What is Ceramide？
Ceramide is a naturally occurring lipid in the skin. Ceramide forms a waterproof barrier on the surface of the skin. They not only help the skin to lock in moisture, but also promote the self-repair of the skin barrier and regulate skin cells. The skin of newborn babies is often covered with a wax-like substance. This substance is called fetal fat and is mainly composed of ceramide, which can prevent skin moisture loss. The secretion of ceramide in the skin will decrease with age, causing dry skin, wrinkles and some skin inflammation.
From its chemical structure, ceramide is composed of sphingosine long-chain bases (accounting for ~50% of the structure) and a fatty acid. Different sphingosine bases and fatty acid combinations form different ceramides.
Currently, 9 naturally occurring ceramides have been discovered. In addition, there are phytoceramides, psuedoceramides and synthetic ceramides.
Ceramide: a natural wax lipid that is pure in the skin. It is composed of long-chain sphingosine bases and a fatty acid.
Phytoceramide: Its sphingosine bases are commonly found in yeast, plants and some mammalian tissues. Don't be confused by the "plant" in the name.
Ceramide-like: It is also a kind of lipid with similar properties but different structure. For example, Ceramide E and Arachidamide MEA are both ceramide-like. Ceramides are usually artificially synthesized, but there may also be naturally occurring forms.
Synthetic ceramide: synthetic naturally occurring ceramide.
In most cases, the ceramide used in cosmetics is synthetic (whether it is ceramide or ceramide-like), because the content of ceramide in plants is too low, and it is too expensive to extract from animals. Whether it is synthetic or natural extraction, as long as the chemical structure is the same, the same effect can be achieved.
2. What are the maintenance effects of ceramide?
(1) The effect of oral ceramide:
At present, only a few relevant studies have shown that oral ceramide can help repair the sebum membrane. A study from Hitex, a company specializing in the production of phytoceramide capsules, found that oral phytoceramide can improve dry skin. Another experiment found that compared with the control group, taking 20 mg or 40 mg ceramide daily for three weeks can reduce transepidermal water loss and increase skin water content. It is worth noting that the US Food Safety Administration FDA published an article proving the safety of oral phytoceramides (and related supplements). But this does not prove the actual effect of ceramide. After all, compared with oral collagen, oral ceramide does not have enough data to prove its effect.
(2) The effect of external use of ceramide
The effect of ceramide as a topical skin care product is more interesting, so there are more experiments around this area. Like previous articles in the anti-aging series, we will use
Kligman three questions and answers
To analyze the external effect of ceramide.
1. What is the mechanism of the external effect of ceramide?
The most well-known effect of ceramide is to form a waterproof barrier on the skin. Moreover, it can strengthen the barrier effect of ceramide in combination with other lipids in a certain proportion. The optimal ratio is 50% ceramide, 25% cholesterol and 15% free fatty acids. This "transparent layered structure" mixture has a unique moisturizing function. Therefore, there is a mechanism to explain the maintenance effect of ceramide.
2What is the transdermal absorption capacity of ceramide?
Since ceramide is naturally present in the epidermis, it is not difficult to explain the penetration of ceramide into the stratum corneum. The "tape sticking" experiment proved that ceramide can penetrate deeper into the epidermis. The "tape sticking" method is to attach a piece of tape to the skin and then tear it off to analyze the components in the skin cells on the tape. Each time the tape is torn off, there is a layer of skin cells attached to it to measure the penetration of a certain component. Here are two examples:
A friend of Dr. Zoe Draelos published a paper on the penetration of ceramides (Zoe Draelos wrote the famous dermatology textbook, Cosmetics and Dermatologic Problems and Solutions). Another experiment affirmed the former conclusion, but also pointed out that the permeability of ceramide may depend on other ingredients in the formulation.
In The Textbook of Cosmetic Dermtology, it is mentioned that without the aid of glycerol ether, the penetration of ceramide will not be much better than placebo.
3 Is there any experiment to prove its ceramide effect?
Many studies have confirmed the efficacy of ceramide, but we need to pay attention to two issues. One, some of these experiments do not use blind testing or comparative experiments. Therefore, even if the experimental results show that ceramide is effective, we cannot know whether a product without ceramide can achieve the same effect. The second problem is that there are too many types of ceramides. In addition, the added concentration and the matching ingredients can be ever-changing, so we cannot confirm which ceramide and which combination works best. Nevertheless, in general, a large number of experimental data show that ceramide is beneficial to skin care. Below we quote several research data.
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