Antioxidants and Free Radicals
Free radicals are negatively charged molecules that are single (and to fight the effects of free radicals in the body, antioxidants are essential). A molecule becomes unstable and reactive if its electron doesn’t have a partner. In order to become stable molecules, free radicals (unstable molecules) steal electrons from other stable molecules. The molecule becomes non-reactive and stable, once their electrons get paired. The stable molecule which have lost their electron, become free radicals themselves and try to steal an electron from yet another molecule. This initiates a destructive cycle. Basically, “A molecule that is damaged by the loss of an electron will damage another molecule in turn”. Radicals are not very selective when they react, but they set off a chain reaction.
Unpaired electrons of 2 free radicals meet to form a stable pair. But in living organisms this doesn’t happen often, because most of their molecules have paired electrons. It specifies that free radicals produced will mostly react with non-radicals and create new free radicals.
Free Radicals are formed during Normal body functions or by the interaction of factors external to the body. As the body creates energy, unpaired electrons with oxygen molecules (free radicals) are created. Large amount of damage is caused to protein, lipids and DNA by the by-products of normal metabolism. Free radicals are also formed by environmental pollutants like car exhaust and tobacco smoke and even exposure to radiation from sun or medical X-rays.
It is important to know that free radicals are not bad altogether. In fact for living, we need free radicals. They help to fight off infection and destroy foreign bacteria and thereby benefit the body. Free radicals activate certain enzymes and are also important in producing vital hormones. They influence the tone of the tissue lining (of the vessels) and help with the constriction of the blood vessels. Only if the body has uncontrolled and excessive amounts of free radicals, it is dangerous. The number of free radicals in the body increases through certain medications, exercise, diet, illness, exposure to radiation and toxin, because it increases the oxygen-related reactions in the body.
Oxygen is necessary for all body functions and is the cause of most free radical activity and so firstly we need to understand oxygen’s contribution to free radical activity and its effects on the body.