Antioxidants and Free Radicals What are antioxidants? Antioxidants are substances, usually vitamins, minerals, enzymes or phytonutrients that protect the body from damage caused by oxidation. Oxidation is a process that causes damage to our body tissues through the work of free radicals. Chemically antioxidants donate an electron to the free radical and convert it to a harmless molecule. |
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The body can also manufacture its own antioxidants. In our body, nutrients such as beta-carotene (a vitamin A precursor), vitamin C, vitamin E, and selenium act as antioxidants. However, an increase in the free radical load would place stress on the body if sufficient dietary antioxidants were not available. What are free radicals? Free radicals are toxic molecules of oxygen that damage most tissues of our body. They are nothing but natural by-products of continuous biochemical reactions in the body, which include routine metabolic processes and immune system responses. A free radical is an unstable molecule because it has deficiency of an electron which exists in pair in stable molecules. Free radicals steal an electron from another molecule, thereby creating another free radical. The new free radical then duplicates the process of oxidation, resulting in a chain reaction of events, which eventually damages the body tissues. The most common free radicals are reactive oxygen species (ROS). For example, superoxide radical, hydroxyl radical, and peroxyl radical. These free radicals are routinely produced in the body by cellular metabolism or inflammation by immune cells. They are generated externally also because our body is exposed routinely to radiation, toxic chemicals, alcohol, smoke and other pollutants, pharmaceutical products, hydrogen peroxide etc. They are also generated by oxidized polyunsaturated fats and cooked food. Free radicals play a very important role the initiation and progression of various diseases including atherosclerosis (leading to heart disease), cancer, cataracts, Alzheimer's disease and weakening of immune system. Free radicals do this by damaging parts of cells such as proteins, DNA, and cell membranes. How antioxidants work? Antioxidants work by neutralizing free radicals. They bind to the free radicals, and then transform them into non-damaging substances. Antioxidants act as buffers. They donate electrons to free radicals, before they steal one from other places. This halts the cascade of damaging events of oxidation. The body creates and circulates antioxidants in the form of nutrients and enzymes for the purpose of controlling free radicals and their destructive chain reactions. Antioxidants help to foil the progression of heart disease by preventing oxidation. Antioxidants fight against chronic inflammation. Vitamin E acts as an antioxidant which suppresses a condition called as platelet aggregation (stickiness), by acting as an anticoagulant to inhibit the formation of clots that cause heart attack and stroke. Vitamin C reduces a blood factor needed to build clots. Antioxidants, cancer and Alzheimer's disease Cancer is thought to be caused by damage to DNA (Deoxyribonucleic acid) by free radicals. Antioxidants thwart cancer induction by neutralizing free radicals. Antioxidants help in preventing injury to blood vessel membranes, and thereby optimizing blood flow to the heart and brain. This helps lower the risk of cardiovascular disease (including heart disease and stroke) and dementia and Alzheimer's disease. Conditions responsible to promote formation of free radicals 1. Pesticides If pesticides and herbicides are used on the crops, consumption of foods prepared from such crops can cause increase in the existing free radical load in the body. It is therefore important to consume food prepared from organically grown crops. 2. Pollution Urban life is full of pollution exposing you to the harmful pollutants thereby increasing your free radical burden. Traffic jams and residing near industrial zones with polluting industrial units will add to the burden. 3. Tobacco smoke All smokers including passive smokers are exposed to enhanced amounts of chemicals generating free radicals in the body. Experts advice consumption of 25 mg of vitamin C for every cigarette smoked. 4. X-rays and other ionizing radiation Like pollutants, ionizing radiation (x-rays, gamma rays, alpha, beta particles, neutrons and cosmic rays) also cause generation of free radicals. If possible, exposure to ionizing radiation should be avoided or at least minimized. 5. Stress Stress related to urban lifestyles and competitive job environments is also a contributing factor to excess free radical generation in your body. 6. Sunlight Consistent exposure to sunlight, especially to ultra-violet radiation, can boost the generation of free radicals in the body. Avoid excessive exposure to sunlight or expose only during early morning or late evening sunlight for the benefit of vitamin D. 7. Food additives Food additives like preservatives, essences and colors are added to improve the appearance, aroma, shelf life and stability of processed foods, but these potentially boost the formation of free radicals in the body. Consume food that is freshly prepared, lightly colored and has minimal additives. 8. Food preparation Cooking, especially frying and deep frying definitely create substances that after consumption enhance the formation of free radicals in your body. |
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