Antioxidants are molecules that inhibit the destructive activity of other chemical substances known as free radicals. Inhibiting the corrosive effects of oxygen is the most common function of antioxidants but there are many other sources of free radicals that living organisms are exposed to. Antioxidants are found in nearly all forms of life, even many viruses, which aren’t really alive.

Free radicals are inherently unstable. The reason for this is in the atomic structure. Free radicals are missing electrons and when free radicals come in contact with other molecules they steal electrons from them, this turns other molecules into free radicals as well. These molecules take electrons from other nearby stable molecules, and a chain reaction ensues. Antioxidants have the ability to stop free radicals from doing damage to nearby cells, antioxidants change the properties of free radicals, rendering them stable.

Free radicals are all around us; they are not easy or even possible to avoid. Many diseases and injuries create free radicals in the body. Alzheimer’s disease, arthritis, asthma, cancer, influenza, sinus infections, and yeast infections all create free radicals. Injuries, even minor ones such as sprains, muscle aches, and strains all generate free radicals. Toxins generate free radicals and toxins are everywhere-in our food, water and even the air we breathe. Even if our air was perfectly clean, simply taking in oxygen throughout the body generates free radicals.

Oxygen molecules generate what is collectively known as oxidative stress. Oxygen is actually highly corrosive. Most of us don’t think of it that way because we need oxygen to live, and without oxygen our cells would die rather quickly. Taking oxygen into the body also generates another free radical- superoxide, an unstable form of oxygen. This free radical is generated as a byproduct of staying alive. (Obviously, there’s no avoiding that one). Oxygen is just one of the unavoidable sources of free radicals that we are exposed to. Metabolizing our food also creates free radicals. Sunlight, smoking, radiation and even eating burnt food can create free radicals in the body.

Like many great discoveries, many of the first antioxidants were discovered by accident. Superoxide dismutase, or SOD, was one of these accidental discoveries. Joe McCord was looking for the function of another enzyme, when he chanced upon superoxide dismutase. McCord discovered a mysterious enzyme (SOD) that seemed to be present in all forms of life. The only exception appeared to be anaerobic bacteria. Anaerobic bacteria did not contain this enzyme SOD. Anaerobic bacteria do not need oxygen to survive. (Interestingly, many of these anaerobic organisms also can cause disease). Just about every other living creature from the top of the food chain to the bottom of the food chain relies on this enzyme superoxide dismutase. In the beginning neither Joe McCord nor his mentor, Irwin Fridovich, understood what this enzyme did, but they were convinced that it was important because of its ubiquity in nearly all forms of life.