The lipid barrier of the skin is part of the epidermal barrier, which is the first in contact with the environment. This is a unique mechanism that has allowed humans, in the course of evolution, to protect themselves from an often aggressive environment.

The stratum corneum of the epidermis consists of 10-25 layers of cells oriented parallel to the surface of the skin and embedded in a lipid matrix (lipid barrier of the skin). It is the cells of the stratum corneum of the epidermis and the lipid matrix that fills the intercellular spaces that provide the barrier functions of the skin, protecting the body from the penetration of bacteria, viruses and other exogenous substances, as well as retaining water and electrolytes.

The lipid matrix of the stratum corneum of the epidermis makes up about 10% of its volume and has a unique structure and chemical composition.

Chemical composition of the skin lipid barrier

Lipids in the epidermal skin barrier mainly consist of:

• ceramides (50%);
• cholesterol and its esters (25%);
• saturated fatty acids (10%).

A balanced ratio of these three categories of lipids is essential to ensure the integrity and protective properties of the skin's lipid barrier.

Ceramides- This is the simplest type of sphingolipids, consisting of sphingosine and a fatty acid (in particular, linoleic acid). Currently, 342 ceramides belonging to 12 different types have been identified in the stratum corneum of the epidermis. Their list is constantly updated.

Ceramides perform a huge number of biological functions. One of the most important is structuring (ceramides are able to form bilayers).

Cholesterol is one of the most important lipids that form the lipid barrier of the skin. It is mainly synthesized directly in the epidermis. A small amount may enter directly into the bloodstream.

The main function of cholesterol as a component of the epidermal barrier is to impart plasticity to the lipid matrix. Without it, the stratum corneum of the epidermis would be very fragile.

Concerning free fatty acids, then in the stratum corneum of the epidermis saturated fatty acids dominate, with long-chain fatty acids predominating. The bulk of them are synthesized in the body itself. Some acids (for example, linoleic, gamma-linolenic) enter the body only with food.

Free fatty acids also play a structuring role.

Lipids in the intercellular spaces of the stratum corneum are organized in the form of plates assembled from 3 layers (wide - narrow - wide). The wide layer is paired bilayers of ceramides and cholesterol, the narrow layer is one unifying layer of ceramides.

The formation of a ceramide bilayer is due to the fact that they unfold with the nonpolar part towards each other, and the polar part outward. This is a unique quality of ceramides that determines the barrier properties of the epidermis.

By placing themselves in this way, the ceramides essentially “stitch” the layers together. Due to this, in a plane perpendicular to the plates, lipids are organized into a rigid rectangular crystal lattice.

Figuratively, this system of organizing the lipid barrier of the skin can be described as a quilt :) The lipid layers are stitched with ceramide chains. In the same way, lipid layers are “sewn” to the cells of the stratum corneum of the epidermis, ensuring the integrity of the epidermal skin barrier.

For the correct structural organization of the lipid barrier of the skin, the chemical composition of lipids and the ratio of the main components are very important. If this balance is disturbed, the stratum corneum of the skin becomes unable to perform its protective functions.

Why is the lipid barrier of the skin destroyed?

Many factors can provoke the destruction of the lipid barrier of the skin:

• any mechanical damage to the skin (wounds, burns, frostbite, cuts, scratches);
• skin diseases (acne, atopic dermatitis, psoriasis, etc.);
• exposure to ultraviolet radiation (see “Photoaging”) and other environmental factors (frequent showering, visiting a swimming pool, dry air from heating systems, cold air);
• exposure to aggressive surfactants in cleansers, shower gels, shampoos, etc.;
• metabolic diseases with impaired lipid synthesis;
• decrease in cholesterol synthesis in the epidermis with age;
• constant contact with chemicals (for example, chemical detergents);
• psychological stress (the epidermal barrier is negatively affected by hormones synthesized during stress);
• oxidative stress - damage to the intercellular structures of the stratum corneum of the epidermis by free radicals (see “Lipid peroxidation”, “Antioxidants and skin”);
• unbalanced diet (lack of fatty acids).

Such a number of provoking factors in everyday life leads to the fact that every day we gradually remove its natural protective barrier from the skin.

The skin tries to replenish the content of lipids (they are stored in the skin’s “storehouses” - lamellar bodies), but its possibilities are not limitless. It takes time for the skin to synthesize new lipids. If the protective barrier of the skin is affected by other unfavorable factors during this period, then it is not able to completely restore itself, and as a result, external signs of destruction of the lipid barrier of the skin appear.

How does the destruction of the lipid barrier of the skin manifest itself?

If this structure is violated, the barrier ceases to partially or completely cope with its task - first of all, preserving water in the body and protecting against the penetration of harmful substances and microorganisms.

The first sign of destruction of the skin's lipid barrier is skin dehydration due to increased water evaporation. Dehydrated skin quickly ages, loses firmness and elasticity. Dry skin, peeling, and fine wrinkles appear.

The skin becomes sensitive and vulnerable to external factors. The destruction of the barrier that protects against the penetration of bacteria and viruses leads to irritation, the development of inflammatory processes in the skin (for example, acne), and skin diseases.

This situation requires urgent measures to restore the lipid layer of the skin:

1. cessation of exposure to factors that provoke the destruction of the epidermal barrier;
2. the use of creams containing physiological lipids (ceramides, free fatty acids and cholesterol) in a balanced combination.

We will talk more about ways to restore the epidermal barrier in the article “Restoring the lipid barrier of the skin.”

The skin protects our body, but who protects the skin itself? Why don't microbes penetrate through it? Why doesn't moisture evaporate? The skin has its own defense system, and first of all it is the epidermal barrier. The condition of the skin largely depends on it.

Often we consider our skin to be problematic and begin to treat it in every possible way. We especially like to do this at home without the supervision of a specialist. However, few people know that many skin problems begin due to a damaged epidermal barrier. And before you engage in treatment, you need to understand it.

In this post we will talk about what the epidermal barrier is, what destroys it, and how to restore it.

Epidermal barrier

The first thing that protects the skin is epidermal barrier.

To better understand what this is, imagine a brick wall. The base of the wall is made of bricks. In the skin, their role is played by dead scales of the upper layer - corneocytes. Corneocytes hold each other like hands with the help of protein bridges (desmosomes). The layer (cement) between the bricks of our skin is fats (also called lipids).

The epidermal barrier is also called the lipid barrier of the skin.

Just as bricks are securely fastened together with cement, so corneocytes are firmly glued together by a lipid layer.

The “cement” of the epidermal barrier consists of three types of lipids - ceramides, free fatty acids and cholesterol. For the barrier to function properly, it is necessary that all of them are constantly present in sufficient quantities.

The epidermal barrier, like a wall, reliably protects our skin. It is very difficult for substances (both harmful and beneficial) to penetrate the wall, and many are not able to overcome the barrier at all.

Let's figure out why?

As we remember from the post about the epidermis, corneocytes are dense dead horny scales consisting of keratin protein. They are like a shell that nothing can penetrate.

The only chance for substances to penetrate into the epidermis is to walk along the “cement”.

Since “cement” consists of fats, it allows only fats and substances that dissolve in them to pass through. Fat-soluble substances penetrate the barrier well and can pull other substances along with them.

Water and water-soluble substances are not able to overcome this barrier, because water does not dissolve in fat. This is how the epidermal barrier protects us from dehydration. It does not let water in and does not let it out.

In addition to being fat-soluble, the substances must be very small. The distance between corneocytes is only millionths of a millimeter. Therefore, only very small molecules can squeeze between them.

How convenient it would be if all the components of our numerous jars were fat-soluble substances with micromolecules. But, unfortunately, this is not the case. Not all components of cosmetics penetrate the epidermis. Many of them have no chance to overcome the epidermal barrier.

The goal of a good cosmetic product is to break through the wall and bring benefits inside. Competent and effective cosmetics overcome the barrier without destroying it.

Hydrolipid mantle

The reliability and strength of the epidermal barrier helps maintain hydrolipid mantle.

This is a film on the surface of the skin, consisting of fat, sweat and acids formed as a result of the vital processes of the epidermis.

Just as the walls are covered with plaster on top, the epidermal barrier is additionally wrapped in a hydrolipid mantle.

The hydrolipid mantle is also called the hydrolipid mantle, the acid mantle, or the Marchionini mantle.

The surface of the skin is an acidic environment. A measure of acidity is pH. The pH scale is from 0 to 14. From 0 to 6.9 is an acidic environment, from 7.1 to 14 is an alkaline environment. Neutral pH is 7, the pH of the hydrolipid mantle of normal healthy skin is from 4.7 to 5.7.

All living cells are sensitive to pH levels. Harmful bacteria cannot tolerate acidification and die. Beneficial bacteria (for example, lactobacilli), on the contrary, feel comfortable in an acidic environment. They live on the skin and fight harmful bacteria.

Frequent contact with alkaline agents (for example, soap) destroys the hydrolipid mantle. Which creates fertile ground for harmful bacteria and extreme discomfort for beneficial ones.

This is why gentle cleansing with foams, gels and other alkali-free products is so important. Alkalies in cleansers come into contact with acids on the surface of the skin, neutralize them and disrupt the natural pH. As a result, the hydrolipid mantle is destroyed, beneficial bacteria die the death of the brave, and harmful ones begin to happily multiply.

Choose soft washes and be sure to use toners after washing. Using toners, especially those containing citric acid, we balance the pH level of the skin.

Violation of the epidermal barrier

What happens to the skin when the protective layer is broken and what consequences does this lead to?

• So, the border has been destroyed and nothing prevents the “export of valuables from the country.” In our case it is moisture. The skin can no longer retain moisture and it begins to evaporate through the gaps in the cement. As a result, we feel a constant feeling of tightness and discomfort. The skin dries, peels, loses elasticity and begins to wrinkle. Red itchy spots may even appear.

• Hypersensitivity appears. The skin reacts sharply to the sun, wind and the application of cosmetics, including cleansers. Many remedies that used to be favorites now bring extreme discomfort. Peels, scrubs, cosmetics with acids move to the attic.

• The door opens to germs, toxins and allergens. This leads to irritation, redness, inflammation, allergic reactions and provokes skin diseases (for example, dermatitis).

Solvents and surfactants (soaps, degreasers, cleaning products). Dissolve the hydrolipid mantle and the lipid layer of the epidermal barrier. Water begins to evaporate from the surface of the skin.

Mechanical damage (scrubs). Excessive exfoliation of corneocytes. The skin becomes thinner and more vulnerable.

UV. Excessive portions of ultraviolet radiation provoke oxidative reactions in lipid layers, damaging them.

Lack of essential fatty acids. Fatty acids build “cement” and are essential for its proper functioning.

Skin diseases (eczema, various forms of dermatitis). The skin dries, loses moisture, and cracks. The hydrolipid mantle is disrupted and the permeability of the barrier increases.

Restoring the epidermal barrier

A healthy epidermal barrier is a key component of a beautiful look and well-being of any skin type - oily, problematic, dry, sensitive. This is why barrier restoration is so important.

We often incorrectly determine our skin type due to a broken epidermal barrier. For example, you think your skin is oily and you start to cleanse it too much and use drying products. You think that this way you will remove excess fat. But in fact, your epidermal barrier is broken. And all your “anti-fat” care not only does not produce results, but also aggravates the situation. The remnants of the barrier “fall”, the skin begins to dry out more and, in response to this, begins to produce fat even more actively. The circle closes.

What to do?

The main thing is not to hang your nose.
In a healthy person, the barrier is restored by 60% after 12 hours and completely after 72 hours. If your barrier is completely destroyed, recovery will take longer (up to a month), but it is quite possible to restore protection.

Gentle cleansing.

Avoid products with surfactants as much as possible, especially harsh ones. It is best to switch to waterless cleansing at the initial stage - use micellar water, wash with a decoction of herbs.

Regular moisturizing.

Use a moisturizer daily and moisturizing masks 2-3 times a week. Choose products that contain amino acids, urea, lactic acid, hyaluronic acid, sorbidol, algae, chitosan, collagen, elastin, aloe vera, glycerin. All these components not only attract moisture, but also contribute to its long-term preservation. Plus, as cliché as it may sound, drink more water.

Smart nutrition.

Use nourishing cream daily, nourishing masks 2-3 times a week, alternate them with moisturizing ones. Choose nutritional products that contain lipids (ceramides, liposomes, base oils) and fatty acids (linoleic, linolenic, gamma-linolenic, oleic, palmitic). These components effectively restore damaged lipid layers. It is important to use fatty acids not only in cosmetics, but also internally in the form of food supplements. Drink and eat oils. Especially flaxseed.

Constant protection.

Avoid strong mechanical impact. While the barrier is being restored, avoid scrubs. Use products containing film-forming components - collagen, elastin, waxes, silicones, lanolin, paraffin. They form a protective film on the skin that will prevent moisture loss and the penetration of dust, allergens, etc.

Summarize

Skin health depends on the epidermal barrier.

Like a brick wall, it consists of bricks (corneocytes) and cement (lipids). Lipids are responsible for the permeability of the epidermal barrier.

On top, the epidermal barrier is “dressed” in a hydrolipid mantle. It must be treated with care and protected from destruction. It prevents the penetration of microbes.

Damage to the epidermal barrier and hydrolipid mantle is stressful for the skin. This can lead to dryness, dehydration, hypersensitivity, and provoke skin diseases.

A damaged barrier can be restored if you choose the right care. It includes gentle cleansing plus creams and masks containing a competent mix of moisturizing components, physiological (skin-related) lipids and film-forming substances.

Still have questions? Ask them in the comments.

See you again on LaraBarBlog. ♫

I am often asked where to start caring for sensitive skin or oily, problematic, age-related skin.

And it often happens that the skin is oily and at the same time dry, it tightens after washing, it reacts to literally everything.

In all these situations, ceramides should be one of the “building blocks” of proper care.

Do you know what it is?

Ceramides are the most important component lipid barrier: they perform a protective function, retain moisture and are responsible for skin renewal.

When the lipid layer is strong, our skin is healthy and looks great, nothing dries or tightens, there is no irritation.

But as soon as the skin barrier is broken or ceramides are no longer produced in the required quantities, the skin begins to “hurt”. Often we ourselves break the lipid barrier aggressive washing and improper care.

Dermatologists believe that for skin diseases the amount of ceramides is also depleted. This applies to acne, atopic dermatitis and psoriasis.

How does the skin behave when the barrier is broken?

If there are not enough ceramides, the barrier is broken. The skin ceases to defend itself: it easily allows allergens and toxins to pass through, and evaporates moisture. Dryness, inflammation and swelling occur. Even oily skin flakes and rashes appear.

What to do?

Restore the lipid barrier.

Use creams with ceramides for healing after peelings and procedures.

According to research, ceramides kill three birds with one stone in the treatment of acne: they soothe, restore and accelerate the healing of inflammation.

Creams with ceramides

Let’s look again at who needs a cream with ceramides:

• restoration of dry, dehydrated and irritated skin
• auxiliary care for acne, rosacea, eczema, dermatitis
• accelerate healing after peelings and aggressive procedures
• Reduce dryness and irritation from retinoids
• with age-related decrease in ceramides in the skin

As you can see, almost everyone!

Ceramides are one of the building blocks that we lay in the foundation of basic skin care and restoration. I will also write about how to restore skin correctly.

I've tried different creams with ceramides, and I like these ones better than others. All compositions are “pure” without controversial components.

AnneMarie Borlind fluid with ceramides

I have been using this fluid for several years in a row, although I am not particularly fond of cosmetics =)

It is lightweight and suitable for all skin types and can be used as a serum or cream, whichever you prefer. It is possible and necessary to take a course for aged and dehydrated skin. There are few soothing components in it, composition is aimed at strengthening.

To care for irritated skin and acne, it is better to consider the options I give below.

Where can I buy: RUB 3,610 for Ceramide Fluid on iHerb.

Dado Sens Soothing emergency cream

This cream is simply the find of the year! I wrote in the material about, but I will repeat it again. The cream is ideal for skin redness, in the treatment of problem skin, acne. Soothes and perfectly restores after retinol and acids.

The cream looks like thick cottage cheese when squeezed out of a tube, without aroma. Apply a thin layer and absorb without residue! The cream is not greasy, but dense. I like a thicker layer as a soothing mask. The skin is like new after.

As part of components soothe and heal: allantoin, panthenol, licorice extract, magnesium, bisabolol, black currant oil, ceramides 3, ceramides 6, yeast extract for problem skin.

In research ceramides 3 in combination with bisabolol have shown high effectiveness in eliminating redness. Both components are here.

Where can I buy: FCX705 for all

Dado Sens Anti-aging fluid cream Ectoin

This ectoine fluid is a great alternative to the AnneMarie Borlind fluid. They are similar in smell and texture, although this brand does not use fragrances at all. Therefore, the fluid is suitable for sensitive skin.

For those who don't know, Dado Sens is the younger brother of AnneMarie Borlind. Both brands are produced in the protected area of ​​the Black Forest. Differences in direction: Borlind is focused on effective premium care, and the Dado brand is ″dermacosmetics″.

The recipes are developed with the participation of dermatologists, the packaging is more modest and the cost is lower. And the compositions are first-class.

Fluid with ectoine restores the skin barrier and works for rejuvenation. Star components: ectoine, ceramides, isoflavones, silicon.

Ectoin strengthens the skin and protects from the negative effects of the environment, prepares it for frost and cold weather. Ceramides restore dehydrated, irritated skin.

Isoflavones of iris and clover increase density. Silicon strengthens connective tissue. It’s nice that with such a cool composition, the cost of the cream is not prohibitive!

Where can I buy: for 4fresh + 5% discount using code FCX705 for all

Many of you have already heard about ectoine, which improves skin immunity and protects against environmental stressors.

Of course you know him! Ectoin is in the cream EO Products, Ageless Skin Care, which I often recommend for the cool season =)

Now it’s your turn, tell me, do you use ceramides? What are you doing to restore your skin?

The molecules of phospholipids and glycolipids are amphiphilic, that is, the hydrocarbon radicals of fatty acids and sphingosine are hydrophobic, and the other part of the molecule, formed from carbohydrates, a phosphoric acid residue with choline, serine, ethanolamine attached to it, is hydrophilic. As a result, in an aquatic environment, the hydrophobic sections of the phospholipid molecule are displaced from the aqueous environment and interact with each other, and the hydrophilic sections come into contact with water, resulting in the formation of a double lipid layer of cell membranes (Fig. 9.1.). This double layer of membrane is permeated with protein molecules - microtubules. Oligosaccharides are attached to the outside of the membrane. The amount of protein and carbohydrates in different membranes is not the same. Membrane proteins can perform structural functions, can be enzymes, carry out transmembrane transport of nutrients, and can perform various regulatory functions. Membranes always exist in the form of closed structures (see Fig. 9.1). The lipid bilayer has the ability to self-assemble. This ability of membranes is used to create artificial lipid vesicles - liposomes.

Liposomes are widely used as capsules for the delivery of various drugs, antigens, enzymes to various organs and tissues, since lipid capsules are able to penetrate cell membranes. This allows drugs to be directed precisely to the affected organ.

Fig.9.1. Diagram of a cell membrane made from a lipid bilayer. The hydrophobic regions of the lipid molecule attract each other; The hydrophilic regions of the molecule are located on the outside. Protein molecules penetrate the lipid bilayer.

Lipid metabolism

In the body, neutral fats are found in 2 forms: storage fat and protoplasmic fat.

The composition of protoplasmic fat includes phospholipids and lipoproteins. They participate in the formation of structural components of cells. The membranes of cells, mitochondria and microsomes consist of lipoproteins and regulate the permeability of individual substances. The amount of protoplasmic fat is stable and does not change depending on fasting or obesity.

Spare (reserve) fat - it consists of triacylglycerols of fatty acids - is located in the subcutaneous fatty tissue and in the fatty depots of internal organs.

The functions of reserve fat are that it is a reserve source of energy available for use during periods of fasting; This is an insulating material against cold and mechanical injuries.

It is also important that lipids, when decomposing, release not only energy, but also a significant amount of water:

When 1 gram of protein is oxidized, 0.4 g is released; carbohydrates – 0.5 g; lipids – 1 g of water. This property of lipids is of great importance for animals living in desert conditions (camels).

Digestion of lipids in the gastrointestinal tract

In the oral cavity, lipids are subjected only to mechanical processing. The stomach contains a small amount of lipase, which hydrolyzes fats. Low activity of gastric juice lipase is associated with the acidic reaction of the stomach contents. In addition, lipase can only affect emulsified fats; there are no conditions in the stomach for the formation of a fat emulsion. Only in children and monogastric animals does gastric juice lipase play an important role in lipid digestion.

The intestine is the main site of lipid digestion. In the duodenum, lipids are affected by liver bile and pancreatic juice, and at the same time neutralization of intestinal contents (chyme) occurs. Emulsification of fats occurs under the influence of bile acids. The composition of bile includes: cholic acid, deoxycholic (3.12 dihydroxycholanic), chenodeoxycholic (3.7 dihydroxycholanic) acids, sodium salts of paired bile acids: glycocholic, glycodeoxycholic, taurocholic, taurodeoxycholic. They consist of two components: cholic and deoxycholic acids, as well as glycine and taurine.

deoxycholic acid chenodeoxycholic acid

glycocholic acid

taurocholic acid

Bile salts emulsify fats well. This increases the area of ​​contact between enzymes and fats and increases the effect of the enzyme. Insufficient synthesis of bile acids or delayed intake impairs the effectiveness of enzyme action. Fats, as a rule, are absorbed after hydrolysis, but some of the finely emulsified fats are absorbed through the intestinal wall and pass into the lymph without hydrolysis.

Esterases break the ester bond in fats between the alcohol group and the carboxyl group of carboxylic acids and inorganic acids (lipase, phosphatases).

Under the action of lipase, fats are hydrolyzed into glycerol and higher fatty acids. Lipase activity increases under the influence of bile, i.e. bile directly activates lipase. In addition, the activity of lipase is increased by Ca ++ ions due to the fact that Ca ++ ions form insoluble salts (soaps) with the released fatty acids and prevent their inhibitory effect on lipase activity.

Under the action of lipase, the ester bonds at the α and α 1 (side) carbon atoms of glycerol are first hydrolyzed, then at the β-carbon atom:

Under the action of lipase, up to 40% of triacylglycerides are broken down to glycerol and fatty acids, 50-55% are hydrolyzed to 2-monoacylglycerols and 3-10% are not hydrolyzed and are absorbed in the form of triacylglycerols.

Feed sterides are broken down by the enzyme cholesterol esterase into cholesterol and higher fatty acids. Phosphatides are hydrolyzed under the influence of phospholipases A, A 2 , C and D. Each enzyme acts on a specific ester bond of the lipid. The points of application of phospholipases are presented in the diagram:

Pancreatic phospholipases, tissue phospholipases, are produced in the form of proenzymes and are activated by trypsin. Snake venom phospholipase A 2 catalyzes the cleavage of the unsaturated fatty acid at position 2 of phosphoglycerides. In this case, lysolecithins with a hemolytic effect are formed.

phosphotidylcholine lysolecithin

Therefore, when this poison enters the blood, severe hemolysis occurs. In the intestine, this danger is eliminated by the action of phospholipase A 1, which quickly inactivates lysophosphatide as a result of the cleavage of a saturated fatty acid residue from it, converting it into inactive glycerophosphocholine.

Lysolecithins in small concentrations stimulate the differentiation of lymphoid cells, the activity of protein kinase C, and enhance cell proliferation.

Colamine phosphatides and serine phosphatides are cleaved by phospholipase A to lysocolamine phosphatides, lysoserine phosphatides, which are further cleaved by phospholipase A 2 . Phospholipases C and D hydrolyze choline bonds; colamine and serine with phosphoric acid and the remainder of phosphoric acid with glycerol.

Absorption of lipids occurs in the small intestine. Fatty acids with a chain length of less than 10 carbon atoms are absorbed in non-esterified form. Absorption requires the presence of emulsifying substances - bile acids and bile.

Resynthesis of fat characteristic of a given organism occurs in the intestinal wall. The concentration of lipids in the blood is high within 3-5 hours after eating food. Chylomicrons– small particles of fat formed after absorption in the intestinal wall are lipoproteins surrounded by phospholipids and a protein shell, containing molecules of fat and bile acids inside. They enter the liver, where lipids undergo intermediate metabolism, and bile acids pass into the gallbladder and then back to the intestines (see Fig. 9.3 on p. 192). As a result of this circulation, a small amount of bile acids is lost. It is believed that a molecule of bile acid completes 4 cycles per day.

Anna Margolina, Ph.D.

Main causes of damage to the epidermal barrier
- Cleansing
- Skin nutrition
- Skin hydration
- Some moisturizing ingredients in cosmetics
- Day protection
- Vegetable oils to nourish and restore the skin

After 30 years, many women note that their skin becomes flabby, dry and dull. Typically, such skin is hypersensitive, often red and inflamed. These symptoms indicate that the skin's epidermal barrier is damaged. If measures are not taken, the skin will become increasingly dehydrated, lose elasticity, and fade.

MAIN CAUSES OF DAMAGE TO THE EPIDERMAL BARRIER:

1. The action of factors that cause the formation of free radicals in the skin and peroxidation of epidermal lipids (UV radiation, radiation, immune reactions).

2. Direct destructive effects of aggressive substances on the stratum corneum (surfactants - P superficial A active IN substances, solvents).

3. Inhibition of the vital activity of epidermal cells that synthesize lipids (surfactants, radiation, UV radiation, aging).

4. Lack of essential fatty acids (linoleic, linolenic, gamma-linolenic).

Violation of the barrier function of the stratum corneum leads to serious consequences and is reflected primarily in the appearance of the skin. The first symptom of damage to the epidermal barrier is dry skin, then the adhesion between the horny scales is disrupted, which leads to increased desquamation, then the normal differentiation of keratinocytes is disrupted and, along with continued desquamation, the stratum corneum thickens. Skin whose epidermal barrier is damaged becomes permeable not only to water, but also to bacteria and toxins, so it often becomes red, itchy and inflamed.

Restoring a damaged epidermal barrier is not easy. First of all, because skin whose barrier properties are impaired becomes more sensitive to the action of factors that cause further damage to the epidermal barrier. The higher the skin's permeability to water, the deeper the surfactants of detergents, microbes and toxins penetrate into it, causing an inflammatory reaction and the formation of free radicals in the skin. Surfactants that penetrate into the deep layers of the epidermis destroy the cells of the basal layer, as a result of which the synthesis of epidermal lipids is disrupted, and free radicals formed in the skin due to inflammatory processes and the action of toxins cause further destruction of lipid layers. A vicious circle arises - the more damaged the epidermal barrier is, the more easily it is damaged. Therefore, the first thing to do to save the skin is to prevent further destruction of the barrier.

PURIFICATION

You need to start by washing your face. Carefully study the cleansers you use - perhaps they are the main reason for the destruction of the epidermal barrier. All cleansers that come into contact with the skin must be very gentle. Try to wash your face with a cleanser no more than twice a day to reduce the possibility of skin irritation - a cleanser, no matter how gentle, aims to remove dirt from the skin and does not differentiate between used and protective oils or between sweat and skin moisture. Contact of the cleansing product with the skin of the face should be very short-term and it should be washed off thoroughly.

Water has become a big problem in modern cities. It often contains substances whose contact with damaged skin is undesirable. Therefore, during periods of exacerbation of skin sensitivity and irritability, it makes sense to wash your face with special purchased water or use floral water obtained by steam distillation from fragrant herbs and flowers.

SKIN NUTRITION

Damage in the barrier should be “patched” with something. For this purpose, lipids are used both in the form of pure oils and in combination with other ingredients in cosmetics. Lipid molecules penetrate into intercellular spaces and are integrated into the lipid barrier. Some of the lipid molecules applied on top gradually move along the intercellular spaces, reach the living layers of the epidermis and are included in cellular metabolism. In particular, they can serve as the foundation for further synthesis of lipids characteristic of the skin barrier.

Most often, oils containing essential fatty acids (linoleic and gamma-linolenic) are used to supply cells with “building material”. They promote accelerated synthesis of lipid barrier components, delivering the necessary lipid precursors directly to the cells, thus having a particularly beneficial effect on the skin (borage, evening primrose, black currant oils). Oils rich in sterols stimulate keratinocytes and have anti-inflammatory properties (rosehip, tamanu, soybean, safflower oils). Oils enriched with saturated and monosaturated fatty acids have a more pronounced occlusive property (blocking moisture evaporation) and help restore barrier properties by moisturizing the epidermis (shea butter, macadamia butter, corn butter, coconut butter, cocoa butter, cashew butter). It is advisable to apply oils to the skin after washing.

SKIN HYDRATION

Restoring the epidermal barrier is just one way to hydrate dry skin. This is a rather slow method, which also takes time. By restoring the barrier, we limit the evaporation of water through the stratum corneum. You can act differently - moisturize the stratum corneum itself or cover it with a damp film. Another way to moisturize the skin is to increase blood flow in the vessels of the dermis, thus increasing the flow of moisture into the epidermis.

The moisture content in the epidermis depends on the amount of moisture entering it from the dermis, as well as on the rate of evaporation of water through the stratum corneum. The upper part of the stratum corneum, in direct contact with air, is practically devoid of lipids, so it dries faster than the epidermis as a whole. However, horny scales have their own autonomous source of water supply - they attract water from the air with the help of special molecules that have high moisture capacity (hygroscopicity). A complex of hygroscopic molecules on the surface of horny scales - natural moisturizing factor (NMF) - consists of:

Free amino acids - 40%
Sodium pyroglutamate - 12%
Urea - 7%
Ammonia, creatinine and other organic compounds - 17%
Magnesium - 1.5%
Potassium - 4%
Calcium - 1.5%
Sodium - 5%
Lactic and citric acids, chloride and phosphate ions - 12%

The elasticity of the stratum corneum depends on the amount of moisture associated with NMF. An insufficiently moistened stratum corneum creates the appearance of dry skin, even if there is enough moisture in the epidermis. In order to increase the moisture content of the stratum corneum, the same substances that are part of the natural moisturizing factor are added to cosmetics. These are urea, amino acids (series, glycine, alanine, proline), minerals (magnesium, potassium, sodium, calcium), Na-PCA, lactic acid,

All substances capable of attracting moisture from the air (having hygroscopicity) have a moisturizing effect. However, glycerin is not recommended in creams for dry skin, since by drawing water from the stratum corneum, it can further dehydrate the skin. Sorbitol is less hygroscopic than glycerin, so there is less risk of drying out the skin.

Recently, natural substances that form a film saturated with moisture on the skin have become increasingly popular moisturizing components. These are hyaluronic acid, chitosan, β-glucan from baker's yeast, protein hydrolysates (for example, collagen or wheat protein). It is not recommended to use petroleum jelly and other heavy oils that form a waterproof film on the skin to moisturize the skin, since they are also impermeable to air and the skin under them suffocates.

SOME MOISTURIZING INGREDIENTS IN COSMETICS

Glycerol
Softens the skin, lowers the freezing point of liquid (prevents the cream from freezing on the face on a frosty day). In humid air it works as a skin moisturizer, attracting moisture from the atmosphere. In dry air it can draw water from the stratum corneum.

Urea
Component of the natural moisturizing factor (NMF) of the stratum corneum. It is introduced into cosmetic formulations in a concentration of about 5%. Not recommended for use in cosmetics for sensitive skin and children's cosmetics. Has moisturizing, exfoliating and antimicrobial effects.

Lactic acid
NMF component of the stratum corneum. Moisturizing, exfoliating, antimicrobial effect.

Sodium pyroglutamate
NMF component of the stratum corneum. It is formed in cells during the process of keratinization from the protein filaggrin. In cosmetics it is used as a moisturizing ingredient. The best results are obtained by introducing Na-PCA into liposomes.

Hyaluronic acid
Glycosaminoglycan, which is the main component of the intercellular substance of the dermis. Forms a film on the surface of the skin. It has a high water-holding capacity, softens and moisturizes the skin, and reduces water loss through the stratum corneum.

Soluble collagen
Forms a moisturizing film on the skin, reduces water loss through the stratum corneum, softens the skin, and accelerates the healing of minor skin damage.

Chitosan
A polysaccharide obtained from the shells of marine crustaceans. Forms a moisturizing film on the skin, softens the skin and protects it from damage

β-glucan
A polysaccharide derived from the cell wall of baker's yeast. Forms a moisturizing film on the skin, protects the skin from UV radiation, and has an immunostimulating effect.

DAY PROTECTION

During the day, the skin should be protected from the damaging effects of UV rays, free radicals and further dehydration. To do this, use creams with hyaluronic acid, chitosan, waxes (jojoba, candelilla, bee), vitamin E, plant extracts with vitamin C and flavonoids (rosemary, grapes, green tea, witch hazel, etc.).

To successfully restore the epidermal barrier, the skin needs essential fatty acids, which are contained in three main oils - black currant, borage, evening primrose. It is advisable not only to apply them to the skin, but also to consume them internally in the form of food additives. Saturated fats and margarine, which consists of hydrogenated fat, should be excluded from the diet. Among the edible oils, soybean, corn, sesame, and rapeseed are very useful.

True restoration of the epidermal barrier occurs only after the epidermal cells receive the necessary building material and produce a sufficient amount of ceramides and other epidermal lipids, from which the epidermal layers will be built. But before this happens, you can apply something like patches to the lipid layer of the epidermis. For this purpose, cosmetics are used that contain ready-made layered structures built from polar lipids.

These can be liposomes or flat membrane-like structures (lamellae). They are sometimes made from ceramides, but more often they are made from phospholipids (they are similar to ceramides, but have two hydrophobic tails). When exposed to a damaged stratum corneum, liposomes or lipid lamellae are embedded in areas devoid of lipids and seal holes in the epidermal barrier.

VEGETABLE OILS FOR NUTRITION AND RESTORE SKIN

Borage oil
Borage, borage
Borago officinalis L.
Borage seeds contain up to 33% oil rich in gamma-linolenic acid (GLA). This determines its unique restorative properties. Recommended for dry and aging skin, also used as a nutritional supplement that improves the structure of skin and hair.

Evening primrose oil
Evening primrose biennial
Oenothera biennis L.
“Evening primrose” is a direct translation of one of the English names of a plant whose flowers open only before sunset. Evening primrose seeds contain from 65 to 80% linoleic and 8 to 14% gamma-linolenic acids. Due to its high restorative properties, it is effective in the treatment of skin diseases (externally and as a dietary supplement). Stimulates nail growth and is used as a softening and moisturizing ingredient in cosmetics.

Blackcurrant seed oil
Black currant
Ribes nigrum L.
Blackcurrant oil is famous for its high content of linoleic and gamma-linolenic acids in an optimal 1:1 ratio. The integrity of the epidermal barrier and the moisture-retaining properties of the skin depend on the GLA content in the epidermis. Used in therapeutic and prophylactic products, especially recommended for dry and aging skin. A necessary component of anti-age therapy.

Rosehip oil (Rose hips seed oil / Rosa mosqueta oil / Musk rose seed oil)
Rose musk (muscat)
Rosa moschata J. Hermann
Fatty rosehip oil is obtained from the seeds of wild rose hips (bush climbing roses). Used in medicine to treat wounds and accelerate the regeneration of damaged tissue. Due to its high content of linoleic acid, it has anti-inflammatory properties. Used in body care products for normal, dry and damaged skin; for weakened, damaged hair. Promotes healing of small wounds and cracks.

Macadamia oil
Macadamia trifolia
Macadamia ternifolia F. Muehl
Macadamia oil is rich in triglycerols, stearic (about 60%) and palmitic (21%) acids, as well as vitamins B and PP. Helps maintain the skin's water balance, is easily absorbed, softens and nourishes the skin.

Soybean oil
Soybean cultivated
Glycine maxima (L.)
Due to the high content of sitosterol, tocopherols and essential fatty acids, it has pronounced regenerating properties, restores the epidermal barrier and moisture-holding capacity of the skin.

Shea butter
Butyrospermum parkii
The seeds of the shea tree (“butter tree”), a herbaceous, dry shroud of West and Central Africa, contain up to 50% fat, which retains the consistency of butter even at a temperature of 35 degrees. It is highly valued by the local population, who call it “karite” or “shea” (“shi”). Due to the exceptionally high content of unsaponifiable components, it has strong antioxidant and regenerating properties. Used in sunscreens, especially recommended for anti-age cosmetics. Restores damaged, dry hair.

Cocoa butter
Cocoa, chocolate tree
Teobroma cacao L.
The oil contains stearic, palmitic, oleic and linolenic acids. It has a healing and tonic effect and is used for dry, sensitive, delicate skin.