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The MCT oil basics An overview of medium-chain triglycerides

Das MCT Öl Einmaleins Ein Überblick zum Thema mittelkettige Triglyzeride

Interest in medium-chain triglycerides (MCTs) has increased rapidly over the last few years. This is at least partly due to the numerous publications on the benefits of coconut oil, which is a rich source of MCTS.

Many proponents of MCTs report that MCTs can aid weight loss. In addition to this, MCTs have become a popular supplement for bodybuilders and other athletes.

This article will take a look at everything you need to know about MCTs and their benefits.

What are medium-chain triglycerides (MCTs)?

The abbreviation MCT stands for medium-chain triglycerides, which are a form of fat found in foods such as coconut oil. These fats are metabolized differently in the body than the long-chain triglycerides found in most other foods. MCT oil is a supplement that contains this special form of fat and is said to have many health benefits.

Triglycerides is nothing more than a technical term for fat. Triglycerides serve two primary purposes in the body - they are transported into the cells where they are burned to provide the body with energy, or they are stored as an energy reserve in the form of body fat.

Triglycerides get their name from their chemical structure and the length of their fatty acid chains. All triglycerides consist of a glycerol molecule to which three fatty acids are attached. Most of the fats contained in food consist of long-chain fatty acids, which comprise 13 to 22 carbon atoms. Short-chain fatty acids, on the other hand, consist of less than 6 carbon atoms.

In the middle between short-chain and long-chain fatty acids are the medium-chain fatty acids contained in MCTs, which consist of 6 to 12 carbon atoms.

These are the primary medium-chain fatty acids:

  • C6: Caproic acid or hexanoic acid
  • C8: caprylic acid or octanoic acid
  • C10: Capric acid or decanoic acid
  • C12: lauric acid or dodecanoic acid

Some experts argue that C6, C8 and C10, which are also known as capra fatty acids, reflect the definition of MCTs more accurately than C12 (lauric acid) (1).

Summary: Medium-chain triglycerides (MCTs) are types of fatty acids that contain 6 to 12 carbon atoms. These include caproic acid (C6), caprylic acid (C8), capric acid (C10) and lauric acid (C12)

Medium-chain triglycerides are metabolized differently

Due to the shorter length of their fatty acids, MCTs are quickly broken down and absorbed by the body. Unlike longer-chain fatty acids, MCTs enter the liver directly. There they can be used as an immediate energy source or converted into ketones, which are substances produced when the liver breaks down large amounts of fat.

Ketones, unlike regular fatty acids, can cross the blood-brain barrier to the brain and serve as an alternative energy source for the brain, which normally uses glucose for energy.

MCTs have the advantage that they can be converted into energy by the body more efficiently than regular fats and are therefore less likely to be stored as body fat.

Summary: Due to their shorter fatty acid length, MCTs are broken down and absorbed more quickly by the body. This makes them a readily available source of energy that is less likely to be stored as fat.

Sources of medium chain triglycerides

There are two different ways to increase the amount of MCTs in your diet: by eating whole foods that contain MCTs or by using supplements such as MCT oil.

Wholesome foods that contain MCTs

The following foods are the richest sources of medium-chain triglycerides and the percentage indicates the proportion of fatty acids they contain that are MCTs (2):

  • Coconut oil: > 60%
  • Palm kernel oil: > 50%
  • Dairy products: 10 to 12%

Even if foods are rich in MCTs, the composition of the MCTs varies. Coconut oil, for example, contains all four types of MCTs and a small amount of long-chain triglycerides. The largest quantity of these MCTs consists of lauric acid (C12), while the capra fatty acids (C6, C8 and C10) are only present in smaller quantities. In fact, coconut oil consists of about 50% lauric acid (C12), making it one of the best natural sources of this fatty acid.

Compared to coconut oil, dairy products tend to have a higher proportion of capra fatty acids (C6, C8 and C10) and a lower proportion of lauric acid (C12). In milk, capra fatty acids make up about 4 to 12% of all fatty acids, while lauric acid (C12) makes up about 2 to 5% (3).

Summary: Food sources of MCTs include coconut oil, palm kernel oil and dairy products, although the MCT composition varies.

MCT oil

MCT oil is a highly concentrated source of medium-chain triglycerides. It is produced using a process known as fractionation. This process involves extracting and isolating MCTs from coconut oil or palm kernel oil.

MCT oils generally contain either 100% caprylic acid (C8), 100% capric acid (C10) or a combination of these two fatty acids. Caproic acid (C6) is usually not included due to its unpleasant taste and odor and lauric acid is often completely absent or only present in small amounts (4).

Considering that lauric acid is the main component of coconut oil, one should be wary of manufacturers selling MCT oil as liquid coconut oil, as this label is misleading. Many people argue about whether lauric acid increases or decreases the quality of MCT oils.

Many manufacturers market MCT oil as better than coconut oil because it is believed that caprylic acid (C89 and capric acid (C10) can be absorbed and processed by the body for energy faster than lauric acid (C12).

Since C13 is a long-chain fatty acid and lauric acid (C12) has a similar structure, some experts argue that lauric acid should behave more like a long-chain fatty acid, which would make it less valuable.

Although there is evidence that lauric acid is absorbed faster by the body than long-chain fatty acids, one study suggests that lengthening the carbon chain of fatty acids can slow their diffusion rate by a hundredfold (5, 6, 7), and for this reason lauric acid may be a slightly less efficient route to energy supply compared to other medium-chain triglycerides.

Regardless of this, lauric acid has its own unique health benefits. For example, lauric acid has significantly stronger antimicrobial properties than caprylic acid (C8) and capric acid (C10), meaning it can help kill harmful bacteria and viruses to a greater extent (8, 9).

Summary: MCT oil is an easy way to consume high concentrations of certain MCTs. It usually contains C8, C10 or a combination of these two fatty acids.

Which source of MCTs should I choose?

The best source of MCTs depends on your goals and the amount of medium-chain triglycerides you want to consume. It is not clear what amount of MCTs is needed to reap potential benefits. The amounts used in studies range from 5 to 7 grams of MCTs per day.

If your goal is to achieve or maintain overall good health, then using coconut oil or palm kernel oil for cooking and frying is probably sufficient. However, if you want to use higher doses, then MCT oil may be a better choice.

One of the advantages of MCT oil is that it is virtually odorless and tasteless. You can therefore consume it straight from the bottle or add it to drinks or food.

MCTs could support weight loss in several ways

There are a number of ways in which MCTs could help with weight loss: - Lower energy density: MCTs provide about 10% fewer calories than long-chain fatty acids, or 8.4 kcal per gram of MCTs vs. 9.2 kcal per gram of long-chain fatty acids (10).

  • Increased satiety: A study comparing long-chain fats and MCTs concluded that MCTs resulted in greater increases in peptides YY and leptin levels, which are both hormones that help reduce appetite and increase satiety (11).
  • Fat storage: Considering that MCTs are absorbed and utilized faster compared to long-chain fats, they are less likely to be stored as body fat (10).
  • Calories burned: Studies conducted with animals and humans show that MCTs (primarily C8 and C10) may increase the body's ability to burn fat and calories (12, 13, 14, 15, 16, 17, 18).
  • Increased fat loss: One study concluded that a diet rich in MCTs caused greater fat burning and fat loss than a diet richer in long-chain fats. However, these effects may disappear after 2 to 3 weeks as the body adapts (18).
  • Low-carbohydrate diets: Very low-carbohydrate or ketogenic diets and diets are an effective way to lose weight. Considering that MCTs produce ketones, supplementing your diet with MCTs could increase the amount of carbohydrates you can eat while remaining in a state of ketosis.

Summary: MCTs could support weight loss via reduced calorie intake, increased satiety, reduced fat storage, increased burning of calories and an increase in the amount of ketones in low-carb diets.

Do MCTs actually cause weight loss?

Although many studies have found positive effects of MCTs on weight loss, other studies have found no such effects (19).

In a review of 14 studies, 7 evaluated satiety, 8 measured weight loss and 6 examined the amount of calories burned. Only one of these studies observed an increase in satiety, while 6 studies observed a reduction in weight and 4 an increase in calories burned (20).

In another review, which looked at 12 studies conducted with animals, 7 studies reported a reduction in weight gain, while 5 observed no difference. In terms of food intake, 4 observed a reduction, 1 an increase and 7 no difference (21).

In addition, the amount of weight loss was very small. One review of 13 studies concluded that the average amount of weight lost on a diet rich in MCTs compared to a diet rich in long-chain fats was only in the range of 0.5 kilos over 3 weeks (19).

Another study found that a diet rich in MCTs resulted in 0.9 kilograms more weight loss over 12 weeks than a diet rich in long-chain fatty acids (22).

Further high-quality studies are needed to determine how effective MCTs are for weight loss and what amounts of MCTs are needed to reap potential benefits.

Summary: A diet rich in medium-chain triglycerides may support weight loss, although the effects are quite modest.

Evidence for performance-enhancing effects of MCTs is weak

MCTs are believed to increase energy levels during high-intensity exercise and could serve as an alternative energy source that protects muscle glycogen reserves. This could have a positive impact on endurance performance and provide benefits for athletes following a low-carbohydrate diet.

A study conducted on animals found that mice fed a diet rich in MCTs performed better in a swimming test than mice fed a diet rich in long-chain fatty acids (23).

In addition, another study showed that eating a diet containing MCTs instead of long-chain fatty acids resulted in increased endurance of recreational athletes during high-intensity exercise after 2 weeks (24).

However, while this evidence may seem positive, there are not enough studies to confirm these benefits and the overall link is weak (25).

Summary: The link between MCTs and increased exercise performance is weak and more studies are needed to confirm such claims.

Other potential health benefits of MCTs

The use of medium-chain triglycerides and MCT oil has been associated with several other health benefits.


MCTs have been linked to lower cholesterol levels in studies conducted in animals and humans. For example, calves fed milk rich in MCTs had lower cholesterol levels than calves fed milk rich in long-chain fats (26).

Several studies conducted with rats have linked coconut oil to improved cholesterol levels and higher levels of antioxidant vitamins (27, 28).

A study of 40 women found that consumption of coconut oil in combination with a low-calorie diet lowered levels of bad LDL cholesterol and increased levels of good HDL cholesterol compared to consumption of soybean oil (29).

Improvements in cholesterol levels and antioxidant levels may lead to a long-term reduction in the risk of heart disease. However, it is important to note that some older studies reported that MCT supplements had no or even negative effects on cholesterol levels (30, 31).

One study conducted on 14 healthy men reported that MCT supplements negatively affected cholesterol levels and increased both LDL cholesterol and total cholesterol levels (31).

Summary: MCT-rich foods such as coconut oil may have positive effects on cholesterol levels, although the study evidence is mixed.


MCTs could help to lower blood sugar levels. In one study, MCT-rich diets improved insulin sensitivity in adults with type 2 diabetes (32).

Another study conducted with 40 overweight individuals suffering from type 2 diabetes found that supplementation with MCTs improved diabetes risk factors. It also reduced body weight, waist circumference and insulin resistance (33).

However, the evidence for beneficial effects of medium-chain triglycerides on diabetes is limited and further research is needed to determine the full effects. Summary: MCTs may help lower blood glucose levels by reducing existing insulin resistance. However, further research is needed to confirm these benefits.

Brain function

MCTs produce ketones, which act as an alternative energy source for the brain and may improve brain function. Recently, there has been increased interest in the use of MCTs to treat and prevent brain diseases such as Alzheimer's and dementia (34).

One study found that MCTs improved learning, memory and information processing in the brains of people suffering from mild to moderate forms of Alzheimer's disease. However, MCTs were only effective in this regard in people who did not have the APOE4 gene variant (35).

All in all, the data are limited to short-term studies with small groups of subjects, which means that further research is needed.

Summary: MCTs may improve brain function in people with Alzheimer's disease who have a certain genetic predisposition, but more research is needed to confirm this.

Other conditions

Because MCTs are an easily absorbed and digestible source of energy, they have been used for years to treat malnutrition and conditions that interfere with nutrient absorption.

Conditions where patients could benefit from MCTs include diarrhea, fatty stools and liver disease. Patients who have undergone gastric or intestinal surgery may also benefit from MCTs.

There is also evidence to support the use of MCTs in ketogenic diets for the treatment of epilepsy.

treatment of epilepsy (36). In these diets, the use of MCTs allows children suffering from seizures to consume more carbohydrates than during a classic ketogenic diet (37).

Dosage, safety and side effects of MCTs

MCT oil appears to be safe and harmless for most people. However, it is not clear what dosage is necessary to reap potential health benefits, but 1 to 3 tablespoons daily is recommended with many supplements.

There are currently no known adverse drug interactions or other serious side effects. However, there are reports of unwanted, albeit harmless, side effects including nausea, vomiting, diarrhea and digestive problems.

These side effects can be avoided by starting use with small doses such as one teaspoon and slowly increasing the dosage. Once a tolerance has been established, MCT oil can be used one tablespoon at a time.

Type 1 diabetes and MCTs

Some sources advise people suffering from type 1 diabetes not to use medium chain triglycerides due to the accompanying production of ketones. It is believed that high levels of ketones in the blood could increase the risk of ketoacidosis - a very serious disorder that can occur in type 1 diabetics.

However, diet-induced ketosis caused by a low-carbohydrate diet is completely different from diabetic ketoacidosis, a very serious condition caused by a lack of insulin. In people with well-controlled diabetes and healthy blood glucose levels, the levels of ketones will remain within a safe range even during ketosis.

There are few studies that have investigated the use of MCTs by type 1 diabetics. However, the studies that have been conducted have not shown any harmful side effects. Summary: MCT oils are safe and safe for most people, but there are no clear dosing guidelines. Start with a low dosage and gradually increase it to avoid side effects.


Medium-chain triglycerides have many potential health benefits. While they may not be the ticket to dramatic weight loss, they may have minor benefits in this regard. The same can be said about their role in endurance sports.

For these reasons, using MCTs could be worth a try. Remember, however, that whole food sources of MCTs such as coconut oil and dairy products from grass-fed cattle may have additional benefits not found in supplements.




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