Mo A, et al. - A population-based case–control study was performed to assess the association between the dietary fat intake and the incidence of early proximal neoplasia (aberrant crypt foci or polyps), detectable by high-definition colonoscopy with contrast dye-spray. For this analysis, average-risk screening patients underwent a high-definition colonoscopy procedure as part of a larger ongoing clinical study of precancerous lesions in the proximal colon. Using the Block Brief Food Frequency Questionnaire, dietary fat intake was assessed. In this study, dietary polyunsaturated fatty acids (PUFAs) could be positively correlated with risk of early neoplasia in the proximal colon. In addition, dietary PUFA composition could play a key role in altering the microenvironment within the human colon.