Oxidative stress is a pathological condition caused by disturbing the physiological balance, in a living organism, between production and elimination of oxidizing chemical species by antioxidant defence systems. We often speak of an oxidative balance that expresses the relationship which exists between the action damaging oxidation and the antioxidant defences. When this ratio is modified due to an abnormal production of oxidizing factors or a reduction of oxidizing defences is present, oxidative stress is then established.
Excessive oxidizing factors implicated in oxidative stress are now considered to be associated with over a hundred human pathologies (such as retrolental fibroplasia, atherosclerosis, arterial hypertension, Parkinson’s disease, Alzheimer’s disease, diabetes mellitus, colitis, rheumatoid arthritis and favism, etc). There is also evidence of their correlation with the ageing process.