Scientists at the University of Washington and Rutgers University are undergoing studies to prove that caffeine, whether applied topically or ingested, could inhibit certain mechanisms that cause skin cancer.

“Our studies on mice strongly suggested a correlation between increased caffeine and decreased skin damage,” said Paul Nghiem, a dermatologist at the University of Washington and Fred Hutchinson Cancer Research Center.

In 2001, scientists began noting the effects of caffeine on the ATR protein, which plays a large role in cell replication. Previous studies already showed that coffee and tea drinkers in several countries tended to develop fewer skin cancers, but formal laboratory testing had yet to prove the theory.

The scientists began tests on hairless mice by feeding them caffeine and applying it to their skin for several weeks. Data from the tests showed reductions in skin damage in the caffeinated mice that were exposed to cancer-causing UVB rays.

A report of the findings published by the American Association for Cancer Research stated that “administration of caffeine enhances the removal of DNA-damaged cells.”

The next step for the scientists will be transferring research to humans.

Despite the low risk involved, human testing is expected to be very difficult.

“One method would be to have people use two different creams on their body at the same time — one caffeinated, one not — for several months,” Nghiem said. “Meanwhile, doctors would study the conditions of any precancerous lesions that had existed on the subjects before the study, under the theory that the caffeine cream might eliminate or slow the development of these lesions.”

While one can count these lesions with the naked eye, knowing the exact number can be difficult without using expensive biopsy procedures. Human studies also involve more unreliable variables.

“Researchers hoping to find certain results might miscount the lesions,” Nghiem said. “Patients using the cream might think they can tell which side of their body is reacting and use that cream on both sides.”

There is also the task of finding two to four dozen willing participants for the study. One viable option would be to draw from those with xeroderma pigmentosum, a rare skin condition that makes people significantly more susceptible to developing cancer. Another option could be to ask U.S. veterans, who tend to be older males who have significant risk of sun damage.

In regards to the difficulty of testing, Nghiem said that academic research tends to take longer than sales-driven corporate work. Researchers must receive federal funding, which has become increasingly competitive with a decreasing budget.

It could easily be another five to 10 years before such products are released on the market, but finding positive results would be well worth the effort.

“Drinking caffeine and tanning are both so common among college students,” junior Arielle Kloss said. “The study would be very relevant.”

For some, the evidence existing may be enough to justify another cup of coffee. However, Nghiem discourages people from attempting to undo hours at the tanning salon by dousing themselves in Red Bull or a frappuccino — most drinks are “too dilute” to have much effect on skin.

[Reach contributing writer Annie Atherton at development@thedaily.washington.edu.]