Associations between dietary patterns and incident colorectal cancer in 114,443 individuals from the UK Biobank: a prospective cohort study.

BACKGROUND: Diet-disease association studies increasingly use dietary patterns (DPs) to account for the complexity of the exposure. We assessed if a DP associated with type 2 diabetes mellitus, CVD, and all-cause mortality is also associated with colorectal cancer (CRC). METHODS: We used reduced rank regression on 24-h recall data to identify DPs explaining the maximum variation in four nutrient-response variables: energy density, saturated fatty acids, free sugars and fibre density. Cox-proportional hazards models examined prospective associations between DP adherence (coded in a continuous scale as z-scores as well as in quintiles) and incident CRC. Subgroup analyses were conducted for tumour site, age, and sex. RESULTS: Post-exclusions, 1,089 CRC cases occurred in 114,443 participants over a median follow-up of 8.0 years. DP1 was characterised by increased intake of chocolate and confectionery, butter, low-fibre bread, red and processed meats and alcohol, as well as low fruit, vegetable, and high-fibre cereal intake. After accounting for confounders, including body mass, there were positive linear associations between DP1 and incident overall CRC (HR of quintile 5 vs. 1: 1.34, 95%CI 1.16-1.53, PTrend=0.005) and rectal cancer (HR of quintile 5 vs. 1: 1.58, 95%CI 1.27-1.96, PTrend=0.009), but not for proximal or distal colon cancers. No DP2-CRC association was observed. CONCLUSION: A DP previously associated with cardio-metabolic disease is also associated with incident CRC, especially rectal cancers. IMPACT: These consistent associations of particular food groups with both cardiometabolic disease and this diet-related cancer strengthen the evidence base for holistic population dietary guidelines to prevent ill-health.