Dietary patterns and risk of stomach cancer mortality: the Japan collaborative cohort study.

PURPOSE We sought to examine associations between dietary patterns and the risk of stomach cancer mortality in a cohort study in Japan. METHODS Factor analysis on food frequency questionnaire was conducted among 25,730 males and 37,673 females in a cohort study in Japan; we identified three dietary patterns, termed "vegetable"; "animal food"; and "dairy product". The Cox proportional hazards model was used to estimate the hazard ratio (HR) with stomach cancer mortality. RESULTS The "vegetable" pattern showed no association with stomach cancer mortality in either sex. The "dairy product" pattern was significantly associated with a decreased risk of stomach cancer in males, with multivariate HRs of 0.82 (95% confidence interval [CI]: 0.61-1.10), 0.74 (95% CI: 0.54-1.01), and 0.72 (95% CI: 0.52-0.99) for the second, third, and fourth quartiles, respectively. In addition, the "animal food" pattern tended to be associated with an increased risk in females, but non-significant, with HRs for respective quartiles of 1.45 (95% CI: 0.92-2.29), 1.32 (95% CI: 0.81-2.16), and 1.51 (95% CI: 0.78-2.21). CONCLUSIONS A diet high in dairy products may be associated with a decreased risk of stomach cancer mortality in males. We did not observe any significant association of this condition with other dietary patterns in either sex.