If you have diabetes, you’ll hear your healthcare team talking to you about cholesterol quite a lot. But what is cholesterol?
High cholesterol is more likely in diabetes and high cholesterol is not good for cardiovascular health. We also know high glucose levels can impact cardiovascular health and so understanding and managing your cholesterol is one of the top priorities in diabetes. In fact, the biggest killer in diabetes is cardiovascular complications.
Your healthcare team may make reference to ‘good’ and ‘bad’ cholesterol and give you some numbers for reference.
Yet, do they ever explain what it all means beyond good and bad cholesterol. If you’e like me, I like to get into the nitty gritty and understand what is happening with me.
Therefore, this blog and video explains how good and bad cholesterol comes about.
Before we answer the question what is cholesterol we need to quickly understand another form of fat – triglycerides. Triglycerides is probably another word you have had mentioned during your visits to the doctors. Triglycerides are fat. In fact, most of the fat in your body is in the form of triglycerides. Specifically, triglycerides are the fat that your body stores and will release for energy.
Triglycerides consist of 2 components. A backbone or a spine called glycerol. Attached to the glycerol are 3 (hence TRIglycerides) fatty acids. You might remember we have different types of fatty acids. Namely, trans, saturated, mono and polyunsaturated fatty acids.
Each type of fatty acid attached to the glycerol backbone has a different effect on your cholesterol levels and overall health.
Digestion and absorption
When you eat fat, it is digested into an emulsion like substance with the help of enzymes and bile. The fat is then packaged into protein balls called chylomicrons to be transported to the liver.
The reason fat needs to be transported by chylomicrons is because fat doesn’t like water. Fat is hydrophobic, meaning it doesn’t mix well with water at all. Think if you add some olive oil to a glass of water, the oil sits on top of the water. Blood, being mostly water, is therefore not a good way to transport fat without the help of these chylomicrons.
Once delivered to the liver, the triglycerides are unpacked from the chylomicrons. Then a decision needs to be made about what to do with the fat.
Different types of cholesterol
The liver decides what to do with the triglycerides. It can send it around the body to be used as energy or store it in fat cells for later. Regardless of the triglycerides final destination, it cannot be transported in blood by itself. Therefore, the liver repackages triglycerides, with cholesterol, into different protein sacks called lipoproteins. These are called very low density lipoproteins or VLDL.
VLDL travel around the body distributing triglycerides and cholesterol to where it is needed. As fat is released from the lipoproteins to the cells the density of the VLDL begins to lower. This is because fat is low density and therefore as less fat remains in the lipoprotein the relative density is higher. So VLDL gradually become low density lipoproteins or LDL.
You may be familiar with VLDL and LDL. These are usually referred to as bad cholesterol. This is because in abundance these little balls of protein and fat can damage your cardiovascular system. However , it’s important to note VLDL and LDL are actually part of a normal functioning body. Only in excess are they problematic.
You also produce another type of lipoprotein called high density lipoproteins or HDL. These work in contrast to the LDL and pick up excess fat and cholesterol in the body and return it to the liver. This is why HDL is referred to as your good cholesterol.
Difference in the type of fatty acids
Remember those fatty acids attached to the glycerol back bone. Each has a different effect on your lipoprotein formation and clearance. Some think saturated fatty acids increase the production of VLDL cholesterol and block receptors on the liver to clear LDL cholesterol.
Whereas, monounsaturated and polyunsaturated increase the clearance of LDL helping to lower your bad cholesterol . It is for this reason dietary guidance focuses on eating healthy fats such as oils, nuts, seeds, fish and avocados. Meanwhile, trying to reduce the amount of saturated fat in the diet and thus limiting the amount of animal fats in the diet.
Being overweight also increases the amount of fat in your body. As a result, more cholesterol and triglycerides is in circulation which can lead to problems. Managing your weight can make a big improvement on your cholesterol.
Hopefully this explains more about how cholesterol or what we think of cholesterol forms in the body. When we talk about LDL or HDL, we are actually referring to the vessels which transport triglycerides and cholesterol around the body.
Having too much triglyceride in the system will raise the amount of cholesterol and total fat in the body, which we know isn’t good for your health.
Therefore, aiming to eat healthy fats and managing your weight is important when thinking about optimising your cholesterol.
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