Ceramides

Scientists are uncovering the important role that ceramides play in the barrier function of the skin. The top layer of the skin is the epidermis and the top layer of the epidermis is the stratum corneum. Even though the stratum corneum is very thin, like one-tenth the thickness of a piece of paper -- it is the main barrier of the skin. It keeps chemicals that come in contact with the skin from absorbing into the body, and it keeps water inside the skin from leaking out.

Ceramides defined by Milady’s Standard Fundamentals for Estheticians, are lipid materials that are a natural part of the intercellular cement. The intercellular cement between the skin cells consists of ceramides, lipids, glycoproteins, and active enzymes.
Ceramides are natural lipids (fats) and a major component of skin structure. These fats allow skin to retain moisture.

The Role of Ceramides
Ceramides are essential in helping to form multiple layers of lipids, which, in turn, retain water. Ceramides play a central role as water regulators primarily because of their abundant presence in the skin and high capacity to prevent water loss. This is why ceramides are so effective in creating a barrier-recovery effect.

Lipids in the Skin
The stratum corneum contains three types of lipids:

• ceramides,
• cholesterol
• and free fatty acids.

These lipids have different chemical compositions and different functions throughout the body.
The quantity of these diminishes as we age, resulting in a decrease in the skin’s suppleness, softness, smoothness, and the tendency towards dryness.

Lipids provide a barrier against the loss of moisture and provide protection from other types of external elements. In the corneum, 40-50% of these lipids are primarily composed of ceramides.
Ceramides and other lipid-type materials have been called “cellular cement,” because they make up the foundation for materials, which hold epidermal skin cells in place. Without these lipids, the cells would simply slough off after moisture is lost. Ceramides are important in the treatment of dry skin. Externally applied ceramides help replenish and improve the skin’s ability to reduce desquamation.

In general, ceramides and synthetic ceramides are added to cosmetic formulations such as moisturizers and other beauty products to replenish the content of lipids within the upper layers of the skin. This leads to an increase in skin softness and smoothness and a reduction in the amount of constantly escaping moisture. Moisture loss leads to dehydration, excessive scaling or flaking, desquamation and increased potential for irritation.

What do Ceramides do?
In cosmetic applications, ceramides provide the skin with materials, which are slowly depleted during the aging process, but are responsible for maintaining a youthful appearance by reinforcing the natural barrier function of superficial epidermal layers.

Ceramides used in cosmetic preparations may be obtained from biological, botanical, marine or synthetic sources. The different types of ceramides are distinguished by analysis of their unique chemical structure.

Most cosmetic labels will accurately list ceramides by using their own specific terminology names such as the following:
Glycosphinogolipids
Sphingolipids
Glycosyl ceramides

Other comparable listings found to be of benefit include:
Phospholipids
Cholesterol
Essential fatty acids (called EFAs)
Linoleic acid
Arachidonic acid

Ceramides are necessary for the skin’s water-retention capacity as well as for cell regulation. Adding ceramides to skin-care products can help to restore the skin’s barrier system.