The ceramides are natural body components that have been demonstrated to be excellent moisturizers and a valuable ally against ageing and certain skin conditions. Given these properties, they are included in the formulations for many currently available cosmetic products.
Ceramides are essential components of the outermost layer of the epidermis, the stratum corneum, which acts as a barrier and helps keep the skin hydrated. The ceramides represent about 40% of the lipids (fats) in this layer (the other lipids are mainly cholesterol and fatty acids). Acting something like cement in a brick wall, the ceramides bind dead cells to each other and so slow down water loss and block penetration by harmful substances from the exterior. They also improve skin elasticity and cohesion.
It has been found that ceramides inhibit the action of certain substances, such as elastase and collagenase, which degrade collagen, elastin and other skin proteins that ensure that the cement that holds the horny cells remains in good condition. The loss of ceramides from the skin causes dryness, peeling, cracking and itchiness.
My cosmetic contains ceramides
Given their excellent moisturizing and firming properties, the cosmetics industry, in its endeavour to treat skin dehydration and the appearance of wrinkles as a result of ageing, has included the ceramides in the composition of many products, including soaps, moisturizers, shampoos, conditioners, sunscreens and a long list of other products. And, since the ceramides can also regenerate the cuticle cells of the scalp, they are also included in shampoos for damaged hair.
Ageing, sunlight, weather and skin disorders like eczema, psoriasis and atopic dermatitis reduce or otherwise alter the production of ceramides. Continuing with the wall analogy above, cracks appear in the cement holding the bricks together. Skin affected by eczema is poor in ceramides, whereas psoriatic skin is imbalanced in its composition. A number of clinical studies endorse the use of lotions containing ceramides as a complementary treatment for these conditions.
Natural or synthetic ceramides
Natural ceramides are very unstable substances that are costly to obtain, so synthetic ceramides are frequently used instead. Although the pseudo-ceramides are harmless and act in a similar way to natural ceramides, they have the drawback that they do not permeate the skin as well as the natural ceramides. However, penetration improves substantially if the ceramides are integrated in liposomes.
Ceramides appear on labels under the following names: Ceramide PC-102 (Hydroxypropyl Bislauramide MEA), Ceramide PC-104 (Hydroxypropyl Bispalmitamide MEA), Ceramide PC-108 (Hydroxypropyl Bisstearamide MEA), Ceramide 1, 2, 3, III, 6-II, etc.
Sources: American Journal of Clinical Dermatology & Dfarmacia.com
By Andrés Martínez, science journalist
