Regular exercise can 'minimise colon cancer risk'

People who take regular exercise can cut their risk of colon cancer by 24%, researchers said today.

A review of 52 studies found that those people who were the most active were far less likely to develop the cancer than people who did very little.

The analysis was carried out by experts in the US and published in the British Journal of Cancer.

Two-thirds of bowel cancer cancers occur in the colon and around a third occur in the rectum.

Regular exercise is known to help cut the risk of bowel cancer, including colon cancer, in several ways.

Obesity is linked to a higher risk of cancer but exercise helps people keep their weight in check.

Substances in undigested food that can cause cancer also move through the bowel quicker in people who exercise.

Furthermore, regular physical activity helps reduce the level of insulin and other hormones, which are linked to the growth of cancer tumours.

Exercise has also been shown to reduce inflammation in the bowel, which could otherwise cause bowel cancer.

The latest study looked at research covering many types of exercise and activity, including manual labour at work, running and going to the gym.

One study – the US Nurses’ Health Study – compared women who walked briskly for five to six hours a week with those who walked for 30 minutes a week or less.

The combined results of all the studies showed that those who took regular exercise cut their risk of colon cancer by 24%. The results were the same for both men and women.

Study author Dr Kathleen Wolin, from the Washington University School of Medicine in St Louis, said: “These results give us a very reliable calculation of the positive effect that exercise can have on reducing colon cancer risk.

“It’s very positive to see that exercise has such a clear benefit in reducing cancer risk and we hope it will encourage people to enjoy a healthy active lifestyle as well as treating it as a way to minimise their colon cancer risk.

“Once future studies have been done, we would like to go on and personalise these results further, taking into account the impact factors such as racial origin, weight and diet have on bowel cancer risk, so that we can make individual recommendations on how people can reduce their chances of getting the disease.”

Bowel cancer is the third most common form of cancer.

Sara Hiom, director of health information at Cancer Research UK, said: “One hundred people a day are diagnosed with bowel cancer in the UK alone, so it’s imperative that we do all we can to prevent the disease.

“This work brings together the findings from many different studies which seek to understand the effect that exercise has on cancer risk – which gives us greater confidence in its results.

“We know that around half of all cancers could be prevented by changes to lifestyle.

“Maintaining a healthy body weight is one of the best ways to lower the risk of bowel and other cancers – potentially helping to avoid an estimated 13,000 cases each year.

“Cancer Research UK recommends that you try to take half an hour’s physical activity a day, five days a week. This should be enough to leave you feeling warm and slightly out of breath and can include housework or walking briskly.”