Coffee and exercise 'no substitute' for proper sun protection

In collaboration with the Press Association

Cancer Research UK has played down reports of a link between caffeine, exercise and skin cancer protection, following the publication of new research in the Proceedings of the National Academy of Sciences (PNAS).

A study by scientists at Rutgers, the State University of New Jersey, has suggested that the combination of lifestyle factors may help to prevent sun-induced skin damage, which can lead to skin cancer.

The study looked at the effects of caffeine and exercise on skin cell growth in 'hairless' mice, developed for research into skin cells and wound healing.

One set of mice drank caffeinated water equivalent to one or two cups of coffee a day, a second were allowed to exercise on a running wheel, a third group were given caffeinated water and allowed to exercise, while the fourth group had neither caffeine nor exercise provision.

All of the mice were then exposed to UVB lamps, which are known to damage the DNA in skin cells.

The researchers found that, while some degree of programmed cell death (apoptosis) was observed in the DNA-damaged cells of all four groups, those mice that drank caffeine and had access to an exercise wheel showed a greater level of cell death, which is thought to be important in preventing tumour development.

Mice that drank caffeine exhibited a 95 per cent increase in apoptosis compared to the control group; those that exercised showed a 120 per cent increase; and those that both drank caffeine and exercised showed a nearly 400 per cent increase.

Study author Allan Conney, director of Rutgers' Cullman Laboratory, commented: "If apoptosis takes place in a sun-damaged cell, its progress toward cancer will be aborted.

"The differences between the groups in the formation of UVB-induced apoptotic cells - those cells derailed from the track leading to skin cancer - were quite dramatic."

The researcher noted that the reasons for the trend are still not clear.

"We need to dig deeper into how the combination of caffeine and exercise is exerting its influence at the cellular and molecular levels, identifying the underlying mechanisms. With an understanding of these mechanisms we can then take this to the next level, going beyond mice in the lab to human trials.

"With the stronger levels of UVB radiation evident today and an upward trend in the incidence of skin cancer ? there is a premium on finding novel ways to protect our bodies from sun damage."

Dr Alison Ross, science information officer at Cancer Research UK, commented: "This study was carried out in mice so there will need to be more research in this area to see if there is a similar effect in humans.

"Drinking a cup of coffee before going out jogging is definitely not a substitute for adequate sun protection - and those who are fair-skinned should take extra care," she added.