Colorectal cancer is a common tumor in China. In recent years, information from all over the world shows that with the improvement of people’s living standard and the change of diet structure, its incidence rate has been on the trend year by year, and its incidence rate has ranked the 3rd-5th in the spectrum of malignant tumors. From many clinical cases, we found that besides the causative factors such as mental stress and fatigue, colorectal cancer patients have the habit of eating irregularly, preferring meat and eating less vegetables in their diet. Years of scientific research have summarized some dietary factors related to the development of colorectal cancer, such as: calcium and vitamins, fat, fiber, etc. Therefore, in order to prevent intestinal cancer and patients who have already suffered from intestinal cancer in the diet due to the following points: 1, supplemental calcium and vitamin D Americans found that in areas receiving sunlight exposure, especially high levels of ultraviolet B, the mortality rate of colorectal cancer is significantly lower, the study has It is confirmed that colorectal cancer is closely related to the metabolism of calcium and vitamin D. It has further been found that the incidence of colorectal cancer in people who consume more than 150 international units of vitamin D in their diet per day is only half that of people who consume a small amount of vitamin D, while the incidence of colorectal cancer in people who consume approximately 1200 mg of calcium per day or more is only one-fourth that of people who consume less than 625 mg of calcium per day. Therefore, scientists have concluded that calcium intake is negatively correlated with the incidence of colorectal cancer, while vitamin D has a potential anti-cancer effect. Some vegetables such as cabbage, rape, fennel and celery also contain about 150 mg of calcium per 100 grams, while soy products, kelp, shrimp and animal bones are also rich in calcium, and vitamin D is mainly found in sea fish, animal liver, egg yolk and lean meat. In addition, foods like skim milk, cod liver oil, cheese, nuts and seafood also contain vitamin D, so we should usually eat more of these foods. 2.Reasonable fat intake Epidemiological studies have found that the diet of countries with high incidence of colorectal cancer is characterized by high fat, while the fat content in the diet of countries with low incidence is low. Studies in Shanghai, China, also found that the increase in the incidence of colorectal cancer is related to the increase of fat in the diet. Studies have proven that high-fat diets promote the occurrence of intestinal tumors, especially polyunsaturated fatty acids, which have a pro-carcinogenic effect, although they can lower blood lipids. Cholesterol itself is not carcinogenic, but reacts with gallstone acid at the same time and has a cancer-promoting effect, indicating that gallstone acid is a cancer-promoting factor. Therefore, patients with colorectal cancer should not eat too much fat, with total fat accounting for less than 30% of total caloric energy, and the ratio of animal and vegetable oils should be appropriate. In other words, in a day’s meal, including the amount of fats in the food itself, plus the oil used in cooking, the daily fat should be less than 50 grams. Some friends are afraid of coronary heart disease, control animal fat is very strict, often to vegetable oil, or even do not eat animal oil, which will cause excessive peroxide in the body. Because the carbon chain in vegetable oil is unstable and easy to oxidize, if you eat some animal fat properly, it will make the carbon chain stable and not easy to oxidize, and reduce the formation of free radicals in the body, so you must eat scientifically and pay attention to the reasonable ratio of fats and oils, it is recommended that the ratio of saturated fatty acids to polyunsaturated fatty acids and monounsaturated fatty acids is 1:1:1. 3, more dietary fiber The incidence of colorectal cancer in black African residents is very low, the science This is closely related to the fact that they take corn, vegetables and other fiber-rich foods as their main food. Further research found that the lack of fiber in food can reduce the amount of stool, slow down the movement of the intestine, increase the concentration of carcinogenic substances in the intestine, and prolong the time for carcinogens to interact with the mucous membrane of the intestinal wall, thus making it easy for colorectal cancer to occur. Colon cancer patients should pay attention to eating more dietary fiber-rich vegetables, such as celery, leek, cabbage, radish and other vegetables. Dietary fiber-rich vegetables can stimulate intestinal peristalsis, increase the number of bowel movements and take away carcinogenic and toxic substances from feces. If colon cancer bulges into the intestinal cavity and the intestinal cavity becomes narrow, the intake of dietary fiber should be controlled, because too much dietary fiber can cause intestinal obstruction. At this time, we should give easily digestible and soft semi-fluid food, such as millet porridge, thick lotus root soup, rice soup, congee, cornmeal porridge, egg custard, tofu brain, etc. These foods can reduce the stimulation of intestine, and pass through the intestinal cavity smoothly to prevent the occurrence of intestinal obstruction. 4.Cultivate some other good dietary habits Scientists in China have shown that carotene, vitamin B2, vitamin C and vitamin E have the function of reducing the occurrence of colorectal cancer. Therefore, if there is a long-term lack of these vitamins in the diet, it may increase the possibility of cancer development in the large intestine. Eat more fresh vegetables and fruits to supplement carotene and vitamin C, such as carrots, sweet potatoes, spinach, oranges, grapefruit and other foods. Our scholars also found that those who often eat pickled foods have an increased chance of developing colorectal cancer, which may be related to the carcinogenic substances produced in the process of food pickling. Many statistical analyses have found that regular consumption of onion and garlic foods can reduce the incidence of colorectal cancer, and the mechanism of cancer inhibition may be to reduce the damage of carcinogenic substances to the mucosa of the colon wall. In addition, the lack of trace elements in food, such as molybdenum and selenium, may also increase the incidence of colon cancer. Paying attention to the intake of foods with high molybdenum content, such as animal liver and kidney, beans and cereals, as well as foods rich in trace elements of selenium, such as malt, fish and mushrooms, can also help prevent the occurrence of colon cancer. In conclusion, if we establish a scientific dietary structure and cultivate reasonable dietary habits, we can effectively prevent the occurrence of bowel cancer, and at the same time, patients who have already suffered from bowel cancer can also prevent the progress and recurrence of the disease through a reasonable and healthy diet.