Cancer avoidance is a very popular issue, and many patients and their families have asked me about this issue. In some countries, the word “cancer” and “crab” are the same word, so their cancer patients do not eat crab and shrimp. Some people think that beef and mutton are hot and should be avoided, but followers of Islam do not see a high incidence of cancer either. It is generally believed that duck meat is not hot, very safe and nutritious; scaly fish, pork, animal offal, shrimp and crab are what folk call “hairy things”, which are prone to allergies and should not be consumed in large quantities by tumor patients for a long time. Wu Yu, Department of Oncology, Xiyuan Hospital, Chinese Academy of Traditional Chinese Medicine Since ancient times, it has been said that medicine and food have the same origin. During the Han Dynasty? Zhang Zhongjing’s “The Essentials of the Golden Horoscope” said: “The taste of food is suitable for disease and harmful to the body. If appropriate is beneficial to the body, harm will become a disease, as a result of the danger, the case are difficult to treat.” Another cloud: “Where the taste of food, to nourish the life, eating the harm, but can be harmful.” It means that the food should be suitable for the disease in order to help the treatment of the disease; on the contrary, it can lead to the recurrence of the disease or aggravate the disease. Since diet is closely related to the occurrence and development of tumor, necessary avoidance of food is necessary. If you are suffering from cancer, which foods can’t be eaten and you are afraid that eating them will cause tumor recurrence or metastasis. The understanding of this issue should be based on scientific analysis. First of all, we should realize that the recurrence or metastasis of tumor is mainly caused by the low resistance of the body, the original cancer cells are not completely destroyed, and the result of blood or lymphatic dissemination, not caused by eating a certain food. Clinically, some tumor patients are very strict in avoiding food and do not eat many things, but the cancer still recurs and metastasizes. Some patients have diversified diet, not partial diet and regular diet, but live well. Therefore, the rumor that chicken, fish, beef, shrimp, etc. can cause tumor recurrence or metastasis is not based on theories and experiments of Chinese medicine and Western medicine. Does it mean that tumor patients do not have the problem of avoiding food? Can they eat anything they want? Is there no scientific basis for the saying of “avoiding food”? This view is also unscientific. Chinese folk medicine has always paid attention to the avoidance of food, and Chinese medicine also pays attention to the choice of food for patients in illness. According to the theory of Chinese medicine, food, just like medicine, has four qualities: cold, hot, warm and cool, and five flavors: sour, bitter, sweet, pungent and salty. Therefore, tumor patients should avoid certain foods according to different conditions. From the theory of Chinese medicine and the historical development of taboos, appropriate dietary taboos are necessary, but the taboos should not be too strict and the recipes should not be too narrow. First of all, there are many records in ancient literature on the opposite of medicine food, food taboos, etc. Secondly, the clinical selection of diet according to the classification of the evidence, to improve the treatment effect, and the recovery of the body is beneficial. The disease has cold, heat and deficiency, food has four different nature, the so-called “the taste of food, there are with the disease appropriate, there are with the body for the harm”, with the disease appropriate, you can eat, and the disease does not fit and harmful to the body, we must avoid. Patients with a hot nature are advised to eat cool foods and avoid hot foods. This is the reason why patients with a cold and deficient body should eat warm food and avoid cold food. Food has five flavors, “heart disease forbidden salty, lung disease forbidden bitter, liver disease forbidden pungent, spleen disease forbidden sour, kidney disease forbidden sweet.” The ancients also put forward the five diseases prohibited: “gas disease without more food pungent, blood disease without more food salty, sweet disease without more food bitter, meat disease without more food sweet, tendon disease without more food acid.” Pungent and spicy food can help fire and disperse qi, so for hot tumor patients, it is advisable to avoid them. Sweet food, greasy food, easy to help dampness and produce phlegm, should be avoided for tumor patients with dampness obstruction. Some foods are hard and hard, not easy to digest, plus fried foods, which should be avoided by patients with indigestion. Tumor patients should also pay attention to the choice of diet when they receive certain treatments. Patients undergoing radiotherapy and chemotherapy often have dry mouth and nose, dry throat and less food, red tongue with less coating, thin pulse and other symptoms of yin deficiency and fire, so they should not eat spicy, dry or fried food. Tumor patients should also avoid certain foods when taking certain traditional Chinese medicines, after taking nourishing traditional Chinese medicines such as ginseng, they should not eat lai suizi (radish seeds) and so on. In fact, in clinical work, we have not yet seen any cases of tumor recurrence or deterioration due to diet. Tumor patients should eat nutritious and easy to digest and absorb food because of their weakness, emaciation and poor appetite. Tumor patient’s diet should be different from disease to disease, from person to person, and from treatment to treatment, not to generalize what can and cannot be eaten. This also “taboo”, that also “taboo”, even eggs, tofu, vegetables are afraid to eat, can only make the patient’s nutritional status worsens, but to the detriment of the recovery of tumor patients.