New Study Reveals Risks of Tanning Beds

For the first time, research has shown that tanning beds can lead to significant DNA damage across a large portion of the skin, which increases the risk of developing melanoma by three times. This finding underscores the serious dangers linked to these devices.

Scientists from Northwestern Medicine and the University of California, San Francisco aimed to explore the connection between indoor tanning and the onset of cancer, especially as these machines grow increasingly popular with younger individuals. In fact, a recent study indicated that Florida has more tanning salons than McDonald’s, and shocking numbers suggest that up to 40% of teenage girls and 20% of young adults (ages 18 to 29) have used tanning beds within the last year.

The study analyzed the medical records of 32,315 patients from Northwestern’s Dermatology service, identifying 7,474 individuals who reported using tanning beds. Details about tanning bed usage were collected from 2,932 patients, forming the core group for the study. A control group was randomly picked from 24,841 patients with no history of tanning bed use, consisting of 2,925 individuals.

The results revealed that 5.1% of indoor tanning users were diagnosed with melanoma, compared to just 2.1% of non-users. After adjusting for factors such as age, sex, and family history, the study found a 2.85-fold increase in melanoma risk linked to tanning bed use. Additionally, these users had a higher likelihood of developing skin cancers in areas that typically see less sun exposure, like the lower back and buttocks.

“With outdoor sun exposure, maybe 20% of your skin absorbs the most damage,” noted Dr. Pedram Gerami, the first author of the study and a professor of skin cancer research at Northwestern University. “But in tanning bed users, we found those harmful mutations present across nearly the whole skin surface.”

Further investigation featured single-cell DNA sequencing of melanocytes, the pigment-producing skin cells where melanoma begins, from three distinct donor groups. The first group had 11 patients with extensive tanning bed experience, the second consisted of nine age- and sex-matched individuals who never used tanning beds, and the third included skin samples from six cadavers as additional controls.

This phase of the research produced some alarming insights. Among the 182 melanocytes analyzed, those from indoor tanners exhibited nearly double the mutations found in the control samples, particularly mutations associated with melanoma. Interestingly, these changes were most prevalent in areas typically shielded from sunlight.

“Even in seemingly normal skin of indoor tanning patients, areas without moles showed preliminary mutations that could lead to melanoma,” said Dr. Gerami. “That’s something we haven’t seen before.”

Essentially, the melanomas developing in these users are similar to those seen in individuals with a genetic predisposition to skin cancer.

“Young people who use tanning beds, even without a family history of melanoma, can end up with multiple melanomas in areas that receive little sunlight,” the researchers observed. “The emergence of these tanning bed-related melanomas resembles those observed in families with a history of melanoma.”

Tanning beds emerged in the U.S. during the 1970s and had blossomed into a $3 billion yearly industry by the mid-2010s. By 2013, approximately 7.8 million women and 1.9 million men frequented tanning beds annually. The World Health Organization categorizes tanning beds as a Group 1 carcinogen, which means there’s solid scientific backing for their cancer-causing capabilities in humans, alongside entities like smoking and processed meats.

“When you purchase cigarettes, there’s a warning about potential links to lung cancer. We should implement a similar awareness campaign regarding tanning beds,” Dr. Gerami remarked.

In 2015, the FDA sought to prohibit tanning bed use by individuals under 18 and to require adult users to sign consent forms acknowledging the associated risks of ultraviolet light exposure. However, a decade later, the responsibility has largely reverted to individual states and local authorities to impose restrictions. California was the pioneer state to ban indoor tanning for minors back in 2012, and since then, over 43 other states have followed suit in limiting, if not outright banning, tanning bed access for those under 18.

Australia, which holds the title for the highest melanoma rate globally, banned tanning beds entirely in 2015, although Brazil had already implemented a ban on cosmetic indoor tanning in 2009—with some medical exceptions. It’s interesting to note that the lobbying forces of the tanning bed industry in these regions were relatively minor at the time. In contrast, both Europe and the U.S. feature substantial lobbying entities resisting further restrictions in the U.S.

“Given the extensive mutational damage observed in skin cells from tanning bed users, the marketing claims suggesting that tanning beds emit safer UV radiation compared to natural sunlight are hard to defend,” concluded the study’s researchers. “Another prevalent assertion by tanning proponents is that getting a tan before a vacation helps the skin adapt to sun exposure. However, our research shows that tanning bed usage heightens mutational burden, specifically in skin cells that don’t typically receive much sunlight.”

Melanoma, which remains the deadliest form of skin cancer, claims around 11,000 lives in the U.S. annually.

The findings were published in the journal Science Advances.