The skin barrier is made up of ceramides, cholesterol and fatty acids that become depleted overtime which can lead to dull, acne-prone, texture-filled skin.
Finding skincare products with the golden ratio of these key components can significantly improve the look of your skin.
Let’s take a look at what each of these ingredients have to offer, and then we’ll look at what this golden ratio is and what it means for your skin.
The skin is made up of a plethora of lipids that keep the skin intact, healthy, and protects it from exogenous stressors. Ceramides make up a portion of this lipid skin layer. It functions to maintain the structural integrity of the skin and keep the water content in the skin balanced (1). In this way, ceramides help to maintain the water permeability barrier – Keeping water in the skin in order to keep it hydrated.
Those experiencing skin conditions such as severely dry skin, acne, dehydrated skin, and irritated skin are often found to have low ceramide content in the skin (1). An improvement in these skin conditions are evident when supplemented with topical application of ceramides.
Ceramide-containing creams have been shown to significantly improve skin hydration after just 24 hours (2). In addition, ceramide application reduces transepidermal water loss, otherwise known as water loss from the outer layer of the skin. This keeps the skin moisturized and hydrated.
Ceramides prevent microbes and other antigens from entering the skin (3). It is an essential component of maintaining the skin barrier and preventing inflammation of the skin.
Lipids make up a large part of the skin’s barrier. The skin’s barrier is an essential component in protecting the skin from external factors such as microbial or toxic substances. Another function of the lipid barrier is to prevent water and electrolytes from leaving the epidermis. This ensures that the water content in the skin remains balanced, maintaining skin hydration and barrier integrity (4).
Cholesterol plays an important role in maintaining both the permeability barrier (that prevents water loss from the skin) and the anti-microbial barrier (which prevents microbes and toxins from entering the skin) (4).
When the barrier is disrupted from stressors such as UV rays, pollution, or even harsh scrubs, the skin immediately begins to make more cholesterol to replenish the barrier (4). When the amount of cholesterol in the skin decreases, the permeability barrier is slow to repair itself.
Fatty acids make up phospholipids, which are essential components of cell membranes (5). The epidermis is made up of many fatty acids which contribute to the permeability barrier of the skin.
Much like cholesterol, damage to the skin barrier encourages an increase in production of fatty acids (4).
Fatty acids, such as polyunsaturated fatty acids, are important in reducing water loss and maintaining the structural integrity of the skin (6).
Linoleic acid is an example of a fatty acid that prevents dry and scaly skin (6). It contributes to the normal function of the skin and reduces inflammation.
The Golden Ratio
These components of the skin barrier form a so-called golden ratio that promotes optimal skin health and integrity of the skin barrier.
The skin barrier is made up of approximately 50% ceramides, 25% cholesterol and 10-20% fatty acids (7).
Topical skincare formulations that mimic this ratio can be an effective way of improving skin barrier function and thus, skin health.
This powerhouse of a product boasts many skin-loving ingredients. Most importantly, it is formulated with the correct ratio of ceramides, cholesterol and fatty acids.
It is important to pay attention to the ingredients in your skincare and be on the lookout for ceramides, cholesterol, and fatty acids that can help to maintain the skin barrier.
- Coderch L, López O, de la Maza A, Parra JL. Ceramides and skin function. Am J Clin Dermatol. 2003;4(2):107-29. doi: 10.2165/00128071-200304020-00004. PMID: 12553851
- Spada F, Barnes TM, Greive KA. Skin hydration is significantly increased by a cream formulated to mimic the skin’s own natural moisturizing systems. Clin Cosmet Investig Dermatol. 2018 Oct 15;11:491-497. doi: 10.2147/CCID.S177697. PMID: 30410378; PMCID: PMC6197824.
- Cha, H. J., He, C., Zhao, H., Dong, Y., An, I., An, S.”Intercellular and intracellular functions of ceramides and their metabolites in skin (Review)”. International Journal of Molecular Medicine 38, no. 1 (2016): 16-22.
- Feingold KR. The outer frontier: the importance of lipid metabolism in the skin. J Lipid Res. 2009 Apr;50 Suppl(Suppl):S417-22. doi: 10.1194/jlr.R800039-JLR200. Epub 2008 Oct 31. PMID: 18980941; PMCID: PMC2674689.
- Berg JM, Tymoczko JL, Stryer L. Biochemistry. 5th edition. New York: W H Freeman; 2002. Chapter 22, Fatty Acid Metabolism.
- Ziboh VA, Miller CC, Cho Y. Metabolism of polyunsaturated fatty acids by skin epidermal enzymes: generation of antiinflammatory and antiproliferative metabolites. Am J Clin Nutr. 2000 Jan;71(1 Suppl):361S-6S. doi: 10.1093/ajcn/71.1.361s. PMID: 10617998.
- Sjövall, P., Skedung, L., Gregoire, S. et al. Imaging the distribution of skin lipids and topically applied compounds in human skin using mass spectrometry. Sci Rep 8, 16683 (2018).