High-iron diet: foe or feat in ulcerative colitis and ulcerative colitis-associated carcinogenesis

Anemia associated with long-standing chronic inflammation and iron deficiency, and the increased risk for the development of dysplasia and carcinoma, are two of the most common complications in patients with ulcerative colitis (UC). Because of iron and nutrition deficiency, UC patients are encouraged to consume a high-protein and high-iron diet. The crucial clinical question is the effect of a high-iron diet on inflammation activity and inflammation-driven carcinogenesis. Is a high-iron diet a foe or a feat in UC and UC-associated carcinogenesis? This review updates the progress and information on (1) iron nutrition and iron-deficiency anemia in patients with UC, (2) experimental evidence of the exacerbating effect of a high-iron diet on UC and its associated carcinogenesis and the difference between a high-iron diet and parental iron supplementation, (3) the clinical efficacy of, and concerns about, oral and intravenous iron supplements in patients with inflammatory bowel disease and iron deficiency anemia, and (4) the clinical implications of long-term iron supplements and management of UC. These experimental findings from animal models provide evidence to warrant further consideration and clinical studies of iron nutrition, inflammation activity, and cancer development.