Association between dietary pattern scores and the prevalence of colorectal adenoma considering population subgroups

The purpose of the current study is to examine the dietary patterns in a diverse cohort of individuals and to see if the identified dietary patterns predict the prevalence of adenoma in a cross-sectional study.

Factor analysis was used to derive both sex- and population subgroup-specific dietary patterns among participants in the screening arm of the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial. Logistic regression was used to assess associations between identified factor scores and colorectal adenoma (CRA) in sex-specific subgroups.

Three diet patterns were observed in this cohort: 'Fruits and vegetables', 'Western' and 'Sweet and salty'. Foods that loaded on each factor were similar between the racial subgroups. In men, being in the highest quintile of 'Western' dietary scores was associated with higher odds of any (adjusted odds ratio (aOR) = 1.21; 95% confidence interval (CI) = 1.03-1.42), advanced (aOR = 1.32; 95% CI = 1.07-1.63) or multiple (>1; aOR = 1.51; 95% CI = 1.17-1.94) adenoma, compared to those in the lowest quintile. These results were most notably seen in Caucasian men. In women, having a 'Fruits and vegetable' score in the highest quintile was associated with lower odds of multiple adenoma (>1; aOR = 0.53; 95% CI = 0.28-1.00).

Of the three dietary factors, the 'Western' diet pattern was most strongly associated with prevalent CRA in Caucasian men. Further research is needed to examine the association between dietary factor scores and adenomas in the proximal colon, where there are larger racial disparities in prevalence.