Cholesterol basics
Lipoproteins to Move Cholesterol in Blood
Since cholesterol is a fat, it can't travel alone in the bloodstream. To get around this problem, the body packages cholesterol and other lipids into minuscule protein-covered particles that mix easily with blood. These tiny particles, called lipoproteins (lipid plus protein), move cholesterol and other fats throughout the body.
Lipoproteins come in a range of shapes and sizes, and each type has its own tasks. They also morph from one form into another. These are the five main types:
• Chylomicrons are very large particles that mainly carry triglycerides (fatty acids from your food). They are made in the digestive system and so are influenced by what you eat.
• Very-low-density lipoprotein (VLDL) particles also carry triglycerides to tissues. But they are made by the liver. As the body's cells extract fatty acids from VLDLs, the particles turn into intermediate density lipoproteins, and, with further extraction, into LDL particles.
• Intermediate-density lipoprotein (IDL) particles form as VLDLs give up their fatty acids. Some are removed rapidly by the liver, and some are changed into low-density lipoproteins.
• Low-density lipoprotein (LDL) particles are even richer in pure cholesterol, since most of the triglycerides they carried are gone. Their primary function is to transport cholesterol from the liver to other tissues in the body.
• High-density lipoprotein (HDL) particles are called "good" cholesterol because some of them remove cholesterol from circulation and from artery walls and return it to the liver for excretion.
Source:
https://www.health.harvard.edu/heart-health/how-its-made-cholesterol-production-in-your-body
What is Cholesterol?
Cholesterol is the principal sterol of all higher animals.
A sterol is any organic compound with a skeleton closely related to cholestan-3-ol.
Total choleseterol: the overall amount of cholesterol in the blood, including HDL cholesterol, LDL cholesterol, etc.
sdLDL Cholesterol:
This is a type of LDL that is smaller and denser, making it more likely to contribute to plaque buildup in arteries and increasing cardiovascular risk.
Remnant Cholesterol:
Calculated by subtracting HDL and LDL from total cholesterol, remnant cholesterol is associated with increased risk of cardiovascular disease, particularly coronary artery disease.
In essence, while LDL is a primary target for cardiovascular risk reduction, remnant cholesterol is emerging as an important factor, and sdLDL is a sub-type of LDL that warrants attention as well.
functions of cholesterol for human body
Cell Membrane Structure:
Cholesterol is a crucial component of cell membranes, maintaining their integrity and fluidity. This allows cells to function properly by controlling what enters and exits.
Hormone Synthesis:
Cholesterol serves as a building block for steroid hormones, including:
- sex hormones: Testosterone, estrogen, and progesterone.
- Adrenal hormones: Cortisol and aldosterone, which regulate stress response, blood pressure, and electrolyte balance.
Vitamin D Production:
Cholesterol is a precursor for vitamin D, essential for calcium absorption and bone health.
Bile Production:
Cholesterol is a key component of bile, which is produced by the liver and stored in the gallbladder. Bile helps digest fats and absorb fat-soluble vitamins.
Other Functions:
Cholesterol also contributes to:
- Nervecell function: Cholesterol is a component of myelin, which insulates nerve cells and helps them transmit signals efficiently.
- Brain health: Cholesterol is involved in brain development and function.
- Immune system regulation: Cholesterol plays a role in immune cell function and response.