It might be coffee-based sunscreen that works best to block damaging ultraviolet light
There might be a time when instead of just drinking that morning cup of coffee you lather it on your skin as a way of preventing harmful sun damage or skin cancer.
A new Rutgers study strengthens the theory that caffeine guards against certain skin cancers at the molecular level by inhibiting a protein enzyme in the skin, known as ATR. Scientists believe that based on what they have learned studying mice, caffeine applied directly to the skin might help prevent damaging ultraviolet light from causing skin cancer.
Prior research indicated that mice that were fed caffeinated water and exposed to lamps that generated UVB radiation that damaged the DNA in their skin cells were able to kill off a greater percentage of their badly damaged cells and reduce the risk of cells becoming cancerous.
“Although it is known that coffee drinking is associated with a decreased risk of non-melanoma skin cancer, there now needs to be studies to determine whether topical caffeine inhibits sunlight-induced skin cancer,” said Allan Conney, professor of Chemical Biology and director of the Susan Lehman Cullman Laboratory for Cancer Research at the Ernest Mario School of Pharmacy.
In this newly-published study in the Proceedings of the National Acacemy of Sciences, instead of inhibiting ATR with caffeinated water, Rutgers researchers, in collaboration with researchers from the University of Washington, genetically modified and diminished the levels of ATR in one group of mice. The results: the genetically modified mice developed tumors more slowly than the unmodified mice, had 69 percent fewer tumors than regular mice and developed four times fewer invasive tumors. When caffeine was topically applied to the regular mice, they had 72 percent fewer squamos cell carcinomas, a form of skin cancer.
The study, funded by the National Institutes of Health, also found, however, that when both groups of mice were exposed to chronic ultraviolet rays for an extended period of time, tumor development occurred in both the genetically modified and regular mice. What this seems to indicate, says Conney, is that inhibiting the ATR enzyme works best at the pre-cancerous stage before UV-induced skin cancers are fully developed.
According to the National Cancer Institute, sunlight-induced skin cancer is the most prevalent cancer in the United States with more than 1 million new cases each year. Although multiple human epidemiologic studies link caffeinated beverage intake with significant decreases in several different types of cancer, including skin cancer, just how and why coffee protects against the disease is unknown.
“Caffeine might become a weapon in prevention because it inhibits ATR and also acts as a sunscreen and directly absorbs damaging UV light,” said Conney.
Media Contact: Robin Lally
732-932-7084, ext. 652
E-mail: rlally@ur.rutgers.edu