Difference Between Good and Bad Cholesterol

Main Difference – Good vs Bad Cholesterol

Cholesterol is a waxy substance that naturally occurs in some food and is produced in the liver. The normal functioning of the body requires cholesterol. Cell membrane contains cholesterol and cholesterol produce some hormones as well. The high consumption of calories increases the levels of cholesterol in the blood. Too much of cholesterol may lead to cardiovascular disease. Good cholesterol and bad cholesterol are the two types of cholesterol that occur in the body. Good cholesterol is the high-density lipoprotein (HDL). Bad cholesterol is the low-density lipoprotein (LDL). The main difference between good cholesterol and bad cholesterol is that good cholesterol takes LDL out of the blood, preventing the buildup of cholesterol on the walls of the arteries whereas bad cholesterol builds up on the walls of the arteries, causing atherosclerosis.

Key Areas Covered

1. What is Good Cholesterol
      – Definition, Role, Normal level
2. What is Bad Cholesterol
      – Definition, Role, Normal level
3. What are the Similarities Between Good and Bad Cholesterol
      – Outline of Common Features
4. What is the Difference Between Good and Bad Cholesterol
      – Comparison of Key Differences

Key Terms: Atherosclerosis, Bad Cholesterol, Bloodstream, Cardiovascular Disease, Good Cholesterol, High-Density Lipoprotein (HDL), Liver, Low-Density Lipoprotein (LDL)

What is Good Cholesterol

Good cholesterol refers to a type of cholesterol that benefits the heart by transporting bad cholesterol from the blood into the liver. It is also called HDL. Since the particle density is high in good cholesterol, is called high-density. The cholesterol molecule is surrounded by a rim of lipoproteins to form the HDL molecule. Lipoproteins are the helper molecules, which aid the transportation of the cholesterol particle in the blood. The structure of a lipoprotein molecule is shown in figure 1.

Main Difference - Good vs Bad Cholesterol

Figure 1: Lipoprotein
T – Triglycerol, C – Cholesterol, phospholipids (green)

Good cholesterol are the scavengers of LDL and removes LDL from the bloodstream. It transports LDL into the liver where the LDL is reused and recycled. Thereby, good cholesterol maintains the inner walls of the blood vessels. This reduces the risk of atherosclerosis, which leads to cardiovascular diseases. The good cholesterol levels should be 60 mg/dL or above. The higher level of good cholesterol is good for the health.

What is Bad Cholesterol

Bad cholesterol refers to a type of cholesterol that increases the risk of cardiovascular disease. It is also called LDL. LDL is an important marker of the development of the cardiovascular disease. It forms clogged arteries, leading to atherosclerosis. Atherosclerosis leads to the cardiovascular disease. The plaques in the walls of the blood vessels are removed by HLD. The role of the bad and good cholesterol is shown in figure 2.

Difference Between Good and Bad Cholesterol

Figure 2: Bad and Good Cholesterol

The normal level of HDL in the blood should be less than 40 mg/dL. The elevated level of bad cholesterol is harmful since it produces the plaques.

Similarities Between Good and Bad Cholesterol

Both good and bad cholesterol are two forms of cholesterol.
The transportation of good and bad cholesterol through the blood occurs by lipoprotein molecules.
Both good and bad cholesterol may lead to the cardiovascular disease.

Definition

Good Cholesterol: Good cholesterol refers to a type of cholesterol which helps the body by transporting bad cholesterol from the blood into the liver.

Bad Cholesterol: Bad cholesterol refers to a type of cholesterol which increases the risk of cardiovascular disease.

Type

Good Cholesterol: Good cholesterol is the high-density lipoprotein (HDL).

Bad Cholesterol: Bad cholesterol is the low-density lipoprotein (LDL).

Particle Density

Good Cholesterol: The particle density of a good cholesterol molecule is high.

Bad Cholesterol: The particle density of the bad cholesterol molecule is low.

Role

Good Cholesterol: Good cholesterol takes LDL out of the blood, preventing the buildup of cholesterol on the walls of the arteries.

Bad Cholesterol: Bad cholesterol builds up on the walls of the arteries, causing atherosclerosis.

Normal Level

Good Cholesterol: The good cholesterol levels should be 60 mg/dL or above.

Bad Cholesterol: The bad cholesterol levels in the blood should be less than 40 mg/dL.

High/Low levels

Good Cholesterol: The higher levels of good cholesterol is beneficial for the health.

Bad Cholesterol: The lower levels of bad cholesterol is beneficial for the health.

Conclusion

Good cholesterol and bad cholesterol are the two major forms of cholesterol in the blood. Both good cholesterol, as well as bad cholesterol, are transported through the blood by lipoprotein molecules. The density of the good cholesterol is higher than that of the bad cholesterol. Therefore, good cholesterol is HDL, and the bad cholesterol is LDL. LDL forms plaques inside the walls of the blood vessels. However, those plaques are removed by HDL and are transported into the liver. Thereby, the main difference between good cholesterol and bad cholesterol is the role of each cholesterol in the blood.

Reference:

1.“HDL Cholesterol: The Good Cholesterol.” WebMD, Available here.
2.“LDL Cholesterol – The “Bad” Cholesterol Explained.” Docs Opinion, 28 Aug. 2017, Available here.

Image Courtesy:

1. “Chylomicron” Autor: Xvazquez – Vlastné dielo (CC BY-SA 3.0) via Commons Wikimedia
2. “máu nhiễm mỡ – cholesterol” by LÊ VĂN THẢO (CC BY-SA 2.0) via Flickr