Where Do High Density Lipoproteins Come From and What Do They Do?

The last type of lipoprotein is HDL. HDL is made in our liver and to a lesser extent in our intestines. It is HDL’s job to circulate and pick up excess cholesterol from tissues throughout our body and return it to the liver. The whole process is very interesting because in order for circulating HDL to return the cholesterol to our liver, some of the cholesterol is first passed to circulating LDLs. The LDL is then subject to removal from our circulation by the liver and broken down. HDL delivers the rest of its cholesterol directly to the liver. In regard to heart disease, if LDL wears the villain’s black hat, as higher levels are linked to increased risk of a heart attack and stroke, then HDL wears the hero’s white hat, as higher levels are linked to lower risk. We will spend more time talking about blood lipids and cardiovascular disease in Chapter 13.