Antioxidant and pro-oxidant dietary consumption patterns and its association with prostate cancer: a case-control study from Mexico City.

To assess the association between dietary consumption patterns of antioxidant and pro-oxidant nutrients with prostate cancer (PC) and its histological differentiation, we analyzed data from 394 histologically confirmed incident cases of PC and 793 age-matched population controls (± 5 years), residents of Mexico City. Cases were classified by Gleason score into well-, moderately-, and poorly differentiated categories. Dietary nutrient intake over the three years preceding diagnosis for cases and before the interview for controls was estimated using a semi-quantitative food frequency questionnaire. Using energy-adjusted residuals and a k-means approach, we identified three consumption patterns: 1) pro-oxidant (PRO), 2) moderate antioxidants/low pro-oxidants (MaLp), and 3) high antioxidants and pro-oxidants (HaHp). Associations were evaluated using independent unconditional logistic regression models; stratified models were analysed based on smoking status. Although proportions differed, the main food contributors to the MaLp and HaHp patterns included green vegetables, corn tortillas, seeds, and fruits. Compared to the PRO pattern, the MaLp (OR: 0.71; 95% CI 0.53-0.97) and HaHp (OR: 0.70; 95% CI 0.50-0.99) patterns were associated with lower odds of having PC. These associations were mainly observed with well-differentiated PC and among ever-smokers. Diets with a higher antioxidant content were associated with a reduced likelihood of PC. Further validation of these findings through prospective studies is needed.