Cholesterol: What it is and What it Does.

Cholesterol is a white, waxy, fatty component of our cell membranes, and a very important one at that. In addition to its role in maintaining healthy cell walls, cholesterol is needed by the body to make vitamin D and certain hormones. Cholesterol is also needed to make the bile acids that help us digest fat.

Normally, about 70% of our cholesterol is made by the liver, and the rest comes from various foods. But some people make more cholesterol than they need. When high levels of cholesterol circulate in the bloodstream, plaque can form in the arteries and this poses the risk of heart disease and stroke. However, not all cholesterol is harmful. Let’s look at the good and the bad.

Types of Cholesterol

Cholesterol doesn’t float loosely in the blood stream. It is transported in particles that resemble little spheres. These spheres are called lipoproteins because they carry lipids and proteins. Each sphere has an Apolipoprotein B (ApoB) molecule attached to it. High levels of ApoB can lead to arterial plaque.

LDL (low-density lipoproteins) can either be larger particles and less likely to stick to the artery wall or even invade it; or they can be small, dense spheres/particles. The latter are much more likely to damage the arterial wall and go beneath the lining of the artery. This is what forms plaque.

Other particles that are dense are VLDL particles. There are three subtypes of VLDL: 1, 2, and 3. VLDL 3 is the most dangerous of these three.

Lp(a) is a very small particle that is the most capable of sticking to and getting beneath the artery wall. See Specialized Tests for how we detect this.

Good cholesterol is also carried in particles and they are known as HDL (high density lipoprotein). Its job is to remove cholesterol from the artery wall and take it back to the liver to be eliminated.

There is some indication that the most vigorous LDL eliminator is HDL2.

Watch this video about cholesterol:

http://youtu.be/UIjkAPn2CRE