What is the skin barrier?
The epidermal barrier - known as the stratum corneum - is the outermost cell layer of our skin. As such, it protects our skin against stressful, health-threatening influences from the outside world. This protective layer consists of horny platelets (with no cell nucleus) which are held together by the skin's lipids. The layer’s structure is often compared to a brick wall: the platelets corresponding to the bricks, the lipids in between corresponding to the binding mortar.
The protective acid layer
In addition, our skin forms a protective hydro-lipid film on the surface of the skin. This layer of sweat, lipids, amino acids, and horny cells is also called the protective acid layer. Depending on the region of our body, the protective acid layer naturally has a slightly acidic pH-value, between 4.1 and 5.8. Most microorganisms such as viruses, bacteria or yeasts need a neutral pH to grow. A slightly acidic pH-value consequently protects our skin from pathogens and environmental pollutants which may otherwise cause irritation, itching, and blemishes.
What are the functions of our skin barrier?
An intact skin barrier ensures that our skin can store enough moisture. This protective layer minimizes water loss, and provides protection against UV radiation, heat, cold, and mechanical and chemical stress. Our skin barrier also protects the skin from harmful environmental influences such as air pollution and microorganisms - it prevents bacteria or viruses from penetrating the skin and causing pimples or skin diseases. A strong skin barrier is an essential prerequisite for healthy skin.
Don‘ts for the skin barrier
As so often, prevention is better than cure. The best way to keep your protective skin barrier intact is to protect it from harmful stimuli:
- Creams with skin-weakening emulsifiers
Emulsifiers hold together the lipid and water components of a cream. Classic emulsifiers, however, have an unpleasant side effect: they continue emulsifying in the barrier layer of our skin. In doing so, they remove skin-specific protective substances from the lipid layer, which are washed out the next time they come into contact with water. The ability of our skin to store moisture is thus weakened and the skin becomes more permeable to pollutants. This leads to chronic dryness, hypersensitivity, pimples, and blemishes. The more we apply emulsifier-containing creams, the worse the symptoms get – causing a vicious circle.
- Ingredients derived from mineral oil
Avoid cosmetics with ingredients from synthetic oils, i.e. mineral oils. Silicones and paraffins are free from allergens, but they weaken the skin barrier. By closing our skin pores, they prevent water loss, which sounds beneficial. In the process, however, they actually prevent our skin from getting what it needs. Frequent use of these cosmetics means that our skin can no longer breathe naturally, and that it ceases to produce its own important lipids.
- Scrubs and exfoliating ingredients
A no-go for sensitive skin are scrubs with rough grains like sand or salt. They damage the protective barrier, and dry out the skin. Then the risk of irritation, redness, itching, and inflammation increases. Also be wary of exfoliating products containing fruit acids, retinol (vitamin A) or vitamin C. Particularly in case of sensitive skin types, these praised beauty boosters – when used in higher concentrations – tend to damage the skin barrier, increasing hypersensitivity (to UV radiation and more).
- Cosmetics with alkaline pH-value
The pH-value of alkaline cosmetics is above 7.0 - in contrast to the healthy, slightly acidic skin surface. Solid hair soaps have an alkaline pH-value as well. Alkaline creams and cleansers weaken the skin's own acid protection, drying out your skin in the long term, making it susceptible to harmful penetrating microorganisms. Therefore, you should better prefer skin-neutral creams, serums and shampoos with a slightly acidic, low pH-value. They strengthen the skin's own protective acid layer, keeping the skin barrier intact.
Many face creams contain alcohol. Especially with sensitive, irritated skin, alcohol worsens these problems. It removes the skin's lipids from it’s barrier, thus weakening the skin's natural protective ability. Consequently, alcohol in face care is never recommended, even if your facial skin gets greasy soon after cleansing. In fact, degreasing the skin with alcohol stimulates sebum production as our skin tries to replace what it has lost. This makes oily skin even oilier, though it’s actually dehydrated and prone to redness, inflammation, and blemishes.
Do’s for strengthening your skin barrier
- Emulsifier-free skin care with hydrogenated lecithin (INCI: Hydrogenated Lecithin)
The saving solution is face care without skin-weakening emulsifiers. Instead of emulsifiers your face cream should contain skin-analogous active ingredients. For example hydrogenated lecithin is rich in cosmetically effective phosphatidylcholine, which resembles the skin's own membrane structure and makes the horny platelet layer water-repellent. Lecithin also stabilizes our cell membranes, stimulating cell metabolism and minimizing trans-epidermal moisture loss (TEWL). Such creams help to rebuild your skin barrier. According to the EU Cosmetics Regulation, they can be advertised as "emulsifier-free".
The natural active ingredient beta-glucan strengthens your skin barrier by improving the immune protection of the cells and maintaining long-lasting moisture. As an essential component of all myrto face creams and serums, beta-glucan soothes irritated and inflamed skin.
- Omega fatty acids
For the regeneration of a damaged skin barrier, skin-identical unsaturated fatty acids (omega fatty acids) from cold-pressed plant oils have also proven their worth:
- Linoleic acid (Omega 6) - high levels are contained in grape seed, black cumin or argan oil,
- Gamma-linolenic acid (Omega 3) - abundant in rose hip, pomegranate, hemp and evening primrose oil,
- Palmitoleic acid (Omega 9) – to be found in avellana, macadamia and sea buckthorn oil.
If you stick to skin-identical natural cosmetics – free from emulsifiers, alcohol, perfume and unnecessary fillers - your skin will soon feel smoother, softer and healthier.