Interesting Facts about Low-Density Lipoproteins

LDL stands for low-density lipoprotein. Its role is to move cholesterol and other fatty substances to the cells where it can be used or stored. LDLs are made in the liver and intestines. LDLs consist of cholesterol wrapped in a protein sheath; hence, the name lipo for fat, and protein – ‘lipoprotein’. The protein wrapping is needed because blood is made up mainly of liquids and the fats in cholesterol would be difficult to transport in the blood stream.  By wrapping the waxy-fatty substances in cholesterol in a protein sheath, the cholesterol can easily move through the bloodstream. 

LDLs are the transport mechanism for cholesterol (think of them as little dump trucks carrying cholesterol) and other fats (triglycerides) to the body’s cells.

 
Newborns have an LDL level between 25 and 40 mg/dL, whereas the average American adult’s LDL level is somewhere between 130 and 160 mg/dL. However, LDL levels below 100 mg/dL are optimal. 

Studies show that LDL levels need not increase with age. 

LDL is recognized by specific receptors on cells that need cholesterol. When cells require more cholesterol for basic functions, they express more receptors, or docking sites, on their surface to bind more LDL. 

Size of LDL particles might be more important than LDL concentration in the blood. This is because the smaller the size of the LDL particles, the easier for them to penetrate the artery-cell walls and accumulate there causing further heart disease. 

A standard lipid profile test (ordinary blood testing that your physician would request for you) will not tell you the size of your LDL particles. You need an advanced blood test. Most labs report your LDL cholesterol pattern. If your LDL particles are ‘large’ then you have the less dangerous LDL pattern A. If your LDL pattern is small you have LDL pattern B. The latter can be changed to pattern A by making lifestyle changes. 

Small, dense LDL cholesterol particles increase your risk of heart disease by as much as six times. 

Small LDL particles are found in patients who have type 2 diabetes or are prediabetic. 

Oolong tea (served in many Chinese restaurants) has been found to increase the size of LDL particles. 

Free radicals are charged molecules that are a result of body processes; they may roam freely in the bloodstream. LDL particles can join with free radicals and become oxidized. When oxidized the LDL particles can easily damage the artery-cell wall, penetrate it, and accelerate the accumulation of cholesterol there. 

Oxidized LDL can act as an inflammatory substance, which initiates an attack of specialized cells called macrophages. The macrophages eat the cholesterol and spit out a burst of toxins that damages the blood vessels. In this manner the body’s own defense system works against itself to facilitate the deposition of cholesterol in artery walls.