Last Updated May 30, 2014 11:55 AM EDT
No matter if you do it indoors or outdoors, tanning may significantly increase your risk of melanoma and other skin cancers, according to two new studies.
In one study, published Thursday in the journal Cancer Epidemiology, Biomarkers & Prevention, researchers found that getting five or more blistering sunburns before age 20 may increase a person's melanoma risk by 80 percent.
Another study, published in JNCI: Journal of the National Cancer Institute, found that indoor tanning raises the risk of developing melanoma even if a person has never experienced burns from either indoor or outdoor tanning.
The report comes as the FDA announced Thursday it will begin requiring new warning labels on tanning beds and sun lamps stating that they should not be used by anyone under age 18. Twenty four states already have laws banning minors from using indoor tanning equipment.
"Our results suggest that sun exposures in both early life and adulthood were predictive of non-melanoma skin cancers, whereas melanoma risk was predominantly associated with sun exposure in early life in a cohort of young women," Dr. Abrar A. Qureshi, the author of the first study and a professor and chair of the Department of Dermatology at Warren Alpert Medical School of the Brown University and Rhode Island Hospital in Providence, said in a statement.
Melanoma is much more common in non-Hispanic whites than people of other ethnicities and races, with whites accounting for about 90 percent of cases, the Centers for Disease Control and Prevention reports. About 68,000 new melanoma cases are diagnosed in the United States annually, according to data from the U.S. National Institutes of Health.
In the study focusing on the impact of sunburns in youth, the researchers followed 108,916 Caucasian women for about 20 years and asked them about their medical histories and potential risk factors for skin cancers, such as the number of moles on legs, the number of blistering sunburns between ages 15 and 20 and their potential family history of melanoma. It turned out that those study participants who had had at least five blistering sunburns between ages 15 and 20 had an increased risk of developing three different types of skin cancer, but the greatest risk was for developing melanoma.
While some people visit tanning salons in the hope of preventing burns from direct sunlight, they may still be raising their risk for developing melanoma -- the most deadly type of skin cancer.
"The bottom-line is that tanning is a biological response to damage to the DNA," DeAnn Lazovich, co-author of the JNCI study and an associate professor of epidemiology at the University of Minnesota in Minneapolis, told HealthDay. "And you're going to get that [ultraviolet light] damage in a tanning booth whether or not you burn."
For the indoor tanning study, researchers compared 1,167 melanoma patients and 1,101 people without skin cancer. People in both groups were of similar age and sex. Nearly 57 percent of the people in the study said that they had had five or more sunburns during their lifetime and about 5 percent said they had never been sunburned. The researchers found that the melanoma patients who reported never having been sunburned were almost four times more likely to be indoor tanners, compared with the people in the melanoma-free group. The melanoma patients who said they had never experienced sunburns also reported that they had started tanning indoors at younger ages and had tanned indoors over a greater number of years than those melanoma patients who reported having been sunburned.
"Basically, there is no safe way to tan," Lazovich said. "Sun protection and avoidance of ultraviolet radiation in any form should be the goal."
Other experts agree with Lazovich.
"Indoor tanning has really high amounts of ultraviolet light that damages the skin and really increases your risk for skin cancer," Dr. Jennifer Stein, an assistant professor in the department of dermatology at NYU Langone Medical Center in New York City, who was not involved in the study, told HealthDay, adding that this type of cancer can be deadly.
"Preventing people from using indoor tanning beds is a very important message, particularly for young people," Stein said.