Which statement about medium-chain triglycerides absorption is true?

Which statement about medium-chain triglycerides absorption is true?

• A. They require carnitine-dependent transport into mitochondria
• B. They are absorbed directly into portal circulation bypassing lymphatics
• C. They must be emulsified by bile and require pancreatic enzymes
• D. They are not absorbed at all

Answer: (B)

Medium-chain triglycerides are absorbed differently from long-chain fats. The medium-length fatty acids (about 6–12 carbons) are more water-soluble, so after digestion by pancreatic lipase they are absorbed directly into enterocytes and enter the hepatic portal circulation, bypassing the lymphatic system and chylomicron formation. This is why they deliver fat to the liver quickly and do not rely on lymphatic transport. They do require pancreatic enzymes for digestion, but bile emulsification is not as essential for MCTs as it is for long-chain fats. They also can enter mitochondria without the carnitine-dependent shuttle used by longer fatty acids. Thus, absorbing directly into the portal circulation bypassing lymphatics is the true statement.

Medium-chain triglycerides are absorbed differently from long-chain fats. The medium-length fatty acids (about 6–12 carbons) are more water-soluble, so after digestion by pancreatic lipase they are absorbed directly into enterocytes and enter the hepatic portal circulation, bypassing the lymphatic system and chylomicron formation. This is why they deliver fat to the liver quickly and do not rely on lymphatic transport. They do require pancreatic enzymes for digestion, but bile emulsification is not as essential for MCTs as it is for long-chain fats. They also can enter mitochondria without the carnitine-dependent shuttle used by longer fatty acids. Thus, absorbing directly into the portal circulation bypassing lymphatics is the true statement.