Medium Chain Triglycerides (MCT’s) are a type of fatty acid. Like all fatty acids, MCT’s contain a glycerol backbone with three fatty acids attached. Unlike long-chain triglycerides the MCT fatty acids are medium in length. Because of these shorter chains, the fatty acids are easier to break down to use as an energy source. Due to their unique structure and ease of assimilation, MCT’s have been considered as an alternative energy source to both fats and carbohydrates.
Milk fat, palm oil and coconut oil all contain some level of MCT’s. Coconut oil has the highest level of this unique substance, though it’s bound to the long chain triglycerides. Because of this, manufacturers must ‘fraction’ off the MCT from the long chain fats in order to be used at functional amounts in supplements.
MCT’s Metabolism: MCT’s have long been given to patients hospitalized for malabsorption of nutrients, especially fats. The ease of absorption allowed significant improvement in their health.
Unlike long chain fats, MCT’s do not require the presence of carnitine in order to be transported into the mitochondria. Because of this MCT’s are rapidly transported into cells and have an ability to be used to help produce an alternative energy; researchers theorized it may help spare glycogen and boost endurance.
The ease by which MCT’s are digested and absorbed led researchers to look at the role these fatty acids might have on athletes as an alternative fuel.
MCT’s and Sport: It’s been well established that consuming fat as a fuel source does not improve endurance performance. In fact, several studies have shown that sprint performance at the end of endurance exercise may be compromised with the consumption of fat. The data on MCT’s in sport is mixed. There are a couple of studies that have found performance benefit through the suppression of lactate and improvement in high-intensity exercise. Other studies have shown evidence that MCT’s do not support any true and meaningful performance benefit. A meta analysis seems to suggest that MCT’s may play a role in enhanced performance for aerobic activity by sparing glycogen.
A 2009 study compared the effects of MCT’s to long chain triglycerides on athletes training over a 2-week period. The group ingesting MCT’s did improve time to exhaustion at 80% of their VO2 peak. Lactate concentration and rate of perceived exertion were also lower in the MCT group. The MCT group also burned fat more efficiently, sparing glycogen.
Research on Health:
A 2016 study looked at the effects of MCT’s on gut health. This study discusses the role MCT’s play to improve the health of the gut. In this study MCT’s were shown to improve both intestinal ecosystem and permeability effectively improving gut microbiota.
Why MCT’s? Consuming long branched fatty acids prior to workouts has been shown to be detrimental to performance. MCT’s on the other hand are far easier to absorb and may offer some health and performance benefit. MCT’s are a healthy alternative to saturated fats and have the potential to improve gut bacteria and health. Some evidence suggests MCT’s may also help athletes become leaner by catabolizing stored fat.
Nosaka et. al: Effect of ingestion of medium-chain triglycerides on moderate and high intensity exercise i recreational athletes. Journal of Nutrition Science and Vitaminol (Tokyo). 2009 Apr; 55(2):120-5
Rial SA et al: Gut microbiota and metabolic health: The potential beneficial effects of medium chain triglyceride diet in obese individuals. Nutrients. 2016 May 12;8 (5). Pii; E281. Doi.
Bueno NB et al: Dietary medium-chain triglycerides versus long chain triglycerides for body composition in adults: systematic reviw and meta-analysis of randomized controlled trials. Journal of American College of Nutrition. 2015; 34(2): 175-83. Doi: Epub Feb 4.