Good vs. Bad Cholesterol

Cholesterol is minimally soluble in water and therefore, it cannot travel freely in the water-based bloodstream. The bloodstream transports cholesterol throughout the body by special carriers called lipoproteins.

Lipoprotein

A typical lipoprotein contains triglycerides and cholesterol in the center, surrounded by phospholipids and water-soluble proteins on the outer surface. The protein helps the lipids move through the watery fluids of the blood.

1. High-Density Lipoprotein (HDL)
Also know as the ‘good’ cholesterol, HDL contains more protein than triglycerides or cholesterol and helps remove cholesterol from artery walls. It carries cholesterol from body cells to the liver, where it is either reused, converted to bile acids or disposed off in the bile. About one-third to one-fourth of blood cholesterol is carried by these high-density lipoproteins. Having large numbers of HDL particles correlates with better health outcomes.

2. Low-Density Lipoprotein (LDL)
Also known as ‘bad’ cholesterol, LDL is the major cholesterol carrier in the blood. LDL cholesterol is more likely to clog blood vessels because it carries the cholesterol away from the liver into the bloodstream, where it can stick to the blood vessels. High levels of LDL lead to oxidization and cholesterol deposits in the walls of arteries. This initiates a condition known as atherosclerosis or hardening of the arteries.

3. Very Low-Density Lipoprotein (VLDL)
Triglycerides are carried in the blood by very low-density lipoproteins. Only a small amount of triglycerides is normally found in the blood, as most are stored in the fat tissues. VLDL is similar to LDL cholesterol as it contains mostly fat and not much protein. VLDLs are converted to LDLs after delivering triglycerides to the muscles and adipose (fat) tissue. A high triglyceride level, along with high LDL cholesterol, can increase the risk of heart attack.

Total cholesterol is the sum of:

* HDL cholesterol
* LDL cholesterol
* 20% of the triglyceride value