A, cholesterol (Cholesterol), also known as cholesterol, is a cyclopentane polyhydric phenanthrene derivatives, was discovered in the 18th century, named by the chemist Benchel. Cholesterol is widely present in the animal body, especially in the brain and nervous tissue is the most abundant, in the kidney, spleen, skin, liver and bile in high content, its solubility and fat similar, insoluble in water, soluble in ether and other solvents, is an indispensable and important substance for animal tissue cells.
Two, cholesterol is also an important indicator of clinical biochemical examination, under normal circumstances, the body in the liver synthesized and ingested from food cholesterol, will be converted into steroid hormones or become a component of the cell membrane, and make the concentration of cholesterol in the blood to maintain a constant. When the liver is severely diseased, the cholesterol concentration decreases. In contrast, cholesterol concentrations tend to increase in patients with jaundiced obstruction and nephrotic syndrome.
Three, cholesterol mainly comes from the body's own synthesis, cholesterol in food is a secondary supplement. Such as a 70kg body weight of adults, the body has about 140g of cholesterol, about 1g per day update, of which 4/5 in the body metabolism, only 1/5 need to be supplemented from the food, each person daily intake of cholesterol from the food 200mg, can meet the body's needs. The absorption rate of cholesterol is only 30%, with the increase of food cholesterol content, the absorption rate will also decline, 200mg is equivalent to the cholesterol content of 1 egg or 3-4 eggs of cholesterol absorption. Experts recommend a daily intake of 50mg to 300mg of cholesterol is good.
Four, in general, lipids are divided into two main categories. Fat (mainly triglycerides) is the most abundant lipids in the human body, is a major source of energy in the body; the other category is called lipids, is a basic component of the biofilm, accounting for about 5% of body weight, in addition to including phospholipids, glycolipids, there is a very important one called cholesterol (cholesterol).
Fifth, cholesterol exists in the blood in lipoproteins, and its presence in the form of high-density lipoprotein (HDL) cholesterol, low-density lipoprotein (LDL) cholesterol, very low-density lipoprotein (LDL) cholesterol several kinds. The vast majority of cholesterol present in the blood is cholesteryl esters bound to fatty acids, with less than 10% of cholesterol present in a free state. HDL helps to remove cholesterol from cells, while excess LDL is generally considered a precursor to cardiovascular disease. Blood cholesterol levels between 140 and 199 milligrams per unit are relatively normal cholesterol levels.