What exactly is oxidative stress

Antioxidants and oxidative stress

Antioxidants (Radical scavengers) are protective substances for body cells that can prevent potentially damaging oxidation of cell structures by neutralizing particularly aggressive chemical compounds. Such damaging compounds are primarily free radicals. Because of this protective effect, antioxidants may prevent cancer and inflammatory processes, such as those that occur in arteriosclerosis.

Free radicals arise in the body during natural metabolic processes or through external influences (cigarette smoke, UV radiation, strong physical stress, certain medications and some food components). Radicals are highly reactive oxygen compounds that try to split electrons from other substances ("oxidize" them). This can damage cell components or disrupt metabolic processes.

In principle, the body has its own defense mechanisms. If these are no longer sufficient, it arises oxidative stress (Imbalance of radicals and antioxidants). A well-balanced diet helps to reduce oxidative stress and the damaging effects it has on the body's cells.

The antioxidants include some vitamins, especially vitamins A, C, E and the provitamin beta-carotene. But many other food components can also have an antioxidant effect, e.g. B. trace elements such as selenium or the active ingredients lipoic acid, lycopene, lutein, flavonoids or the coenzyme Q10 (= ubiquinone), which plays an important role in the body for energy supply and cell protection. The red pigment resveratrol contained in red wine is also said to have antioxidant power, which may be responsible for the vascular protective effect of red wine, although this has not yet been scientifically clarified.

Because the antioxidants in the diet are only one As a factor in the oxidative balance of the body, it is difficult to define what exactly is meant by adequate intake. In addition, the antioxidant potential of food can neither be measured nor is there scientific evidence for the effectiveness of antioxidants supplied in isolation - unfortunately the concept of antioxidants, which is sensible in itself, is becoming a field of activity for health apostles and traders of all kinds who pretend that their products are aging and to be able to prevent diseases.


Dr. med. Herbert Renz-Polster in: Gesundheit heute, edited by Dr. med. Arne Schäffler. Trias, Stuttgart, 3rd edition (2014). | last changed on at 12:30