Scientists have recently found evidence to support their theory about how caffeine reverses the ultraviolet (UV) light-induced damage linked to non-melanoma skin cancers. Researchers atRutgers University in Piscataway, New Jersey and the University of Washington in Seattle created mice that had deceased levels of the enzyme ATR in their skin. They exposed these so-called “transgenic” mice to UV light and found that, compared to their normal littermates, their lack of ATR inhibited the development of UV-induced skin cancer.
In a paper published online on August 16 in the journal Proceedings of the National Academy of Sciences, researchers found that the transgenic mice developed tumors more slowly than their normal littermates following chronic UV light exposure, had 69 percent fewer tumors than the regular mice, and developed four times fewer invasive tumors.
The team was looking to see if the lack of ATR itself inhibited the development of UV light-induced skin cancers, Allen Conney, a professor of chemical biology and director of the Susan Lehman Cullman Laboratory for Cancer Research at the Ernest Mario School of Pharmacy at Rutgers, tells Daily Glow. He adds that, “The PNAS paper that just came out says that yes, it does.”
According to Conney, the background of this work goes back a decade or more. “We were looking at the effects of green and black tea on UV-induced non-melanoma skin cancer in mice,” he says. His team found that caffeinated green and black tea inhibited UV-induced skin cancers, but decaffeinated tea did not.
They then found that the major effects of the teas were due to caffeine. “When we gave mice pure caffeine, we saw strong inhibition of UV-induced skin cancers,” says Conney.
The investigators then collaborated with the Seattle group to figure out how caffeine prevents skin cancer. They found it worked by two mechanisms, one of which involved the enzyme ATR. That is the focus of the current paper. The team wanted to know what would happen if they generated mice that lacked or had decreased expression of ATR, says Conney.
Caffeine can also act as a sunscreen. The scientists have found that mice exposed to UVB light developed 72 percent fewer non-melanoma skin cancers following topical application of the renowned pick-me-up compared to untreated mice.
The next step is to look at the effect of caffeine in people, Conney says. For example, does coffee have an effect on UV-induced cellular damage? He points out that studies have been done in coffee drinkers, which found that regular coffee drinkers had a decreased risk of non-melanoma skin cancers compared to decaf drinkers.
A Few to Try
No, you do not need to smear yourself with Diet Coke. Some sunscreens on the market have caffeine in the formula. Jeannette Graf, an assistant clinical professor of dermatology at Mount Sinai Medical Center, recommends SkinMedica Environmental Defense Sunscreen SPF 50+, $45.00, skinmedica.com, and Blue Lizard Australian Sunscreen Daily Moisturizer Face SPF 30+, $15.99, drugstore.com.