. “They had effectively accumulated a lifetime’s worth of UV-induced damage by age 30 because of continuous, year-round access to artificial UV radiation.”

The team’s findings were published Friday in Science Advances.

What to do about tanning beds

Given these risks, tanning beds warrant increased regulation, particularly for younger people not up to speed on the danger, the authors argue. Groups like the World Health Organization have long stated that no one under 18 should be allowed to use tanning beds, and some countries have banned their use among minors.

“Many of the patients dealing with the consequences of tanning bed usage were primarily exposed as minors and hence may not have had the maturity or wisdom to make optimal decisions regarding their health,” study author Pedram Gerami, a professor of skin cancer research at Northwestern University’s Feinberg School of Medicine, told Gizmodo.

At the very least, there should be more education about the threat posed by these devices. Gerami notes that it might take as little as ten uses of a tanning bed to more than double your lifetime risk of melanoma, which is the deadliest form of skin cancer. Skin cancer in general is estimated to kill 11,000 Americans a year, with over 8,000 caused by melanoma.

“Even those who may not die from the disease may have to deal with significant morbidity and emotional distress,” Gerami said.

The team plans to continue investigating how tanning beds can shape a person’s cancer risk. Since these beds can emit unusual blends of UV radiation not naturally created by the Sun, they might cause uniquely damaging mutations as well, Shain says. And it’s a possibility they’re now actively studying.