HDL (High Density Lipoproteins) and LDL (Low Density Lipoproteins) - together with VLDL (Very Low Density Lipoproteins) - are very important for the transport of cholesterol and triglycerides within the body. In fact, although an excess of these latter lipid compounds causes many problems, the organism needs their presence in order to function properly.
Lipoproteins are particles made up of a lipid heart wrapped in a protein shell. Inside the bloodstream, all fats - including cholesterol - are enclosed in lipoproteins. Only in this way can they reach the various tissues of the body and carry out their functions.
of the organism. Normal LDL values are not dangerous for the individual, but on the contrary, they are necessary for the correct functioning of the organism. On the contrary, an excess of them can lead to serious health risks, especially increasing the risk of events cardiovascular.
In fact, excess LDL can undergo structural modifications - in detail, oxidations - due to the action of unstable and hyper-reactive molecules from the chemical cyst point, such as free radicals. These modifications allow cholesterol to be able to infiltrate the walls of the large arterial vessels, favoring the appearance of problems, such as:
- Mechanical obstacle to blood flow: oxidized LDLs are deposited on the wall of large arterial vessels after being engulfed by macrophages. In these sites the muscle cells that make up the vessel wall also begin to multiply. A plaque is thus formed, called atherosclerotic, which tends to grow over time. In this way the lumen of the vessel is progressively reduced and the blood flows with greater difficulty.
- Reduced elasticity of the artery walls: the elasticity of the arteries is very important, since together with the propulsive action of the heart pump, it helps to push the blood downstream. Since atherosclerotic plaques decrease arterial elasticity, their presence translates into a further obstacle to circulation.
- Thrombus formation: some parts of the atherosclerotic plaque can detach, becoming real stray mines which, when they block certain capillaries, prevent the arrival of blood to the affected tissue.
To learn more, read also: Atherosclerosis - Good eicosanoids and bad eicosanoids.
Therefore LDL, called bad cholesterol, are such only when they are in excess and when they are oxidized. In normal situations they are indispensable for the good health of the organism.
