Antioxidants are substances that counteract the damage caused by free radicals. Free radicals can be formed by natural causes in the body, but also by harmful external influences such as cigarette smoke, environmental toxins or UV radiation from the sun.

Antioxidants are chemical compounds that slow down or completely prevent the oxidation of other substances. Due to their effect as radical scavengers, they are of great physiological importance.

Oxidation is a chemical reaction that produces free radicals that can damage cells and DNA. Excessive levels of ROS (reactive oxygen species) are associated with the ageing process and the development of a number of diseases, including cancer. Low levels of ROS, on the other hand, are necessary as signaling molecules that increase the ability to defend against stress and increase life expectancy. According to certain studies, dietary intake of antioxidants may lead to increased cancer incidence and mortality risk in humans.

Antioxidants are an important part of our daily lives. They are used in a variety of products, from food to cosmetics, and they can help prevent the oxidation of sensitive molecules. Oxidation reduces the value of some ingredients or components by altering their taste or odor, reducing their effectiveness or forming harmful degradation products. Antioxidants can also improve the physical properties of products such as plastics.

Chemical antioxidants are divided into radical scavengers and reducing agents. In a broader sense, antioxidant synergists are also counted as antioxidants.

Chain-like radical transfers are frequently encountered in oxidation reactions between organic compounds. A common example is when a substance with a sterically hindered phenol group becomes an effective radical scavenger and forms an inert stable radical in the course of these transfers. This stable radical does not react any further, thus ending the reaction cascade (radical scavenger).

These substances include natural substances such as tocopherols as well as synthetic substances such as butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT) and gallates. They are effective in lipophilic environments.

Antioxidants are a group of substances that protect the body from damage caused by free radicals. They are found in nature, are produced naturally in the body and help to neutralize and destroy these harmful free radicals before they can damage the cells.

In the mammalian organism, glutathione is an important antioxidant, as are uric acid and melatonin. Several proteins such as transferrin, albumin, coeruloplasmin, haemopexin and haptoglobin also have an antioxidant effect.

Antioxidant enzymes such as superoxide dismutase (SOD), glutathione peroxidase (GPX) and catalase play an important role in the detoxification of free radicals in the body's cells.

Trace elements such as selenium, copper, manganese and zinc are essential for their enzymatic activity. Ubiquinone-10 should be mentioned as an antioxidant coenzyme. Substances with an antioxidant effect that are vital for humans include ascorbic acid (vitamin C), tocopherol (vitamin E) and beta-carotene (provitamin A). A number of antioxidants are passed on to the infant via the mother's milk so that they can develop their effect there.

Antioxidants are a type of secondary plant substance found in many types of fruit and vegetables and in foods made from them. Examples of antioxidants are carotenoids and polyphenolic compounds (flavonoids, anthocyanins, phytoestrogens and nordihydroguaiacetic acid). The German Nutrition Society (DGE) does not consider the scientific data to be sufficient to make recommendations for the intake of individual antioxidants.