Oxidation and Free Radical Damage
Although oxygen is absolutely essential to metabolism, it can play a role in damaging cells. Most of the damaging effects of oxygen result from oxygen – containing free radicals.
Free radicals contain atoms with one or more unpaired electrons. A free radical is unstable and tends toward stabilization by pairing the electron; this can destabilize a neighboring molecule through the removal of one of its electrons. This sets up chain reaction as each seceding molecule is made reactive and then seeks to stabilize itself.
During these reactions, free radical oxidative damage can destroy cells. The basic process may be compared to the damage done to food as it becomes rancid.
Antioxidants
The destructive chain reaction started by free radicals can be broken by antioxidants, which are converted by the process into harmless derivatives.
Antioxidants help to maintain a stable internal environment in plants and animals. The body has many natural protective mechanisms to contain oxidative damage:
- Antioxidant nutrients such B-carotene, vitamin C and E
- Other small molecules with antioxidant properties, for example, glutathione and uric acid
- Enzymes such as superoxide dismutase and glutathione peroxidase.
Antioxidants, Free Radicals and Cancer
If free radical damage occurs in the nucleus cell and damages DNA, it can cause mutations. If certain segments of the DNA are affected it may initiate malignant change, potentially leading to caner.
Since antioxidants can protect cells from free radical damage, it is possible that antioxidants may protect against carcinogenic agents.
Antioxidant Function of Vitamin