What is an antioxidant?
An antioxidant is a molecule capable of slowing or preventing oxidation of other molecules. An antioxidant, in a biologic setting, prevents uncontrolled and destructive chemical reactions between highly reactive oxidizing molecules and the biological milieu. Antioxidants are reducing agents that react with potentially damaging oxidizing species produced as a part of normal cellular function, and antioxidant systems have co-evolved to accommodate them safely thus preventing their toxicity. Indeed, an aerobically respiratory cell is awash in high concentrations of a variety of endogenous and exogenous antioxidant molecules. It is necessary for antioxidants to be abundant in biological systems because once they react with a highly reactive oxidizing species via a redox reaction, they can no longer function as an antioxidant and must be replaced.
Anti-oxidants — processes within humans require oxygen and there is a byproduct or oxidants of those processes which cause cell damage. Theses oxidants are also known as “free radicals” which are also caused by stress, the environment, unhealthy foods and habits. The cell damage caused by free radicals weakens the immune system, is linked to several diseases such as cancer and heart disease and speeds up the aging process. Antioxidants reduce the effect of these free radical oxidants by binding with them and decreasing their destructive power and repairing damage. According to the USDA’s latest study, cranberries contain one of the highest levels of ORAC’s – oxygen radical absorbance capacity.
September 14, 2006 You may have heard about the health benefits of antioxidants, but do you know what an antioxidant is — and how they actually work? Antioxidants are dietary substances including some nutrients such as beta carotene, vitamins C and E and selenium, that can prevent damage to your body cells or repair damage that has been done. Antioxidants work by significantly slowing or preventing the oxidative — or damage from oxygen — process caused by substances called free radicals that can lead to cell dysfunction and the onset of problems like heart disease and diabetes. Antioxidants may also improve immune function and perhaps lower your risk for infection and cancer. In your body, the antioxidant process is similar to stopping an apple from browning. Once you cut an apple, it begins to brown, but if you dip it in orange juice, which contains vitamin C, it stays white.
An antioxidant is a substance that counters the negative effect of oxygen. In foods anti-oxidants prevent the oxidation of different food components. Oxidation of foods results for example in an undesirable brown colour and/or off-odours and off-flavours known as rancidity. Antioxidants are substances that react with oxygen and thus counteract the negative effects. Examples are vitamin C (E300) and vitamin E (E308). In the body antioxidants protect key cell components by neutralizing the damaging effects of “free radicals,” natural byproducts of cell metabolism. Free radicals form when oxygen is metabolized, or burned by the body. They travel through cells, disrupting the structure of other molecules, causing cellular damage. Such cell damage is believed to contribute to aging and various health problems. Example of anti-oxidants which are active in the body are the vitamins A, C and E, and polyphenols (a group of plant chemicals, present in for example tea and fruits).
