Cholesterol (medical abbreviation: CHOL) is defined as an essential fat with an animal sterol (organic molecules) found in blood, different organs, body tissues and fluids for use by the body cells.
It is present in every single cell of the body but is most abundant in the brain, nervous tissue, skin, and adrenal glands.
There are three types of cholesterol, which in effect are lipoproteins:
- Low-density lipoproteins (LDL), referred to as the “bad cholesterol”
- High-density lipoproteins referred to as the “good cholesterol”
- Very low-density lipoproteins (VLDL)
There are also the triglycerides, which together with the above three make up the lipid panel or profile. All these are described below.
What is blood cholesterol?
Cholesterol is a waxy-natured fat, which cannot dissolve in blood. At the same time, it has to be carried by the blood to the various parts of the body for the useful functions it performs.
It, therefore, requires a sort of a vehicle to transport it. Proteins in blood help do the job of transporting it to the various body organs and the tissues through the blood. Cholesterol sort of piggy rides on the proteins to flow in the blood stream.
It is obtained by your body mainly by being manufactured in the liver and is also derived from certain foods, which are of animal origins such as meat, poultry, and full-fat dairy products.
The liver produces 80% of your body requirement and only 20% comes from the foods that you eat. This 20% is the cholesterol absorbed by the intestines from the foods, which is 300 to 500 mg. This external cholesterol comes from the animal and dairy products that you consume.
And, even if you consume foods that do not contain cholesterol, carbs, fats, and proteins in your diet ultimately break down and release carbon, which the liver turns into cholesterol.
This shows that the body will strive to have enough of it always, and this is proof of its importance to the body.
The blood cholesterol combines with the proteins in the blood and this combination is called lipoproteins. This is the form in which it exists in the blood.
What are Lipoproteins?
Cholesterol, being insoluble in blood travels in the bloodstream piggy riding on proteins in the blood and this combination is called lipoproteins (lipo meaning fat).
Cholesterol is waxy in nature, insoluble in blood and therefore, excess levels of it in the blood cause plaques to get deposited or stuck on the inner walls of the arteries, clogging them over time.
This condition is called atherosclerosis, which can lead to heart diseases due to clogging of the heart arteries. This results when the levels of low-density lipoproteins or LDL rise in blood.
11 unknown cholesterol facts
- Very essential. You can’t live without cholesterol.
- More than half of the American population has higher than normal levels of blood cholesterol.
- According to the Centers for Disease Control and Prevention (CDC), about 74 million U.S. adults have raised levels, but only less than half of them are taking treatment to lower those levels and protect their heart health.
- The liver produces about 2 grams of cholesterol per day from nutrients. That accounts for 80% of the body requirement.
- The more saturated fats in your diet, the more of it is produced by the liver.
- Its blood levels can be brought down merely by eating the right foods and having an active lifestyle. Medication may not be necessary.
- Cholesterol is obtained only from the animal food sources in your diet. It is not present in any plant foods.
- The increase in its blood levels doubles your risk of getting heart disease.
- Every medical checkup should contain a lipid profile, which will show your blood cholesterol levels.
- Women tend to have lower levels than men
- It is believed that high levels are strongly influenced by the genetic factor.
- The liver produces more of HDL, the good cholesterol and less of LDL, the bad cholesterol that is responsible for heart disease and stroke.
- But, if you have a fatty liver, it produces more of the bad cholesterol increasing the LDL levels in the blood. This can lead to atherosclerosis, which can make you more prone to complications that can be fatal. To make matters more dangerous, the triglycerides also build up and increase your risk.
How often should you check your blood cholesterol?
After the age of 20 years, blood cholesterol levels should be checked every 5 years. After the age of 35 years, such a medical checkup should be carried out every 6 months or every year, depending on the risk factors you carry.
Children, too, are advised to undergo the cholesterol test at specific age group depending on the risk factors they carry such as a family history, obesity, etc.
This post on the cholesterol levels by age describes it all and why.
Types of Cholesterol
Cholesterol, however, is of one type only. It is the cholesterol and protein complex or a combination called lipoproteins, as mentioned above, which is of three different types.
The three types of lipoproteins are:
- Low-density lipoproteins (LDL) or the bad cholesterol
- High-density lipoproteins (HDL) or the good cholesterol.
- There is a third type of lipoproteins, however, called as the very low-density cholesterol (VLDL).
1. Low-Density Lipoproteins or LDL
LDL is usually referred to as the “bad cholesterol”. It carries the cholesterol from the liver through the blood to the various body cells. It causes build up of plaques inside the arteries, narrowing the arterial lumen and limiting blood flow. LDL makes up 60%-70% of the total cholesterol in the body.
2. High-Density Lipoproteins or HDL
HDL is usually referred to as “good cholesterol”. It carries the LDL from the bloodstream to the liver to be excreted through the bile into the small intestines. HDL also reduces the plaques formed. These are the reasons why it is referred to as the good cholesterol. It makes up 20%-30% of total cholesterol.
3. Very Low-Density Lipoproteins or VLDL
VLDL is not referred to much in everyday language. This is a combination of cholesterol and triglycerides and is heavier than LDL. VLDL is the precursor of LDL and is also referred to as the bad cholesterol. It makes up 10%-15% of the total cholesterol.