Cholesterol
Cholesterol is the main sterol in the human body and precursor of all other steroids body. It is part of cell membranes, lipoproteins, bile acids and steroid hormones.
Cholesterol is an important constituent of gallstones, but its main pathological feature, is for the production of atherosclerosis of vital arteries, causing heart disease, stroke and peripheral vascular disease.
The origin of cholesterol in the body has two sources: external and produced by the body itself. Because the body can produce its own cholesterol, the possibility exists that people who do not consume cholesterol, high blood levels have to have a genetic-metabolic disorder that leads to this elevation.
These disorders are more common than thought and are the leading cause of atheroma and vascular diseases, including acute myocardial infarction. Hence the importance of identifying early as high cholesterol levels in patients.
Animal-derived foods are rich in cholesterol, especially eggs, dairy and meat. Most of this is in esterified form. The body absorbs about half the cholesterol content in the diet. Plant sterols are poorly absorbed by the body.
Cholesterol is synthesized by virtually all nucleated cells of the body. The liver is the principal producer (10% of total), with other major organs in producing the intestine, adrenal cortex, testes and ovary. Cholesterol synthesis is regulated primarily by the intake of dietary cholesterol.
Cholesterol because a fat is slightly soluble in water, so that if free transport by the blood would be in the form of drops of cholesterol and would be in our blood like drops of fat. But the fact is that nature has devised a way to make water-soluble and transport cholesterol in the blood and this is by lipoproteins.
Lipoproteins are complex whereby lipoprotein cholesterol, cholesterol esters, triglycerides and phospholipids are transported through the blood.
Cholesterol associated with low-density lipoproteins is called LDL-cholesterol, and is known as “bad cholesterol” because it is the main lipoprotein that carries cholesterol from the liver to the rest of the body.
When lipoprotein cholesterol associated with HDL is called HDL-cholesterol, and is called “good cholesterol” because its main function is to collect tissue cholesterol, and bring to the liver.
The increase in LDL-cholesterol blood level leads to a set of process leading to the formation of unstable plaques in blood vessel walls, known as atheroma. These plaques narrow the passageways of the arteries and veins, and if one of these plates can produce either follows an acute myocardial infarction or stroke in the brain.
Source: www.geosalud.com/Nutricion/colesterol.htm
image source: www.3dchem.com/imagesofmolecules/Cholesterol.jpg