Animal foods contain cholesterol. Some experts blame animal foods for the increase in cholesterol in the human body, especially “red meat”. They believe that high cholesterol is closely related to eating more meat. Is it true?
Cholesterol in the human body is mainly derived from the body’s synthesis and has little to do with whether or not to eat meat. Some people who do not eat meat will also suffer from hypercholesterolemia. The cholesterol in the diet only accounts for a small part of the blood cholesterol in the body. In the case of strict control of cholesterol intake in the diet, the production of endogenous cholesterol will increase and even become the main source.
Except for the brain and red blood cells, almost all tissues and organs in the adult body can synthesize cholesterol. The liver is the main organ for the body to synthesize cholesterol, followed by the intestines, adrenal cortex, ovaries, testes, skin, etc., which also have strong synthesizing functions. However, the amount of cholesterol synthesized by most tissues and organs cannot meet their own needs, and the cholesterol produced by the liver needs to be transported to the whole body for use through the blood. Carrying cholesterol from the liver to the whole body is not enough to have blood. A lipoprotein is needed to dissolve the lipid cholesterol into the water-quality blood, and carry the cholesterol to various tissue cells. This lipoprotein responsible for the transportation of cholesterol is low-density fat. Protein, when low-density lipoprotein is combined with cholesterol, is what experts call “bad cholesterol”.
The ability of the human body to synthesize cholesterol is very strong, and the raw materials are sufficient. What are the raw materials for synthesizing cholesterol? Looking at these raw materials for synthesizing cholesterol, everyone can understand why the intake of cholesterol in the diet is so insignificant.
In the cholesterol molecule, all carbon atoms come from acetyl CoA. Of the 27 carbon atoms in cholesterol, 15 are derived from the methyl carbon atoms of acetyl CoA, and the other 12 are derived from the carbonyl carbon atoms of acetyl CoA.
The hydrogen atoms in cholesterol molecules mainly come from NADPH.
Acetyl CoA is the common intermediate product of the metabolism of the three major nutrients in the body of protein, carbohydrate and fat. It is precisely with acetyl CoA that the three major energy-producing nutrients can be converted into each other. NADPH is a kind of coenzyme, called reduced coenzyme II, which mainly comes from the pentose phosphate pathway of glucose. Acetyl CoA and NADPH are stable sources of raw materials for the body’s endogenous synthesis of cholesterol.
In general, dietary sugars and fats have the greatest impact on cholesterol synthesis. The fat mentioned here includes polyunsaturated fats that experts have always admired. In the case of controlling fat intake, the synthesis of cholesterol in the body cannot be inhibited, because the sugar in the diet is also the main expectation for the synthesis of cholesterol. Sugars include sweet foods (such as fruits, sucrose, ice cream, candy, etc.) and non-sweet foods (such as rice, white flour products and various grains containing oil starch, etc.).
As long as human cells exist, cholesterol is needed, and low-density lipoproteins need to be transported to various tissue cells in the body through blood. If human cells cannot get the cholesterol they deserve, it will reduce the resistance to harmful substances, and even Cellular mutations occur, leading to cancer. Experts regard low-density lipoprotein + cholesterol as “bad cholesterol”. This view is wrong. Without this so-called “bad cholesterol”, there would be no life and no health. As for what experts call “good cholesterol”, it is the basic function of the body to collect the cholesterol after cell metabolism and transport it back to the liver for reprocessing.
Now that we know that the synthetic raw materials of cholesterol in the body are sugars, fats, and proteins, and not the cholesterol in the diet, we should not wrong the cholesterol.
Finally, why does the cholesterol in the human body rise? This is caused by metabolic problems. For example, the polyunsaturated fat in low-density lipoprotein is oxidized, resulting in low-density lipoprotein cholesterol not being used by the body’s receptors; and trans fatty acids cause blood abnormalities, etc., which will lead to Abnormal cholesterol metabolism.
To sum up, the main reason for high cholesterol is not eating meat, but metabolic disorders. There are many factors leading to metabolic disorders, but I think it is related to chemically synthesized additives and chemical residues in food. Abnormal cholesterol metabolism, lowering blood cholesterol through drugs inhibiting cholesterol synthesis, cannot solve the problem of abnormal cholesterol metabolism.