Que sont les céramides et quels sont leurs rôles?
Ceramides are a family of non-comedogenic lipids that play a vital role in the barrier function and are found naturally in the skin. Lipids in the stratum corneum (the skin’s outer layer) are composed of 50% ceramides, 25% cholesterol, and 15% free fatty acids, with smaller quantities of phospholipids and cholesterol sulphate.
Ceramides act as a glue that holds skin cells together to create a semi-permeable barrier. Some skincare products may contain ceramide precursors which are ingredients that have the ability to stimulate the skin to create natural ceramides. Common ceramide precursors are phytosphingosine and sphingosine.
Why do you need ceramides in your skincare regimen if your body already contains them?
As the skin matures, there is a reduction of ceramides naturally present in the skin, resulting in a compromised barrier function that weakens the skin’s moisture-retaining properties. In our 30s, our skin’s naturally produced ceramides are reduced by up to 40%, and in our 40s this loss can increase up to 60%.