Background: Examining the effects of dietary patterns on cancer risk may provide insights beyond the assessment of individual foods or nutrients.
Design: In the health professionals follow-up cohort, associations between the 'prudent' and the 'western' dietary pattern and risk of colon cancer and adenomas were examined in 561 colon cancer cases and 1207 distal colon adenoma cases.
Results: Higher prudent pattern scores were only weakly and non-significantly associated with decreased risk of colon cancer or distal colon adenoma (highest versus lowest quintile: colon cancer: multivariate adjusted relative risk (RR) = 0.84 (95% confidence interval (CI) = 0.64-1.10); p(trend) = 0.37; distal adenoma: multivariate odds ratio (OR) = 0.88 (95% CI = 0.73-1.08); p(trend) = 0.12). Our findings suggest a moderately increased risk of colon cancer and distal adenoma with higher western pattern scores (colon cancer: RR = 1.27 (95% CI = 0.96-1.69), p(trend) = 0.05; distal adenoma: OR = 1.28 (95% CI = 1.05-1.56), p(trend) = 0.01). Adding body mass index, which is positively related to western pattern and thus may be considered an intermediate endpoint between western pattern and colon cancer, attenuated associations somewhat but not substantially.
Conclusion: Our data do not provide evidence for an appreciable inverse association between higher prudent pattern scores and risk of colon cancer or distal colon adenomas, but do support a moderate positive association between higher western pattern scores and risk of colon cancer or distal colon adenomas.