Chronic gastritis and gastric cancer are indeed related to dietary and environmental factors. First of all, it is well known that Japan is a country with a high incidence of stomach cancer, however, the incidence of stomach cancer among the first generation of Japanese immigrants to the United States decreases by about 25%, the second generation decreases by about 50%, and by the third generation the incidence of stomach cancer is comparable to that of local American residents. This suggests that dietary and environmental factors influence the incidence of gastric cancer. Epidemiological studies show that eating more fresh vegetables and fruits, using refrigerators and storing food properly can reduce the occurrence of gastric cancer, while frequent consumption of moldy foods, salted vegetables, pickled and smoked products and excessive salt intake can increase the risk of gastric cancer. As for chronic gastritis, long-term consumption of strong tea, strong alcohol, coffee, too hot, too cold and too rough food can lead to repeated damage of gastric mucosa and cause chronic gastritis. In addition, excessive nitrate and nitrite in soil and water, imbalance in the ratio of trace elements, lack of fresh vegetables and fruits and the necessary nutrients, frequent consumption of fast food such as moldy, pickled, smoked and fried foods, excessive salt intake, and family history of gastric cancer can increase the risk of chronic atrophic gastritis, aggravate the condition of chronic atrophic gastritis, and even increase the possibility of cancer.