Iron intake and markers of iron status and risk of Barrett's esophagus and esophageal adenocarcinoma

OBJECTIVE: To investigate the association between iron intake and iron status with Barrett’s esophagus (BE) and esophageal adenocarcinoma (EAC). METHODS: 220 BE patients, 224 EAC patients, and 256 frequency-matched controls completed a lifestyle and food frequency questionnaire, and provided serum and toenail samples between 2002 and 2005. Using multiple logistic regression, odds ratios (OR) and 95% confidence intervals (95%CI) were calculated within quartiles of intake/status. RESULTS: Comparing the fourth to the first quartile, ferritin (OR 0.47; 95%CI: 0.23, 0.97) and transferrin saturation (OR 0.41; 95%CI: 0.20, 0.82) were negatively associated with BE; whilst total iron binding capacity was positively associated per 50 µg/dl increment (OR 1.47; 95%CI: 1.12, 1.92). Comparing the fourth to the first quartile, iron intake (OR 0.50; 95%CI: 0.25, 0.98), non-heme iron intake per 10 mg/day increment (OR 0.29; 95%CI: 0.08, 0.99), and toenail iron (OR 0.40; 95%CI: 0.17, 0.93) were negatively associated with EAC; whilst heme iron intake was positively associated (OR 3.11 95%CI: 1.46, 6.61). PRINCIPAL CONCLUSION: In contrast to the hypothesis that increased iron intakes and higher iron stores are a risk factor for BE and EAC, this study suggests that higher iron intakes and stores may have a protective association with BE and EAC, with the exception of what was found for heme iron intake