Too much TV may raise men's colorectal cancer risk
Men who watch more than four hours of TV a day significantly increase their risk of developing bowel cancer, researchers have found.
Experts tracked 500,000 British people for six years - and found a significant link between sedentary behavior and bowel cancer risk.
But the strongest risk was found among men, particularly those who watched lots of television.
The scientists, from the University of Oxford, Imperial College London and the UN International Agency for Research on Cancer, found men who sat in front of the television for more than four hours a day were 35 percent more likely to develop bowel cancer.
For women the increased risk of television watching was just 11 percent - but when they examined the figures they found this was not statistically significant.
Intriguingly, they found no link between computer screen time and bowel cancer risk.
The researchers suspect men are more likely to smoke, drink and eat junk food than women while watching TV.
The findings, published in the British Journal of Cancer, revealed 2,391 people of the 500,000 went on to develop bowel cancer.
Dr Neil Murphy, lead researcher based at IARC in France, said: 'Previous research suggests that watching TV may be associated with other behaviors, such as smoking, drinking and snacking more, and we know that these things can increase the risk of bowel cancer.
'Being sedentary is also associated with weight gain and greater body fat. Excess body fat may influence the blood levels of hormones and other chemicals which affect the way our cells grow, and can increase bowel cancer risk..'
Professor Linda Bauld, Cancer Research UK's prevention expert, said: 'This study poses interesting questions such as why screen time from computers didn't increase the risk of bowel cancer but watching TV did.