Why free radicals are harmful to our body? How our body can be prevented from damage caused by free radicals? To understand these questions we need to know at least some basic information about the structure and function of our body as well as some knowledge about chemical reactions. The body formation steps from the top can be presented this
way : body-cells-molecules-atoms. Atoms form molecules by sharing electrons and gain the maximum stability for the molecule. Molecules also can form another bigger molecule with chemical bonds.



Body's immune system,  radiation, UV light, high temperature, toxins, viruses, some chemical substances etc can split weak bonds and form an unstable molecules with
unpaired electrons - the free radicals. They may react quickly with any other compound
to gain stability by stealing electron and forming stable bond. Free radicals usually  attack the closest molecule which may become a new free radical if loses electron or may become unusably as a functional unit.