Which lipoprotein is the 'good' cholesterol that transports excess cholesterol back to the liver where it is broken down?

• A. Low Density Lipoproteins
• B. Chylomicrons
• C. High Density Lipoproteins
• D. Triglyceride-rich lipoproteins

Answer: (C)

Reverse cholesterol transport is the process where a lipoprotein collects excess cholesterol from peripheral tissues and macrophages and brings it to the liver for excretion. The lipoprotein that performs this cleanup role is high-density lipoprotein. HDL is rich in protein and carries apolipoprotein A-I, which helps pick up cholesterol and cholesterol esters from cells. It then delivers this cholesterol to the liver, where it’s processed and excreted in bile, reducing the amount of cholesterol available to form arterial plaques. This protective recycling is why HDL is labeled the “good” cholesterol.

In contrast, other lipoproteins have different primary roles: low-density lipoprotein delivers cholesterol to tissues, which can contribute to atherogenesis; chylomicrons transport dietary lipids from the gut; triglyceride-rich lipoproteins (like VLDL and chylomicrons) primarily shuttle triglycerides to tissues after meals. Their main functions aren’t to remove cholesterol from the body.