Teen Tanning Habits Raise Skin Cancer Risks
Tanning, Skin Cancer Myths Debunked by Dermatologists
Sunscreen 101 continued...
"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.