LONDON (Canadian Press) -- Around 10,000 cases of breast and bowel cancer could be avoided every year in Britain if people did a bit more brisk walking, the World Cancer Research Fund said Tuesday.

Health experts have long recommended people stay physically active to maintain a healthy weight and thus reduce their risk of all cancers. Physical activity is believed to reduce cancer risk in ways such as impacting hormone levels.

The research fund's scientists estimated that about 4,600 bowel cancer cases and 5,000 breast cancer cases could be prevented in the United Kingdom if people engaged in moderate activities that made their hearts beat faster, such as by walking. Around a half-hour of such activity every day would help, the fund said in a statement.

"These figures also show you do not have to go to the gym every day to benefit," Dr. Rachel Thompson, deputy head of science for the research fund, said in the statement. "By taking up walking as a hobby or even walking to the shops instead of taking the bus or car, people can make a real difference to their health."

The American Cancer Society has said that physical activity is thought to reduce the risk of breast and prostate cancer by regulating hormone levels. For colon cancer, exercise may speed up the digestive process, reducing the exposure of the bowel lining to potentially dangerous substances.

In Europe, being obese or overweight is linked to about 8 per cent of cancers. In a study published last year in the medical journal Lancet, researchers predicted that obesity could in the future overtake smoking and hormone replacement therapy to become the leading cause of cancer in women.

The Canadian Press, 2010