Antioxidants are molecules that fight free radicals in your body.

Free radicals are compounds that can cause harm if their levels become too high in your body. They’re linked to multiple illnesses, including diabetes, heart disease, and cancer.

Your body has its own antioxidant defences to keep free radicals in check.

However, antioxidants are also found in food, especially in fruits, vegetables, and other plant-based, whole foods. Several vitamins, such as vitamins E and C, are effective antioxidants.

Antioxidant preservatives also play a crucial role in food production by increasing shelf life.

Antioxidants are chemicals that help stop or limit the damage caused by free radicals. Your body uses antioxidants to balance free radicals. This keeps them from causing damage to other cells. Antioxidants can protect and reverse some of the damage. They also boost your immunity.

There are thought to be hundreds and possibly thousands of substances that can act as antioxidants. Each has its own role and can interact with others to help the body work effectively.

“Antioxidant” is not really the name of a substance, but rather it describes what a range of substances can do.

Antioxidants are compounds that inhibit oxidation. Oxidation is a chemical reaction that can produce free radicals, thereby leading to chain reactions that may damage the cells of organisms. Antioxidants such as thiols or ascorbic acid (vitamin C) terminate these chain reactions. To balance the oxidative stress, plants and animals maintain complex systems of overlapping antioxidants, such as glutathione and enzymes (e.g., catalase and superoxide dismutase), produced internally, or the dietary antioxidants vitamin C and vitamin E.

Antioxidants are classified into two broad divisions, depending on whether they are soluble in water (hydrophilic) or in lipids (lipophilic). In general, water-soluble antioxidants react with oxidants in the cell cytosol and the blood plasma, while lipid-soluble antioxidants protect cell membranes from lipid peroxidation. These compounds may be synthesized in the body or obtained from the diet. The different antioxidants are present at a wide range of concentrations in body fluids and tissues, with some such as glutathione or ubiquinone mostly present within cells, while others such as uric acid are more evenly distributed (see table below). Some antioxidants are only found in a few organisms and these compounds can be important in pathogens and can be virulence factors.

Due to its high concentration and its central role in maintaining the cell’s redox state, glutathione is one of the most important cellular antioxidants.