At a recent American Institute for Cancer Research conference presenters suggested that up to 43,000 cases of colorectal cancer occurring each year in the US are linked to being sedentary. Occupational activity is associated with around 22% reduction in colorectal cancer risk with recreational activity being associated with a 23% reduction in risk.
Dr Neville Owen Professor of Health Behaviour at the University of Queensland indicated that "sitting time is emerging as a strong candidate for being a cancer risk factor in its own right. It seems likely that the longer you sit, the higher your risk"
The mechanisms by which physical activity decreases cancer risk might include decreases in body fat, sex hormones, prostaglandins and gastrointestinal transit time and increases in insulin sensitivity, immune and pulmonary function.
Whilst maintaining a healthy diet, a sensible alcohol intake and not smoking are all critical for health and cancer prevention. The message is also clear that exercise is good for you and it too reduces cancer risk.