Having scientific and effective preventive measures can allow us to avoid the disease to bring us more harm. Prevention means to take certain measures to prevent the occurrence and development of diseases. The Nei Jing calls this “treating the untreated”. It is pointed out that “the sage treats the sick before they get sick, and does not treat the chaotic before they get chaotic” (Su Wen – The Great Treatise on the Regulation of the Four Energies). It can be seen that it is very important to know the prevention of diseases and to prevent them before they happen. Gastric cancer is a common and frequent disease in internal medicine. In daily life, it is important to pay attention to dietary habits and develop good health awareness to prevent the occurrence of gastric cancer. Avoid eating moldy food. We often encounter moldy food in our daily life, which is caused by contaminated mold, some of which are poisonous fungi and strong carcinogenic substances, while some foods produce a lot of nitrite and secondary amines under the action of poisonous fungi, which can synthesize nitrosamines and cause cancer under certain conditions after entering the body. 2.Eat less pickles. Pickles contain a large amount of nitrite and secondary amines, which can synthesize nitrosamines under the action of suitable acidity or bacteria in the stomach, and these compounds are very strong carcinogenic substances. So the food should be fresh, and advocate the use of refrigerator refrigeration. 3. Eat less smoked and fried food. Smoked fish and bacon contain a lot of carcinogenic substances, such as 3-4 benzo(a)pyrene and cyclic aromatic hydrocarbons. Fried, baked, burnt food and reused high temperature cooking oil also contain such carcinogenic substances, so they should be consumed sparingly. 4. Do not smoke and drink less alcohol. Smoking has a certain relationship with stomach cancer because smoke contains many carcinogenic and carcinogenic substances such as benzo(a)pyrene, polycyclic aromatic hydrocarbons and dibenzocarbazole, which can lead to the occurrence of esophageal cancer and stomach cancer. Although alcohol itself is not a carcinogen, strong alcohol can stimulate the gastric mucosa, damage the mucosal tissue and promote the absorption of carcinogenic substances. If you drink alcohol and smoke at the same time, it is even more harmful because alcohol can enhance the permeability of cell membranes, thus strengthening the absorption of carcinogenic substances in smoke. Second, four should 1, drinking water hygiene. Because contaminated water contains many kinds of carcinogenic metal ions, you must use regular tap water, and try to use well water in rural areas. 2. Fresh vegetables and fruits. Eat more food containing vitamins A, B and E, and strengthen protein intake appropriately, so as to protect the gastric mucosa. 3, good eating habits. If the diet is not regular and quantitative, overeating, eating too fast or too hot, it will produce damaging stimulation to the stomach, which can also lead to the occurrence of stomach cancer, while high salt intake and good sulking during meals are also related to stomach cancer. 4.Actively treat precancerous lesions. Atrophic gastritis is closely related to gastric cancer and is a precancerous lesion; gastric ulcer malignant gastric cancer accounts for 5-10%; gastric polyadenomatous polyp is more common than single polyp, and polyp diameter over 50px shows a tendency of malignant transformation; pernicious anemia is also related to gastric cancer. Therefore, people who suffer from atrophic gastritis, gastric ulcer, gastric polyadenomatous polyp and pernicious anemia must go to hospital frequently for examination and treatment to eliminate precancerous lesions and prevent the occurrence of gastric cancer.