Vitamin C, found in citrus fruits and many vegetables, may lower risks for cancers of the esophagus and stomach. Vitamin C acts as an antioxidant, neutralizing cancer-causing chemicals that form in the body. It also blocks the conversion of nitrates to cancer-causing nitrosamines in the stomach. Selenium is found in whole grains and has the same antioxidant effects as vitamin C and beta-carotene. Vitamin E also has this effect.
Caution is advised in supplementing selenium, which is toxic in large doses.
Alcohol Excessive intake of alcohol raises one's risks for cancers of the breast, mouth, pharynx, and esophagus. When combined with smoking, these risks skyrocket. It also raises risks for stomach, liver, and colon cancers. Not surprisingly, vegetarians, whose diets easily meet these requirements, are at the lowest risk for cancer. Vegetarians have about half the cancer risk of meat-eaters.