[Associations between dietary patterns and colorectal neoplasia in Chinese adults]

Objective: To identify dietary patterns among Chinese adults and examine their associations with colorectal neoplasia. Methods: Based on a national multicenter randomized controlled trial of colorectal cancer screening, 4 257 subjects who underwent colonoscopy and had complete dietary data were included. The intake frequencies of various types of food of the subjects were obtained through a food frequency questionnaire. The sociodemographic and lifestyle information of the subjects were obtained through a questionnaire survey. Factor analysis was used to extract dietary patterns, and multivariate logistic regression models were used to analyze the correlation between colorectal neoplasia and dietary patterns. Results: Three dietary patterns were extracted: the Healthy Balanced Pattern was characterized by the primary consumption of dairy products, fruits, whole grains, and eggs; the Vegetable-Refined Grain Pattern was characterized by the primary consumption of refined grains and vegetables; the High-Protein Meat Pattern was characterized by the primary consumption of red meat, white meat, and processed, salted, or smoked food. Multivariate logistic regression analysis showed that as the Healthy Balanced Pattern score increased from Q₁ to Q₄, the risk of non-advanced adenoma and advanced neoplasia both showed a decreasing trend (P for trend <0.001). For the Vegetable-Refined Grain Pattern, the risk of non-advanced adenoma in the Q₂-Q₃ groups was higher than that in the Q₁ group, but the linear trend test was not statistically significant; however, as the score levels of the Vegetable-Refined Grain Pattern increased from Q₁ to Q₄, the risk of advanced neoplasia significantly increased (P for trend < 0.001). As the score levels of the High-Protein Meat Pattern increased from Q₁ to Q₄, the risk of non-advanced adenoma and advanced neoplasia both showed an increasing trend (P for trend < 0.001). Subgroup analyses showed that sex and age showed significant interactions in the associations between the three dietary patterns and the risks of non-advanced adenoma and advanced neoplasia (P for interaction <0.05). Conclusions: Dietary patterns are associated with colorectal neoplasia. The Healthy Balanced Pattern is associated with reduced risk, whereas the Vegetable-Refined Grain Pattern and High-Protein Meat Pattern are associated with increased risk of colorectal neoplasia.