Good Cholesterol vs Bad cholesterol
The rise in non communicable diseases all over the world during the past five decades makes cholesterol a hot topic, and there is urgency among individuals to gather correct information about cholesterol. Cholesterol is a chemical compound found in animals, which are made up of fatty acids and steroids. Cholesterol plays a major role in maintaining good health, by creating cell membranes and hormones like oestrogen and testosterone, and as an intracellular messenger. Endogenous production of cholesterol is mostly done in the liver, with the rest being taken in with the diet. We will see what these good and bad twins of cholesterol are, and how they compare with each other in production, action and outcome.
The good cholesterol is the high density lipoproteins (HDL), and it creates a protective effect on the cardio vascular system. This is done through extraction of cholesterol particles from the arterial walls, and transporting them to the liver to be excreted as bile, thus, preventing the formation of atherosclerotic plaques. High levels of HDL are associated with long life and reduction in morbidity, whilst lower levels of HDL are related with a higher incidence of heart attacks and strokes. Elevation of HDL levels can be achieved by positive lifestyle modifications and medications like nicotinic acid, gemfibrozil, oestrogen and statins.
The bad cholesterol is the low density lipoproteins (LDL), which carries the newly formed cholesterol from the liver to the other tissues in the body, and is related to earlier atheroma formation progressing into atherosclerosis with narrowing of arteries and leading up to cardiovascular disease (heart attacks and strokes) at an early age, and death. It is related with HDL, so that as the HDL level falls the LDL levels will rise posing the above mentioned threats. Reduction of LDL levels can be achieved through positive lifestyle modifications and compliant use of the medication statin, and to a lesser level with fibrates, nicotinic acid, gemfibrozil and resins like cholestyramine.
Difference between Good Cholesterol and Bad cholesterol
HDL and LDL, are both lipoproteins used in the transport of lipids from one organ to the other, and has a similar basic make up at the molecular level with hydrophilic heads jutting out and hydrophobic/lipophilic tails jutting in to covert the cholesterol particles. The differences in the structure are due to the apolipoprotein particles, which intermit the above mentioned phospholipids. Functionally, the HDL levels are expected to be in the high range and the LDL levels to be in the low range, to maintain good health. HDL transports the cholesterol from the tissues to the liver to be excreted, while the LDL transport them from the liver to the tissues to be deposited. Cardiovascular diseases resulting in heart attacks and strokes are associated with high LDL and low HDL levels. In reducing LDL levels, statin drugs have a major role to play, whereas in elevating the HDL level it is minute. Nicotinic acids, fibrates, and gemfibrozil have the majority action in elevating HDL, whereas reduction in LDL levels by it is negligible. The resin cholestryramine acts to reduce LDL level, but it has no effect on the HDL level.
In summary, cholesterol is important for the good health of the human body as it puts together the building blocks of cells and system function. High LDL : HDL level is associated with atherosclerosis causing morbidity and mortality. More than one drug is necessary to reduce LDL levels, and to elevate HDL levels in significant amounts.