Intake of whole grains from different cereal and food sources and incidence of colorectal cancer in the Scandinavian HELGA cohort

A high intake of whole grains has been associated with a lower incidence of colorectal cancer, but few studies are available on the association with whole grains from different cereals, for example, wheat, rye and oats, and none has addressed these separately. The objective of this study was to investigate the association between whole-grain intake and colorectal cancer. We used data from the large population-based Scandinavian cohort HELGA consisting of 108,000 Danish, Swedish, and Norwegian persons, of whom 1,123 developed colorectal cancer during a median of 11 years of follow-up. Detailed information on daily intake of whole-grain products, including whole-grain bread, crispbread, and breakfast cereals, was available, and intakes of total whole grains and specific whole-grain species (wheat, rye, and oats) were estimated. Associations between these whole-grain variables and the incidence of colorectal cancer were investigated using Cox proportional hazards models. Intake of whole-grain products was associated with a lower incidence of colorectal cancer per 50-g increment (incidence rate ratio [IRR], 0.94; 95 % confidence interval [CI], 0.89, 0.99), and the same tendency was found for total whole-grain intake (IRR pr. 25-g increment, 0.94; 95 % CI, 0.88, 1.01). Intake of whole-grain wheat was associated with a lower incidence of colorectal cancer (IRR for highest versus lowest quartile of intake, 0.66; 95 % CI, 0.51, 0.85), but no statistical significant linear trend was observed (p for trend: 0.18). No significant association was found for whole-grain rye or oats. Whole-grain intake was associated with a lower incidence of colorectal cancer.