VITAMIN E WARDS OFF PARKINSON’S DISEASE
Since free-radical damage to the brain is considered a culprit in Parkinson’s disease, it makes sense that eating lots of antioxidants might help prevent the disorder. Dutch researchers at Erasmus University Medical School in Rotterdam have found evidence supporting the theory. They surveyed 5324 individuals, ages fifty-five to ninety-five. Those ingesting the most vitamin E were least likely to develop Parkinson’s. High vitamin C and beta carotene in food also showed some protection, but not nearly as much as vitamin E.
However, giving high doses of vitamin E to treat Parkinson’s has been only mildly effective. What this means, say experts, is that vitamin E and perhaps other antioxidants may work to help prevent brain disorders and may even help forestall progress in the early stages, but are less effective once the disease is advanced. “Prevention is more powerful than treatment,” says vitamin E expert Andreas Papas, Ph.D., at Eastman Kodak (a supplier of raw materials for vitamin supplements) and author of a recent book, The Vitamin E Factor.
WHAT TYPE VITAMIN E?
Vitamin E comes in eight different chemical forms—four tocopherols and four tocotrienols (designated as alpha, beta, gamma, and delta), as found naturally in food. The most common, put into most vitamin preparations, is alpha tocopherol, either synthetic or natural. Of this form, many experts favor “natural” vitamin E, noted on labels as d-alpha tocopherol. However, other types of vitamin E, particularly gamma tocopherol and gamma tocotrienol, also promise brain protection. Gamma, too, is a potent antioxidant protector of cell membranes, and may have special powers against degenerative brain diseases.
One reason: Gamma vitamin E is uniquely potent in neutralizing a class of free radicals known as “nitrogen” free radicals that are particularly lethal to nerve cells. These nitrogen radicals are primary culprits in brain diseases, including Alzheimer’s. Thus, many leading antioxidant researchers now say you need a full range of vitamin E, including both alpha and gamma types of vitamin E, as well as tocotrienols to fully protect the brain.
When choosing vitamin E for brain protection, Dr. Packer advises looking for “mixed” tocopherols that include gamma as well as alpha. You can also buy tocotrienols alone or in mixtures with tocopherols—for example, one new vitamin E supplement contains 400 IU of tocopherols and 400 milligrams of tocotrienols.
How much? Four to five hundred IUs of natural vitamin E daily is usually considered adequate for good antioxidant protection. Take no more than 1000 IU of vitamin E daily, except on a doctor’s advice. The potential hazard: excessively thin blood, notably if you also take anticoagulants. Vitamin E has been reported to accentuate bleeding in a dose of 800 IU daily when taken with a blood thinner, such as Coumadin.
BRAIN MESSAGES FROM THE LABORATORY
For decades, scientists have known from studies of laboratory animals that a vitamin E deficiency strikes the nervous system with a vengeance. Vitamin E-deficient rats and their offspring often suffer paralysis and “nutritional muscular dystrophy.” Rhesus monkeys, as well as chicks and rats, fed vitamin E-deficient diets develop ataxia (loss of balance), weakness, and other neurologic disturbances. Giving animals high vitamin E doses has reduced the damage to hippocampus cells following a stroke; and pretreating animals with vitamin E speeds recovery of motor function after spinal cord injury.
Simply giving animals twice the amount of vitamin E in their diets over a period of time substantially reduced the amount of brain damage following a brain hemorrhage or stroke. Thus, some experts suspect that modest doses of vitamin E supplements-100 to 400 IU daily—may help protect humans from neurological damage after a stroke.
Aucun commentaire:
Enregistrer un commentaire