Background: Despite a declining incidence, stomach cancer is still a dominant cancer in Japan. The association between dietary habits and stomach cancer risk was investigated in a large prospective study in Japan.
Methods: Data were obtained using a self-administered questionnaire from 1988 through 1990. Food frequency questionnaire was used to evaluate the consumption of 33 selected food items. Proportional hazard model was used to determine the hazard ratios (HRs) and their 95% confidence intervals (CIs) of stomach cancer for different levels of the dietary intakes.
Results: A western style breakfast showed an inverse association with stomach cancer risk in males (HR=0.49, 95% CI: 0.35-0.70). Women who consumed liver three to four times per week and more than once per day had a significant increased risk, respectively (HR=2.02, 95% CI: 1.12-3.63, HR=3.16, 95% CI: 1.16-8.62 ). A clear dose-response relationship between the intake of liver and stomach cancer risk was observed. We found no association between stomach cancer mortality and the consumption of fruit such as mandarin orange, and vegetables such as carrots and spinach in both men and women. The consumption of high salt foods such as miso soup and pickles was also not significantly associated with the mortality of stomach cancer in both sexes.
Conclusion: This prospective study suggested that a western-style breakfast is associated with a lower risk of stomach cancer, although some differences in the association were seen between men and women.