To our knowledge, no studies of associations between intake of whole grain (WHG) and survival of colorectal cancer have been published, despite evidence that dietary fiber, and to some extent WHG, are associated with lower risk of colorectal cancer. Scandinavia is an area where the WHG consumption traditionally is high. We performed a case-only (N = 1119) study in the Scandinavian HELGA cohort of pre-diagnosis WHG intake (total WHG, WHG wheat, WHG rye, and WHG oats) and survival of colorectal cancer. Cox regression analyses were used to study the associations, both in categorical and continuous models, stratified by location (proximal, distal, rectum) and country. No evidence of an association was found, neither for total WHG intake (hazard ratio = 1.32, 95% confidence interval: 0.88-1.97 lowest vs. highest tertile, adjusted for age at diagnosis, metastasis status, smoking, folate, margarine, and energy), nor for specific grains. Prediagnosis consumption of WHG does not seem to improve survival of colorectal cancer in subjects diagnosed within this prospective population-based Scandinavian cohort.
Few prospective studies have investigated the association between whole-grain consumption and incidence of oesophageal cancer. In the Scandinavian countries, consumption of whole grains is high and the incidence of oesophageal cancer comparably low. The aim of this paper was to study the associations between consumption of whole grains, whole-grain products and oesophageal cancer, including its two major histological subtypes. The HELGA cohort is a prospective cohort study consisting of three sub-cohorts in Norway, Sweden and Denmark. Information regarding whole-grain consumption was collected through country-specific food frequency questionnaires. Cancer cases were identified through national cancer registries. Cox proportional hazards ratios were calculated in order to assess the associations between whole grains and oesophageal cancer risk. The analytical cohort had 113,993 members, including 112 cases, and median follow-up time was 11 years. When comparing the highest tertile of intake with the lowest, the oesophageal cancer risk was approximately 45 % lower (adjusted HR 0.55, 95 % CI 0.31-0.97 for whole grains, HR 0.51, 95 % CI 0.30-0.88 for whole-grain products). Inverse associations were also found in continuous analyses. Whole-grain wheat was the only grain associated with lower risk (HR 0.32, 95 % CI 0.16-0.63 highest vs. lowest tertile). Among whole-grain products, the results were less clear, but protective associations were seen for the sum of whole-grain products, and whole-grain bread. Lower risk was seen in both histological subtypes, but particularly for squamous cell carcinomas. In this study, whole-grain consumption, particularly whole-grain wheat, was inversely associated with risk of oesophageal cancer.