Diet and stomach cancer risk in Warsaw, Poland.

Some of the world's highest rates of stomach cancer are found in Poland. Reasons for the increased incidence are not known, but high intake of sausages and other preserved foods and low intake of fresh fruits and vegetables may be involved. A case-control study comprising residents newly diagnosed with stomach cancer during 1994-96 and controls randomly selected from the general population was conducted in Warsaw, Poland. Standardized interviews were conducted to ascertain usual consumption of 118 common foods and beverages and other exposures. Using data from direct interviews with 274 cases and 463 controls, odds ratios of stomach cancer were calculated as estimates of risks associated with dietary factors, adjusting for age, sex, education, smoking, and caloric intake. Risk of stomach cancer was inversely related to intake of total fruits and dark green-yellow vegetables and to indices of vitamins C and E and alpha- and beta-carotenes. However, risk was not significantly increased among those with high intake of pickled/salted vegetables and sausages. Risks were positively associated with increased intake of breads/cereals/rice/pasta and other refined grains, as well as a high carbohydrate index. Our findings add to the evidence of a protective effect of fruits and certain vegetables on stomach cancer risk, but do not indicate that high intake of sausage and other preserved foods typical in the Polish diet has contributed to the country's elevated stomach cancer incidence. Our data also suggest that high carbohydrate consumption may influence risk, but further confirmation is needed.