title: Should supplemental antioxidant administration be avoided during chemotherapy and radiation therapy?
abstract: Despite nearly two decades of research investigating the use of dietary antioxidant supplementation during conventional chemotherapy and radiation therapy, controversy remains about the efficacy and safety of this complementary treatment. Several randomized clinical trials have demonstrated that the concurrent administration of antioxidants with chemotherapy or radiation therapy reduces treatment-related side effects. Some data indicate that antioxidants may protect tumor cells as well as healthy cells from oxidative damage generated by radiation therapy and some chemotherapeutic agents. However, other data suggest that antioxidants can protect normal tissues from chemotherapy- or radiation-induced damage without decreasing tumor control. We review some of the data regarding the putative benefits and potential risks of antioxidant supplementation concurrent with cytotoxic therapy. On the basis of our review of the published randomized clinical trials, we conclude that the use of supplemental antioxidants during chemotherapy and radiation therapy should be discouraged because of the possibility of tumor protection and reduced survival.
authors.affiliation: Radiation Oncology Division, Breast Health Center, Naval Medical Center San Diego, San Diego, CA, USA. brian.lawenda@med.navy.mil
authors.forename: Brian D
authors.initials: BD
authors.lastname: Lawenda
authors.forename: Kara M
authors.initials: KM
authors.lastname: Kelly
authors.forename: Elena J
authors.initials: EJ
authors.lastname: Ladas
authors.forename: Stephen M
authors.initials: SM
authors.lastname: Sagar
authors.forename: Andrew
authors.initials: A
authors.lastname: Vickers
authors.forename: Jeffrey B
authors.initials: JB
authors.lastname: Blumberg
mesh_terms: D000971:Antineoplastic Combined Chemotherapy Protocols / Q000008:administration & dosage*; D000975:Antioxidants / Q000008:administration & dosage / Q000009:adverse effects / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D019587:Dietary Supplements / Q000009:adverse effects*; D004334:Drug Administration Schedule; D019317:Evidence-Based Medicine; D006801:Humans; D009154:Mutation / Q000187:drug effects; D009369:Neoplasms / Q000188:drug therapy* / Q000235:genetics / Q000378:metabolism / Q000473:pathology / Q000532:radiotherapy*; D018384:Oxidative Stress / Q000187:drug effects* / Q000528:radiation effects*; D016032:Randomized Controlled Trials as Topic; D015996:Survival Rate; D016896:Treatment Outcome
chemical_list: D000975:Antioxidants