Fat linked to many types of cancer

Diet and exercise can
prevent cancer, a
researcher said.

TORONTO GLOBE AND MAIL

The most comprehensive study ever undertaken on the association between cancer and obesity concludes that excess body fat triggers many types of the disease, as does the consumption of even moderate amounts of alcohol, red meats and processed meats.

The study, released this week in Washington by the American Institute for Cancer Research and the World Cancer Research Fund, shows food, nutrition and lack of exercise appear critical in causing many cases of all cancers. That means controllable lifestyle factors associated with diet and weight have about the same impact on cancer rates as smoking.

“The most striking finding in the report is that excess body fat increases risk for numerous cancers,” said Phillip James, one of the study’s authors and chairman of the International Obesity Taskforce in Britain.

The international team of medical experts, which conducted an exhaustive, five-year review of more than 7,000 research papers that investigated whether food, nutrition or lack of physical exercise had an impact on cancer incidence, made 10 recommendations for preventing the disease. They include eating diets containing large quantities of vegetables and fruits and, most important, staying as thin as possible within the normal range of a person’s body weight.

“Cancer is preventable. There are changes you can make in your daily life that will reduce your chances of developing cancer,” James said. “Let’s get more vegetables, fruits. ... Let’s get off our backsides, however and whenever we can.”

Among the cancers convincingly linked to excess body fat, particularly if it is carried around the waist, are colon, kidney, pancreas, uterine, adenocarcinoma of the esophagus, and postmenopausal breast cancer.

The new research also made some unusual findings about cancer. One is that there is convincing evidence linking being tall to a higher risk of colorectal and postmenopausal breast cancer. Another is that an association exists between high birth weight and increased risk for premenopausal breast cancer — probably due to body fat.

Although many medical researchers have presented studies before linking cancer to weight and diet, the new study makes the case even more convincingly because it draws together most of the available evidence on the subject.

“This report today is showing us that the evidence is becoming more and more clear about the relationship between how we live, what we eat, and our individual risk of developing cancer,” said Heather Logan, a spokeswoman for the Canadian Cancer Society in Toronto.