Caffeine and Skin

But researchers are finding that the presence of caffeine is giving the mice they’re testing a better shot at getting rid of damaged skin cells over-exposed to sunlight.

“It looks to us from several types of experiments that caffeine can selectively kill those damaged cells,” says Nghiem.

When skin is exposed to even moderate amounts of sunlight, there is damage and most of it, says Nghiem, “is repaired very quickly.” But some cells are too damaged to be repaired and they are killed before they can cause any problems. Nghiem says this is a good thing because, “Presumably we can decrease the rate of skin cancer and sun damage’s long-term effects.”

Nghiem’s team of researchers exposed hairless mice to a medium dose of ultra-violet light. Afterwards, one group had a solution put on the skin that contained caffeine while a control group had a solution without caffeine. As a further control, other mice received the caffeine or non-caffeine treatments without any ultra violet light exposure. The amount of caffeine, says Nghiem, is similar to the caffeine already present in anti-cellulite creams: about one percent. The results, he says were, “That more than doubled the number of these (damaged) cells that were deleted…and that also correlated with fewer changes, long-term changes…like wrinkling.”

Writing in the journal, “Cancer Research” Nghiem’s team says the caffeine appears to inhibit a protein called ATR. This protein helps make sure that a cell’s DNA is copied correctly. If it’s inhibited, Nghiem says normal cells are okay, but cancer cells are selectively killed.

Nghiem notes the research is so far just in mice, and that no one should head to the beach with a homemade mix of their favorite java and sunscreen. He says the next step in the research will be to work with mice that are genetically predisposed to skin cancers to see if they’re responsive to the caffeine.

He says the research is not about finding a cure for sun induced wrinkling but fundamental research about the cell cycle in cancer. That means he hopes to find even better cancer inhibitors than caffeine, but adds, “We also want to study if this could be useful in humans directly as caffeine. And one way that’s particularly interesting is as a sunscreen agent. Caffeine itself has the capacity to block ultra violet rays and could be, presumably, incorporated into our routine sun screens.”

Nghiem says the discovery, “was definitely an accidental or back-door kind of thing,” that had its origins in research into the health properties of green tea. Nghiem says that in 2001, Allen Cooney of Rutgers, “was already hot on the path of saying what is it about tea that’s important and he found that it was caffeine.” Nghiem was researching the ATR protein and saw a report about Conney’s work and wondered if the caffeine was somehow targeting the ATR. Nghiem contacted Conney and they began exploring the caffeine-ATR connection.

This research appears in the April 1, 2008 issue of the journal, “Cancer Research” and was funded by a grant from the National Institutes of Health.