The Good and The Bad
The word cholesterol can be quite a scary one, quite often it’s because we don’t fully understand what cholesterol actually is and only tend to hear about it in a negative way. In fact, did you know that there are both good and bad cholesterol? If you didn’t, that’s totally ok, there’re plenty of people out there who thought that same way you did. We’re going to take you right to the beginning to give you a better understanding of where cholesterol comes from, how it makes its way into our blood stream and how it can be harmful to our body if we abuse it.
Once we consume any food containing fat, the body needs to digest it and it does so by breaking down Triglycerides into fatty acids and Glycerol and these are shipped out into the bloodstream once they’ve been assorted in numerous ways.
You might remember the process that Carbohydrates go through when they travel through the system and the next phase of the Fatty Acids journey is no different as they make their way into the pancreas and are broken down by Pancreatic Lipase (An enzyme that breaks down fatty acids from their glycerol backbone).
It can take quite some time for the body to break down fat and thus it may take 3-4 hours before the fat makes its way into our blood stream.
The Triglycerides found floating within the blood stream are then broken down once again into fatty acids and glycerol with the help of another enzyme known as Lipoprotein Lipase (most enzymes end in ase) so that they can begin the journey into the tissues of our body. This is where it gets interesting and where all the information above will start to make more sense.
Once they pass through the cell membrane the Fatty Acids and Triglycerides are either oxidised where they’re used to transfer energy into either muscle or other tissues. If not they are converted back to Triglycerides where they’re stored in fat tissue and muscle.
Without getting into too much detail (your heads will start to hurt just like ours was) we’ll explain the transportation of fat through the body. Fat doesn’t dissolve in water and therefore can’t travel through blood on its own it takes a ride in what is known as a Lipoprotein (carrier of triglycerides and cholesterol) instead.
Whilst there’re quite a few forms of Lipoproteins, we’re going to focus on these 4 for now:
Chylomicron 1% Protein 99% Lipids: These are by far the biggest of the 4 and they carry Triglycerides from the intestines to the liver, muscle and fat tissue.
Very Low Density Lipoproteins 8% Protein 92% Lipids: These carry freshly packaged triglycerides from the liver to the fat tissue.
Low Density Lipoproteins 20% Protein 80% Lipids: Carriers of cholesterol to all cells in the body, these come in two types (Very Important). Large Buoyant particles = Good Health Small Dense particles = Poor Health
High Density Lipoproteins 50% Protein 50% Lipid: These reverse the cholesterol transport by bringing the fat and cholesterol from the cells back to the liver where it can be excreted (sorry about that).
Okay, this is where we finally answer the question of what is good cholesterol and what is bad cholesterol.
As explained just above, High Density Lipoproteins reverse the transport of cholesterol and this makes them heart healthy. If the cholesterol content of HDL particles are higher it’s an indicator of a high functioning reverse cholesterol system which obviously lowers the rate of cardiovascular disease risk.
LDL on the other hand is a dangerous Lipoprotein. It was explained to us in the form of an analogy. Your arteries are the highway, your LDLs are the bad drivers and the HDLs are the paramedics. As an LDL (Bad Driver) crashes into the wall of the artery, it leaves plaque that can build up over time and create a blockage if nothing is done about it. The HDLs (Paramedics) pick up the injured driver and transport him/ her to the hospital (Liver) for excretion.
In another chapter, we’ll discuss fats, both good and bad but for now we’ll leave you with the this and we hope that this gives you something to think about until then.
Justin Beard Pn1