#uncat 

## Uses
Cholesterol:
- protects the integrity of cell membranes
- helps nerve cells to send messages
- is a building block ffor vitamin D
- enables your gallbladder to make *bile acids*
- a base on which steroid hormones are built

## In heart disease
The more cholesterol you have floating in your blood, the more cholesterol is likely to cross in your arteries, where it may lead to a heart attack or stroke.

## Lipoproteins

Your body makes 5 types of [[Proteins|lipoproteins]]: very low-density lipoproteins (VLDLs), low-density lipoproteins (LDLs), intermediate-density lipoprteins (IDLs), high-density lipoproteins (HDLs). As a rule of thumb, LDLs take cholesterol into blood vessels, while HDLs carry it out of the body.

A special case is known as a **chylomicron** (ultra low-density lipoproteins, ULDL) made in your intestinal cells from protein and triglycerides. After 12 hours of travelling through your blood and around your body, a chylomicron has lost virtually all its fats. By the time the chylomicron makes its way to the liver, the only thing left is protein.

As VLDLs travel through your bloodstream, they lose triglycerides, pick up cholesterol, and turn into LDLs. Both VLDLs and LDLs are soft and small enough to pass through blood vessel walls, which means they are more likely to slide into your arteries and block them.

![[Pasted image 20241220190528.png]]


## Limits
![[Pasted image 20241220190650.png]]

Most of the cholesterol you need is made in your liver, some is in food, which is the cause for a debate about whether lowering the cholesterol in your food really lowers the overall amount that much.

![[Pasted image 20241220190856.png]]
![[Pasted image 20241220190905.png]]