“The health of our body is maintained by the equilibrium of redox control. Redox control means maintaining the balance between active oxygen species and antioxidant enzymes. Excessive external factors can disturb this equilibrium triggering disease and illnesses. Most of the diseases are caused by oxidative stress due to active oxygen, other free radicals and lipid peroxides. Active oxygen, though vital to our body, causes considerable damage to the essential components of human body and disturbs the physiologically important functions of proteins, lipids, enzymes and DNA bearing the genetic code. DNA damage caused by oxidative stress is particularly dangerous and has the potential to lead to serious disorders like cancer,” writes Dr. RD Khanna, Professor Emeritus and Former Head Department of Biophysics, Institute of Medical Sciences at Banaras Hindu University, India.
“Normally about 2% of oxygen inhaled by our respiratory system turns into active oxygen in our body and is used to protect us against external attack from bacteria, germs, viruses and other foreign substances. However, when levels of active oxygen species are increased by tobacco, alcohol, ultra-violet rays, air-pollution, food additives, emotional stress, etc., excessive active oxygen starts attacking not only dangerous substances but also normal functioning cells, damaging proteins, lipids, enzymes and DNA. This state is called oxidative stress. As long as a balance exists between oxidative stress and our antioxidant system, our body is maintained in a healthy state.”
 Inflammation, Free Radical Damage, Oxidative Stress and Cancer. International Journal of Inflammation, Cancer and Integrative Therapy. Department of Biophysics, Institute of Medical Sciences, Varanasi, India. Department of Chemistry, Faculty of Science, Banaras Hindu University, Varanasi, India https://www.omicsonline.org/open-access/inflammation-free-radical-damage-oxidative-stress-and-cancer-ijm.1000109.php?aid=32604