RESUMO
The frequency of Crohn disease shows a significant increase in the last century. Affected patients show a misbalance between production of free radicals and anti oxidant defenses. Thus, one of the increasingly accepted htypotheses to explain the origin of this disease, is the oxidative stress that occurs in the intestinal mucosa. Dietary factors including self administered vitamin and mineral supplemets may play a role, especially when they contain excessive amounts of iron and copper, known for their prooxidant capacities. Unfortunately, little is known about how these metals may influence the antioxidant defenses in the intestinal mucosa. This article reviews the literature on the why and how these elements may act on individuals susceptible to develop Crohm disease, including the evidence supporting the hypothesis that oxidative stress in the intestinal mucosa is an important pathogenetic factor.