These days, people are being encouraged to consume food items that are rich in Vitamin A, C and E (alpha-tocopherol), mainly because of their antioxidant properties. Have you ever sat back and wondered what exactly are antioxidants and how do they work in our body. Let us start with the first part of your question. Antioxidants, as their very name suggests, are those substances that have the ability to neutralize the damaging, though normal, effects of the physiological process of oxidation in the tissues. Antioxidants are inclusive of nutrients (such as vitamins and minerals) as well as enzymes (like proteins). By offsetting the harmful effects of oxidation, they help the body prevent a number of chronic diseases as cancer, heart disease, stroke, Alzheimer's disease, Rheumatoid arthritis, and cataracts. Now, let us move on to the working of antioxidants.
Free Radicals
In order to understand how antioxidants work, we first need to get a clear idea on the concept of free radicals. Free radicals can be described as chemically active atoms or molecular fragments in the body, which have a charge, owing to either excess or deficient number of electrons. Since free radicals have one or more unpaired electrons, they tend to be quite unstable. As they move around your body, they try to grab or donate electrons, scavenging it in turn and leading to damaged cells, proteins, and DNA (genetic material). Free radicals arise from sources both inside (endogenous) and outside (exogenous) our bodies and are almost impossible for us to avoid.
Antioxidants Working Process
Antioxidants work against free radicals, neutralizing them and blocking the process of oxidation in turn. This procedure leads to oxidation of antioxidants as well, which makes it necessary for us to replenish our antioxidant resources on a constant basis. The exact working of antioxidants can be classified into the following two ways:
Chain-breaking
By now, we know that free radicals roam around in our body, trying to release or steal an electron. As their task gets accomplished, a second radical is formed. This radical, in turn, tries to give or get electrons as well, causing another molecule to become a free radical. This process goes on and on, if not stopped, leading to excessive free radicals in the body. This is where the antioxidants, such as beta-carotene and vitamins C and E, come into picture. They terminate the process by breaking the chain and leading to the creation of a stabilized radical. In other words, antioxidants help stop the generation of more unstable products inside the body.
Preventive
Antioxidants not only help break the chain of free radicals, but can also help prevent the main culprit behind them - oxidation, as well. Enzymes like superoxide dismutase, catalase and glutathione peroxidase reduce the rate of chain initiation. They hunt for, and neutralize, the chain-initiating free radicals. With this, they prevent an oxidation chain from ever setting in motion. Antioxidant enzymes can also stabilize transition metal radicals, such as copper and iron, and thus prevent oxidation. As the oxidation process does not take place, the body is saved from its harmful effects, which manifest themselves in the form of various chronic diseases.