Can taking collagen play a cosmetic role? Is it the legendary effect on the human body? Wang Xingguo, director of the Nutrition Department, clinical nutritionist and attending physician of Dalian Central Hospital, said: The reason why oral collagen has become a fashionable health care method is of course inseparable from the efforts of manufacturers, but the main reason is that consumers don't understand the basic knowledge of life science. Eating collagen can not directly increase the synthesis of collagen in the body, but it has a certain nutritional effect on the body (including skin, joints, bones, organs, muscles, etc.). (especially in experimental animals). However, there is no evidence (and the theory does not support it) that its nutritional function will surpass that of protein in common foods such as eggs and soybeans. Wang Xingguo also summarized six basic problems of collagen: 1. Collagen is one of the common protein in human daily diet, and we consume various protein through food every day. Such as whey protein (from milk), casein (milk), ovalbumin (egg), lecithin (egg), soybean protein (soybean), myosin (meat), glutenin (rice and wheat), gliadin (wheat), albumin (meat, liver and blood), hemoglobin (blood) and elastin. These protein have different structures and characteristics, some are spherical (such as globulin) and some are fibrous (such as collagen). Some are white (such as albumin) and some are red (such as hemoglobin); Some can be dissolved (such as albumin), and some can form jelly (such as collagen) ... but their nutritional effects on human body are very similar, that is, after being digested and absorbed by gastrointestinal tract, they are mainly used to construct human protein in the form of raw materials (amino acids), such as tissues and organs (such as blood, muscles, internal organs, skin, bones, etc. ) and active substances (such as various enzymes, peptide hormones, lipoproteins, etc. ). Part of the raw materials (amino acids) that make up protein of human body are digested and absorbed by food protein, and the other part is synthesized by the body. Therefore, protein in food is the most important nutrient. 2. Collagen in human body is synthesized by cells and has little to do with eating collagen. There are many kinds of protein in human body, including albumin (blood), globulin (blood), hemoglobin (blood), myosin (muscle) and collagen (bone, skin, tendon, hair, etc. ), enzyme protein (various cells) ... seems to be similar to those in animal food. This understanding is a complete ignorance of the great achievements of life science in the past 100 years. Under normal circumstances, every protein in the human body, including collagen, is composed of various cells. The general process is to "translate" various protein molecules (buildings) under the guidance of various enzymes (masons) with genetic DNA molecules as templates (drawings) and RNA as "transcription" tools (porters). Protein synthesized in cells, some of which play a physiological role in situ (such as hemoglobin, enzyme protein, etc.). ), and some of them are transported outside the cell to play a physiological role (such as collagen, insulin, etc.). ). Collagen in human body (as do most animals) is synthesized by cells and secreted out of cells, and it is fibrous (its molecular structure is like three strands of hemp rope twisted together). The amount of collagen is huge, accounting for 30% of the total protein in the body. It is distributed in various organs and tissues, especially in bones, skin, tendons and hair. They form a fiber framework structure in the intercellular matrix, which has the functions of supporting, connecting, retaining water and protecting cells, and also affects the growth, differentiation, metabolism and movement of cells. In the complex synthesis process of collagen and other protein, food only provides raw materials (amino acids), not protein itself. In other words, eating collagen will not directly increase the collagen in your body. Just like eating hemoglobin (such as animal blood) does not directly become your hemoglobin; Eating muscle protein (such as pork) will not directly become your muscle protein; The albumin (pharmaceutical preparation) you eat will never directly become your albumin (if you want to increase the albumin in the patient's blood clinically, you must adopt the method of injection, but oral administration is ineffective). In fact, this is also the basic condition for human beings to maintain the stability of species form. Otherwise, this animal, man, would have evolved into something strange! Clinically, in order to directly supplement some protein in the body, whether it is high molecular weight (such as albumin, immunoglobulin, antibody, etc. ) or small molecular weight (often called peptide, such as insulin, oxytocin, growth hormone, cell growth factor, etc. ), must be injected directly into the blood, and can not be taken orally through the gastrointestinal tract, otherwise it will be digested and decomposed into amino acids equivalent to ordinary food.