As a teenager, American Heidi Tarr frequented a tanning salon several times a week with her friends to look like a celebrity. Years later, she survived melanoma and participated in a study that showed a threefold increased risk of this cancer associated with using tanning beds.
“Everyone wanted that beautiful, tanned skin,” the 49-year-old market research specialist told AFP during a video call from Chicago. But one day, when she was in her thirties, Heidi Tarr noticed a strange mole on her back.
It was a melanoma, the deadliest form of skin cancer. This tumor resembles a mole, often with certain characteristics (asymmetry, irregular borders, multiple colors, enlargement or change in appearance).
Heidi Tarr spotted it in time, but had to undergo a dozen procedures to remove other moles.
Today, her 15-year-old daughter, Olivia, is watching trending videos on TikTok of people showing off their tan lines, and is asking her mother how to get them too.
Heidi Tarr therefore decided to have another piece of skin removed, this time for research.
The main finding of this study, published Friday in the journal Science Advances, is that people who frequent tanning salons are almost three times more likely to develop skin cancer.
The researchers also identified precisely for the first time how these artificial tanning devices cause DNA mutations in the skin, making their users more vulnerable to cancer.
According to the International Agency for Research on Cancer (IARC), which is part of the World Health Organization (WHO), cutaneous melanoma, which is increasing sharply, is attributable in more than 801% of cases to exposure to ultraviolet (UV) radiation. Some UV rays, such as those from the sun, are natural, while others are emitted by artificial tanning beds.
Pedram Gerami, a dermatologist and researcher at Northwestern University in Illinois, began to take an interest in this subject, he explained to AFP, when he saw an "unusually" high number of young women with multiple melanomas arriving at his clinic. Sometimes these melanomas were located in parts of the body that are normally "relatively protected from the sun."
After comparing the medical records of 3,000 people who had used tanning beds with those of people of the same age who had not used them, his team concluded that melanoma had been diagnosed in 5% of the tanning bed users, compared to 2% in the other group.
– Cellular damage –
After taking into account various factors (age, history of sunburn, family history, etc.), the researchers estimated that users of tanning booths were 2.85 times more likely to develop melanoma.
These people also appeared more likely to develop this cancer on parts of the body normally protected from the sun, such as the lower back and buttocks.
To try to measure the extent of the damage caused by tanning beds to the DNA of skin cells, scientists sequenced 182 biopsies, including that of Heidi Tarr.
They used a new technology to specifically examine melanocytes, cells in the superficial layer of the skin whose proliferation creates a mole.
The result: melanocytes from tanning booth users showed almost twice as many mutations.
And "tanning booth users aged 30 to 40 showed far more mutations than people in the general population aged 70 to 80," noted study co-author Dr. Bishal Tandukar in a statement.
According to the IARC, which classifies the cancer risk from tanning beds at the same level as smoking and asbestos, melanoma killed nearly 60,000 people worldwide in 2022.
Some countries, like Australia and Brazil, have banned these booths. Others, like the UK and France, have prohibited them for those under 18. In the US, it depends on the state.
“At the very least, they must be banned for minors,” argued Mr. Gerami. Heidi Tarr strongly recommends that everyone refrain from using them. And she advises former regular users to inspect their skin and even consult a dermatologist.
"If you want a tanned complexion, self-tanner is better," she suggests.
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