What is cholesterol?
Cholesterol is a chemical compound that is normally produced by the body and its structure is a combination of fat and steroid. It is not necessarily a harmful substance. Instead it is a basic component of the cell membrane and for hormone production. Most of the cholesterol in our body is produced by the liver (around 80%), while the rest comes from our food. Meat, poultry, fish, and dairy products are the main sources of dietary cholesterol. Animal liver is especially high in cholesterol, while fruits and vegetables contain little or no cholesterol.
"LDL is the bad cholesterol, while HDL is the good one."
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| A typical burger and fries meal may contain up to 12 g of saturated fat which increases LDL cholesterol. |
Types of cholesterol
There are four types of cholesterol found in the human body. They are low density lipoproteins (LDL), high density lipoproteins, very low density lipoproteins (VLDL) and triglycerides.LDL cholesterol is also known as the 'bad' cholesterol. High levels of LDL cholesterol in the blood can cause the formation of cholesterol plaques in the walls of blood vessels, causing problems like coronary heart disease, stroke, and peripheral artery disease. Cholesterol plaque can eventually causes thickening of the blood vessel walls and narrowing of the arteries. This is known as atherosclerosis.
HDL cholesterol is also known as the 'good cholesterol'. High levels of HDL cholesterol helps our body to get rid of the bad cholesterol, thus preventing the formation of plaque. That's why the higher your HDL levels are, the better.
A high LDL/HDL ratio (high levels of LDL and low levels of HDL) increases the risk to contract atherosclerosis. Conversely, a low LDL/HDL ratio protects the blood vessels from plaque formation.
VLDL is pretty much similar to LDL. It consists of mostly fat and not much protein, unlike HDL.
Triglycerides are carried by very low density lipoproteins. The levels might increase after consumption of alcohol or high calorie food. Excess glucose is also transformed into triglycerides and this is why people with diabetes tend to have high levels of it.
Total cholesterol is the sum of LDL cholesterol, HDLcholesterol, and VLDL cholesterol. The VLDL levels are usually calculated as approximately one-fifth of the triglycerides levels.
The desirable levels of total cholesterol is <200 mg/dL (<5.2 mmol/L). Levels of 200-239 mg/dL (5.2-6.19 mmol/L) is considered borderline, while levels ≥240 mg/dL (≥6.2 mmol/L) is considered high. Starting from the age of 20 everyone should get their cholesterol levels checked at least once every five years.
