Corley AD et al. (2008) Iron intake and body iron stores as risk factors for Barrett's esophagus: a community-based study. Am J Gastroenterol [doi:10.1111/j.1572-0241.2008.02156.x]

Barrett's esophagus is associated with a 30–40-fold increase in risk for esophageal adenocarcinoma. Animal studies suggest that high iron intake and elevated body iron stores enhance risk of both Barrett's esophagus and esophageal adenocarcinoma.

Corley et al. conducted a case–control study among 3.3 million members of Kaiser Permanente in Northern California. Data were collected on 319 individuals with Barrett's esophagus, 312 patients with GERD, which is a risk factor for Barrett's esophagus, and 313 population controls. Risk of Barrett's esophagus was significantly lower in individuals whose dietary iron intake was in the highest quartile than in those whose intake was in the lowest quartile (a 63% decrease in risk versus that of controls, and a 58% decrease versus patients with GERD). Risk was not significantly associated with total iron intake (dietary and supplements). Risk of Barrett's esophagus was also significantly reduced in individuals in the fourth quartile versus the first of body iron stores, as measured by their serum ferritin levels (a 76% decrease in risk versus controls, and of 40% versus patients with GERD) and by transferrin saturation (a 34% decrease in risk versus controls only).

Antioxidants may limit iron-related oxidative damage, but the authors found no evidence of a confounding effect of antioxidant intake on their findings. Consequently, high iron levels do not seem to be a risk factor for Barrett's esophagus; in fact, they might have a protective effect.