They are rarely the main argument in the sales points leaflet of a cosmetic. However, they are used in the formulae of innumerable products, with a mission: to prevent and fight oxidation. Their named-code: Tocopherol. Their weapons: all the arms offered by vitamin E.
Vitamin E is a lipo-soluble (which dissolves in fats) vitamin.
This strong antioxidant, widely naturally found in vegetable oils and cereals, almonds, fatty fish, is recommended in food to fight free radicals that harm cells and speed up ageing. It may be used for medical reasons, to prevent some cancers or to treat the cholesterol level.
Vitamin E is also used as food supplement (E 306 to E 309), and, obviously, in cosmetics.
Mission: fight oxidation
When vitamin E goes to war against oxidation, it is not only one agent that is involved in the fight, but a small army of fighting agents. Indeed, vitamin E contains eight organic molecules: four tocotrienols and four tocopherols: alpha-, beta-, gamma- and delta-tocopherols.
These latter ones are in the front line.
One must know that most of the fatty acids (the basis of all fats, oils, waxes, butters …) contain carbon-carbon double bonds. A mono-unsaturated acid contains only one double bond; poly-unsaturated acids contain several double bonds.
Tocopherols have the property to prevent double bonds breaking, which lead to oxidation, and make fatty acids go rancid.
The more double bonds, the higher the risks that they are damaged (in contact with air, light, …
