Sunday, September 21, 2008

Understanding Vitamin E

Every animal, including you, needs vitamin E to maintain a healthy reproductive system, nerves, and muscles. You get vitamin E from tocopherols and tocotrienols, two families of naturally occurring chemicals in vegetable oils, nuts, whole grains, and green leafy vegetables — your best natural sources of vitamin E.
Tocopherols, the more important source, have two sterling characteristics: They’re anticoagulants and antioxidants that reduce blood’s ability to clot, thus reducing the risk of clot-related stroke and heart attack. Antioxidants prevent free radicals (incomplete pieces of molecules) from hooking up with other molecules or fragments of molecules to form toxic substances that can attack tissues in your body. In fact, nutrition scientists at Purdue University released a study showing that vitamin E promotes bone growth by stopping free radicals from reacting with polyunsaturated fatty acids to create molecules that interfere with the formation of new bone cells.
But some claims about E’s heart health benefits are now considered iffy. True, a recent clinical trial at Cambridge University in England showed that taking 800 IU (International Units) of vitamin E, two times the RDA, may reduce the risk of nonfatal heart attacks for people who already have heart disease. And, yes, the federal Women’s Health Study found that older women taking 600 IU vitamin E per day had a lower risk of heart attack and a lower risk of death from heart disease. But the Heart Outcomes Prevention Evaluation (HOPE) study showed no such benefits. In fact, people taking 400 IU per day vitamin E were more likely to develop heart failure. No one (and no study) has found similar problems among those taking less vitamin E, say 100 IU/day. Whew. The best sources of vitamin E are vegetables, oils, nuts, and seeds. The RDA is expressed as milligrams a-tocopherol equivalents (abbreviated as a-TE).

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