May 3, 2004 (New York) -- Being bronzed like Britney or tan in time for prom may be putting teenagers at risk for skin cancer.
New research shows a growing number of teenagers are tanning outdoors or using indoor tanning salons despite the known skin cancer risks associated with exposure to ultraviolet (UV) radiation from the sun or artificial sources.
"UV exposure before the age of 20 is strongly correlated with the most common skin cancer, which is basal cell carcinoma with almost a million cases a year," says James Spencer, MD, vice chairman of the department of dermatology at the Mount Sinai School of Medicine. "UV exposure before the age of 20 is also associated with the most deadly form of skin cancer, melanoma."
Spencer says that's extraordinary because skin cancer isn't confusing at all.
"We know what causes it. It's excessive exposure to ultraviolet light, whether it be from the sun or artificial sources, such as indoor tanning," says Spencer.
Spencer announced a new public education campaign to educate teens about the dangers of tanning at a news conference today in New York sponsored by the American Academy of Dermatology (AAD).
Teens and Tanning
A recent study showed that nearly 37% of teenage girls and 11% of boys have used an indoor tanning booth at least once in their life, and 28% and 7% of girls and boys, respectively, have used them three or more times.
The study also showed that the popularity of tanning booths also increased with age in girls. Eleven percent of 13- to 14-year-olds reported using indoor tanning booths more than three times, but that number grew to 47% among 18- to 19-year-olds.
The ADD recently issued a new position statement on indoor tanning, encouraging states to ban the use of tanning equipment for nonmedical purposes. The organization also advocates enacting legislation to bar minors from using tanning devices and placing a Surgeon General's warning stating that UV radiation is a known carcinogen on all tanning devices.
Spencer says recent attempts to market tanning beds as safer than sun are "nonsense."
He says early tanning beds were equipped with light bulbs that emitted less of the UVB rays associated with sunburns and more UVA rays than natural sunlight. But newer bulbs contain the same amount of burning UVB rays and up to 15 times higher concentrations of aging UVA rays.
Researchers say sunscreens are the most common form of sun protection, but many people are confused about how to use them correctly. Sunscreen is formulated to boost the body's natural defenses against harmful ultraviolet radiation by absorbing, reflecting, or scattering the sun's rays on the skin.
The sun protection factor (SPF) of a sunscreen is calculated by comparing the amount of time needed to cause sunburn on unprotected skin. For example, a sunscreen with an SPF of 15 would allows someone to extend that burning time by 15, so it would take 15 times longer for the skin to become burned if the product is used correctly.
But the SPF only reflects the product's protection against the burning UVB rays and doesn't say anything about the protection it provides against the aging UVA rays.
"The only way you can tell if a product provides UVA protection is it will be labeled as broad spectrum," says sunscreen expert Zoe Draelos, MD, associate professor of dermatology at Wake Forest University in Winston-Salem, N.C.
The AAD recommends using a broad-spectrum sunscreen with an SPF of at least 15 for basic, year-round protection. A sunscreen with an SPF of 15 provides protection against about 93% of the sun's burning UVB rays.
Draelos says reaching for a higher SPF doesn't necessarily provide significantly more protection and may be much more uncomfortable to wear. To increase the SPF beyond 15, additional active ingredients are needed that often cause the sunscreen to become sticky or pasty, which may make people less likely to use them properly.
"If you go from a 15 to a 30, for the increase in stickiness you only get 4% increase in sun protection, from 93% to 97%," says Draelos. "To go from a 30 to a 45, you've got to add even more of the sticky and pasty sunscreen ingredients, but you only get a 1% increase in the protection against UVB light."
For maximum protection, sunscreen should be applied 15-30 minutes before going outdoors and reapplied every two hours. The active ingredients in sunscreens begin to degrade after two hours and are virtually gone after four hours, says Draelos.
Vitamin D and the Sun
Researchers also addressed recent reports linking the health benefits of vitamin D to unprotected sun exposure. Vitamin D is a vital nutrient that is converted from the inactive to active form in the body with exposure to sunlight.
Dermatologist Darrell Rigel, MD, says normal vitamin D levels are easily obtained through routine daily activities and intentional, unprotected exposure to UV rays does not produce additional health benefits.
He also debunked the myth that sunscreen interferes with vitamin D absorption.
"There is no data to show that low vitamin D levels exist from the use of sunscreen," says Rigel, who is a professor at New York University Medical Center. "There is no such thing as a safe tan."
Blacks Not Immune to Melanoma Risk
Researchers say no ethnic group is immune to the risks of skin cancer, and some may actually face greater risks due to lax screening practices or mistaken beliefs.
For example, melanoma is the deadliest form of skin cancer, and new research shows that blacks diagnosed with the disease are much more likely to die from it than whites.
"There is a universal belief that African Americans do not develop melanoma," says Susan Taylor, MD, assistant clinical professor of dermatology at Columbia University. "Physicians and patients are not suspicious of melanoma, and if you're not suspicious of melanoma, you don't look for it."
Taylor says that blacks are more likely to have their melanoma diagnosed at a more advanced stage than others groups, which might explain why it tends to be more deadly. A recent study showed more than 32% of blacks with melanoma were diagnosed with stage III or stage IV melanoma compared with only about 13% of whites.
Melanoma may also be harder to spot in blacks because it usually develops in different locations than those commonly examined in melanoma skin cancer screenings.
The same study showed that 90% of whites developed melanoma on skin that is regularly exposed to the sun, but only 33% of blacks developed the cancer in these areas. Instead, blacks most often developed melanoma on the feet, toenails, and mucous membranes of the mouth, nasal passages, or genitals.