MCT Oil Benefits, Side Effects, Sources, and More

Interest in MCT oil has continued to rise over the past decade.  In particular, it’s become a popular supplement amongst dieters due to a number of purported benefits related to weight loss.  

MCT oil is most commonly added to food and beverages like salads, smoothies, and coffee.  While you may have heard something about it or even tried it, you might still be wondering what exactly it is.  

In this article, we’ll be going over everything you need to know about MCT oil, from what it is and where it comes from to how it can benefit your overall health.

What is MCT Oil?

MCT oil is a refined source of medium-chain triglycerides which is often extracted from coconuts or palm kernels.  Triglycerides are the most abundant form of fat in the human body.  

In general, triglycerides have two basic functions -- your body either converts them into energy or stores them in adipose tissue (body fat) to be used at a later time.  

All triglycerides are made up of three fatty acid chains attached to a glycerol molecule.  Medium-chain triglycerides (MCTs) get their name from the length of their fatty acid chain, which ranges from 6 to 12 carbons.⁽¹⁾

In contrast, Short-Chain Triglycerides (SCTs) have less than 6 carbons, while Long-Chain Triglycerides (LCTs) contain 13 to 21 -- most of the fat that’s consumed in your diet consists of long-chain triglycerides. 

As opposed to other types of triglycerides, which go through a relatively complicated digestion process, MCTs are rapidly absorbed by your body, allowing them to be quickly metabolized for energy.⁽²⁾ Because of this, MCTs are less likely to end up being stored in your body’s adipose tissue.  

MCT Oil Benefits

Medium-chain triglyceride oilhas been investigated in a number of human-based trials, which have examined its effects on everything from weight loss to Alzheimer’s disease.  

While research on the subject is not yet conclusive, the findings up until this point have illuminated several potential benefits associated with MCT oil intake.  

1. Help With Weight loss and Body Composition

There is a sizeable body of evidence that MCT oil may help with weight loss and body recomposition in multiple ways.  For example, a 2015 systematic review analyzed 13 different human-based trials comparing the effects of MCTs to long-chain triglycerides on weight loss and body composition.⁽³⁾

The researchers ultimately found that across the 13 studies, participants who were eating diets rich in MCTs lost significantly more weight and body fat compared to those who were eating a traditional diet high in long-chain triglycerides.  On top of that, the researchers also found that a diet high in MCTs, on average, lead to significantly greater reductions in waist and hip circumference as well.  

Energy Expenditure

The science suggests that MCTs may help to improve your weight-loss potential, in part, through increasing your daily energy expenditure.  For example, a 2003 randomized, controlled study published in Obesity Research compared the effects of MCT oil and olive oil (LCT) on the daily energy expenditure of healthy, overweight men.⁽⁴⁾

After two days, the researchers observed that following a meal, energy expenditure was significantly greater in participants who were given MCT oil compared to those given olive oil (1.04 cal/min vs 0.99 cal/min respectively).  After 28 days, the MCT oil group’s post-meal energy expenditure averaged out to 1.01 cal/min compared to 0.98 cal/min for the olive oil group.  

Food Intake, Appetite, and Satiety

On top of increasing your energy expenditure after consumption, medium-chain triglycerides may also help you to decrease your daily food intake.  Research shows that in comparison to a diet rich in long-chain triglycerides, consuming an MCT-rich diet may help to set off your body’s satiety signaling mechanisms more effectively.       

For example, a 2014 study published in the European Journal of Clinical Nutrition investigated the effects of medium and long-chain triglycerides on participants’ subsequent food intake.⁽⁵⁾

Participants were given 20 mg of either MCT oil or corn oil (LCT) for breakfast and then served lunch three hours later.    

The researchers ultimately found that, on average, the group who were given MCT oil consumed significantly fewer calories at lunch in comparison to the corn oil group (532 calories vs 804 calories respectively).  

2. Decrease Metabolic Syndrome Risk Factors

Along with weight loss, research shows that a diet rich in MCTs may also help to reduce your risk of several metabolic syndrome risk factors.   Metabolic syndrome is a group of disorders that have all been found to increase the risk of cardiovascular disease and death.⁽⁶⁾

Insulin Sensitivity

Some research shows that participants who lost weight with an MCT-rich diet also experienced improved insulin sensitivity.⁽⁷⁾ For example, one study published in the Diabetes Journal examined the effects of Dietary MCTs on both diabetic and non-diabetic subjects.⁽⁸⁾

For 5 days, participants were given one of two different diets each consisting of 40% fat.  One group received medium-chain triglycerides as their primary fat source, while the other group was predominantly given LCTs.  

At the conclusion of the study, the researchers ultimately found that an MCT-rich diet significantly increased insulin-mediated glucose metabolism in test subjects both with and without diabetes.  

Cholesterol

On top of improving your insulin sensitivity, research also suggests that MCTs may help to lower your cholesterol as well.  For example, a 2007 study published in Metabolism Clinical and Experimental investigated the effects of MCT oil vs. corn oil (LCTs) on overweight test subjects with type 2 diabetes.⁽⁹⁾

 After 90 days, the researchers observed that the MCT group saw significant decreases in LDL, HDL, and total cholesterol, while the corn oil group saw no statistically significant changes at all.

3. Support Gut Health

MCTs are also known to support gut health -- they’re commonly used in the treatment of a number of different gastrointestinal disorders such as steatorrhea.⁽¹⁰⁾

Your gut microbiota -- the trillions of microorganisms that live in your gut -- plays an important part in several different metabolic processes that are vital to your overall health.  

This ecosystem can become impaired by a number of different environmental and physiological factors such as your diet and lifestyle. Impairment in the composition and diversity of your gut microbiota can lead to various metabolic issues like insulin resistance and obesity.  

Recent research, however, suggests that dietary MCTs may help to bolster your intestinal ecosystem and improve its permeability, reducing the risk of several metabolic diseases.⁽¹¹⁾

4. Enhance Exercise Performance

There is also some evidence that dietary MCTs may help improve exercise performance through reducing the build-up of lactate in your muscles -- lactate buildup happens when your muscles don’t have enough oxygen to continue breaking down glucose.⁽¹²⁾

For instance, a 2009 study published in the Journal of Nutritional Science and Vitamintology examined the effects of MCTs vs LCTs on recreational athletes’ exercise performance over the course of 2 weeks.⁽¹³⁾

The researchers ultimately found that during exercise, blood lactate concentration was significantly lower in the group of participants who were given dietary MCTs.  Consequently, the MCT groups’ time exhaustion while working at 80% peak capacity was significantly longer in comparison to the LCT group’s exercise performance.

5. Improve Cognition

A number of different studies have also demonstrated that dietary MCTs may help to improve certain elements of mental function.  It’s important to point out, however, that most research up until this point has involved subjects with various diseases and conditions; few if any studies have recruited healthy adults.  

With that being said, a 2015 placebo-controlled study involving subjects with mild cognitive impairment ultimately found that over the course of 24 weeks, participants who were given 56 grams a day of MCTs demonstrated significant improvement in memory compared to a placebo group.⁽¹⁴⁾

Another 2009 study published in the Journal of Diabetes investigated the effects of dietary MCTs on the cognitive performance of subjects with type 1 diabetes.⁽¹⁵⁾

At the conclusion of the study, the researchers ultimately found that compared to a placebo group, subjects who were given medium-chain triglycerides demonstrated significant improvements in several aspects of cognition including verbal memory, map searching, and digit symbol coding.   

MCT Oil Side Effects and Risks

Research shows that when incorporated into a healthy weight-loss diet, there are few if any serious health risks associated with dietary MCTs.  For example, a 2009 study published in the Journal of the American College of Nutrition compared the effects of MCT oil and olive oil on metabolic health.⁽¹⁶⁾

After a 16-week weight loss program, the researchers found that like with olive oil, which is usually described as a “good fat”,  MCT oil had no adverse effects on any metabolic risk factors.

With that being said, overconsumption of MCT oil has been linked with several side effects, including gastrointestinal pain and discomfort, bloating, cramping and diarrhea.  

It must also be taken into consideration that medium-chain triglycerides are a form of fat, and like any kind of fat, they contain calories -- MCTs contain 8.3 calories per gram to be exact.  

While they may offer a number of benefits when appropriately incorporated into your diet, consuming MCT oil in excess can drastically increase your calorie intake, which in turn, can lead to weight gain and increase your chances of several metabolic risk factors. 

Sources of MCTs

MCTs are more difficult to find in natural food sources compared to LCTs, which make up the fats found in most animal and plant-based foods.  Natural sources of medium-chain triglycerides include palm kernel oil, dairy fat, and coconut oil, which is where most MCT oils are derived.⁽¹⁷⁾

MCT oil itself is a semi-man-made substance.  Some products may contain naturally derived MCTs which have been extracted from coconuts or dairy fat and processed into a highly concentrated formulation, while other substances may contain MCTs that are completely synthetic, being formulated almost completely in a laboratory.⁽¹⁸⁾

Types of MCTs

There is still some debate amongst scientists as to what does and does not constitute a medium-chain triglyceride, however, in most cases, the following substances are generally categorized as MCTs: caproic acid (C6), caprylic acid (C8), capric acid (C10), and lauric acid (C12).⁽¹⁹⁾

Most MCT oils are made up of either caprylic acid (C8) or capric acid (C10), although some products may contain a mixture of both or include other substances as well.  

MCT Oil Vs Coconut Oil

While coconut oil is rich in medium-chain triglycerides -- particularly C12 -- some MCTs may be more beneficial than others when it comes to weight loss, which is why most MCT oils generally only contain C8 and/or C10.    On top of that, coconut oil also includes LCTs and other substances that are removed in the making of MCT oil.    

Another difference between the two is that unlike coconut oil, which can be used as a substitute for olive oil or other vegetable oils, MCT oil has a low smoke point, which makes it unsuitable for use as a cooking oil.  

MCT Oil and the Ketogenic Diet

The ketogenic (keto) diet is a high-fat, low carb diet that prompts your body to use ketones instead of glucose as its main energy source.  Your body shifts to converting fat into ketones when it doesn’t have the carbohydrates it needs to produce glucose.  

Numerous studies have demonstrated that in combination with a restricted calorie intake, the keto diet can be an effective tool for weight loss and body recomposition.      

Medium-chain triglycerides may help to maximize your fat-burning potential when you go keto through increasing your body’s production of ketones.  Because they’re able to avoid much of the digestive process, MCTs are more easily broken down into ketones compared to LCTs, helping to increase the number of ketones your body has available for energy.⁽²⁰⁾

Research shows that because an MCT-rich keto diet helps you to produce more ketones, you’re ultimately able to consume less fat and more carbohydrates while still remaining in ketosis.⁽²¹⁾

Wrap Up

Research suggests that an MCT-rich diet may offer several potential health benefits, especially when it comes to weight loss.  A number of studies have demonstrated that in comparison to other forms of fat, MCTs may lead to greater reductions in weight and waist circumference when incorporated into a hypocaloric diet.  

Although MCT oil may be derived from coconut oil, they’re not the same thing.  MCT oils are generally highly concentrated sources of C8 and/or C10, while coconut oil only contains these substances in small amounts.  On top of that, coconut oil also contains LCTs and other ingredients.  

Adding a healthy supply of MCTs into your diet may be particularly advantageous if you’re on the keto diet as research shows that your body is more easily able to convert them into ketones in comparison to long-chain triglycerides.

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