Endogeny

Chemistry

Nucleic acid

Antioxidant

Free-radical theory of aging

Macromolecule

Biochemistry

Reactive oxygen species

Biology

Cell biology

Radical

Mitochondrion

Oxygen

Free radicals have acquired growing importance in the fields of biology and medicine. They are produced during many different endogenous and exogenous processes. Mitochondria are the main source of endogenous reactive oxygen species (ROS) produced at cell level. The overproduction of free radicals can damage macromolecules such as nucleic acids, proteins and lipids. This leads to tissue damage in various chronic and degenerative diseases. Antioxidants play a crucial role in the body’s defense against free radicals. This review concerns the main properties of free radicals, their sources and deleterious effects. It highlights the potential role of the dietary supplementation of antioxidants and discusses unsolved problems regarding antioxidant supplements in the prevention and therapy of diseases.

Free Radical Properties, Source and Targets, Antioxidant Consumption and Health