What causes cancer?
Experts link diet and
behaviors to many cancers

The growing incidence of cancer has most of us wondering: What causes cancer? I have a personal interest in the answer as there have been several cases of cancer in my immediate family, and I want to weave cancer prevention strategies into my daily life. The research shows there are things we can do to lower the risk for cancer.

In late 2007, the World Cancer Research Fund and the American Institute for Cancer Research released a report linking cancer to diet, physical activity and body weight.

Medical scientists from the United States, England, China, Japan, New Zealand, Nigeria, Japan, Mexico and Chile joined forces and reviewed 7,000 scientific studies to identify what causes cancer.

What causes cancer -
Here's what the experts say in their 2007 report:

• "Maintenance of a healthy weight throughout life may be one of the most important ways to protect against cancer." The research found that being overweight was linked to greater incidence of cancer of the breast (in postmenopausal women), colon, pancreas, oesophagus, kidney and gall bladder. This report recommends that adults aim for a body mass between 21 and 23 and that people limit fruit juice, and avoid sugary drinks, packaged and fast food, which promote weight gain.
• Sedentary living is a contributing factor to some types of cancer, according to this exhaustive report. Review of scientific literature revealed that there is strong evidence that regular physical activity can ward off colon cancer and exercise has some protective effect in cancer of the breast (pre and postmenopausal women), pancreas and lung. The report's authors recommend moderate physical activity, such as 30 minutes of brisk walking, each day.



• Consumption of alcohol has been clearly linked to six types of cancer: mouth/larynx, oesophagus, liver, colon, and breast (pre and postmenopausal women). This worldwide study states: "based solely on the evidence on cancer, even small amounts of alcohol should be avoided."

  However, the report recognizes that modest amounts of alcohol may reduce the risk of coronory disease, so the panel recommends no more than one drink a day for women and two drinks a day for men.

• Cancer rates are lower among individuals who eat a diet that is based on plants. Review of available research found that a diet high in non-starchy vegetables (green leafy vegetables, broccoli, okra, eggplant, carrots, arthichokes, rutabaga, turnips) result in decreased risk for cancers of the mouth/larynx, oesoophogus, lung and stomach. See our list of cancer-fighting vegetables.

The research shows that eating a diet high in fruits is linked to a decreased risk for cancer of the mouth/pharynx, oesophogus, lung, stomach, pancreas, liver and colon. We've compiled a list of fruits that fight cancer.



• Eating red meat and processed meat is linked to a higher risk for colon cancer, according to the report. The report's doctors recommend eating no more than 18 ounces of cooked red meat a week with very little or none of that meat in a processed form, such as hot dogs, sausage, and packaged lunchmeats.

Other research on what causes cancer:

• A higher intake of fat, especially animal fat, is linked to higher rates of breast cancer, according to The Cancer Project, a nonprofit group dedicated to cancer prevention through educating people about the link between diet and cancer.

  In 2003, Harvard University scientists studied the diets of 90,000 women and found that women who ate the most animal fat had higher incidence of breast cancer compared to women who ate the least animal fat. In 1988, the U.S. Surgeon General's Report on Nutrition and Health said, "a comparison of populations indicates that death rates for cancers of the breast, colon and prostate are directly proportional to estimated dietary fat intakes."



• Smoking is the leading cause of lung cancer and is attributed to causing 87 percent of lung cancer deaths, according to the National Cancer Institute. But smoking is also linked to other cancers. The National Cancer Institute reports that smoking is a cause of kidney, pancreatic, cervical, and stomach cancers.

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