Clinical cases show that besides mental stress and fatigue, colorectal cancer patients have irregular eating habits, preferring to eat meat and eating less vegetables. In this society where everyone talks about cancer, how many people think of establishing healthy eating habits to prevent such maladies? In the case of colon cancer, dietary habits are very closely related to disease prevention. Many years of scientific research have concluded that some dietary defects are related to the development of colon cancer. 1, calcium and vitamin D Americans found that the mortality rate of colorectal cancer is significantly lower in areas that receive high levels of sunlight exposure, especially B-group ultraviolet light, and research has confirmed that it 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 daily is only half that of people who consume small amounts of vitamin D; while the incidence of colorectal cancer in people who consume approximately 1200 mg of calcium or more per day is only one-fourth that of people who consume less than 625 mg of calcium per day. Therefore, scientists concluded that calcium intake is negatively correlated with the risk of colorectal cancer, while vitamin D has potential anti-cancer effects. 2.Fat Epidemiological studies have found that the diet of countries with high incidence of colorectal cancer is characterized by high fat, while countries with low incidence have a lower fat content in their diet. Studies in Shanghai also found that the increase in the incidence of colorectal cancer is related to the increase of fat in the diet. In-depth studies have found that a high-fat diet can cause an increase in bile acid metabolites (deoxycholic and lithocholic acids), cholesterol metabolites (steroids and steroid-like ketones), and bacterial β-glucuronidase activity in the stool, which are either carcinogens or carcinogenic, and can lead to colorectal cancer. Therefore, excessive fat diet is directly or indirectly related to colorectal cancer. 3.Fiber The incidence of rectal cancer in black African residents is very low. Scientists found after research that this is closely related to their diet with corn, vegetables and other fiber-rich foods. Further research found that the lack of fiber in food can reduce the amount of stool and slow down the movement of the intestine, so the concentration of carcinogenic substances in the intestine increases, and the role of carcinogens and the mucosa of the intestinal wall is prolonged, so colorectal cancer is likely to occur. 4, pickled food and onion and garlic Our scientists found that carotene, vitamin B2, vitamin C and vitamin E have a role in reducing the occurrence of colorectal cancer, so if there is a long-term lack of these vitamins in the diet, it is easy to suffer from colorectal cancer. Our scholars also found that those who often eat pickled foods have an increased chance of developing colon cancer, which may be related to the carcinogenic substances produced during the process of food pickling. Many statistical analyses have found that regular consumption of onion and garlic foods can reduce the occurrence of colon cancer, and the mechanism of cancer inhibition may be related to reducing the damage of carcinogens to the mucosa of the colon wall. In addition, the lack of trace elements such as molybdenum and selenium in food may also increase the incidence of colon cancer.