Long-chain triglycerides (LCTs), which have 13 or more carbon atoms, have a complex digestion and absorption process that can take several hours. Digestion requires bile from the liver to emulsify (break down) the triglycerides (fat) and pancreatic enzymes called lipases to further break down the triglycerides in the small intestine into fatty acids and monoglycerides. After digestion, LCTs are packaged into fat-transport particles, called chylomicrons, which are absorbed into the lymphatic system and eventually enter the bloodstream, where they can be stored as fat or used for energy.[1]
However, the digestion process for medium-chain triglycerides (MCTs) is much simpler and faster. MCTs are smaller (6 to 12 carbon atoms) and more water-soluble than LCTs. Consequently, they do not require bile from the liver for emulsification and are enzymatically broken down in the stomach and small intestine into fatty acids and monoglycerides. These are then absorbed directly through the intestinal wall into the bloodstream via the portal vein, which bypasses the lymphatic system and delivers the MCT-derived fatty acids directly to the liver. This is important because the liver rapidly metabolizes the medium-chain fatty acids into ketones,[2] a type of energy the body can use immediately, especially when blood glucose concentrations are low.[1]