Caffeine May Protect Skin

“Caffeine might become a weapon in prevention because it inhibits ATR and also acts as a sunscreen and directly absorbs damaging UV light,”

Coffee may be more than a great morning pick-me-up. Suntan lotion laden with caffeine might be an effective way to prevent harmful sun damage or skin cancer.

A new study published in the Proceedings of the National Academy of Sciences, adds weight to the theory that caffeine guards against certain skin cancers at the molecular level by inhibiting ATR, a protein enzyme in the skin. Scientists believe, based on what they have learned studying mice, caffeine applied directly to the skin might help prevent damaging ultraviolet light from causing skin cancer.

Earlier 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 at Rutgers and director of the Susan Lehman Cullman Laboratory for Cancer Research.

Instead of inhibiting ATR with caffeinated water, Conney and colleagues in collaboration with researchers from the University of Washington, genetically modified and diminished the levels of ATR in one group of mice.

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 squamous cell carcinomas, a form of skin cancer.

But 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. This seems to indicate inhibiting the ATR enzyme works best at the precancerous stage before UV-induced skin cancers are fully developed.

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, Conney says.

“Caffeine might become a weapon in prevention because it inhibits ATR and also acts as a sunscreen and directly absorbs damaging UV light,” he said.