Vitamin E Functions
Vitamin E Functions
Vitamin E serves multiple important functions in the human body, but probably the most important and the one for which it is most widely known pertains to its antioxidant properties. Because vitamin E is fat-soluble rather than water-soluble, the foods that are naturally the best sources of this nutrient are fatty foods like oils, nuts, and full-fat salad dressings. As a result, diets that are low in fat tend also to be low in vitamin E. To help you understand why vitamin E is necessary and why even if you are watching your weight and calories, some fat in the diet is also necessary, we will now summarize the major functions of vitamin E.
Vitamin E acts as a powerful antioxidant.
Vitamin E, along with many other nutrients, including vitamin C, vitamin B3, selenium, and glutathione, helps to prevent oxidative stress. Antioxidants like vitamin E promote good health by preventing free radicals, in the form of unstable oxygen molecules, from becoming overly reactive and thereby causing damage to the cells. Excess free radical formation is caused by a variety of factors. Chemical pollutants in the environment (especially ozone and nitrogen oxide), cigarette smoke and other toxins to which the body might be exposed, certain components of the diet like polyunsaturated fats and hydrogenated oils, and chemical reactions taking place in the body all contribute. If left unchecked, the resulting oxidative damage to the cells can lead to chronic inflammation and increased risk for major health problems. Oxidative stress has been linked to a variety of potential diseases including cardiovascular disease, arthritis, asthma, diabetes, Alzheimer’s disease and other forms of dementia, and certain types of cancer. Fortunately, antioxidants, such as vitamin E, are an important weapon in the body’s line of defense in protecting the tissues from damage associated with the oxidation of free radicals.
Some researchers believe that out of all the nutrients that contribute to preventing oxidative stress, vitamin E is the most important. Clearly, vitamin E is the most important fat-soluble antioxidant in the cells.
The cell membranes are comprised of a phospholipid bilayer in which numerous organelles are encased. Therefore, maintaining the integrity of the membranes is essential for the cells and their organelles to function properly. Vitamin E, which is located in the lipid portion of the cell membrane, plays a key role in this process. By donating hydrogen atoms to the free radicals, it makes them more stable so that oxidative damage to the unsaturated fatty acids in the phospholipid bilayers does not occur. This process is known as the termination of a chain reaction or free radical scavenging.
This protection against oxidative damage provided by Vitamin E is particularly important in red blood cells and in cells in the skin, lungs, heart, brain, eyes, liver, breasts, and testes, all of which are highly sensitive to the effects of oxidation.
The antioxidants in vitamin E also help counteract the cardio-toxic effects of the anti-cancer drug Adriamycin and even offer some protection against the highly damaging effects of tobacco and alcohol.
Keep in mind, however, that vitamin E is only one of a multitude of antioxidants working synergistically. The effectiveness of vitamin E in protecting against cell membrane damage is enhanced in the presence of such antioxidants as vitamin C and selenium. Vitamin E also works together with various enzymes such as superoxide dismutase, glutathione peroxidase, and glutathione reductase.
Vitamin E supports a healthy immune system.
It stands to reason that because vitamin E is such a potent antioxidant, it is also conducive to building and maintaining a healthy immune system. However, just as vitamin E doesn’t act alone in helping to prevent oxidative damage to the cells from increasing the risk for serious diseases, the same applies to overall immune function. The body’s ability to resist relatively minor annoyances like the common cold, upset stomach, etc., prevent certain autoimmune disorders, and delay aging depends on a variety of nutrients all working synergistically together. Recent research has specifically focused on the presumed ability of vitamin E supplements to improve immune functioning in the elderly. However, the results thus far provide little evidence to back up the hypothesis that high-dose supplementation of vitamin E is warranted, especially among older adults who are not vitamin E-deficient.
Vitamin E facilitates effective communication both within cells and between cells.
Recent research has focused on the capability of vitamin E to facilitate the transfer of chemical information both within cells and between cells. This transfer of information is called cell signaling. Effective intra- and intercellular communication is important because it significantly impacts gene expression, enzyme activity, and protein concentrations. For example, genes regulated by vitamin E are involved in a wide range of functions, including suppressing cholesterol synthesis, inflammation, cell adhesion, and blood clotting. Furthermore, recent research has focused not only on the role of alpha-tocopherol in cell signaling but also on the contribution of the tocotrienols. These components of vitamin E are involved in the anti-inflammatory activity, lowering cholesterol, inhibiting the action of estrogen, and promoting abnormal cell apoptosis, thereby fighting cancer. It is believed that these and other examples of cell signaling cannot take place in the absence of vitamin E.
Vitamin E supports good skin health and protects the skin from ultraviolet light.
Numerous research studies have shown that vitamin E applied to the skin prevents damage from ultraviolet light. Similarly, a diet high in vitamin E rich foods is capable of having the same protective effect on skin cell membranes.