Here are some good bets, plus a few educated guesses and theories. A healthy diet, on the other hand, is high in vegetables, fruits, and whole grains, and low in animal fats. Eating large amounts of fat may be unhealthy for the colon. Some fat passes into the colon undigested, and the bacteria there act upon the fat, producing potentially carcinogenic substances that may damage the colon lining. High-calorie diets often lead to weight gain, particularly in sedentary people.
Obesity increases the risk of colon cancer.
This kind of diet promotes constipation, and chronic constipation may in turn promote colon cancer. It is naturally high in fiber, which may protect against colon cancer, though studies have yielded conflicting results. High intakes of beta carotene, calcium, and the B vitamin folic acid, all of which are abundant in a healthy diet, seem to protect against colon cancer. Vitamin C is protective, too. Vitamin D may also play a role.