Eat less total fat. Limit your daily fat intake to no more than 20 percent of your total food calories. This means that if you average 2 500 calories a day, fat should provide no more than 500 of these calories. 

This means you should eat around 55 grams of fat per day, maximum.

Eat the right fat. Eating the wrong kinds of fat may be even more cancer-causing than eating too much fat.

Increase Your Fiber Intake. In all the research between food and cancer, the evidence for a relationship between a high fiber diet and lower chances of colorectal cancer is the most conclusive.

It follows common sense as well. Fiber moves potential carcinogens through the intestines faster, decreasing the contact time between carcinogens and the intestinal wall.

Eat lots of raw fruits and vegetables. The consensus of the hundreds of studies exploring the link between diet and cancer is that eating more fruits and vegetables reduces the risk of all types of cancers. Eating more fruits and vegetables decreases your appetite for fatty foods, which themselves increase the risk of cancer. Plants also contain phytochemicals. Substances that may help your body fight cancer.

Switch from red meat to seafood. Populations who eat the most red meat and fat in their diet have the highest incidence of colon cancer

1. Switch from an animal-based diet to a plant-based diet. The most compelling research linking diet to cancer are studies of groups of people who have primarily plant-based diets, for example vegetarians and Seventh Day Adventists, and who have a much, lower risk of cancer.

2. Eat more soy products. Soy is a more healthful source of protein than meat. The primary anti-cancer value of soy seems to come from phytonutrients (for example, isoflavones) which inhibit the growth of new blood vessels necessary for tumor survival. Soy also protects against colon cancer by blocking the carcinogenic effects of bile acids (a process called angiogenesis).

3. Change your oils. Oils that are rich in omega-3 fatty acids (that is, fish and flax oils) have anti-cancer properties. Monounsaturated oils, such as olive oil, also play a role in cancer prevention. Populations with an olive oil-rich diet, such as Mediterranean cuisine, have a lower incidence of cancer.

Eat foods containing calcium: Studies have shown that populations with a high intake of calcium (e.g., people in Sweden) have a lower incidence of colorectal cancer. Calcium controls the multiplication of epithelial cells lining the colon. When these cells proliferate at a fast rate, the risk of cancer increases. Calcium also binds cancer-producing bile acids and keeps them from irritating the colon wall.

Eat a diet high in antioxidants: While there are many unsubstantiated claims about the benefits of antioxidants, there is reliable scientific evidence that beta carotene, vitamin C and vitamin E definitely lower the risk of colorectal cancer.