Medium chain triglycerides (MCT) are a category of fats containing a specific fatty acid chain length. They differ from the common long chain fatty acids by the number of carbon atoms as well as by their digestive properties. MCT oils are currently being researched to determine their effect on blood glucose levels, appetite control and life expectancy.
MCT Structure
Fats and oils in your diet are made of triglycerides, structures that contain three fatty acids attached to one glycerol molecule. The fatty acids are chains of 2 to 22 carbon atoms, with hydrogen atoms attached to them. Long chain triglycerides (LCT), ranging from 12 to 18 carbons, are most common in the diet, estimated by the Coconut Research Center to comprise 98 to 100 percent of dietary fats. Medium chain triglycerides are 6 to 10 carbons in length.
Digestive Properties
These shorter chains are more quickly absorbed into the bloodstream than long chain triglycerides. MCTs do not require bile salts, which must be present in the small intestine to help emulsify other dietary fats. Once absorbed in the blood, MCTs do not require carnitine for cellular absorption as LCTs do. MCTs actually provide fewer calories: 8.3 per gram vs. 9 calories per g of LCT.
Dietary Sources
Coconut oil and palm kernel oil are the dietary sources of MCTs. The MCTs are only part of the triglycerides present in the oil. Manufacturers must separate out the fraction of fatty acids that are medium chain from the longer chain portion of the oil. The medium chain fatty acids are the only ones that go into a bottle of MCT oil.
Dietary Consumption
Cooking the oil above 300 to 320 degrees Fahrenheit causes structural changes that affect the flavor. It can be poured over or mixed into any food in which it will be palatable. The oil is most often consumed as a salad dressing. It is also mixed into tube feeding formulas for patients who benefit from the advantages of MCT oil.
Therapeutic Uses
Because MCT oil bypasses some digestive and absorptive processes required by the longer chain fatty acids, it provides an easily absorbable form of calories for people with digestive disorders. This benefits patients with cystic fibrosis, pancreatitis, intestinal disorders such as Crohn's disease and even newborn babies with malabsorptive problems. The pediatric department at the University of Louisville cautions that MCT oils do not contain the essential fatty acids required for optimal nutrition and therefore cannot be the sole source of fats in the diet.
Researching Health Benefits
MCT oils have a protective effect against heart disease, lowering the risk of atherosclerosis. Ongoing studies on humans support animal studies showing other health benefits such as enhancing immune function, appetite suppression, weight loss and increased endurance during exercise.
