We keep hearing Lipoprotein as an indication for our cholesterol levels. HDL, High-Density Lipoproteins is the good cholesterol and the LDL, Low-Density Lipoproteins is the bad cholesterol. So, why lipoprotein is always connected to cholesterol?
Cholesterol is a kind of fat, produced and controlled by the liver through our blood. As our blood is like water, it doesn’t mix with fat, that’s why cholesterol can’t easily dissolve in the blood. It needs lipoprotein, a water soluble particle in our blood which carries fats (lipo = fat), proteins and cholesterol (lipids).
Lipoprotein is the vehicle for transporting cholesterol through our blood stream, which also carry other molecules, such as triglycerides (fats), phospholipids and fat-soluble vitamins. Lipoproteins are basically a core full of fat and cholesterol, along with a lipid membrane that contains proteins called apolipoproteins.
There are many types of lipoproteins, but HDL and LDL are the two most important ones. LDL is responsible in transporting cholesterol from the liver through the blood stream to all over the body then the cholesterol is separated from the LDL and used by the body’s cells for various purposes. HDL is responsible in transporting the excess or unused cholesterol from the body’s tissues back to the liver, where the cholesterol is broken down then disposed.
Cholesterol extracted by the body cells from the blood by receptors, then bind together with the LDL particles, including the cholesterol attached to it. The body cell has a certain limits to how much cholesterol needed. The unused cholesterol remains in the bloodstream, increasing the risk of accumulating it and becoming atherosclerotic buildup of fatty deposits on the blood vessel walls. While HDL particles actually reduce such atherosclerotic buildups.
That’s why the LDL is considered as the bad cholesterol while HDL is a good cholesterol. This term is actually misleading, because all cholesterol is the same, it’s the lipoproteins that make the difference. Heart disease is not really a cholesterol disease, actually it is a lipoprotein disease.