Body fat, red meat linked to cancer

Excess body fat and red meat are linked to an increased risk of common cancers and should be avoided, the World Cancer Research Fund and the American Institute for Cancer Research said.

About 40 percent of all cancers are linked to food, lack of exercise and body weight, the organizations said in a 571-page report released Wednesday. This is the most comprehensive evaluation of evidence linking personal habits to cancer risk, expert panelists said.

The findings are meant to guide future scientific research, cancer prevention education programs and health policy around the world, panelists said. The recommendations could prevent about a third of all cancers if adopted worldwide, said W. Philip T. James, panel member and chairman of the International Obesity Task Force in London.

"Part of the purpose of the report was to show that prevention of cancer by means of food, nutrition, and associated factors is as feasible and crucial as prevention of coronary heart disease," researchers said. "The evidence that high body fatness and also physical inactivity are causes of a number of cancers, including common cancers, is particularly strong."

Cancers start as a single cell that has lost control of its normal growth and replication process, according to the report. About 10 percent of cancers result directly from inheriting genes associated with a cancer. Most cancers develop through changes over time to the genetic material within cells. Damage to the genetic material is caused internally or through other factors, such as the type of foods a person eats, panelists said.

Hundreds of experts evaluated more than 7,000 studies over five years to compile the report, the organizations said. Panelists found "convincing evidence" that carrying extra weight, particularly around the waist, may lead to cancer of the esophagus, pancreas, colon, kidney and uterus, as well as post-menopausal breast cancer.

They recommended keeping extra weight off, exercising at least 30 minutes a day and limiting consumption of alcohol and high-fat foods, such as burgers, French fries, milk shakes, pastries and sugary drinks. The guidelines also apply to cancer survivors, panel members said in the report.

Alcohol consumption may cause cancers of the mouth, pharynx, larynx and esophagus, as well as colorectal cancer. Researchers said men should limit their alcohol intake to two drinks a day, and one is allowed for women.

Red meat, such as beef, pork and lamb, which are linked to colorectal cancer, should be replaced with poultry, fish and eggs. Processed meats that include ham, bacon, sausage and lunchmeat should also be avoided, researchers said.