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| Vitamin E (Tocopherol) is a light yellow oil, a fat-soluble vitamin, that is actually a family of compounds, the tocopherols, found in nature. Alphatoxopherol is the most common and the most active of the seven currently described forms—alpha, beta, gamma, delta, epsilon, and zeta. Specifically, d-alpha tocopherol is the most potent form, more active than the synthetic dl-alpha tocopherol. Alpha-tocopherol is basically stable in heat and in acids; other forms are lost in heat, with storage or freezing, or when oxidized by exposure to the air. All vitamin E's are slightly unstable in alkali and are readily used up when in contact with polyunsaturated oils or rancid fats and oils, which are protected from oxidative destruction by vitamin E. Frying oils, the processing and milling of foods, the bleaching of flours, and cooking remove much of the vitamin E content of whole foods. During the refinement and purification of vegetable oils, vitamin E is lost; the vitamin E-rich by-products of this process are used to make some of the E used in supplements. Vitamin E is absorbed from the intestines, along with fat and bile salts, first into the lymph and then into the blood, which carries it to the liver to be used or stored. Vitamin E is not stored in the body as effectively as the other fat-soluble vitamins, A, D, and K. Over half of any excesses may be lost in the feces, but some vitamin E is stored in the fatty tissues and the liver and to a lesser degree in the heart, muscles, testes, uterus, adrenal and pituitary glands, and in the blood. Vitamin E is partially absorbed through the skin when used as an ointment or oil application. Intestinal absorption, however, is reduced somewhat with chlorine, inorganic iron, and mineral oil. Unsaturated oils and estrogen also deplete vitamin E, increasing the body’s demand for it. 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. Although vitamin E was first discovered as the fertility, or at least the antisterility, nutrient, there is no clear evidence that it enhances fertility if there is not a specific deficiency prior to its use. Many people, especially men, take vitamin E with some claimed success in regard to sexuality and vitality. Much of this effect, however, may be due to the antioxidant function and improved circulation and oxygenation. Vitamin E, as its various tocopherol forms, is found in both plant and animal foods. In general, the animal sources of E are fairly poor, with some being found in butter, egg yolk, milk fat, and liver. The best sources of vitamin E are the vegetable and seed or nut oils. It was first isolated from wheat germ oil, which is still a commonly used, rich source of vitamin E. The oil component of all grains, seeds, and nuts contain tocopherol. The protective covering or germ part of the grains is what contains the E, and this is lost easily in the milling of flour or in the refinement of grains. For the vitamin E to be preserved, extraction of the oils from nuts and seeds must be done naturally, as by cold pressing, rather than by heat or chemical extraction, used commonly in food processing. Because of these forms of processing, the average American diet has lost many of its natural sources of tocopherols, and intake is commonly very low. The cold-pressed vegetable oils are really the best source of vitamin E, and these are most healthfully used in their raw form in salad dressings and sauces rather than in cooking, since most are polyunsaturated oils, which are adversely affected by heating. With refined or cooked polyunsaturates, more vitamin E is needed to prevent oxidation, which could lead to free radical formation, the invisible, underlying cause of many diseases. Free-radical-induced changes occur at the cellular level, the primary processes leading to many chronic degenerative diseases. The vitamin E content of most foods is related to the content of linoleic and linolenic acids, our most essential fatty acids (see Chapter 4, as well as Vitamin F). Also, the content of active alpha-tocopherol varies among the different foods and oils. Safflower oil is one of the best sources, with about 90 percent of the E being the alpha variety. Corn oil has only about 10 percent alpha-tocopherol. Some other foods that contain significant amounts of vitamin E are soybeans, some margarines and shortenings made from vegetable oils, and a few vegetables, such as uncooked green peas, spinach, asparagus, kale, and cucumber; tomato and celery also have a little. The amount of vitamin E required depends upon body size and the amount of polyunsaturated fats in the diet, since vitamin E is needed to protect these fats from oxidation. More is needed when any refined oils, fried foods, or rancid oils are consumed. Supplemental estrogen or estrogen imbalance in women increases the need for vitamin E, as does air pollution. And, as I have mentioned, vitamin E should not be taken with iron, especially inorganic iron, such as ferrous sulfate or the iron added to food products. Selenium, another important antioxidant, however, may increase the potency of vitamin E. Even though the RDA for vitamin E is really quite low, many people do not consume this in their diet alone.
For the d-alpha tocopheral form of this vitamin, 1 mg. equals 1.49 IUs. The different forms of vitamin E have various potencies, with d-alpha the most active and most prevalent in nature. Vitamin E extraction, purity, and activity also vary. The best forms, in my opinion, are those that contain the natural, unesterified d-alpha tocopherol along with the other (beta, gamma, and delta) naturally occurring tocopherols. This type of E is not easy to find because it is more difficult and costly to produce. The vitamin E palmitates and acetates are synthetic water-dispersible forms of vitamin E that have a good level of activity and are often easier to take, as they can be taken with other vitamins. Vitamin E oil is taken ideally in the morning before breakfast or at night before bed. It can also be taken after meals containing some fat. Approximately 400–600 IUs is used preventively, whereas for therapeutic effects, an amount between 800–1600 IUs daily is suggested. With therapeutic uses of vitamin E, it is best to start with a low level and gradually increase it. Levels over 1,600 IUs per day are not recommended unless there is close medical supervision. Because of vitamin E's effect on blood clotting, don't take supplements for two days before or after any type of surgery (including dental surgery). The minimum amount of vitamin E it takes to alter blood clotting is about 30 IU a day. A number of chemotherapy and radiation treatments are designed to actually create free radicals for the purpose of killing cancer cells. If you are undergoing cancer treatment, don't take antioxidants such as vitamin E supplements without consulting your oncologist first. Otherwise, you may be working counter to what the cancer treatment is designed to do. Consult your doctor before taking vitamin E if you have high blood pressure that is poorly controlled; the increased risk for bleeding with vitamin E could possibly lead to a greater risk for the complications of high blood pressure, such as hemorrhagic stroke (bleeding in the brain). |
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