Wednesday, August 1, 2007

Coffee and exercise reduce the risks of skin cancer

Another evidence that coffee is good for you!! (^o^)


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 (the human equivalent of one or two cups of coffee a day); 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. Apoptosis is a way in which cells with badly damaged DNA commit suicide – UVB-damaged cells in this case. “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.

Compared to the UVB-exposed control animals, the caffeine drinkers showed an approximately 95% increase in UVB-induced apoptosis, the exercisers showed a 120% increase, while the mice that were both drinking and exercising showed a nearly 400% 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.


Source:
BBC News
Science Daily
Scientific America
Yahoo News HK

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