Caffeine Linked to Lower Skin Cancer Risk
Still, Best Protection Is Minimizing Sun Exposure
No Link to Risk of Other Skin Cancers continued...
With another 10 years of follow-up, though, he and his colleagues might observe a difference in squamous cell cancer risk between the highest and lowest levels of caffeine consumption, Han says.
Caffeine intake was not associated with a lower risk of melanoma, the deadliest and least common of the three major types of skin cancer. There were only 741 cases of melanoma among the study participants.
Decaf coffee was not associated with a lower risk of skin cancer, so, Han says, "most likely we think [reduced skin cancer risk] is due to caffeine."
Mouse studies in which the animals received caffeinated water to drink have also linked the compound to a lower risk of skin cancer, says Han, an epidemiologist at the Harvard School of Public Health and Brigham and Women's Hospital.
And other studies in which caffeine was applied to the skin of mice have also found a connection to a lower skin cancer risk. The mouse studies have shown that caffeine promotes the elimination of skin cells damaged by ultraviolet light before they have a chance to develop into tumors.
"I'm not recommending people drink coffee only because of this paper," Han says, although he noted that other studies have shown that the beverage is linked to a decreased risk of diabetes, certain cancers, and Parkinson's disease. Linked is a key word with this type of research. Although this type of study can show a strong association between caffeine and skin cancer, it cannot prove cause and effect.
And, Han says, he's not advising that people drink coffee and then bake at the beach. The best way to prevent skin cancer is to minimize exposure to ultraviolet light from the sun or tanning booths, he says.
A Little Caffeine With Your Sunscreen?
Because topical caffeine reduces the risk of skin cancer in mice, should you expect to see a line of "Coffee-tone" sunscreen products any time soon? Some pricey sunscreens already list caffeine among their ingredients.
"It's not been studied carefully," says Allan Conney, PhD, a toxicology professor at Rutgers who's conducted research into the relationship between topical and oral caffeine and skin cancer in mice. "We've been trying to interest some of the major companies to put caffeine into products and do some studies."
Adding caffeine to sunscreen wouldn't be difficult, Conney says, but no company has yet expressed willingness to invest the time and money into clinical trials required to convince the FDA to allow a claim of reduced skin cancer risk.
Han's study appears in Cancer Research.