What is Oxidative Stress?

Oxidative stress is defined as a persistent imbalance between antioxidants and pro-oxidants in favor of the latter, resulting in (often) irreversible cellular damages.

The mitochondrial respiratory chain plays a key role in the generation of pro-oxidants, especially the so-called reactive oxygen species (ROS) which notably include free radicals like the superoxide anion and the hydroxyl radical OH·. When the ROS are produced in excessive amount, they have harmful effects because they induce apoptosis in otherwise healthy cells or activate various genes coding for pro-inflammatory cytokines or adhesion proteins. In addition, their unstable nature makes them particularly reactive and capable of inflicting major cell damage by causing breaks and mutation in DNA, by inactivating proteins and enzymes, by oxidizing sugars, and by inducing lipid peroxidation among the polyunsaturated fatty acids of lipoproteins or of the cell membrane.

In normal physiological situations, the ROS are constantly produced in our organism, where they even play several physiological role, and their production is regulated by an efficient antioxidant defense (vitamins, oligoelements, proteins and enzymes) to prevent excessive cell damage.

Modern life however confronts us with pollution, prolonged exposure to sunlight, consumption of alcohol and medications, unbalanced physical activities, smoking, and oxidant deficient diets, all situations that leads to a weakening of our antioxidant defenses and also cause cell damage. Our antioxidant defense system also weaken with aging.

Several large epidemiological studies have shown that low circulating levels of antioxidants and oligoelements are closely linked to a higher incidence of cardiovascular diseases, cancers et more generally all diseases linked to aging. Moreover experimental and epidemiological studies also showed that complementary supplementation of antioxidant vitamins or selenium in patients with antioxidant deficiencies can decrease the incidence of cardiovascular diseases, several types of cancer and arteriosclerosis.

A regular diagnostic of the balance between oxidants and antioxidants is a key tool to achieve an optimal expression of our physical and mental potentials during the whole life.