Medium Chain Triglycerides

MEDIUM-CHAIN TRIGLYCERIDES (MCT)

Description
Commercial medium-chain triglycerides (MCT) are composed of 8 to 10 carbon fatty acids synthesized from palm kernel and coconut oils (1). MCT provide 8.3 kcal per g and 116 kcal per tablespoon (2).

Indications
MCT are indicated in conditions where long-chain triglycerides (LCT) are not well tolerated. MCT are commonly used in fat-controlled diets to provide increased calories and improve the palatability of a reduced-fat diet See Fat-Controlled Diet. The following properties of MCT may make it useful in disorders where LCT are problematic:

Absorption can occur despite pancreatic lipase deficiency (2).
Bile salts or micelles are not required for dispersion in water and subsequent absorption (2).
Transport across the intestinal mucosa occurs more readily than with LCT (2).
MCT are not dependent upon chylomicrons for transit and consequently do not require lipoprotein lipase for oxidation (2).
Transport does not occur through the lymphatic system. MCT travel directly to the liver via the portal vein, as free fatty acids bound to albumin (2).
MCT hydrolyzes to fatty acids more quickly (2) and oxidizes more rapidly and efficiently than LCT (1).

MCT may be adjunctive to a fat-controlled diet in the following conditions:

pancreatic insufficiency (1)
cystic fibrosis (1)
intestinal resection (1)
hepatobiliary disease (1)
lymphangiectasia (2)
chyluria (2)
chylous ascites (2)
chylothorax (2)
secondary carnitine deficiency syndromes (3)
whipple’s disease (4)
hyperchylomicronemia(4)

MCT may be therapeutically incorporated into the ketogenic diet, which is used to control epileptic seizures (see Ketogenic Diet) and may also be used in adjunct with antineoplastic treatment for pediatrics (5).

Contraindications
Under normal physiologic conditions, MCT are ketogenic. Therefore, MCT are contraindicated in persons who are prone to diabetic ketoacidosis (2).

In cirrhosis, MCT accumulate in the blood, resulting in a condition that presents with symptoms similar to hepatic encephalopathy, including hyperlactacidemia, hyperammonemia, hyperventilation, and altered EKG findings (2).

Nutritional Adequacy
MCT are used in conjunction with specific diets, such as fat-controlled or ketogenic diets. Nutritional adequacy will depend on the prescribed diet.

How to Order the Diet
MCT are generally ordered in conjunction with a fat-controlled diet. The order should specify the number of mL or g MCT to be added to the diet. For example: “____ g Fat-Controlled Diet plus ____ mL (g) MCT”.

Planning the Diet

MCT are available as MCT oil or in formulas containing MCT.
MCT should be introduced slowly to avoid the abdominal distention and pain, nausea, vomiting, and diarrhea associated with rapid infusion or high dose (2).
MCT in divided doses of no more than 15 to 20 mL (3 to 4 tsp) at a time are generally well tolerated (2). Patients should initially receive no more than 20 to 30 mL per day, increasing by 5 to 10 mL per day as tolerated until the MCT goal is met.
To incorporate MCT into the diet, the following are suggested (2):
- Add 1 tsp MCT oil to 4 oz fat free milk, carbonated beverages, juices, or flavored drinks. If patient is prescribed a ketogenic diet, use sugar-free beverages and follow fluid restrictions.

Substitute an equal amount of MCT oil for other fats when cooking and baking.
Prepare salad dressings with MCT oil.

References

Babineau TJ, Pomposelli J, Forse RA, Blackburn GL. Specific nutrients: carbohydrates, lipids, nucleic acids. In: Zaloga GP, ed. Nutrition in Critical Care. St. Louis, Mo: Mosby; 1994:196-197.
Nelson JK, Moxness KE, Jensen MD, Gastineau CF, eds. Gastrointestinal diseases and disorders. In: Mayo Clinic Diet Manual: A Handbook of Nutrition Practices. 7th ed. St. Louis, Mo: Mosby; 1994:230-232.
Pons R, De Vivo DC. Primary and secondary carnitine deficiency syndromes. J Child Neuro. 1995;10:S8-S24.
Long-chain trigylceride restricted medium-chain triglyceride diet. In: Manual of Clinical Dietetics. 6th ed. Chicago, Ill: American Dietetic Association; 2000: 725.
Nebeling LC, Lerner E. Implementing a ketogenic diet based on medium-chain triglyceride oil in pediatric patients with cancer. J Am Diet