Medium-chain triglyceride explained

A medium-chain triglyceride (MCT) is a triglyceride with two or three fatty acids having an aliphatic 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 and coconut oil.

Sources of MCTs

MCTs are found in palm kernel oil and coconut oil and can be separated by fractionation.^{[1] [2]} They can also be produced by interesterification.^[3] 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

Lipid number	Name		Salt/ester name		Formula		Mass (g/mol)	Appearance	Chemical structure
	Common	Systematic	Common	Systematic	Molecular	Structural
C6:0	Caproic acid	Hexanoic acid	Caproate	Hexanoate			116.16	Oily liquid
C8:0	Caprylic acid	Octanoic acid	Caprylate	Octanoate			144.21	Oily liquid
C10:0	Capric acid	Decanoic acid	Caprate	Decanoate			172.26	White crystals
C12:0	Lauric acid	Dodecanoic acid	Laurate	Dodecanoate			200.32	White powder

With regard to MCFAs, apart from the above listed straight chain (unbranched chain) fatty acids, side chain (branched chain) fatty acids also exist.^[4]

Applications

Calorie restriction

A 2020 systematic review and meta-analysis 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.^[5]

Dietary relevance

Molecular weight analysis^[6] 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 horses, cows, sheep, and goats were medium-chain fatty acids.

Some studies have shown that MCTs can help in the process of excess calorie burning, thus weight loss.^{[7] [8] [9]} MCTs are also seen as promoting fat oxidation and reduced food intake.^[10] MCTs have been recommended by some endurance athletes and the bodybuilding community.^[11] 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.^[12]

Pharmaceutical relevance

MCTs can be used in solutions, liquid suspensions and lipid-based drug delivery systems for emulsions, self-emulsifying drug delivery systems,^[13] 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.^[14]

Medical relevance

MCTs passively diffuse from the GI tract to the hepatic 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 absorption. Patients who have malnutrition, malabsorption 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 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.^[15] 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.^[4]

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.^[16] MCTs are an ingredient in some specialised parenteral nutritional emulsions in some countries.^{[17] [18]} Studies have also shown promising results for epilepsy through the use of ketogenic dieting.^{[4] [19] [20]}

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, and are quickly metabolized via coenzyme A intermediates through β-oxidation and the citric acid cycle to produce carbon dioxide, acetate and ketone bodies.^[4] Whether the ketones β-hydroxybutyrate and acetone have direct antiseizure activity is unclear.^{[21] [22] [23] [24]}

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.^[25]

See also

• List of carboxylic acids
• Ketogenic diet
• List of saturated fatty acids

Further reading

• Aoyama T, Nosaka N, Kasai M . Research on the nutritional characteristics of medium-chain fatty acids . The Journal of Medical Investigation . 54 . 3–4 . 385–388 . August 2007 . 17878693 . 10.2152/jmi.54.385 . 905470 . free .
• Babayan VK . Medium chain triglycerides and structured lipids . Lipids . 22 . 6 . 417–420 . June 1987 . 3112486 . 10.1007/BF02537271 . 3942399 .
• Bach AC, Babayan VK . Medium-chain triglycerides: an update . The American Journal of Clinical Nutrition . 36 . 5 . 950–962 . November 1982 . 6814231 . 10.1093/ajcn/36.5.950 .
• Hayasaka K, Numakura C, Toyota K, Kakizaki S, Watanabe H, Haga H, Takahashi H, Takahashi Y, Kaneko M, Yamakawa M, Nunoi H, Kato T, Ueno Y, Mori M . Medium-chain triglyceride supplementation under a low-carbohydrate formula is a promising therapy for adult-onset type II citrullinemia . Molecular Genetics and Metabolism Reports . 1 . 42–50 . 2014 . 27896073 . 5121258 . 10.1016/j.ymgmr.2013.12.002 .
• Heydinger JA, Nakhasi DK . 1996 . Medium Chain Triacylglycerols . Journal of Food Lipids . 3 . 4 . 251–257 . 10.1111/j.1745-4522.1996.tb00072.x.
• Kaunitz H . Medium chain triglycerides (MCT) in aging and arteriosclerosis . Journal of Environmental Pathology, Toxicology and Oncology . 6 . 3–4 . 115–121 . 1986 . 3519928 .
• Labarthe F, Gélinas R, Des Rosiers C . Medium-chain fatty acids as metabolic therapy in cardiac disease . Cardiovascular Drugs and Therapy . 22 . 2 . 97–106 . April 2008 . 18253821 . 10.1007/s10557-008-6084-0 . 25297875 .
• Nagao K, Yanagita T . Medium-chain fatty acids: functional lipids for the prevention and treatment of the metabolic syndrome . Pharmacological Research . 61 . 3 . 208–212 . March 2010 . 19931617 . 10.1016/j.phrs.2009.11.007 .

Notes and References

1. Book: Gervajio GC . Fatty Acids and Derivatives from Coconut Oil . 10.1002/047167849X.bio039 . Bailey's Industrial Oil and Fat Products . 2005 . 978-0471678496 . 98315975.
2. Book: Raymond ER, Kent JA . Soap, Fatty Acids, and Synthetic Detergents . Riegel's Handbook of Industrial Chemistry . 10th . https://books.google.com/books?id=j3AwCqvqIzEC&pg=PA1100 . 20 October 2012 . 2003 . Springer . 978-0-387-23816-6 . 1100–1117 . 10.1007/0-387-23816-6_27 .
3. Mensink RP, Sanders TA, Baer DJ, Hayes KC, Howles PN, Marangoni A . The Increasing Use of Interesterified Lipids in the Food Supply and Their Effects on Health Parameters . Advances in Nutrition . 7 . 4 . 719–729 . July 2016 . 27422506 . 4942855 . 10.3945/an.115.009662 . free .
4. Chang P, Terbach N, Plant N, Chen PE, Walker MC, Williams RS . Seizure control by ketogenic diet-associated medium chain fatty acids . Neuropharmacology . 69 . 105–114 . June 2013 . 23177536 . 3625124 . 10.1016/j.neuropharm.2012.11.004 .
5. Maher T, Clegg ME . A systematic review and meta-analysis of medium-chain triglycerides effects on acute satiety and food intake . Critical Reviews in Food Science and Nutrition . 61 . 4 . 636–648 . 2021 . 32212947 . 10.1080/10408398.2020.1742654 . 2021-06-24 . live . 214683227 . https://web.archive.org/web/20210715214001/http://centaur.reading.ac.uk/89667/5/CRIFSAN.%20MCT%20and%20satiety%20-%20A%20systematic%20review%2010.3.20.pdf . 2021-07-15 .
6. Breckenridge WC, Kuksis A . Molecular weight distributions of milk fat triglycerides from seven species . Journal of Lipid Research . 8 . 5 . 473–478 . September 1967 . 6049672 . 10.1016/S0022-2275(20)38904-5 . free .
7. St-Onge MP, Jones PJ . Greater rise in fat oxidation with medium-chain triglyceride consumption relative to long-chain triglyceride is associated with lower initial body weight and greater loss of subcutaneous adipose tissue . International Journal of Obesity and Related Metabolic Disorders . 27 . 12 . 1565–1571 . December 2003 . 12975635 . 10.1038/sj.ijo.0802467 . 21935201 . free .
8. Medium-chain triglycerides . Marten B, Pfeuffer M, Schrezenmeir J . International Dairy Journal . 16. 11. 2006. 1374–1382 . 10.1016/j.idairyj.2006.06.015 . 2020023.
9. St-Onge MP, Jones PJ . Physiological effects of medium-chain triglycerides: potential agents in the prevention of obesity . The Journal of Nutrition . 132 . 3 . 329–332 . March 2002 . 11880549 . 10.1093/jn/132.3.329 . free .
10. Clegg ME . Medium-chain triglycerides are advantageous in promoting weight loss although not beneficial to exercise performance . International Journal of Food Sciences and Nutrition . 61 . 7 . 653–679 . November 2010 . 20367215 . 10.3109/09637481003702114 . 6128370 .
11. Book: Talbott, Shawn M. . Hughes, Kerry . 2006 . The Health Professional's Guide to Dietary Supplements . Lippincott Williams & Wilkins . 60–63 . 978-0781746724.
12. Rego Costa AC, Rosado EL, Soares-Mota M . Influence of the dietary intake of medium chain triglycerides on body composition, energy expenditure and satiety: a systematic review . Nutricion Hospitalaria . 27 . 1 . 103–108 . 2012 . 22566308 . 10.3305/nh.2012.27.1.5369 .
13. Banov D, Liu Y, Ip K, Shan A, Vu C, Zdoryk O, Bassani AS, Carvalho M . Analysis of the Physical Characteristics of an Anhydrous Vehicle for Compounded Pediatric Oral Liquids . Pharmaceutics . 15 . 11 . 2642 . November 2023 . 38004620 . 10674891 . 10.3390/pharmaceutics15112642 . free .
14. Web site: Kollisolv MCT 70 . 2021-04-27 . pharmaceutical.basf.com . en.
15. Wanten GJ, Naber AH . Cellular and physiological effects of medium-chain triglycerides . Mini Reviews in Medicinal Chemistry . 4 . 8 . 847–857 . October 2004 . 15544546 . 10.2174/1389557043403503 .
16. Vignes S, Bellanger J . Primary intestinal lymphangiectasia (Waldmann's disease) . Orphanet Journal of Rare Diseases . 3 . 5 . February 2008 . 18294365 . 2288596 . 10.1186/1750-1172-3-5 . free . Free full text .
17. Waitzberg DL, Torrinhas RS, Jacintho TM . New parenteral lipid emulsions for clinical use . JPEN. Journal of Parenteral and Enteral Nutrition . 30 . 4 . 351–367 . July–August 2006 . 16804134 . 10.1177/0148607106030004351 . 24109426 .
18. Krohn K, Koletzko B . Parenteral lipid emulsions in paediatrics . Current Opinion in Clinical Nutrition and Metabolic Care . 9 . 3 . 319–323 . May 2006 . 16607135 . 10.1097/01.mco.0000222118.76536.ad . 27961868 .
19. Neal EG, Cross JH . Efficacy of dietary treatments for epilepsy . Journal of Human Nutrition and Dietetics . 23 . 2 . 113–119 . April 2010 . 20487176 . 10.1111/j.1365-277X.2010.01043.x .
20. Liu YM . Medium-chain triglyceride (MCT) ketogenic therapy . Epilepsia . 49 Suppl 8 . 33–36 . November 2008 . 19049583 . 10.1111/j.1528-1167.2008.01830.x . free .
21. Chang P, Augustin K, Boddum K, Williams S, Sun M, Terschak JA, Hardege JD, Chen PE, Walker MC, Williams RS . Seizure control by decanoic acid through direct AMPA receptor inhibition . Brain . 139 . Pt 2 . 431–443 . February 2016 . 26608744 . 4805082 . 10.1093/brain/awv325 .
22. Viggiano A, Pilla R, Arnold P, Monda M, D'Agostino D, Coppola G . Anticonvulsant properties of an oral ketone ester in a pentylenetetrazole-model of seizure . Brain Research . 1618 . 50–54 . August 2015 . 26026798 . 10.1016/j.brainres.2015.05.023 .
23. Rho JM, Anderson GD, Donevan SD, White HS . Acetoacetate, acetone, and dibenzylamine (a contaminant in l-(+)-beta-hydroxybutyrate) exhibit direct anticonvulsant actions in vivo . Epilepsia . 43 . 4 . 358–361 . April 2002 . 11952765 . 10.1046/j.1528-1157.2002.47901.x . 31196417 .
24. Ma W, Berg J, Yellen G . Ketogenic diet metabolites reduce firing in central neurons by opening K(ATP) channels . The Journal of Neuroscience . 27 . 14 . 3618–3625 . April 2007 . 17409226 . 6672398 . 10.1523/JNEUROSCI.0132-07.2007 .
25. Book: Akoh CC . Handbook of Functional Lipids . Taylor & Francis . Washington, DC . 2006 . 978-0849321627 .