Cholesterol is a waxy substance critical to the normal function of all cells. The body needs cholesterol for making hormones, digesting dietary fats, building cell walls, and other important processes.
Our liver makes all the cholesterol we need and circulates it through the blood; but cholesterol is also in some of the foods we eat, mainly in meat and full-fat dairy products. Many people inherit genes from their mother, father or even grandparents that cause them to produce too much.
When there is too much cholesterol in our blood, it can build up on the walls of the arteries creating the so-called atherosclerosis (hardening of the arteries). Atherosclerosis will progress slowly and silently and will eventually cause narrowing of the arteries. This can lead to carotid artery disease and stroke, coronary disease and heart attack and peripheral vascular disease and need for amputation.
Cholesterol circulates in the blood in various modes that can have different effects in our body, good or bad. This is the reason doctors report about “bad”, “good” and total cholesterol.
When we talk about the specific types of cholesterol, we’re actually talking about the different types of proteins that carry the cholesterol molecules through the bloodstream.
The two most important types are:
· LDL (low-density lipoprotein) cholesterol. LDL is one of the two most important fatty proteins (HDL is the other). LDL cholesterol is usually referred to as “bad” cholesterol because it deposits its cholesterol on the walls of arteries. LDL is also the type of cholesterol that becomes oxidized and damages the lining of your arteries, setting the stage for atherosclerosis.
· HDL (high-density lipoprotein) cholesterol. Unlike LDL, HDL hangs on tightly to the cholesterol it carries and won’t let it get loose to attach to arterial walls. In some cases, it may even snatch up additional cholesterol already stuck to a wall, reducing the size of a plaque or buildup. HDL keeps cholesterol in solution and moves it safely throughout the body. For these reasons, HDL cholesterol is considered to be “good” cholesterol. A healthy level of HDL cholesterol may also protect against heart attack and stroke, while low levels of HDL cholesterol have been shown to increase the risk of heart disease.
LDL cholesterol and HDL cholesterol, along with one fifth of your triglyceride level (see relevant section), make up your total cholesterol count.
It's important to know your blood cholesterol levels so that you and your doctor can determine the best strategy to lower your risk.