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BERNE, SWITZERLAND. Vitamin E occurs in eight different forms of which the two most important are
alpha-tocopherol and gamma-tocopherol. Alpha-tocopherol is the predominant form found in human tissues
and blood plasma and the primary form used in vitamin supplements. It is a powerful antioxidant, which is
incorporated into very low-density cholesterol and helps protect against atherosclerosis. Gamma-tocopherol
is the most abundant vitamin E form in the diet and tends to accumulate primarily in the skin, muscles, veins
and fat tissue.
A team of American and Swiss researchers now suggests that gamma-tocopherol may be equally important
for human health. They point out that a large portion of the gamma-tocopherol obtained from the diet
(walnuts, pecans, peanuts, and sesame seeds are good sources) is metabolized into gamma-CEHC, which
in itself has diuretic and anti-inflammatory properties. Gamma-tocopherol is an excellent inhibitor of reactive
nitrogen oxide species that are associated with inflammation. There is also substantial evidence that
gamma-tocopherol helps prevent heart disease and prostate cancer. Unfortunately, there is also substantial
evidence that supplementing with alpha-tocopherol "crowds out" the gamma-tocopherol in tissues and blood
plasma. Thus people who supplement solely with alpha-tocopherol may deprive themselves of the benefits
of gamma-tocopherol. In contrast, supplementation with gamma-tocopherol increases blood and tissue
concentrations of both alpha- and gamma-tocopherol. The researchers conclude that controlled intervention
studies in humans are clearly required in order to establish the relative merits of supplementation with these
two forms of vitamin E.
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