Functions: The primary function of vitamin E is as an antioxidant, which is very important, I believe, in our present-day society with widespread pollution, processed food diets, and chemical exposure. Vitamin E is protective because it helps reduce oxidation of lipid membranes and the unsaturated fatty acids and prevents the breakdown of other nutrients by oxygen. This protective, nutritional antioxidant function is also performed and enhanced by other antioxidants, such as vitamin C, beta-carotene, glutathione (L-cysteine), and the mineral selenium. Oxidation in our body of such substances as the fat molecules, particularly from polyunsaturated fats, and from eating other oxidized fats such as hydrogenated oils and rancid oils, causes the genesis of free radicals, unstable molecules that can lead to cellular and tissue irritation and damage, which leads to chronic inflammation, especially in the vascular lining. Excess free radical formation comes from a variety of chemical reactions in the body and is the biochemical basis of many diseases, such as atherosclerosis, heart disease, hypertension, arthritis, senility, and probably even cancer. A number of experiments have shown that the antioxidant nutrients such as vitamin E can protect the tissues from oxidation and free radicals.
Without vitamin E, cell membranes, active enzyme sites, and DNA are less protected from free radical damage. Oxidation by circulating peroxides and superoxides (two types of free radicals) is also reduced by enzymes such as glutathione peroxidase and superoxide dismutase. As does vitamin E, these antioxidant enzymes also protect, by indirect mechanisms, the polyunsaturated fatty acids and vitamin A from oxidative destruction. Fried foods have more oxidized fat by-products, which increase the requirement for vitamin E, but they do not contain any E. This is partly why they are so dangerous when consumed on a regular basis.
More specifically, vitamin E as an antioxidant helps to stabilize cell membranes and protect the tissues of the skin, eyes, liver, breast, and testes, which are more sensitive to oxidation. It protects the lungs from oxidative damage from environmental substances. And vitamin E helps maintain the biological activity of vitamin A, another very important oil-soluble vitamin. Vitamin E protects the unsaturated fatty acids in the body and prevents the oxidation of some hormones, such as those released from the pituitary and adrenal glands. Free radical formation and oxidation are tied to cancer development, so the family of nutritional antioxidants, including vitamin E, may help in preventing tumor growth. More definitive research is needed in regard to this important function.
In simple terms, vitamin E’s key function is to modify and stabilize blood fats so that the blood vessels, heart, and entire body are more protected from free-radical-induced injury. Vitamin E also has some anticlotting (antithrombotic) properties and protects the red blood cells’ membranes from oxidative damage. Because it helps heart and muscle cell respiration by improving their functioning with less oxygen, vitamin E may help improve stamina and endurance and reduce cardiovascular disease (CVD) risk, especially in those with already existing CVD. Vitamin E has recently been shown to reduce platelet aggregation and platelet adhesiveness to collagen, even more so than aspirin. These platelet functions are linked to an increased risk of atherosclerosis and cardiovascular disease, especially in high-risk groups. Vitamin E has also been shown to neutralize free radicals generated during surgery, particularly cardiopulmonary bypass surgery. It would also protect against the toxicity of some of the gases used in anesthesia.