<p>Sequential stratification/adjustments to the model comparing the risk of incident colorectal cancer associated with DP1 and DP2. Top, sequential changes to the HRs for quintiles 5 versus 1 for DP1 and DP2. Bottom, sequential changes to the HRs for DP1 and DP2 <i>z</i>-scores in continuous form. The <i>X</i>-axis represents HRs on the log-scale. CIs were obtained using the floating absolute risk method (<a href="#bib34" target="_blank">34</a>). χ<sup>2</sup> and <i>P</i> values were calculated by likelihood ratio tests to assess the heterogeneity in the associations with sequential adjustments for covariates. Behavioral factors included smoking status, physical activity level (MET-hours/week), and total energy intake (ln-kJ). SES* comprises TDI and educational attainment. Models were stratified by covariates violating the proportional hazards assumption: physical activity, family history of colorectal cancer, education, and BMI. SES, socioeconomic status.</p>
ARTICLE ABSTRACT
Diet–disease association studies increasingly use dietary patterns (DP) to account for the complexity of the exposure. We assessed if a DP associated with type 2 diabetes mellitus, cardiovascular disease, and all-cause mortality is also associated with colorectal cancer.
We used reduced rank regression on 24-hour recall data to identify DPs, explaining the maximum variation in four nutrient-response variables: energy density, saturated fatty acids, free sugars, and fiber 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 colorectal cancer. Subgroup analyses were conducted for tumor site, age, and sex.
After exclusions, 1,089 colorectal cancer cases occurred in 114,443 participants over a median follow-up of 8.0 years. DP1 was characterized by increased intake of chocolate and confectionery; butter; low-fiber bread; red and processed meats; and alcohol, as well as low intake of fruits, vegetables, and high-fiber cereals. After accounting for confounders, including body mass, there were positive linear associations between DP1 and incident overall colorectal cancer (HR of quintile 5 vs. 1, 1.34; 95% confidence interval, 1.16–1.53, Ptrend = 0.005) and rectal cancer (HR of quintile 5 vs. 1, 1.58; 95% confidence interval, 1.27–1.96, Ptrend = 0.009) but not for proximal or distal colon cancers. No DP2–colorectal cancer association was observed.
A DP previously associated with cardiometabolic disease is also associated with incident colorectal cancer, especially rectal cancers.
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.
