The major function of vitamin E is as an antioxidant. It is the major lipid soluble antioxidant stabilizing cell membranes, protecting membrane polyunsaturated fatty acid components from attack by damaging free radicals. Free radicals are harmful molecules generated as unwanted by-products of normal metabolism within the body, as well as following exposure to environmental chemical pollutants. In addition to its role in cell membrane repair, vitamin E helps to maintain a healthy cardiovascular function, by protecting LDL cholesterol against oxidative damage, promoting normal blood clotting/platelet aggregation and healthy blood pressure. Vitamin E also promotes normal wound healing. Vitamin E is used as an additive in foods with a high content of fat or oils, to prevent oxidation and rancidity.