Free radicals are atoms with an odd number of electrons and are formed when oxygen interacts with certain molecules.
The chief danger of free radicals comes from the damage they can do when they react with important cellular components such as DNA, or the cell membrane.
If this occurs, cells may function poorly or die.
To prevent free-radical damage, the body has a defense system of antioxidant molecules that can safely neutralize free radicals and prevent damage from being done to a living cell.
Some free radicals are produced normally by the body.
However, environmental factors such as pollution, radiation, cigarette smoke, and herbicides can also generate free radicals.
If the free-radical production becomes excessive, damage can occur.
It is important to note that free-radical damage accumulates with age.