What are Medium Chain Triglycerides (MCTs)?
[Pronounced: TRI- glis-er ide | trī-ˈgli-sə-ˌrīd]
Medium chain triglycerides (MCTs) are a special type of fat. They are an ingredient in specialized infant formulas designed for babies with medical conditions affecting the GI tract and for babies who are not growing well.
Why Are MCTs Added to Infant Formula?
Fat digestion would take more time to explain than is needed for this post, so I’ll jump to the long-story short: MCTs are absorbed through a different system than other fats. This system does not use energy and does not need bile. Therefore, a baby with malnutrition or a medical condition of the GI tract usually benefits from a formula higher in MCTs than standard formulas provide.
What Makes a Triglyceride “Medium” ?
As explained in the article on coconut oil, almost all the fat in human milk is in the form of triglycerides. Triglycerides aren’t unique to human milk; they are the universal form of fat in food. The start of the word tri means three and gives a big hint that glycerides must have three parts or elements. Indeed, this is the case! Each triglyceride has three fatty acids.
Fatty acids are the building block of fats. Essentially, fatty acids are chains of carbon molecules held together by bonds. The type of bonds between the carbons influence the structure of the fat. The familiar terms saturated and unsaturated fat relate to this structure. Fatty acids can also be names based on where double bonds happen along the carbon chain. Omega-3 fats are unsaturated fats that have a double bond at the third from the end of the chain.
Fatty acids are also described by number of carbons found in their long chains:
Short: fewer than 6
Medium: 6–12
Long: 13–21
Very-long: 22 or more
The number of carbons is what makes MCT special, because they are brought to the liver through the bloodstream. This also the case with short chain fatty acids; however, little short chain fatty acids are in food. Most short chain fatty acids are made when beneficial bacteria digest fiber in the large intestine.
Regulations and Safety
MCT oil is generally regarded as safe (GRAS). However, finding this information online is not straightforward because MCT is a generic name and the process used for designating it as GRAS (affirmative petition) is no longer used by the FDA. MCTs were recognized as safe (GRAS) through an affirmation petition by the Stepan Company, a maker of MCTs, in June 1994. Specific forms of MCTS, such as caprylic acid, can be easily found in the FDA databases.
The European Food Safety Authority (EFSA) reevaluated the safety of fatty acids in 2017 and found there to be “no safety concerns.” Neither the FDA nor the EFSA have set limits for the amounts of specific medium chain fatty acids in infant formula. The EFSA stated in their 2014 Scientific Opinion on the composition of infant formulas that there isn’t a specific amount of MCTS needed by infants, at least based on current research studies. Up to 28% of the fatty acids in human milk are in the form of MCTs.
Dietary Considerations
MCTs are made from coconut or palm oils and are therefore appropriate for vegans, vegetarians, and religious groups.