Dietary antioxidants, fruits, and vegetables and the risk of Barrett's esophagus

OBJECTIVE: The present study evaluated the associations among antioxidants, fruit and vegetable intake, and the risk of Barrett's esophagus (BE), a potential precursor to esophageal adenocarcinoma. METHODS: We conducted a case-control study within the Kaiser Permanente Northern California population. Incident BE cases (N = 296) were matched to persons with gastroesophageal reflux disease (GERD) (GERD controls N = 308) and to population controls (N = 309). Nutrient intake was measured using a validated 110-item food frequency questionnaire. The antioxidant results were stratified by dietary versus total intake of antioxidants. RESULTS: Comparing cases to population controls, dietary intake of vitamin C and beta-carotene were inversely associated with the risk of BE (4th vs 1st quartile, adjusted odds ratio [OR] 0.48, 95% confidence interval [CI] 0.26-0.90; OR 0.56, 95% CI 0.32-0.99, respectively), and the inverse association was strongest for vitamin E (OR 0.25, 95% CI 0.11-0.59). The inverse trends for antioxidant index (total and dietary) and fruit and vegetable intake were statistically significant, while most total intakes were not associated with reduced risk. The use of antioxidant supplements did not influence the risk of BE, and antioxidants and fruits and vegetables were inversely associated with a GERD diagnosis. CONCLUSION: Dietary antioxidants, fruits, and vegetables are inversely associated with the risk of BE, while no association was observed for supplement intake. Our results suggest that fruits and vegetables themselves or associated undetected confounders may influence early events in the carcinogenesis of esophageal adenocarcinoma.