Gastric cancer is one of the common malignant tumors of the digestive system. According to the statistical data of International Agency for Research on Cancer in 2008 – the incidence rate ranks fourth and accounts for the second place of cancer mortality, and the statistical survey results of China in 2006: the incidence rate accounts for 12.8% of malignant tumors, ranking second. Scholars at home and abroad have conducted a lot of research on the relationship between dietary habits, nutrient intake and gastric cancer. Most results show that the occurrence of gastric cancer is a multi-factorial and multi-stage development process. N-nitro compounds and polycyclic aromatic hydrocarbons in the common diet of pickled and high-salt diets are the high risk factors for the occurrence of gastric cancer. I. High-salt and salt-based foods Although salt is not a carcinogen, many studies have found that excessive intake of salt or salt-based foods leads to the occurrence of atrophic gastritis, which is a precancerous lesion of gastric cancer, and about 10% of patients with atrophic gastritis will eventually become gastric cancer; therefore, scholars believe that high salt is a cancer-promoting agent. Through animal models and a large number of epidemiological surveys, high salt intake has been shown to be positively associated with cancer. Pickled foods contain a large amount of nitrite. In the process of curing meat and fish, proteins will form amines and amides, which will react with nitroso compounds to produce mutagenic and carcinogenic N-nitroso compounds. Fresh vegetables and fruits contain a large amount of antioxidants, plant compounds and dietary fiber, which can reduce the attack of free radicals, inactivate some chemical carcinogens and block the process of carcinogenesis, and dietary fiber can dilute carcinogens or combine with carcinogens to block the absorption of carcinogens. High intake of vegetables and fruits can reduce the risk of gastric cancer by 40-50%. The WCRF/AICR 2007 edition report confirms that a daily dietary intake of 50g of onion vegetables is associated with a 23% reduction in the risk of gastric cancer. The results of the study on shallots reinforced this point, as people who ate at least one serving of shallots daily had a 59% lower risk of stomach cancer compared to those who did not eat shallots. In vitro experiments have shown that the isoflavones in soy foods can effectively inhibit the proliferation of cancer cells and the formation of tumor neovascularization. The WCRF/AICR 2007 report shows that the more you eat beans and products, the lower the risk of stomach cancer. V. Green tea The polyphenols in green tea have anti-cancer effects. Experimental studies have shown that green tea can inhibit the proliferation, metastasis and neovascularization of tumor cells, block the carcinogenic effect of carcinogens, inhibit gene mutation and prevent the occurrence of cancer. Nutrient supplements and gastric cancer Epidemiological survey: non-smokers and drinkers with higher concentrations of blood vitamin C have a statistically significant lower risk of gastric cancer. In addition, the level of carotenoids in the body was also negatively correlated with gastric cancer. Researchers followed up on the intake of different amounts of vitamin C in people with a high incidence of gastric cancer and found that oral intake of vitamin C 500 mg/d, showed a statistically significant improvement over oral intake of 50 mg/d in people with obscene gastric mucosa. In addition supplementation with vitamin E, vitamin A and other nutrients have some preventive effect on gastric cancer. Another study showed that supplementation of vitamin A with zinc reduced the incidence of gastric cancer by 62%. However, the American Physicians’ Health Study, showed that supplementation with 50 mg of carotenoids had no effect on the incidence of gastric cancer. Similar results were obtained in the Finnish ATBC cohort study, where the combination of vitamin E and carotene had no effect on the incidence of gastric cancer. The occurrence of gastric cancer is a multifactorial and multi-stage development process, which is correlated with diet. We should control poor dietary practices and increase favorable diets to achieve control and prevention of the occurrence and development of gastric cancer.