Non-communicable diseases, including cancer, are a very serious problem of the 21st century not only in Poland but all over the world as well. Cancers of digestive tract such as esophageal cancer and stomach cancer significantly affect the quality of life of the patient. Adequate nutrition plays a big role in preventing cancer, but it also has a meaning in people already sick, because of the very frequent incidence of malnutrition, which slows down the process of wound healing, increases the incidence of infection and mortality. Despite the undoubted influence of diet on the risk of cancer, its prevention and positive impact on treatment, not all the mechanisms explaining these relationships are understood, so it is necessary to continue the research to determine the impact of individual components of the diet on the prevention of cancer.

Key words: cancers, esophageal cancer, stomach cancer, nutrition, prevention.