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Even tanning slowly and carefully is dangerous. Darrell Rigel, M.D.,
clinical assistant professor of dermatology at New York University,
Manhattan, maintains, There's no such thing as a safe tan. That's the key
point. You have to think about why you tan. The body senses that it is being
injured by UV radiation and, to protect itself, it produces melanin.
(Melanin is the body's natural sun block, the dark pigment that skin cells
produce to block out damaging rays and that cause tanning.)

But further damage occurs at the cellular level, he explains. When the sun
hits the skin, the DNA in the skin cells gets distorted. Think of the DNA
in the cell as a spiral staircase," he says. What happens is that the two
chains of the DNA are no longer connected and the stairs go off at a funny
angle. Normal people have the enzyme that attempts to repair the damage.?
But, he adds, the repair is never total; some damage always remains, and it
accumulates over the years.