Medium-chain Triglyceride Structural Formula V

A medium-chain triglyceride (MCT) is a

triglyceride A triglyceride (from '' tri-'' and '' glyceride''; also TG, triacylglycerol, TAG, or triacylglyceride) is an ester derived from glycerol and three fatty acids. Triglycerides are the main constituents of body fat in humans and other vertebrates ...

with two or three

fatty acid In chemistry, in particular in biochemistry, a fatty acid is a carboxylic acid with an aliphatic chain, which is either saturated and unsaturated compounds#Organic chemistry, saturated or unsaturated. Most naturally occurring fatty acids have an ...

s having an

aliphatic In organic chemistry, hydrocarbons ( compounds composed solely of carbon and hydrogen) are divided into two classes: aromatic compounds and aliphatic compounds (; G. ''aleiphar'', fat, oil). Aliphatic compounds can be saturated (in which all ...

tail of 6–12 carbon atoms, i.e. a medium-chain fatty acid (MCFA). Rich food sources for commercial extraction of MCTs include

palm kernel oil Palm kernel oil is an edible plant oil derived from the kernel of the oil palm tree ''Elaeis guineensis''. It is related to two other edible oils: ''palm oil'', extracted from the fruit pulp of the oil palm, and ''coconut oil'', extracted from ...

and

coconut oil Coconut oil (or coconut fat) is an edible oil derived from the kernels, meat, and milk of the coconut palm fruit. Coconut oil is a white solid fat below around , and a clear thin liquid oil at higher temperatures. Unrefined varieties have a disti ...

Sources of MCTs

MCTs are found in

and

and can be separated by

fractionation Fractionation is a separation process in which a certain quantity of a mixture (of gasses, solids, liquids, enzymes, or isotopes, or a suspension) is divided during a phase transition, into a number of smaller quantities (fractions) in which t ...

. They can also be produced by interesterification. Retail MCT powder is MCT oil embedded in starch and thus contains carbohydrates in addition to fats. It is manufactured by spray drying.

List of MCFAs

With regard to MCFAs, apart from the above listed straight chain (unbranched chain) fatty acids, side chain (branched chain) fatty acids also exist.

Applications

Calorie restriction

A 2020

systematic review A systematic review is a scholarly synthesis of the evidence on a clearly presented topic using critical methods to identify, define and assess research on the topic. A systematic review extracts and interprets data from published studies on ...

and

meta-analysis Meta-analysis is a method of synthesis of quantitative data from multiple independent studies addressing a common research question. An important part of this method involves computing a combined effect size across all of the studies. As such, th ...

by '' Critical Reviews in Food Science and Nutrition'' supported evidence that MCT decreases subsequent energy intake compared to Long-Chain Triglycerides (LCTs). Despite this, it does not appear to affect appetite, and thus the authors stated that further research is required to elucidate the mechanism by which this occurs.

Dietary relevance

Molecular weight analysis of milk from different species showed that while milk fats from all studied species were ''primarily'' composed of long-chain fatty acids (16 and 18 carbons long), approximately 10–20% of the fatty acids in milk from

horse The horse (''Equus ferus caballus'') is a domesticated, one-toed, hoofed mammal. It belongs to the taxonomic family Equidae and is one of two extant subspecies of ''Equus ferus''. The horse has evolved over the past 45 to 55 mi ...

cow Cattle (''Bos taurus'') are large, domesticated, bovid ungulates widely kept as livestock. They are prominent modern members of the subfamily Bovinae and the most widespread species of the genus '' Bos''. Mature female cattle are called co ...

sheep Sheep (: sheep) or domestic sheep (''Ovis aries'') are a domesticated, ruminant mammal typically kept as livestock. Although the term ''sheep'' can apply to other species in the genus '' Ovis'', in everyday usage it almost always refers to d ...

, and

goat The goat or domestic goat (''Capra hircus'') is a species of Caprinae, goat-antelope that is mostly kept as livestock. It was domesticated from the wild goat (''C. aegagrus'') of Southwest Asia and Eastern Europe. The goat is a member of the ...

s were medium-chain fatty acids. Some studies have shown that MCTs can help in the process of excess calorie burning, thus weight loss. MCTs are also seen as promoting fat oxidation and reduced food intake. MCTs have been recommended by some endurance athletes and the

bodybuilding Bodybuilding is the practice of Resistance training, progressive resistance exercise to build, control, and develop one's skeletal muscle, muscles via muscle hypertrophy, hypertrophy. An individual who engages in this activity is referred to a ...

community. While health benefits from MCTs seem to occur, a link to improved exercise performance is inconclusive. A number of studies back the use of MCT oil as a weight loss supplement, but these claims are not without conflict, as about an equal number found inconclusive results.

Pharmaceutical relevance

MCTs can be used in solutions, liquid suspensions and lipid-based drug delivery systems for emulsions, self-emulsifying drug delivery systems, creams, ointments, gels and foams as well as suppositories. MCTs are also suitable for use as solvent and liquid oily lubricant in soft gels. Brand names of pharma-grade MCT include Kollisolv MCT 70.

Medical relevance

MCTs passively diffuse from the

GI tract The gastrointestinal tract (GI tract, digestive tract, alimentary canal) is the tract or passageway of the digestive system that leads from the mouth to the anus. The tract is the largest of the body's systems, after the cardiovascular system. T ...

to the

hepatic portal system In human anatomy, the hepatic portal system or portal venous system is a system of veins comprising the portal vein and its tributaries. The other portal venous system in the body is the hypophyseal portal system. Structure Large veins that ar ...

(longer fatty acids are absorbed into the

lymphatic system The lymphatic system, or lymphoid system, is an organ system in vertebrates that is part of the immune system and complementary to the circulatory system. It consists of a large network of lymphatic vessels, lymph nodes, lymphoid organs, lympha ...

) without requirement for modification like

long-chain fatty acids In chemistry, in particular in biochemistry, a fatty acid is a carboxylic acid with an aliphatic chain, which is either saturated or unsaturated. Most naturally occurring fatty acids have an unbranched chain of an even number of carbon atoms, ...

or very-long-chain fatty acids. In addition, MCTs do not require bile salts for absorption. Patients who have

malnutrition Malnutrition occurs when an organism gets too few or too many nutrients, resulting in health problems. Specifically, it is a deficiency, excess, or imbalance of energy, protein and other nutrients which adversely affects the body's tissues a ...

malabsorption Malabsorption is a state arising from abnormality in absorption of food nutrients across the gastrointestinal (GI) tract. Impairment can be of single or multiple nutrients depending on the abnormality. This may lead to malnutrition and a varie ...

or particular fatty-acid metabolism disorders are treated with MCTs because MCTs do not require energy for absorption, use, or storage. Medium-chain triglycerides are generally considered a good biologically inert source of energy that the

human body The human body is the entire structure of a Human, human being. It is composed of many different types of Cell (biology), cells that together create Tissue (biology), tissues and subsequently Organ (biology), organs and then Organ system, org ...

finds reasonably easy to metabolize. They have potentially beneficial attributes in protein metabolism, but may be contraindicated in some situations due to a reported tendency to induce ketogenesis and

metabolic acidosis Metabolic acidosis is a serious electrolyte disorder characterized by an imbalance in the body's acid-base balance. Metabolic acidosis has three main root causes: increased acid production, loss of bicarbonate, and a reduced ability of the kidn ...

. However, there is other evidence demonstrating no risk of ketoacidosis or ketonemia with MCTs at levels associated with normal consumption, and that the moderately elevated blood ketones can be an effective treatment for

epilepsy Epilepsy is a group of Non-communicable disease, non-communicable Neurological disorder, neurological disorders characterized by a tendency for recurrent, unprovoked Seizure, seizures. A seizure is a sudden burst of abnormal electrical activit ...

. 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

Waldmann disease Waldmann disease, also known as Primary Intestinal Lymphangiectasia (PIL), is a rare disease characterized by enlargement of the lymph vessels supplying the lamina propria of the small intestine. Although its prevalence is unknown, it being cl ...

. MCTs are an ingredient in some specialised

parenteral nutrition Parenteral nutrition (PN), or intravenous feeding, is the feeding of nutritional products to a person intravenously, bypassing the usual process of eating and digestion. The products are made by pharmaceutical compounding entities or standard ph ...

al emulsions in some countries. Studies have also shown promising results for epilepsy through the use of

ketogenic diet The ketogenic diet is a high-fat, adequate-protein, low-carbohydrate diet, low-carbohydrate dietary therapy that in conventional medicine is used mainly to treat hard-to-control (refractory) epilepsy in children. The diet forces the body to b ...

ing. Orally ingested medium chain triglycerides would be very rapidly degraded by first-pass metabolism by being taken up in the liver via the

portal vein The portal vein or hepatic portal vein (HPV) is a blood vessel that carries blood from the gastrointestinal tract, gallbladder, pancreas and spleen to the liver. This blood contains nutrients and toxins extracted from digested contents. Approxima ...

, and are quickly metabolized via

coenzyme A Coenzyme A (CoA, SHCoA, CoASH) is a coenzyme, notable for its role in the Fatty acid metabolism#Synthesis, synthesis and Fatty acid metabolism#.CE.B2-Oxidation, oxidation of fatty acids, and the oxidation of pyruvic acid, pyruvate in the citric ac ...

intermediates through β-oxidation and the

citric acid cycle The citric acid cycle—also known as the Krebs cycle, Szent–Györgyi–Krebs cycle, or TCA cycle (tricarboxylic acid cycle)—is a series of chemical reaction, biochemical reactions that release the energy stored in nutrients through acetyl-Co ...

to produce

carbon dioxide Carbon dioxide is a chemical compound with the chemical formula . It is made up of molecules that each have one carbon atom covalent bond, covalently double bonded to two oxygen atoms. It is found in a gas state at room temperature and at norma ...

acetate An acetate is a salt formed by the combination of acetic acid with a base (e.g. alkaline, earthy, metallic, nonmetallic, or radical base). "Acetate" also describes the conjugate base or ion (specifically, the negatively charged ion called ...

and ketone bodies. Whether the ketones β-hydroxybutyrate and

acetone Acetone (2-propanone or dimethyl ketone) is an organic compound with the chemical formula, formula . It is the simplest and smallest ketone (). It is a colorless, highly Volatile organic compound, volatile, and flammable liquid with a charact ...

have direct antiseizure activity is unclear.

Technical uses

MCTs are bland compared to other fats and do not generate off-notes (dissonant tastes) as quickly as LCTs. They are also more polar than LCTs. Because of these attributes, they are widely used as carrier oils or solvents for flavours and oral medicines and vitamins.