Oxygen is one of the primary components of nature that supports life. The same oxygen, when inside the body, through certain molecules, becomes overly reactive and starts causing damage through the formation of free radicals. This is called oxidative stress. Vitamin E, as an antioxidant, helps prevent oxidative stress, thereby preventing cell damage and aging of the cells.
The body absorbs cholesterol, a fatty substance in foods, and this is transferred from the liver to different tissues to be stored as fats. They are carried in the bloodstream by a molecule called Low Density Lipoproteins (LDL). When LDL gets oxidized, they react with cholesterol and a waxy fat substance called plaque is deposited on the walls of the arteries, which results in the stopping of blood flow, high blood pressure and cardio-vascular diseases.
Vitamin E helps prevent the conversion of cholesterol into plaque, and this is done by alpha-tocopherol, not any other form of vitamin E, because liver places it preferentially in the bloodstream through a protein called alpha-tocopherol transfer protein.
The effect of vitamin E in preventing cancer has not conclusively been established. According to a study by The American Association of Cancer Research, reduced risk of cancer is associated with an intake of vitamin E-rich foods. Contradictorily, a study done by Iowa Women’s Health Study finds little evidence that vitamin E has protective effect against breast cancer in women after menopause. Hence, researchers have noted that not just vitamin E alone, but foods rich in antioxidants may be able to protect from cancer.