During the study, Nghiem's team looked at caffeine's effect on human skin cells in a laboratory that had been exposed to ultraviolet radiation. They found that in cells damaged by UV rays, caffeine interrupted a protein called ATR-Chk1, causing the damaged cells to self-destruct.
According to Ngheim, caffeine has no effect on undamaged cells.
ATR is essential to damaged cells that are growing rapidly and caffeine specifically targets damaged cells that can become cancerous. Caffeine more than doubles the number of damaged cells that will die normally after a given dose of UV, added Nghiem. this is a biological mechanism that explains what we have been seeing for many years from the oral intake of caffeine.
On a topical study, Nghiem has been experimenting by applying caffeine directly on the skin (of mice and humans. According to Nghiem, "It suppresses skin cancer development by as much as 72 percent in mice." (more on website, FloridaSpaGirls.net)