WASHINGTON — Caffeine, the chemical stimulant in coffee and tea, has been found to lower the risk of skin cancer in lab mice.
A study suggests that a skin lotion spiked with caffeine or with another compound found in green tea can reduce by more than half the number of cancer tumors on the skin of hairless mice exposed to brutal levels of ultraviolet radiation, said Dr. Allan Conney, a professor of cancer and leukemia research at Rutgers University in New Brunswick, N.J.
"We had between 50% to 70% tumor formation inhibition in the mice that were treated with caffeine or with EGCG," the other chemical compound, said Conney, senior author of a study appearing this week in the online site of the Proceedings of the National Academy of Sciences.
Skin cancer is the most common cancer in the U.S. The American Academy of Dermatology estimates about 1 million cases will be diagnosed in the country this year. Among them will be more than 88,000 new cases of melanoma, the disease's deadliest form.
To test effects of caffeine on skin cancer, Conney and his colleagues exposed 90 mice to high levels of ultraviolet radiation twice a day for 20 days. After the mice got their UVB doses, they were divided into three groups. One group was slathered with a solution of acetone and caffeine. Another group received acetone and EGCG. The third group got skin applications of acetone only. Acetone is an organic solution often used on skin.
Conney said mice in all three groups developed malignant skin tumors, called squamous cell carcinomas, but the number of tumors per mouse was reduced by 72% in those treated with caffeine and by 66% among those treated with EGCG, compared to the controls treated only with acetone.