antioxidants definition
Free radicals. These free radicals are capable of attacking the healthy cells of the body. This may lead to damage, disease and severe disorders. Cell damage caused by free radicals appears to be a major contributor to aging and diseases like: cancer. heart disease. decline in brain function. decline in immune system etc. While antioxidant supplementation is widely used in attempts to prevent the development of cancer, antioxidants may interfere with cancer treatments, since the environment of cancer cells causes high levels of oxidative stress, making these cells more susceptible to the further oxidative stress induced by treatments. An antioxidant is a molecule that inhibits the oxidation of other molecules. Oxidation is a chemical reaction that can produce free radicals, leading to chain reactions that may damage cells. Antioxidants such as thiols or ascorbic acid terminate these chain reactions. The term antioxidant is mainly used for two different groups of substances: industrial chemicals which are added to products to prevent oxidation, and natural chemicals found in foods and body tissue which are said to have benef Sources. 1  http://acudoc.com/Antioxidants.PDF. 2  http://ocw.jhsph.edu/courses/humannutrition/PDFs/Lecture8.pdf. 3  http://www.womenfirst.net/pdf/ADA/ADA_Antioxidants.pdf. 4  http://class.fst.ohio-state.edu/fst821/Lect/AA.pdf. 5  http://www.medlabs.com/Downloads/Antiox_acti_.pdf. These free radicals are capable of attacking the healthy cells of the body. 1  This may lead to damage, disease and severe disorders. Cell damage caused by free radicals appears to be a major contributor to aging and diseases like: 2  cancer. 3  heart disease. 4  decline in brain function. 5  decline in immune system etc. An antioxidant is a molecule that inhibits the oxidation of other molecules. Oxidation is a chemical reaction that can produce free radicals, leading to chain reactions that may damage cells. Antioxidants such as thiols or ascorbic acid (vitamin C) terminate these chain reactions. The term antioxidant is mainly used for two different groups of substances: industrial chemicals which are added to products to prevent oxidation, and natural chemicals found in foods and body tissue which are said to have beneficial health effects. : a substance that is added to food and other products to prevent harmful chemical reactions in which oxygen is combined with other substances. Model of the antioxidant metabolite glutathione. The yellow sphere is the redox-active sulfur atom that provides antioxidant activity, while the red, blue, white, and dark grey spheres represent oxygen, nitrogen, hydrogen, and carbon atoms, respectively. When there is deficiency of these antioxidants damage due to free radicals can become cumulative and debilitating. Antioxidants are capable of stabilizing, or deactivating, free radicals before they attack cells. Antioxidants from food. There are several nutrients in food that contain antioxidants. Vitamin C, vitamin E, and beta carotene are among the most commonly studied dietary antioxidants. Vitamin C is the most important water-soluble antioxidant in extracellular fluids. Vitamin C helps to neutralize ROS in the water or aqueous phase before it can attack the lipids. Vitamin E is the most important lipid soluble antioxidant. It is important as the chain-breaking antioxidant within the cell membrane. Although certain levels of antioxidant vitamins in the diet are required for good health, there is considerable debate on whether antioxidant-rich foods or supplements have anti-disease activity. Moreover, if they are actually beneficial, it is unknown which antioxidant(s) are needed from the diet and in what amounts beyond typical dietary intake.
An antioxidant is a molecule that inhibits the oxidation of other molecules.