Medium Chain Triglycerides or (MCT / TCM)
In the ketogenic ( keto) diet medium chain triglycerides are advocated as an effective and fast source of energy. These can be consumed as oil, powder or cream.
MCT
The term MCT stands for medium-chain triglycerides, a form of saturated fatty acids. 100% MCT products, in the form of oil, powder or cream, are therefore a pure source of fatty acids.
The chemical structure
All types of fatty acids are made up of interconnected carbon and hydrogen chains. The name MCT therefore comes from the chemical structure of this type of fatty acid.
There are three types of fat, classified according to the number of carbons they contain: short-chain (such as butyric acid), which have fewer than six carbons; medium-chain -between six and 12 carbons- and long-chain fats (such as omega-3).
Types of MCT
Medium-chain triglycerides are classified according to the length of their fatty acid chain, from shortest to longest. There are therefore four types of MCT:
- C6: caproic acid (or hexanoic acid), consisting of 6 carbon atoms.
- C8: caprylic acid (or octanoic acid), contains 8 carbon atoms.
- C10: capric acid or (decanoic acid) has 10 carbon atoms.
- C12: lauric acid (or dodecanoic acid), with 12 carbon atoms. This is often classified as a long-chain acid, as it is digested and absorbed much more slowly than other MCT4 5.
Specifics
- C6 is an oily liquid at room temperature and stimulates blood ketone production. It is present in animal fats and in several plants. It is slightly soluble in water and has an unpleasant odour.
- Caprylic acid (C8) boosts energy, stimulates ketone production and aids weight loss; some studies show it also has anti-cancer and anti-microbial properties.
- The properties of C10 resemble those of C8: it increases ketones, is anti-microbial and can help reduce body fat. The most important difference is that it takes a little longer for the body to convert it into ketones.
- Lauric acid (C12) -presented in large quantities in coconut oil- also has antimicrobial properties; however, it is a larger molecule (more carbon atoms connected to each other), which is why it takes longer to break down and is less efficient at producing ketones.15
MCT products
Coconut oil (coconut oil) is the most abundant natural source of medium-chain triglycerides1: 42% lauric acid, 7% caprylic acid and 5% capric acid.
MCT products have undergone a refining process to become medium chain triglyceride concentrates; coconut or palm oil are worked to remove other compounds and concentrate the MCTs present in these oils. This means that an MCT product will contain 100% medium chain triglycerides, double what is found in coconut oil.
C6 is not marketed pure because of its smell. The MCT products that are marketed today are either 100% C8 or a mixture between C8 and C10 -some may have a proportion of C6, and are therefore to be avoided as they may cause stomach upsets.
With regard to the different types of MCT, caprylic acid (C8) appears to be, according to studies, the most metabolically active medium-chain fatty acid18, hence the fact that it is the most present in MCT oils.
The body process
Being shorter chains of fatty acids, medium-chain triglycerides are absorbed more readily than longer-chain fatty acids, since the body has less work to do to break down the carbon bonds: MCTs are broken down more quickly. A large proportion of medium-chain triglycerides pass directly into the portal vein, which serves the gastrointestinal tract, and, through the blood, are transported directly to the liver. In contrast, long-chain fatty acids must be absorbed by chylomicron triglycerides and enter the bloodstream via the lymphatic system19. Once in the liver, fatty acids are converted to ketones before being returned to the blood where they are transported for use by other cells, particularly the brain.
Benefits
As explained, MCTs are easily digested and sent directly to the liver; here, their thermogenic effect has the ability to positively alter metabolism. Also, this type of fatty acid contributes to satiety by increasing peptide YY and leptin, two hormones responsible for reducing appetite.
Since medium-chain triglycerides are absorbed and digested faster than long-chain acids, they are used as an energy source instead of being stored as fat.
Some studies have shown that consuming MCTs such as C8 and C12 could help burn more calories and promote greater fat loss than other acids; however, once the body adapted to MCTs (about two to three weeks), this effect would disappear.
MCTs would, potentially, have an effect on reducing LDL 29 cholesterol and increasing HDL30. These fatty acids would also help control diabetes by increasing insulin sensitivity31. Regarding these potential
Benefits, more research is required, as there are also studies that show conflicting results.
With respect to the brain, the effect of MCTs as ketone boosters, one can expect a greater concentration effect, as the brain works better due to the ketone bodies.
Studies on the role of MCTs in neurodegenerative diseases such as Alzheimer's33 have recently been conducted; one showed that they can improve memory, learning and brain function in people with a moderate version of this disease who did not have the APOE434 gene variant.
Preparations and consumption
In a low-carb keto (ketogenic or low-carb) diet, MCTs (or TCMs) are very often used for the preparation of fatty coffee or bulletproof coffee. The powder can also be included in baked goods or savoury dishes in general to add this type of fatty acid to the diet. MCT oil works very well in salads and hot preparations, but it should not be heated above 120ºC, its burning point.
When starting to consume MCT, in any format, one should start with a small dose of about 5 grams to avoid stomach upsets. Once the body is accustomed, the dose can be increased gradually.
MCTs and the Keto diet
Medium chain fatty acids are an effective source of energy that can be included on a daily basis as part of a low carbohydrate keto (ketogenic or low-carb) diet. MCTs go directly into the liver to create ketone bodies. MCT can be found in a variety of healthy forms such as:
When choosing the product, care should be taken and preference should be given to those containing 100% C8 or a mixture of C8 and C10.
