Tanning beds and lamps age the skin of 30-year-olds by decades and damage DNA, promoting mutations that pave the way for cancer.
Young people who use sunbeds and sunlamps subject their skin to genetic changes normally seen in people twice their age, and accumulate mutations that increase the risk of melanomas even in areas of the skin not normally exposed to sunlight.
Research that compared the incidence of melanoma between sunbed users and non-users, and which sequenced the genetic skin profile of both populations, demonstrates for the first time a probable cause-effect link between these devices and a three times higher risk of developing skin cancer.
Skin like that of grandparents
The transition between indoor tanning and oncogenic risk is represented by an artificially accelerated aging of the skin, whose cells change in a way that is not comparable to that caused by “only” natural sun exposure (however harmful, if not controlled). “We found that tanning bed users in their 30s and 40s had even more mutations than people in the general population in their 70s and 80s,” explains Bishal Tandukar, a dermatologist at the University of California at San Francisco and co-author of the study. “In other words, the skin of those who use sunbeds appears decades older on a genetic level.”
These alterations are also found in areas without moles and are precursors of the mutations that predispose to cutaneous melanoma, one of the most aggressive forms of skin cancer, the incidence of which is growing. The research, coordinated by Pedram Gerami, professor and researcher expert in skin tumors at the Northwestern University Feinberg School of Medicine (United States), started from the observation of an unusually high number of women under 50 with a history of multiple melanomas: the use of sunbeds is concentrated precisely in this population.
Skin comparison
Experts have long been warning about the dangers of sunbeds and sunlamps, which have already been linked to an increase in skin cancers. But a precise biological mechanism behind this link had not yet been identified, and proponents of fake tanning argue that fake tanning causes no more harm than simple exposure to the Sun’s ultraviolet rays. The new study casts doubt on this assumption.
The authors of the study compared data on the use of tanning beds, on the history of sunburn and on family cases of melanoma of over 32,000 dermatological patients, and analyzed skin samples from 26 donors (users and non-users), from which they extracted and sequenced the DNA of 182 melanocytes (the cells of the epidermis that produce melanin, the pigment that protects against UV rays and which forms the tan).
Tripled risk
The diagnosis of melanoma was incurred in 5.1% of sunbed users and only 2.1% of non-users: after taking into account other factors such as age, sex, family history and history of sunburn, artificial tanning was associated with a 2.85 times higher risk of skin melanoma.
Young people who used tanning beds and lamps showed more mutations in the DNA of melanocytes than is normal for people their age, especially in the lower back, which is normally little damaged by solar radiation but highly exposed to artificial tanning. In short, UV ray baths and showers create more extensive genetic damage than the classic sea tan: «When you expose yourself to the sun, perhaps 20% of your skin is more damaged» explains Gerami. “In sunbed users, we observed the same harmful mutations across almost the entire surface of the skin.”
Greater caution
“The skin of sunbed users was full of cancer seeds, that is, cells with mutations known to cause melanoma,” explains A. Hunter Shain, a dermatologist at the University of California, San Francisco who coordinated the study. What worries scientists is the fact that it is often the youngest and most vulnerable who are exposed to these rays, who are still little aware of the risks of this practice. The World Health Organization classifies sunbeds and sunlamps as Group 1 carcinogens, because they emit ultraviolet radiation which is proven carcinogenic: in Australia, Europe and the United States alone they are responsible for 10,000 cases of melanoma and 450,000 cases of other skin cancers every year.
According to the authors of the study, greater caution is needed, especially for minors, and warnings on the possible risk of cancer similar to those currently present on cigarette packets.
