Tocopherols are the most important lipophilic antioxidants. They protect polyunsaturated fatty acids in cell membranes and lipoproteins from oxidation. In addition, they exhibit a number of other biological activities, including effects on cellular signalling and the prevention of infertility in animals, and are believed to play a preventive role in diseases associated with oxidative stress like cancer, cardiovascular diseases, cataracts, age-related macular degeneration, central neurodegenerative diseases and diabetes mellitus