title: Selenium and other antioxidants for chemoprevention of gastrointestinal cancers.
abstract: Antioxidants such as selenium, vitamin E and C and carotenoids have been hypothesized as chemopreventive agents for several cancers. In the current review, we evaluate the results of epidemiological and interventional studies and summarize current knowledge of the prevention potential of the antioxidants, specific to gastrointestinal cancers. While early studies based on animal models and cell lines showed promise for antioxidants as chemopreventive agents for several gastrointestinal cancers, results from epidemiological studies and randomized trials do not support this promise. One large randomized trial, conducted in a region with widespread nutritional deficiency, showed that antioxidant use may confer protection against gastrointestinal cancers. However, this result has not been replicated in other epidemiological studies or the 10 other randomized trials conducted in developed Western countries. Overall, currently there is no evidence that antioxidants are protective against gastrointestinal cancers in populations whose members are replete in antioxidant intake.
authors: Department of Social and Preventive Medicine, State University of New York at Buffalo, Roswell Park Cancer Institute, 901 Washington Street, Buffalo, NY 14263, USA. vijay.jayaprakash@roswellpark.org
authors: Vijayvel
authors: V
authors: Jayaprakash
authors: James R
authors: JR
authors: Marshall
mesh_terms: D000818:Animals; D016588:Anticarcinogenic Agents / Q000627:therapeutic use*; D000975:Antioxidants / Q000627:therapeutic use*; D018890:Chemoprevention; D004032:Diet; D019587:Dietary Supplements; D005638:Fruit; D005770:Gastrointestinal Neoplasms / Q000453:epidemiology / Q000378:metabolism / Q000517:prevention & control*; D006801:Humans; D009752:Nutritional Status; D018384:Oxidative Stress / Q000187:drug effects*; D012643:Selenium / Q000627:therapeutic use*; D016896:Treatment Outcome; D014675:Vegetables
chemical_list: D016588:Anticarcinogenic Agents; D000975:Antioxidants; D012643:Selenium