Medium-chain triglycerides

Medium-chain triglycerides (MCTs) are medium-chain (6 to 12 carbons) fatty acid esters of glycerol.

MCTs passively diffuse from the GI tract to the portal system (longer fatty acids are absorbed into the lymphatic system) without requirement for modification like long-chain fatty acids or very-long-chain fatty acids. In addition, MCTs do not require bile salts for digestion. Patients that have malnutrition or malabsorption syndromes are treated with MCTs because they do not require energy for absorption, utilization, or storage. Coconut oil is composed of approximately 66% medium-chain triglycerides. Other rich sources of MCTs include palm kernel oils and camphor tree drupes. The fatty acids found in MCTs are called medium-chain fatty acids. The names of the medium-chain fatty acids (and the corresponding number of carbons) found in MCTs are caproic acid (C6), caprylic acid (C8), capric acid (C10) and lauric acid (C12). MCTs are composed of a glycerol backbone and three of these fatty acids. The approximate ratios of these fatty acids in commercial MCT products derived from coconut oil are 2(C6):55(C8):42(C10):1(C12).

Dietary relevance

The milk fats of humans and guinea pigs are largely made up of long-chain fatty acids. The milk fats of cows, sheep, and goats are rich in short-chain fatty acids. The milk fats of horses contain large amounts of medium-chain fatty acids.^[1]

Some studies have shown that MCTs can help in the process of excess calorie burning, and thus weight loss.^{[2][3][4][5][6][7]} MCTs are also seen as promoting fat oxidation and reduced food intake.^[8] Mary G. Enig reviewed in detail the medical factors and health benefits of medium-chain triglycerides.^[9] There has also been interest in MCTs from endurance athletes and the bodybuilding community.^[10] While there seem to be health benefits from MCTs, a link to improved exercise performance is weak.^[8]

Medical uses

Medium-chain triglycerides are generally considered a good biologically inert source of energy that the human body finds relatively easy to metabolize. They have potentially beneficial attributes in protein metabolism but may be contraindicated in some situations due to their tendency to induce ketogenesis and metabolic acidosis.^[11] Their use is not recommended for diabetics unless under supervised medical treatment and those with liver problems due to the added stress they may put on the organ.^[10]

Due to their ability to be absorbed rapidly by the body, medium-chain triglycerides have found use in the treatment of a variety of malabsorption ailments. MCT supplementation with a low-fat diet has been described as the cornerstone of treatment for primary intestinal lymphangiectasia (Waldmann's disease).^[12] MCTs are an ingredient in parenteral nutritional emulsions.^[13][14] Studies have also shown promising results for epilepsy treatment through the use of ketogenic dieting.^[15][16]

Technical uses

MCTs are bland compared to other fats, and do not generate off-notes as quickly as LCTs. They are also more polar than LCTs. Because of these attributes, they are widely used as solvents for flavours and oral medicines and vitamins.^[17]

See also

• Caprylidene

References

Further reading