Tuesday, November 28, 2006

Vitamin E

"Vitamin E consists of eight different compounds — four tocopherols and four tocotrienols (sic...). A varied diet eaten by humans may contain all eight compounds. The most abundant sources of tocotrienols are the oil fractions from cereal grains, including barley, rice, rye and wheat, and the fruit of the oil palm. Commercial quantities of tocotrienols are currently extracted from palm oil and rice bran oil. Tocopherols are also present in these sources but are more abundant in the oils extracted from soybean, corn (maize), cottonseed and sunflower seed, which are now the primary commercial sources for natural vitamin E products.

Y-Tocopherol appears to be more potent than A-tocopherol in increasing superoxide dismutase (SOD) activity in plasma and arterial tissues as well as manganese SOD and copper/zinc SOD protein expression in arterial tissues. SOD is a major antioxidant enzyme" (1.)

"Benefits for cardiovascular health —
The strongest evidence yet for tocotrienols comes from a clinical study conducted by the Kenneth Jordan Heart Research Foundation in New Jersey, USA. The study, now in its fifth year, has been evaluating 50 patients who had stenosis of the carotid artery. It is appropriate here to explain what stenosis is and the problems associated with its treatment. Stenosis means constriction or narrowing — the accumulation of plaque over time causes stenosis of the arteries. Stenosis of the carotid artery can cause stroke. "(2.)

"In addition to enzymes, the animal cell uses many other chemicals to protect against oxygen free-radicals. Vitamin E is the main free-radical trap in the (lipid) membranes. Vitamin C acts as an anti-oxidant in the non-lipid ("watery") portions of cells, between cells and in the bloodstream. Melatonin, a hormone produced by the pineal gland in decreasing quantities with aging, efficiently crosses membranes (including the nucleus) and is effective against hydroxyl radicals." (3.)

(1.) Li, D. et al. (1999) Relative effects of Y- and A-tocopherol on low-density lipoprotein oxidation and superoxide dismutase and nitric oxide synthase activity and protein expression in rats. Cardiovasc. Pharmacol. Ther., 219–226.

(2.) Watkins, T.R. et al. (1998) Tocotrienols: biological and health effects. In: Antioxidant Status, Diet, Nutrition and Health, (see ref. 2) pp.479–496.

(3.) THE FREE RADICAL THEORY OF AGING, Ben Best
http://www.benbest.com/lifeext/aging.html#radical