Intake of foods and nutrients and cancer of the exocrine pancreas: a population-based case-control study in The Netherlands.

During 1984-88 a population-based case-control study was carried out in the Netherlands in collaboration with the International Agency for Research on Cancer in order to investigate the role of diet in exocrine pancreatic carcinoma. A semi-quantitative food-frequency questionnaire was used to comprehensively assess usual diet about 1 year prior to diagnosis of 164 cases or interview of 480 controls. More than half of the cases were directly interviewed. After controlling for age, gender, response status, life-time cigarette consumption and dietary intake of total energy, monotonic, significantly inverse dose-response effects with estimates of daily consumption of vegetables were found. The significant inverse effect of total cooked vegetables was primarily concentrated in cruciferous vegetables. Consumption of fresh vegetables was also significantly and inversely related to risk. A monotonic, positive dose-response gradient was seen for the consumption of eggs, while consumption of fish was significantly related to risk as well. Among direct respondents, significantly inverse relationships were found for the consumption of legumes, tomatoes, cheese and fermented milk products. Inverse associations with consumption of (subgroups of) fruits were observed in women only. The monotonic, significantly inverse relationship for consumption of low-fibre vegetables and the somewhat weaker, inverse association for high-fibre vegetables in directly interviewed subjects only, may point to protective agents other than vegetable fibre. Although intake of dietary fibre and beta-carotene were both inversely related to risk, simultaneous estimation suggested that beta-carotene or other as yet unknown correlated constituents, rather than dietary fibre, might explain the inverse relationships. A significant protective effect of vitamin C was demonstrated in women but not in men. Our study suggests that, independent of smoking and dietary intake of total energy, low consumption of specific vegetables and possibly fermented milk products and high consumption of eggs and fish may have influenced the development of exocrine pancreatic cancer.