Cruciferous vegetables and colorectal cancer risk: a hospital-based matched case-control study in Northeast China.

BACKGROUND/OBJECTIVES: Conflicting results have been reported on the association of cruciferous vegetable intake and colorectal cancer risk. This study aimed to clarify the relationship of cruciferous vegetables and colorectal cancer among individuals in Northeast China, where large amounts of cruciferous vegetables are consumed habitually.

SUBJECTS/METHODS: We conducted a hospital-based case-control study in the First Hospital of China Medical University, the Shengjing Hospital of China Medical University and the First Hospital of Dalian Medical University from 2009 to 2011. Patients in the study were matched individually by age, gender, and city of residence. The study ultimately included 833 case-control pairs. A structured questionnaire was applied to collect data on general characteristics, dietary habits, and selected dietary intake. Differences between cases and controls were ascertained with the chi-square test or the Mann-Whitney U test. Unconditional logistic regression was employed to compute odds ratios (ORs) and 95% confidence intervals (CIs). Stratified analyses were conducted by gender.

RESULTS: In the total study cohort, no significant association was found between total cruciferous vegetable intake and colorectal cancer risk. The adjusted OR for the highest versus the lowest intake was 0.83 (95% CI: 0.59-1.18). In stratification analyses by gender, reduced colorectal cancer risk was related to higher consumption of total cruciferous vegetables in women but not in men. Significant inverse correlations were found in analyses of individual cruciferous vegetables, including greens (OR = 0.47; 95% CI: 0.32-0.68), cabbage (OR = 0.61; 95% CI: 0.44-0.86), and cauliflower (OR = 0.66; 95% CI: 0.48-0.92).

CONCLUSIONS: No significant association was found between total cruciferous vegetable intake and colorectal cancer risk. However, specific types of cruciferous vegetables might have protective roles against colorectal cancer.