This word “lipoprotein” broken down in short = “lipo” = fat and “proteins” = proteins. Lipo-proteins are clusters of fats (or “lipids”) + proteins are the main Uber drivers for dietary fat & cholesterol throughout the blood. There are four types of lipoproteins, but the main one we are focusing on today is going to be “low-density lipoproteins” (LDLs) -often deemed the most villainous of the four because they’re loaded with cholesterol.
Well...what the heck is cholesterol?
Because cholesterol cannot dissolve in water or blood, it must be sew itself to proteins (**cue the LDL’s**) to flow through the blood (source). From a high level, cholesterol can be created in two ways - it’s either (1) made by your cells or (2) consumed via food (like meats or dairy).
Your body needs some cholesterol to make hormones (SUPER IMPORTANT!) and build protective barriers for cells. But too much cholesterol leads to severe heart diseases. Research has shown that it’s a wise idea to rethink the quantity of saturated & trans fats (higher cholesterol) we eat because of the link between LDL and heart disease. These types of low-nutrient fats tend to be those that are solid at room temperature - like butter, lard and margarine sticks!
Plaque Build Up
LDLs get such a bad wrap because they lead to blood clots and plaque build up in your arteries (source). An analogy I like to use for plaque build up in the arteries is a messy hallway of your house. Picture this: you’re walking down the hallway from the kitchen to the bathroom, looking down at your phone, and trip over a huge pile of clothes that your lovely roommate (and/or kids) left in the middle of the hall. In this scenario, the hallway is the artery, you are the blood flowing through your body, and the piles of clothes are those pesky LDLs that cause the blood to trip up and mess with its consistent flow.
When lipoprotein lipase breaks down fats from diet, the fat molecules are either (1) used by the body as energy or (2) stored in fatty tissue for later use...as we saw in the “I = insulin” email! (source)
The "good" guys and the "bad" guys
Because everyone loves a good villain/hero story...High density lipoproteins (HDLs), LDLs counterparts, are the “good guys”! High amounts of HDL is associated with less risk of heart disease because they are responsible for shoveling the LDL out of the blood, and back to the liver - where it’s re-broken down into smaller, less harmful particles. So, it’s not only important to keep the quality of fats you consume in check to ensure greater amounts of HDL than LDL, but it’s also vital to keep your liver in tip-top-shape!