When it comes to the maintenance of dermis, collagen is usually the first thing that comes to mind. Recently, I have often heard terms such as elastin and hyaluronic acid.

Here, let's review collagen again. Although collagen is red, its effect is actually controversial.

However, as long as you have read this section, I believe that you can distinguish the authenticity of all the circulated information according to the basic knowledge of skin.

Seeing the advertising words of "moisturizing cream containing collagen" and "shark fin pot filled with collagen makes your skin tender and elastic", I really feel very moist, as if it can make your skin firm again. However, it's a pity-it didn't work, as I mentioned clearly in the first chapter.

Before explaining, let's recall what collagen is.

When it comes to collagen, most people usually associate it with skin. But in fact, it is a kind of protein that exists in all parts of the human body. It can play the role of skeleton and keep the shape of various organs. It belongs to structural protein, accounting for about 30% of protein in the body.

40% of collagen in the body is concentrated in the skin and 20% in the bones. Old people often suffer from osteoporosis, one of the reasons is that collagen in bones decreases and degenerates with age, which makes the structure of bones no longer flexible.

Collagen is located in the dermis under the skin. The dermis is about 90% composed of collagen, and other substances in the dermis include elastin and hyaluronic acid.

Collagen will maintain the shape and elasticity of skin together with elastin. When we talk about skin firmness or wrinkles, the background is no longer epidermis, but dermis.

Painting is useless, the problem is "molecular weight"

Then, why on earth does collagen have no effect on dermis whether it is smeared or eaten?

Let's take a look at the situation when smearing. Why won't it increase after painting? The reason is simple, because collagen can't reach the dermis at all.

The limit value of substance penetrating through skin is "molecular weight 500 Daltons".

The molecular weight is calculated by the total number of atoms that make up the molecule. For example, H2O (water) is a combination of two hydrogen atoms and one oxygen atom. The atomic weight of H (hydrogen) is one, and that of O (oxygen) is sixteen. So the molecular weight of water is 1× 2+ 16 = 18.

Because the molecular weight of water is much less than 500, it is easy to penetrate the skin.

When sweating, water will come out with potassium chloride and sodium. Because these substances are much smaller than 500 Daltons, they can pass smoothly. Steroid ointment is just at the critical point of 500 daltons, so it can pass.

But the molecular weight of collagen is hundreds of thousands. It's too big to penetrate the skin. In this way, even if collagen is coated, it will only stick to the skin surface. Even if it does penetrate, it can only run to the place where the skin barrier is stripped, and at most it penetrates into the stratum corneum.

In a word, collagen can't penetrate into the dermis, replenish the original elasticity of the skin and bring it back to life.

Comprehensive ability is declining year by year.

Next, let's see why eating can't increase collagen.

Let's think about it first. How many steps does it take from eating imported food to reaching the dermis?

First, the digestive juice secreted by the stomach and duodenum breaks down collagen into peptides and amino acids. Then, they will be absorbed by the small intestine-at this time, they can enter the intestinal wall because they are less than 500 daltons in size.

Then, it will enter the blood and finally reach the dermis. At this point, the original collagen has already become a fragmented "part". Can these parts that reach the dermis return to the original collagen? The answer is "difficult".

Because with the increase of age, the enzyme intensity of collagen synthesis will gradually weaken. For example, it's like the parts arrive at the factory, but the assembly machine doesn't work.

At the age of twenty, the power of synthetase will gradually decline. Basically, metabolism has been declining since birth, and it has dropped even more after the age of 20.

On the other hand, what was I like before I was twenty? Before you reach this age, the synthetase will be very active and the metabolism will be quite vigorous. Even if ultraviolet rays damage the dermis, they can be synthesized immediately without leaving black spots and wrinkles.

The most vigorous skin metabolism is the baby. Even if the baby is burned, it can recover immediately, leaving almost no trace. I think this should surprise many people. The speed of wound healing is also overwhelming in children.

Dermal is not renewable like epidermis, so once it is damaged by ultraviolet rays, it cannot be recovered. This is why deep wrinkles can't be removed.

The effect of the injection is only temporary.

Then talk about the "collagen needle" that people use to eliminate wrinkles.

In short, even if it is effective, it is only temporary.

Hearing that collagen is injected into the skin, some people may worry, "Does that matter?" But in fact, it is injected after removing antigenicity (the part that will be regarded as a foreign body by immune cells), so there will be no problem in immunology.

Indeed, injection of substances similar to dermal tissue components can temporarily swell the dermis, restore firmness, and even wrinkles seem to be smoothed. But you can't stay in the skin for too long, and it will decompose soon.

Therefore, in those medical beauty clinics that inject collagen, doctors will tell patients that "repeated injections can maintain the effect" and "the effect has disappeared, try again" and let patients continue to inject expensive collagen.

These are only symptomatic treatments for temporary relaxation, not etiological treatments. And the more collagen, the better. The key is its quality. The relationship between collagen and elastin binding it is also important.

Hyaluronic acid and elastin

Finally, let's take a look at the elements other than collagen contained in dermis-hyaluronic acid and elastin. Both of them often appear in the ingredient list of cosmetics, and will definitely be advertised as "moisturizing the skin" and "giving a firm luster".

But both of them are actually the same as collagen, and their molecular weights are very large, so they can't enter the dermis even if they are coated. The edible effect is the same as collagen.

Having said that, all the above are facts inferred from the logic of skin structure. There is no problem in smearing or eating products added with collagen, hyaluronic acid and elastin.

However, from the point of view of etiology and treatment, it is still recommended that you do a good job in skin maintenance, give full play to its original strength based on skin structure, and let the skin achieve physical and immune barrier functions.

As for the treatment of intra-articular injection of hyaluronic acid in orthopedics and traumatology department, because the purpose is to supplement the intra-articular lubricating fluid reduced by aging, it does have a certain effect.

How to maintain the genuine leather? Please remember the following suggestions first-dermis is closely related to the health of epidermis, and epidermis should be well maintained.

Basically, as long as the epidermis is healthy, the dermis will follow the health. Because once the physical barrier of epidermis is destroyed, even the dermis will be damaged.

Besides, exercise is really important. There are blood vessels carrying nutrients and water in the dermis, which not only send nutrients and water to the dermis, but also to the epidermis. After exercise, the blood circulation becomes better, which can transport a lot of nutrients and water and promote the metabolism of epidermis. As long as the blood flows smoothly, the metabolism and regeneration ability will be improved.

(Excerpted from Qiu Forum)