“Somewhere, over the rainbow, way up tall, there’s a land where they've never heard of cholesterol.” You might have heard these words of Allan Sherman. It shows how scared human beings are of this compound that people actually dream of living in such a place that has never heard of it at all. Cholesterol is, in fact, a causative factor of heart attack but, all types of cholesterol are not harmful. In fact, cholesterol is an essential fat which supports the cell membranes and provides stability to body cells. However, some kinds of cholesterol, if present in excess, may cause coronary heart diseases also. Being insoluble in water, cholesterol is transported through blood with the help of carrier proteins. These carriers are called lipoproteins and, depending on the density of the protein, cholesterol can be LDL (low-density lipoprotein), HDL (high density lipoprotein or VLDL (very low density lipoprotein). To understand more about cholesterol, you need to understand all the types of cholesterol and the importance of each. This following section seeks to introduce you to different types of cholesterols. Take a look!
Cholesterol And Heart Disease
Learning about cholesterol is very important because it is directly associated with many serious health issues. Learning about cholesterol can help you lead a healthy life. Cholesterol is a fat, essential for the normal functioning of body cells. But if present in excess, it forms plaque in blood vessels and narrows the coronary arteries (arteries supplying blood to the heart muscles). Over a period of time, the plaque clogs the arteries and causes atherosclerosis (hardening of the arteries) which can lead to fatal heart attacks.
Different Kinds Of Cholesterol
Cholesterol is transported in the body through blood. In blood, it binds with protein and forms a cholesterol-protein complex called lipoprotein. This lipoprotein is classified into three different groups depending on the ratio of protein to cholesterol. These three types are also the major types of cholesterol found in our bodies.
High Density Lipoprotein (HDL)
High density lipoprotein or HDL is known as the ‘good cholesterol’. This compound consists of a ring of lipoprotein surrounding the cholesterol center. This association makes it denser than other cholesterols and hence the name ‘High Density Lipoprotein’. HDL is considered ‘good’ because it picks up the extra cholesterol molecules and transports them back to liver for metabolism and thus, regulates the level of cholesterol in blood. The higher the level of HDL, the lower the bad cholesterol you have in your blood.
Low Density Lipoprotein (LDL)
LDL has a single apolipoprotein (a protein that can bind with lipid) that binds with cholesterol, making it soluble in aqueous medium. It has a highly hydrophobic (water-hating) core consisting of polyunsaturated fatty acids and about 1500 esterified cholesterol molecules. LDL varies in size and density. Small LDL particles are more dangerous and increase the risk of coronary heart disease as compared to the larger LDLs.
LDL cholesterol is lighter than HDL cholesterol. Just like the HDL cholesterol, LDL cholesterol is also circulated through blood but, unlike the HDL cholesterol, it has a tendency to adhere to the wall of blood vessels. The white blood corpuscles swallow the cholesterol molecules deposited on the walls of blood vessels to protect the blood vessels. The WBCs which ingest the cholesterol molecules oxidize and get converted into toxic substances. With continuous deposition of LDL on the wall, more and more white cells migrate to this area to digest the cholesterol. These depositions, over a period of time, form plaques and impede the blood flow through the artery. Thus, when the coronary arteries that supply blood to the heart get clogged due to cholesterol, it affects the cardiac muscle cells and causes heart attack.
Very Low Density Lipoprotein (VLDL)
VLDL is another type of lipoprotein made by the liver. This lipoprotein enables fats and cholesterol to move in the bloodstream. VLDL is a very small compound with a size of 30-80 nm. It is involved in transporting triglycerides, phospholipids, cholesterol and cholesterol esters and thus, works as an internal lipid transport mechanism for the body. Though a lipid binding compound, VLDL is also identified as a contributor in increasing the risk of coronary artery diseases due to the high levels of triglycerides present in it. VLDLs contribute not only to coronary artery diseases but also increase blood pressure and may even lead to a stroke. VLDL is not mentioned during the regular check-ups of cholesterol because there is no simple, direct method to measure its level. It is usually estimated on the basis of the percentage of triglyceride in your body. Normally, VLDL cholesterol level is about 5-30 ml/dl.
Cholesterol is known and dreaded as a triggering factor of heart attacks. You now know that all cholesterol is not bad; there are some beneficial types as well which help you lead a healthy life. So, from now on, try increasing the level of good cholesterol in your blood and avoid the bad one and enjoy a happy and healthy living!