EP154: Moving Fat Around The Body - Lipoprotein

Welcome to my podcast. I am Doctor Warrick Bishop, and I want to help you to live as well as possible for as long as possible. I’m a practising cardiologist, best-selling author, keynote speaker, and the creator of The Healthy Heart Network. I have over 20 years as a specialist cardiologist and a private practice of over 10,000 patients. Podcast Summary Introduction Dr. Warrick Bishop is a practicing cardiologist and passionate health educator who hosts this podcast to help patients understand their heart health through education. In this episode, Dr. Bishop explains how fats and lipids are transported throughout the body, building on previous discussions about hydrocarbons and basic fat chemistry. The episode focuses on the structure and function of lipoproteins—the specialized particles that act as delivery vehicles for fats and cholesterol in the bloodstream. Key Takeaways: Lipids (fats, cholesterol, and triglycerides) are hydrophobic (water-repelling) and cannot travel freely through the bloodstream, requiring special transport mechanisms. Phospholipids are unique because they have both hydrophobic and hydrophilic (water-attracting) properties, making them ideal for forming the outer shell of transport particles. Apolipoproteins are special proteins that can bind and carry hydrophobic lipids while remaining water-soluble, allowing them to transport fat through the aqueous bloodstream. Lipoproteins are spherical particles with a protein and phospholipid shell on the outside and a fatty core (triglycerides and cholesterol esters) on the inside. The density of a lipoprotein particle increases as fatty content is removed during transport, which is why we classify them as "low-density" or "high-density" based on their composition. Chylomicrons are the largest lipoprotein particles (approximately 500 nanometers in diameter), produced in the gut to transport absorbed dietary fats. Very Low-Density Lipoproteins (VLDL) are produced by the liver and transport triglycerides and cholesterol for distribution throughout the body. Lipoprotein lipase is an enzyme that breaks down and extracts fat from chylomicrons and VLDL particles at the capillaries, allowing tissues to access energy and storage lipids. Fat-soluble vitamins (A, D, E, and K) and antioxidants like vitamin E travel within lipoprotein particles as they move through the body. The apoprotein on each lipoprotein acts as a "key" that determines which tissue receptors the particle can bind to, directing lipids to their appropriate destinations.