A run to the coffee shop may prevent skin cancer

Jul 30 2007

Researchers in the United States have discovered that the combination of daily exercise and a cup of coffee may help prevent skin cancer.

The scientists at Rutgers University in New Jersey say a low to moderate intake of caffeine combined with exercise can be good for health and prevent damage caused by the Sun’s ultra violet rays.

They have arrived at this conclusion after conducting a study on mice and suggest that a duo of caffeine and exercise appears to collude to kill off pre- cancerous cells whose DNA has been damaged by radiation from the sun's UVB-rays.

Skin cancer is one of the most common cancers and is becoming more prevalent across the world; each year in the U.S. there are 1000,000 new cases of non-melanoma skin cancer and 2000 deaths; in Britain, there are more than 65,000 new cases of non-melanoma skin cancer and more than 8,000 new cases of malignant melanoma.

While non-melanoma is nearly always curable if caught early enough around 1,800 people die from malignant melanoma skin cancer annually and most of those deaths are preventable.

For the study the researchers used groups of hairless mice, whose skin is as a result far more vulnerable to the sun.

One group were given caffeinated water to drink, the equivalent of up to two cups of coffee for humans, another group voluntarily exercised on a running wheel, while a third group both drank caffeine and ran; a fourth group, which served as a control, neither ran nor drank caffeine.

All of the mice were then exposed to lamps that generated UVB radiation that damaged the DNA in their skin cells.

They were then examined for evidence of programmed cell death, also known as apoptosis which is the process by which cells with badly damaged DNA destroy themselves as a natural defence against illness and infection.

The team of researchers found that compared with the UVB-exposed control group, the caffeine drinkers showed an increase of about 95 per cent in UVB-induced apoptosis, the exercisers showed a 120 per cent increase, while the mice that were both drinking and exercising showed a nearly 400 per cent increase.

One of the study's authors Dr. Allan Conney says if apoptosis takes place in a sun-damaged cell, its progress toward cancer will be aborted.

The team say drugs which induce apoptosis are currently being researched as a method of preventing different types of cancer, but the combination of caffeine and exercise appears to have a similar protective effect.

Dr. Conney says the cumulative difference seen in the caffeine-drinking runners is possibly due to some form of synergy between the two factors.

Coffee is not the only beverage to contain caffeine, but it does contain the most and recent research has found that while those with high blood pressure, and pregnant women should limit their caffeine consumption, coffee may reduce the risk of developing gallstones, kidney stones and colorectal cancer.

Interesting though the research is, more is needed to establish if the findings are similar in humans; people are advised to use adequate sun protection when exercising in the sun.

The study is published in Proceedings of the National Academy of Sciences.