Nutrient antioxidants in gastrointestinal diseases.

Oxidative stress appears to play a role in the pathogenesis of a number of gastrointestinal disease states, including pancreatitis; gastric and duodenal ulcer disease; IBD; gastric, esophageal, and colon cancers; and hepatic injury secondary to alcohol, metal storage disorders, hepatitis, and ischemia/reperfusion injury. The nutritional antioxidants are attractive potential therapeutic and chemopreventive agents because they are inexpensive and have a relatively low toxicity profile. A word of caution should be noted: Some antioxidants, such as vitamin C, can be prooxidant under certain conditions, and systemically altering the redox state may have untoward effects on the inflammatory response in certain disease states. Thus, at the current time, antioxidant therapy should be restricted to randomized, controlled clinical trials, in which treatment effects can be closely monitored, and therapeutic efficacy can be determined with scientific accuracy.