Great Health Guide
WHAT IS CHOLESTEROL? Part 2
The good & the bad cholesterol.
The production of cholesterol within the body is predominantly within the liver. That process has a number of steps and one of the steps that produces cholesterol involves an enzyme called HMG-CoA reductase. It is this enzyme that the statins (the medications commonly used to lower cholesterol) can block. By blocking that enzyme, the production of cholesterol by the body, will be reduced.
When cholesterol is produced within the body, it needs to move around the body and be taken to the tissues. That’s where the lipoprotein carriers come into play. There are a number of primary transport lipoproteins, which move cholesterol from the gut and the liver and then into the circulation of the blood. As the lipoprotein carries its load of fatty material, various components of the ‘payload’ are taken from those lipoproteins until eventually, the result is a lipoprotein called, the Low Density Lipoprotein. We often refer to this as ‘LDL’ cholesterol. It is the LDL cholesterol that we’re concerned about when we are talking about coronary artery disease.
WHAT ARE LOW-DENSITY AND HIGH-DENSITY LIPOPROTEINS?
It is likely that you may have heard of both of these, particularly since they are often requested when you have your blood tested for ‘cholesterol’. We loosely talk about High Density Lipoprotein (HDL) as the ‘good’ cholesterol and the Low Density Lipoprotein (LDL) as the ‘bad’ cholesterol. The reason is that in simple terms, LDL puts cholesterol INTO the tissues via the blood vessels and HDL
takes cholesterol OUT OF the tissues. Since the HDL particle is not as rich or engorged with cholesterol and it has a high density, thus it is able to pick up some more cholesterol as it travels back to the liver. So, High Density Lipoprotein (HDL) is able to pick up cholesterol from the periphery of the body tissues and bring it back to the liver or to the organs that use cholesterol as the building block for hormone production.
Thus, remember that ‘bad’ LDL cholesterol is moving cholesterol from the liver INTO the body as the ‘cholesterol transport’ and the ‘good’ HDL cholesterol is picking up more cholesterol, taking it OUT OF the tissues and bringing cholesterol back to the liver as the ‘reverse cholesterol transport’.
HOW DO WE CONSUME CHOLESTEROL?
When we eat fatty food, it is digested, ingested and absorbed by the intestinal tract. As it is absorbed, it is organized in packages to allow it to be transported, by the lipoprotein. These transport modules or these lipoproteins then drain through the liver as does the rest of the blood from the gut. The mechanism of cholesterol