Before medical school, when a doctor started talking to me about “good cholesterol” and “bad cholesterol,” my eyes glazed over. Say what? Now, when a doctor talks to me about “good cholesterol” and “bad cholesterol,” my eyes still glaze over, but for a different reason–because when you go down the rabbit hole, the good/bad analogy becomes laughably simplistic.
The previous section focuses on the LDL story because, all else equal, more LDL particles floating around for longer means higher disease risk. High-density lipoproteins, or HDL, the “good cholesterol,” on the other hand, are less well understood–but just like LDL, the total amount of cholesterol in your HDL test may be less important than the number of healthy, functional particles you have.
HDL particles are thought to benefit your health because they are sort of like the cleanup trucks. They pick up excess cholesterol from the far reaches of your body and deliver it back to your liver, where it is converted to bile and passed. In fact, a low HDL-LDL or HDL-triglyceride ratio is a stronger predictor of heart disease risk than high “bad cholesterol.”
Interestingly, saturated fat–while it does raise the amount of LDL in the body–also raises HDL, maintaining a cardiovascular-favorable lipoprotein ratio. But the amount of HDL you have isn’t the whole story. Newer tests are being developed to look at the functionality of the HDL recycling system. We call it efflux capacity: how efficiently your HDL scavenges cholesterol from the overworked white blood cells in your damaged arterial plaques and shuttles it back to the liver. The other aspects of functional HDL are still being discovered.