Lipoproteins and Your Risk for Heart Disease

Lipoproteins — such as HDLs and LDLs — are compounds made from a fat (lipid) and protein. Too many LDLs can increase your risk for heart disease. The job of lipoproteins is to carry cholesterol around your body through the bloodstream.

Your body can produce four types of lipoproteins:

High-density lipoproteins (HDLs)
Low-density lipoproteins (LDLs)
Very low-density lipoproteins (VLDLs)
Chylomicrons

Sometimes in the news you read or hear about HDL being “good” cholesterol and LDL being “bad” cholesterol. However, HDL and LDL are lipoproteins, not cholesterol molecules. They just attach to and transport cholesterol. Here is what is “good” and “bad” about the lipoproteins.

Chylomicrons are very small, newly created lipoproteins that fall into the VLDL category. VLDLs have very little protein and a lot of fat. (Fat is less dense than protein, like fat “weighs” less than muscle.)

As VLDLs travel through your bloodstream, they lose some lipids, pick up cholesterol, and become LDLs. The LDLs deliver the cholesterol to cells in your body that need it, but along the way, VLDLs and LDLs can squeeze through blood vessel walls. While doing that, the cholesterol can get stuck to the wall of the blood vessel, causing deposits (plaque) to form.

If enough cholesterol gets stuck, an artery may get clogged, which means blood cannot flow through. If that happens, a heart attack or stroke may occur.

Although LDLs help the body by transporting cholesterol, if you have too many of them, the cholesterol may start to block blood vessels, which increases your risk of heart disease, heart attack, and stroke.

HDLs, on the other hand, are the lipoproteins that contain more protein than lipid, which makes them more dense and gives them their name. Because they are more dense, they cannot squeeze through the blood vessel walls, so they shuttle cholesterol right out of the body. They are not able to deposit cholesterol in blood vessels, because they cannot get into them, so they do not increase the risk of heart disease, heart attack, or stroke. Ideally, you want to have more of these dense little guys floating in your blood than you want the LDLs or VLDLs.