Vitamin E or tocopherol is one of the versatile nutrients that is equally beneficial when applied topically as well as when it is ingested. Deficiency of vitamin E can lead to many diseases as it is a major co-factor in many immune-related and defensive body processes and is an essential in every diet plan to maintain a healthy body and mind. It is a common constituent in almost all in skin care products; if you want to know whether a product has vitamin E, look for tocopherol or tocopheryl on the ingredient list. It is one of the most powerful antioxidants and prevents many degenerative processes inside the skin and the body.
Skin structure and the causes of its damage:
The uppermost layer of our skin is known as epidermis and it is composed of five layers. The top layer of theepidermis is known as stratum corneum and like all cell membranes, its cells’ membranes are also made up of the lipid bilayer. This lipid bilayer act as a barrier against all the foreign agents entering our skin. The weakening of the skin barrier function results in making the skin more prone to dehydration, irritation, and infection while the skin permeability is also affected. The barrier of the lipid bilayer is destroyed by two ways:
- Glycation: it is a natural ageing process in which sugar attaches itself to the carrier proteins in lipid bilayers in a cross-link resulting in denaturing of the proteins and impairing their functions. The structures which are formed as the result of glycation are called AGE’s (Advanced Glycation End Products). In skin, AGE’s bind strongly to elastin and collagen, forming chemical bridges causing the elastin and collagen to become stiff and non-functional; the skin becomes thinner and loses its flexibility, elasticity and firmness. AGE’s also make skin sallow (yellow-brown in colour) over a long period due to the improper breakdown of collagen and elastin. The cross linking makes the breakdown of abnormal collagen and elastin fibre clumps very difficult and as a result, they accumulate inside the skin as cellular garbage. This causes age-related brown spots (lipofuscin) to appear on the skin.
- Free radical formation: Lipid peroxide is the reactive oxygen species which causes the breakdown of the lipids by lipid peroxidation. In this process, the ROS steals the electrons of the lipids causing the lipids to lose its structure and damages the cell. When the lipids in the lipid bilayer are oxidised, cell membrane loses its permeability which causes infections and irritation.
Functions of Vitamin E:
- It acts as a chelating agent and binds to the AGE’s preventing it from cross-linking with collagen and elastin. Alpha-tocopherol has been studied extensively and it has proven that it inhibits the glycation of the albumin invitro. Alpha lipoic acid and vitamin C both have the ability to regenerate the oxidised vitamin E and hence are used in combination with vitamin E in skin care products to combat the effects of AGE’s.
- Similarly, it also binds to the lipid peroxide, preventing it from binding to the lipids in the cell membrane, as a result, the lipid bilayer retains its structure and its permeability.
- Due to its oil soluble nature, it acts as a skin emollient.
While vitamin E has also been attributed to the scar healing, the studies have been unable to prove this benefit. Furthermore, synthetic forms of vitamin E have been found to cause skin irritation and in extreme cases has also been associated with dermatitis.
Forms of vitamin E
There are 8 forms of vitamin E inside the skin. Alpha, beta, gamma and delta tocopherol, and alpha, beta, gamma, and delta tocotrienol. Alpha-tocopherol is the most commonly studied form of vitamin E but it is poorly absorbed into the skin, therefore, the ester form of vitamin E is most commonly used.