Exercise Protects Against Skin Cancer

Study has shown that exercise can protect against skin and bowel cancer.

A study found that voluntary exercise decreased body fat and that the number of tumours decreased with decreasing amounts of fat.

During the study a female mice had 24-hour access to running wheels and were exposed to ultraviolet B light (UVB). These mice took longer to develop skin tumours, developed fewer and smaller tumours, and had decreased amounts of body fat compared to mice that did not have access to running wheels.

Dr Allan Conney, Garbe Professor of Cancer and Leukemia Research and Director of the Susan Lehman Cullman Laboratory for Cancer Research at Rutgers University, New Jersey, USA, said that programmed cell death (apoptosis), triggered by exercise, might explain why the running wheel mice did better.

"Preliminary indications from follow-up work in the laboratory suggest that voluntary exercise enhances UVB-induced apoptosis in the skin, and that it also enhances apoptosis in UVB-induced tumours."

"So, although UVB is triggering the development of tumours, exercise is counteracting the effect by stimulating the death of the developing cancer cells.

Dr Conney emphasised that it was not known yet whether exercise decreased the risk of sunlight-induced skin cancer in humans, and clinical trials were needed to investigate this further.

However, in bowel cancer, evidence from population studies already suggests that physically active people have a reduced risk of developing the disease, but the mechanisms remain unclear.