**8. Diet, nutrition, and cancer**

According to a report "Food, Nutrition, Physical Activity, and the Prevention of Cancer: A Global Perspective" published by World Cancer Research Fund and American Institute for Cancer Research, it is convincing that adult body fatness has increased risks of esophageal, pancreatic, liver, colorectal, postmenopausal breast, endometrial, and kidney cancer. As for diets and nutrition, there exist causal relationships between aflatoxin and liver cancer, lean and processed meat and colon cancer, arsenic in drinking water and lung cancer, and high-dose beta-carotene supplements and lung cancer. On the other hand, whole grains and food containing dietary fiber decrease colorectal cancer. Non-starchy vegetables and fruits decrease aerodigestive cancer and some other cancers [49]. It is not fully understood how each diet and nutrition has effects on carcinogenesis, a diet with enough vegetables and fruits, less lean and processed meat, reduced carbohydrate and fat to prevent obesity, and low in salt might be useful to reduce cancer incidence.
