Understanding cholesterol and its effects on the body can be very complicated, so let me try to break it down into easier to digest pieces (pun intended).

What is Cholesterol?

Cholesterol is a collection of fat molecules so when you look or feel Cholesterol it is a waxy, oil-based, fat-like substance that’s found in all cells of the body.  Your body needs cholesterol to make hormones, vitamin D, and substances that help you digest foods (bile).

Where does it come from?

Your body makes all the cholesterol it needs; Your liver is the primary organ responsible for the production of cholesterol in your body, although a small amount is made by the lining of the small intestine and the individual cells.  Cholesterol also is found in some of the foods you eat; specifically, any food product produced by an animal.  If a food does not come from an animal it does not have cholesterol in it.

Triglycerides

After you eat, during the digestion phase the body breaks down the fat you consume in food into fatty acids, which can then be absorbed into the blood. Fatty acid molecules are usually joined together in groups of three, forming a molecule called a triglyceride. Triglycerides are also made in our bodies from the carbohydrates that we eat.

The broken-down dietary fats (or any calories the body doesn’t need to use right away) gets reassembled in your small intestine into triglycerides. The triglycerides are then stored in your fat cells. Later, hormones release triglycerides for energy between meals or as needed. There are several types of triglyceride, with the main division between saturated and unsaturated types.

Triglycerides and cholesterol are separate types of lipids (or fats) that circulate in your blood. Triglycerides store unused calories and provide your body with energy, where cholesterol is used to build cells and certain hormones.

Lipoprotein

Because cholesterol is oil based and blood is water based (oil and water do not mix well) the liver packages cholesterol with protein and other compounds creating a lipoprotein (lip-o-PRO-teens) before it is released into the bloodstream. These packages are made of fat (lipid) on the inside and proteins on the outside. Cholesterol travels through your bloodstream in small packages (or ships) called lipoproteins.

These protein ships or lipoproteins come in four types, Chylomicrons, high-density lipoproteins (HDL), low-density lipoproteins (LDL), and very low-density lipoproteins (VLDL). The type of lipoprotein is determined by how much protein there is in relation to fat content.  Contained within these lipoproteins are triglycerides, cholesterol, proteins

VLDL – LDL – HDL

The cholesterol that is made (not consumed) in the liver is transported out of your liver by very low-density lipoproteins (VLDLs). VLDLs transport lipids from the liver to body cells, and they contain an elevated level of triglycerides. If you have a lot of VLDLs in your blood, then you have a lot of triglycerides in your blood

The broken-down dietary (or consumed) fats that find their way into your small intestine get reassembled into triglycerides. Triglycerides are the most common type of lipid in your body and a major source of energy, so moving them out of your digestive tract and into your body cells is an important job. This is accomplished by chylomicrons, which are a type of lipoprotein that transports lipids from the mucosal cells of the small intestine to the body cells.  So, chylomicrons are the first stage of transport out of the digestive tract into the blood.

The LDL (low-density lipoprotein) has been called the bad lipoprotein because It is comprised mostly of fat which then gets deposited.  It gets deposited all over the body, but one place where the deposits that cause significant problems is in the arteries of the heart creating plaques. This leads to atherosclerosis, which is a hardening and narrowing of the arteries of the heart and potentially causes a heart attack.

The HDL (high-density lipoprotein) is considered the “good” lipoprotein because its role is to transport LDL’s back to the liver where it can be reprocessed. HDL is comprised of mainly protein and it helps prevent atherosclerosis by preventing LDL cholesterol from.

Now that you under understand the basics, tune in for part two where I discuss why cholesterol is a necessity for life, LDL is not bad and HDL is not good and what can cause the entire system can go haywire and cause a heart attack or stroke.

Corey Feldman
MMS, PA-C, ACSM-CPT

Corey Feldman