Friday, May 17, 2013

Vitamins and Minerals as Antioxidants

Several vitamins and minerals are considered antioxidants. These include vitamins E and C, beta-carotene (which can be converted to vitamin A), other carotenoids (some may be converted to vitamin A and also play a role in cell development), and the minerals selenium, copper, zinc, and manganese.  What are antioxidants?  What do they do? Every cell in our body needs oxygen to use the nutrients that food provides.  However, when oxygen is used by cells, by-products called free radicals are formed.  If allowed to accumulate, these free radicals can damage tissues, cells, and deoxyribonucleic acid (DNA, the genetic material of cells).  The process of oxidative damage can be observed as the browning that occurs when sliced apples or potatoes are exposed to the air or the rancid flavor that butter and cooking oils develop when stored for long periods. Environmental pollutants such as cigarette smoke and ultraviolet light from the sun also contribute to the formation of free radicals in our bodies.  Although not proved, studies suggest that excess free-radical production can increase the risk of cancer, heart disease, cataracts, and the other types of cell deterioration that are associated with aging. Just as the vitamin C in lemon juice can prevent sliced apples from browning, antioxidants scavenge and neutralize the effects of free radicals in our bodies.  Each antioxidant has its own unique effect.  Vitamin C, which is water soluble, removes free radicals from body fluids and cell structures composed mainly of water.  Beta-carotene and vitamin E are fat-soluble.  They seem to be active primarily in fat tissues and cell membranes throughout the body.  The mineral selenium is an antioxidant that assists vitamin E.  What is the best source of antioxidants?  With the possible exception of vitamin E, the best source of antioxidants is food.  Fruits, vegetables, and grains provide a wide variety of both known and yet to be discovered antioxidants that appear to protect your body’s vital functions.

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