LiveScience: A cup of joe a day may help keep skin cancer away. A new study shows that caffeine helps kill off human cells damaged by ultraviolet light, one of the key triggers of several types of skin cancer.
The finding, detailed in Feb. 26 online issue of the Journal of Investigative Dermatology, could one day lead to the development of caffeine creams or ointments to help reverse the effects of UV damage in humans and prevent some skin cancers.
Nonmelanoma skin cancers, which rarely metastasize or cause death, are the most common form of cancer in humans, with more than 1 million new cases occurring each year in the United States alone. (Melanoma is, however, one of the deadlier cancers.)
Exposure to ultraviolet light is one of the most important factors in causing nonmelanoma cancers. The rays cause DNA damage to skin cells, which then mutate or become cancerous.
Several studies have shown that people who regularly drink coffee or tea seem to have lower incidences of nonmelanoma skin cancers. One recent study of more than 90,000 Caucasian women found that with each additional cup of caffeinated coffee consumed, there was an associated 5 percent decreased risk of developing one of these skin cancers (decaf coffee had no effect).
Caffeine also seemed, in another study, to have a protective effect on mice that had been exposed to UV light, whether they ingested it or it was applied to their skin.
But researchers didn't know how caffeine exerted its cancer-preventing influence, said Paul Nghiem of the University of Washington and a team member of the new study.
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