Dietary factors and stomach cancer: a case-control study in Korea.

Stomach cancer is the most common cancer among Koreans. There is wide agreement that dietary factors are important in gastric carcinogenesis, but the role of many Korean food items remains unknown. A case-control investigation involving 213 incident cases of histologically confirmed stomach cancer and an equal number of controls, matched by age (within 2 years) and sex, was conducted from June 1990 to October 1991. An increased risk of stomach cancer was noted among those with high consumption of stewed foods such as soybean paste stew and hot pepper-soybean stew, broiled fish, and those who liked salty food. However, mung bean pancake, tofu (soybean curd), cabbage, spinach, and sesame oil decreased the risk of stomach cancer. Stratified analysis by salt in combined foods, such as stewed foods and pickled vegetables, disclosed salt as being an important risk factor. Analysis of cooking methods showed that broiling and salting increased the risk of stomach cancer, but that frying tended to decrease the risk. These results suggest that the cooking method might modify the gastric carcinogenicity of foods. As non-dietary factors, smoking and a family history of stomach cancer increased the risk, but use of a refrigerator decreased the risk of cancer. Heavy salt consumption and cooking methods like broiling and salting seem to play a major role in gastric carcinogenesis among Koreans.