Healthy skin barrier, Have you ever heard of this?
The skin barrier is a very important factor in skincare, and as a lot of consumers have become aware of it, many cosmetics with the keyword ‘skin barrier’ have been released in recent years.
People with healthy skin barrier maintain a good oil-water balance, protect their skin from external harmful substances, and prevent various skin diseases such as atopy, psoriasis, acne, and contact dermatitis. Besides, if your skin barrier is healthy, you’ll have good results even if you put on makeup.
So today, we will look into our important skin barrier in more detail and how we can strengthen it.
Structure and Role of Skin Barrier
We tend to think of only the stratum corneum on the surface of our skin that is visible when we hear the word ‘skin barrier’, but in fact, it is divided into various layers in the epidermis and works in various ways to protect our skin.
Skin is the largest organ in the body and covers the body’s entire external surface. It is made up of three layers, the Epidermis, Dermis, and the Hypodermis. The Epidermis is located just above the Dermis and refers from the Basal Layer(①) to the Stratum Corneum(④).
On the outside of the epidermis, our visible skin layer is Stratum Corneum(④). It is a physical barrier that forms the 1st skin barrier against all things in the atmosphere, including dust, pollen, germs, chemicals, and ultraviolet rays.
The structure of the epidermis is piled up in the order ① Basal Layer, ② Spinous Layer, ③ Granular Layer, and ④ Stratum Corneum as in the above image.
⑤ Keratinocyte produces new cells through mitosis for 10 days in ① Basal Layer and supplies them upside, and then they pass through ② Spinous Layer and ③ Granular Layer, becoming Keratins, which have only calcium and shell left, at the end, and they are naturally falling away from the skin. In our epidermis, this process continues to repeat.
In general, epidermal cells take 14 days to create and mature, and 14 days for them to age, resulting in a turnover in a total cycle of 28 days. The turnover cycle of epidermis cells is about two to three weeks for young people in their 20s and 30s, but older people are twice as long as they are.
As we age, our skin loses elasticity due to many wrinkles because the turnover cycle of these epidermal cells is prolonged, and new cells are not formed quickly.
Have you ever touched a child’s skin?
The skin of children has a short turnover cycle of these epidermal cells, so this is why their skin is elastic and clean.
The Granular Layer below the Stratum Corneum, secretes two granules below.
- Keratohyalin Granule: It secretes the famous Filaggrin, Natural Moisturizing Factors you know.
- Lamellar Granule: It secretes a lipid called Ceramide.
These are very important actions to make our skin barriers strong.
When epidermal cells age and become Keratins, which have only calcium and shell left, Lipids and Ceramides seep between them and bond them strongly.
This skin barrier forms a very powerful protective layer that even water cannot easily enter. Atopic skin is in such a state that the skin barrier does not perform its role.
If the skin barrier is abnormal, the skin becomes easily dry as the moisture in the body escapes to the outside through the epidermis, and the probability of absorption of allergy-causing substances outside into the skin increases, resulting in an immune response such as itching. Repeated itching causes you to scratch your skin, which becomes a vicious cycle in which physical stimulation damages the skin barrier and becomes worse and worse when repeated itching.
In the Granular Layer, there is a Tight Junction(⑥), an important structure that glues between cells. It is a structure that allows the keratinocytes to physically adhere and acts as a rivet, acting as a strong 2nd skin barrier.
Below the Basal Layer is the Basement Membrane(⑦).
It completely distinguishes the epidermis from the dermis, allowing signals between cells to interact. It is so dense that it acts as the 3rd skin barrier that cells and materials cannot easily pass through.
In addition to these three types of skin barriers, the skin barrier of the immunological concept is also working in our epidermis.
The Langerhans Cells are widely distributed in the Spinous Layer, so when a substance enters inside the epidermis through the dead keratinocyte, the cells check whether the substance is problematic or not, and if there is a problem, it summons T cells and attacks them. As such, The Langerhans Cells act as the 4th skin barrier as a skin immune system.
Our skin barrier is likely to be damaged or weakened by various causes such as seasonal changes, stress, side effects of cosmetics use, lack of sleep, and irritating exfoliation.
If the skin barrier becomes weak, our skin becomes dry easily due to the skin’s oil-water balance is not balanced, accelerates aging, and causes skin trouble, redness, and itching. If we leave these skin conditions unattended, the skin will react sensitively to external stimuli, allergies, and sudden changes in external temperatures and humidity, leading to a vicious cycle of getting drier and more sensitive.
So what should we do to strengthen the skin barrier?
4 ways to build up and maintain a healthy skin barrier.
1) Keeping a daily routine to have a healthy Keratinocyte
Only when Keratinocyte is healthy can it build up a healthy skin barrier. To do so, we have to keep the following basic 5 things in our daily lives.
- Should eat nutrients evenly through healthy foods, not junk food.
- Should smooth blood circulation through appropriate exercise.
- Should get regular sleep.
- Get away from possible stress or drug.
- Best temperature and humidity for skin barrier
- Temperature: 18 to 23 degrees
- Humidity: 50% to 60%
2) Should apply sunscreen
If your skin is exposed to UV rays for more than two hours, it is likely to damage the skin barrier, causing various skin diseases such as pigmentation and skin aging, so you must apply sunscreen after applying skincare products. Women in their 30s and older, in particular, need to pay more attention to UV rays as their skin ages faster.
Therefore, you must wear sunscreen and sunglasses when you go out to prevent damage to the skin barrier caused by UV rays.
If you want more information about blocking UV rays, I recommend reading the May article.
3) Use a soft formula type of cleansing oil.
When the skin barrier begins to collapse, there is a situation where there is a lot of dead keratinocytes, and it is necessary to remove them by hand. At this time, it is better to use a soft oil-type product with a moisturizing effect rather than a stimulating product like a scrub containing grains.
The most important process when you use cleansing oil is to have an Emulsified Process.
You massage your entire face with a little water on your oiled hands. The important thing here is to massage the face until the transparent oil looks milky. (This is called the Emulsified Process)
After this process, you don’t need to double cleansing because you don’t feel any residue left on your skin.
There is a misunderstanding that cleansing oil is not suitable for oily skin, but this is a false prejudice.
There may be concerns that cleansing oil that is not completely washed away from your skin will remain on your skin to block pores, but it is a very effective product for face cleansing because it can take off makeup such as foundation, mascara, lipstick, and even waste in pores.
In other words, it can be called ‘a Hypoallergenic Item that protects the skin barrier. What you need to be careful about is that you shouldn’t apply too much force to your hands to avoid damage to your skin barrier when you massage your face.
Experts recommend that you should finish cleansing as soon as possible using a low pH cleanser that does not break the pH balance of your skin because long cleansing times can make sensitive skin drier.
Another advantage of cleansing oil is that it contains moisturizing ingredients and does not make the skin dry. If double cleansing is unavoidable, experts recommend using a muslin cloth or konjac sponge together during the first cleansing step because if you use it to wipe the wastes piled up on your skin upside and outside, you can manage it to the inside of the follicle.
4) Use skincare products that can strengthen your skin barrier daily.
Products containing ceramide ingredients help strengthen the skin barrier. However, when you choose skincare products that strengthen the skin barrier, if you choose products that contain the only ceramide a lot, it can be harmful to maintaining the skin barrier. Therefore, it is very important for you to check whether other moisturizing ingredients and skin protective ingredients are properly mixed with it in addition to ceramide.
For example, EGF(Epidermal Growth Factor) is also an effective ingredient in protecting and strengthening your skin barrier. It is one of the peptides that promote the proliferation of epithelial cells and is an ingredient that helps regenerate when the skin is damaged. So if you regularly use skincare products containing 1 to 10 ppm of EGF ingredients, it helps maintain healthy skin barrier.
In addition, the extract of Centella Asiatica, Madecasoside, is also worth noting. It is the main ingredient of ointment applied to skin wounds and is well known to people around the world, but these days, it is also used in skincare products as an important ingredient to help heal damaged skin barriers. Recently, many skincare products that strengthen the skin barrier have been released, so your regular use of these products can also help strengthen the skin barrier.