A research team at Rutgers, The State University of New Jersey, showed that a combination of exercise and some caffeine protected against the destructive effects of the sun’s ultraviolet-B (UVB) radiation, known to induce skin cancer. The caffeine and exercise seemingly conspire in killing off precancerous cells whose DNA has been damaged by UVB-rays.

Groups of hairless mice, whose exposed skin is vulnerable to the sun, were the test subjects in experiments in which one set drank caffeinated water. Another voluntarily exercised on a running wheel while a third group both drank and ran. A fourth group, which served as a control, didn’t run and didn’t caffeinate. All of the mice were exposed to lamps that generated UVB radiation that damaged the DNA in their skin cells.

Some degree of programmed cell death, also known as apoptosis, was observed in the DNA-damaged cells of all four groups, but the caffeine drinkers and exercisers showed an increase over the UVB-treated control group. “If apoptosis takes place in a sun-damaged cell, its progress toward cancer will be aborted,” said Allan Conney, director of Rutgers’ Cullman Laboratory and one of the paper’s authors.

“The differences between the groups in the formation of UVB-induced apoptotic cells were quite dramatic,” Conney said. Compared to the UVB-exposed control animals, the caffeine drinkers showed an approximately 95 percent increase in UVB-induced apoptosis, the exercisers showed a 120 percent increase, while the mice that were both drinking and exercising showed a nearly 400 percent increase. “The most dramatic and obvious difference between the groups came from the caffeine-drinking runners, a difference that can likely be attributed to some kind of synergy,” Conney said.

The authors suggested several mechanisms at the biochemical level that might be responsible for the protective effects of caffeine and exercise, but acknowledged that what is happening synergistically is still somewhat of a mystery.

MEDICA.de; Source: Rutgers, the State University of New Jersey