Oxidative Stress, Antioxidants, Physical Activity, and the Prevention of Breast Cancer Initiation and Progression.

Abstract

Oxidative stress has a role in the initiation and progression of breast cancer (JezierskaDrutel, A., et al 2013). Oxidative stress results from an imbalance between antioxidants and unstable reactive oxygen and nitrogen species (superoxide anion, hydrogen peroxide, reactive nitrogen species) that lack one or more unpaired electrons (Jezierska-Drutel, A., et al 2013). Oxidative stress occurs when antioxidants are unable to scavenge excess oxygen free radicals (Zarrini, A.S., et al 2016). Redox imbalance contributes to cancer and other chronic diseases. The activity of reactive oxygen species on DNA, proteins, and lipids promotes changes in cell physiology that can interfere with its normal functioning (Panis, C., et al 2016). High levels of reactive oxygen species disrupt cellular processes by nonspecifically attacking DNA, proteins, and lipids (Schumacker PT., 2015). Lower levels of reactive oxygen species can act as cell signaling messengers by reversibly oxidizing protein thiol groups and modifying protein structure.