What are ceramides? What are their benefits?

1. What are ceramides?

Ceramides are a family of structurally heterogeneous lipids that belong to the family of sphingolipids (complex lipids derived from the sphingosine molecule). A ceramide is the product of a reaction between a fatty acid and a sphingosine. Several ceramides have been identified, in varying proportions and differing in structure. Ceramides have been classified according to the number of carbon atoms in the fatty acid in question (between 16 and 36 carbons), its degree of unsaturation (saturated or monounsaturated) and the length of the chains of sphingoid residues. In the Stratum corneum, ceramides NS (21%), NP (13%), AS (18%) and NH (22%) are predominant  (Drakou et al., 2021).

Similar structures are found in many living organisms such as plants and animals. In humans, ceramides are essential lipids in the outermost layer of the epidermis, known as the Stratum corneum, because of their role in the formation of the lipid bilayer, giving the skin the impermeability it needs for optimal barrier function.

2. What are skin ceramides used for?

Synthesized by keratinocytes, the majority of cells in the epidermis, ceramides play an essential role in the function of the skin barrier. They are strongly involved in skin homeostasis due to their important structural role in the lipid bilayer of the stratum corneum, maintaining hydration and protecting the skin against the exposome.

A reduction in the quantity and/or quality of ceramides can lead to dry skin and other skin disorders such as atopic dermatitis, psoriasis, acne, seborrhoeic dermatitis, etc. As ceramides are subject to hydrolysis and oxidative processes due to constant exposure to the environment, their composition is significantly altered in amount and quality both in aged skin and skin disorders.

Ultimately, as a result of the alteration of the ceramides, the skin's barrier function is impaired, water loss is increased, and the skin becomes more fragile and more sensitive to external aggression. Over the long term, a deterioration in ceramide content leads to premature aging. It is therefore essential to preserve ceramides for healthy skin.

3. How can the quality and quantity of ceramides in the skin be improved?

Ceramides belong to the family of cosmetic star ingredients. They are well-known cosmetic active ingredients whose synthetic form has been handed down from several generations. However, there are ceramides present in plants, also known as phytoceramides, which have a similar structure to skin ceramides and therefore offer the same benefits. They can be extracted from oats, wheat, rice or even corn, like CERAMOSIDES^TM HP, which in a formula provides anti-ageing and moisturizing benefits, as well as acting as a skin shield for perfect skin.

But that's not all! Several natural ingredients stimulate the production of ceramides in the skin, reinforcing its barrier function. They can be extracted from marine plants such as rare halophytic plants, like "sea fennel", from which NATIVE ESSENCE^TM is extracted. It has been shown to be effective in vitro, boosting the synthesis of ceramides 3 & 6 on reconstructed human epidermis and offering radiance, oxygenation and complete protection to the skin, which is then sublimated. 

This is also the case with terrestrial plants such as Centella Asiatica leaf extract, HETEROSIDES, which stimulates the synthesis of ceramides 2 with a positive correlation proven in vivo with a reduction in IEP. It guarantees a complete reinforcement of the cutaneous barrier for mature skin.

Finally, specific ingredients obtained through sugar chemistry also have a role to play. AQUAXYL^TM, a patented combination of sugars, stimulates the synthesis of ceramides 1 & 2, while controlling the circulation of water and its reserves for an "anti-dehydration shield" action.

As discovered in this article, it is important to maintain the quantity and quality of ceramides in the skin so that they can fulfill their role in the skin barrier. This is why some cosmetic products contain active ingredients with a structure similar to that of skin ceramides, but of plant origin, which provide similar benefits. Similarly, certain active ingredients derived from plant extraction or green chemistry can increase the production of skin ceramides.