Dietary habits and pancreatic cancer risk in a cohort of middle-aged and elderly Japanese.

Few epidemiological studies have examined associations between diet and pancreatic cancer in Japan. In the Japan Collaborative Cohort Study for Evaluation of Cancer Risk, we evaluated the relationship between dietary factors, including meat, vegetable, and fruit intake, and the risk of pancreatic cancer deaths. Among the original cohort established between 1988 and 1990, 46,465 men and 64,327 women aged 40-79 yr were followed-up through December 31,1999. During 1,042,608 person-years of follow-up, we documented 300 deaths from pancreatic cancer. A 33-item food-frequency questionnaire was used to assess dietary intake at the baseline survey. Cox proportional-hazards models were used to estimate the relative risks of pancreatic cancer death in relation to the intake frequency of food items. We did not observe an overall association between meat intake and pancreatic cancer risk. Except for a 50% decrease in risk associated with high fruit intake among men, we did not find other significant inverse relationships between vegetable and fruit intake and pancreatic cancer risk. Smoking did not modify the associations with dietary habits. Our study suggested that high consumption of pickles and wild edible plants, mainly bracken, might be related to increased pancreatic cancer risk; however this finding should be confirmed in other epidemiological studies.