Intakes of selected foods and beverages and the incidence of gastric cancer among the Japanese residents of Hawaii: a prospective study

Background We report on the associations between the intake of certain foods and beverages and the incidence of gastric cancer in a cohort of 11 907 randomly selected Japanese residents of Hawaii (6297 women and 5610 men). Methods The daily intake of six beverages, cigarettes and alcohol and the weekly frequency of intake of 13 foods and food groups was estimated with a short food frequency questionniare. Over an average follow-up period of 14.8 years, 108 cases of gastric cancer (44 women, 64 men) were identified via Linkage to the Hawaii Tumor Registry. Results In gender-combined proportional hazards analyses, the consumption of fresh fruit seven or more times per week was associated with a significantly reduced risk of gastric cancer, compared to lower levels of consumption (relative hazard (RH): 0.6, 95% confidence interval (CI) :0.4-1.0, P = 0.03). The combined intake of fresh fruit and raw vegetables was inversely associated with the risk of gastric cancer in the total cohort, and among the men (P < 0.05). No significant relationships were found between gastric cancer incidence and the intake of pickled vegetables, mise soup, dried or salted fish, or processed meats among either gender. Compared to non-drinkers, men who drank one cup of coffee per day had a significantly elevated risk of gastric cancer (RH: 2.5, 95% CI : 1.0-6.1, P = 0.05), but there was no evidence of a dose-response relationship. Cigarette smoking and consumption of alcohol were not related to gastric cancer, in analyses restricted to the men. Conclusions The results related to fruit and vegetable intake are consistent with an anti-nitrosating effect of these foods, while the unexpected association between coffee consumption and gastric cancer is difficult to explain and may represent a chance finding.