Newsletter

[ Vol. 13 No. 2 ] (May - August 2012 )
The effect of antioxidants on cancer chemotherapy

Vanessa Fuchs-Tarlovsky
Department of Oncology, Hospital General de México (Mexico)

Oxidative stress is a key component in linking environmental toxicity to the multistage carcinogenic process. Reactive oxygen species (ROS) are generated in response to both endogenous and exogenous stimuli. In order to counterbalance ROS-mediated injury, an endogenous antioxidants defense system exists; however, when oxidation exceeds the control mechanisms, oxidative stress arises. Chronic and accumulative oxidative stress induces deleterious modifications to a variety of macromolecular components, such as DNA, lipids and proteins.

A primary mechanism of many chemotherapy drugs against cancer cells is the formation of reactive oxygen species (ROS), or free radicals. Radiotherapy is based on the fact that ionizing radiation destroys tumor cells. Radiotherapy induces direct lesions in the DNA or biological molecules, which eventually affect DNA. Free radicals produced by oncology therapy are often a source of serious side effects, as well. This review explores the effects of antioxidants such as vitamin C, E and A as well as other molecules over the oncology treatments adverse events and efficacy.

Much debate has arisen about whether antioxidant supplementation alters the efficacy of cancer chemotherapy. There is still limited evidence both in quality and sample size suggesting that certain antioxidant supplements may reduce adverse reactions and toxicities. Significant reductions in toxicity may alleviate dose-limiting toxicities so that more patients are able to successfully complete prescribed chemotherapy regimens and the subsequent potential for increased tumor response and survival.

From  
The 14^th Congress of Parenteral and Enteral Nutrition Society of Asia
“From Nutrition Support to Nutrition Therapy”
October 14-16, 2011, Taipei, Taiwan 
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