The report on this “protective effect of caffeinated beverage intake” was published in the August 15 issue of the Proceedings of the National Academy of Sciences and detailed in the February 26 online edition of the Journal of Investigative Dermatology.
Several studies have shown that people who regularly consume coffee or tea to have a lower incidence of nonmelanoma skin cancer, the most common form of cancer, with more than 1 million new cases occurring each year in the United States alone. One 1997 study of nearly 100,000 Caucasian women found that with each additional cup of caffeinated coffee consumed, there was an 5 percent decrease in the risk of developing one of these skin cancers.
Women who drank six or more cups of coffee a day enjoyed a 40 percent reduction in risk of contracting nonmelanoma skin cancer! And it is the caffeine at work here. Decaffeinated coffee had no effect.
Studies of mice have found that the protection was experienced whether the caffeine was ingested or topically applied. Lab trials conducted on mice seem to indicate that caffeine rubbed directly on the skin can prevent harmful UV light from causing skin cancer. Evidently, the caffeine molecule itself functions as a natural sunscreen, prompting researchers to conjecture if adding caffeine might significantly increase the safety of sunscreens.
Many human epidemiologic studies associate caffeinated beverage consumption with substantial decreases in several different types of cancer, including Pancreatic, liver, head and neck and other cancers. The ways in which caffeine delivers protection these cancers still remains mysterious.