Medium-chain triglyceride (MCT) oil has gained popularity, especially among those following a ketogenic diet. It can be a quick energy source and may support weight loss. It may also fight bacterial growth and aid in managing certain neurological conditions. But what exactly is MCT oil, and how can it benefit those on a keto diet?
What is MCT Oil?
Medium-chain triglyceride (MCT) oil is a processed product sourced from coconut or palm kernel oil. MCTs are also found in other foods, such as dairy products. As its name suggests, MCT oil contains medium-length chains of fats called triglycerides. Triglycerides are a type of saturated fat found in your body, formed from three fatty acid molecules. MCT stands for medium-chain triglyceride, and its name describes the chemical makeup of the fatty acids in triglycerides. MCTs are distinguished from other triacylglycerols by the number of their carbon chains, ranging from 6-12. (1) The length of these chains determines their effects.
Due to their shorter length, the body may digest medium-length chain fatty acids faster than longer-chain fatty acids found in many other foods. The body absorbs MCTs more rapidly than long-chain triglycerides (LCTs), which contain more carbons in their fatty acid chains. Due to their shorter chain length, MCTs travel more quickly from the gut to the liver and do not require bile to break down like longer-chain fats. The liver breaks down fats for fuel or stores them as body fat. Since MCTs easily enter the bloodstream without breaking down, they can be used as an immediate energy source.
Four main types of medium-chain fatty acids exist:
- Lauric acid
- Caproic acid
- Caprylic acid
- Capric acid
MCT oil is almost entirely caprylic and capric acid. Also, MCT oil is deliberately produced to contain only the most effective types of fatty acids, caprylic acids and caproic acids.
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MCT Oil vs. Coconut Oil and Palm Kernel Oil
Before we move on, you may be wondering if it’s worth the trouble to find and use MCT oil, since coconut oil and palm kernel oil each contain MCTs as well. MCTs are naturally present in some dairy products, including full-fat cow’s milk and goat’s milk so that’s an easy way to get some MCTs into your diet. Coconut oil and palm kernel oil can be used in salad dressings and sauces as well as in cooking, so that’s another way you can consume medium-chain triglycerides. However, MCT oil has a low smoke point. It’s a great ingredient for salad dressings or sauces, but it can’t be used to cook with. Coconut oil is a much better choice in that case. (One more clarification: palm kernel oil isn’t the same as palm oil.
MCT Oil and the Ketogenic Diet
MCT oil is valuable to those on a ketogenic eating plan. Keto (and other low-carb weight loss diets like paleo) place severe restrictions on the number of carbohydrates you can eat. Under normal circumstances, the body turns the carbohydrates we eat into glucose (also known as blood sugar), and glucose serves as the fuel that powers the body and the brain. In that situation, it enters a metabolic state called ketosis, in which it burns stored body fat to produce molecular bodies called ketones. If you’re following a ketogenic diet, taking MCT oil may help you stay in the fat-burning state known as ketosis. Ketogenic diets are very low in carbs and high in fat. While some studies suggest this diet can aid weight loss, the long-term effects of following a ketogenic diet are not known. Individuals may also have different responses to these diets.
When you’re on a ketogenic diet, the liver may also convert MCTs into ketones. These ketones can pass through your blood-brain barrier (the protective membrane that acts as a filter to protect the brain), making them an alternate energy source for brain cells.
So far, so good. First of all, MCTs don’t have to be digested in the gastrointestinal system the way that long-chain fats do. They are sent right to the liver, where ketones are produced. Second, “surplus” LCTs from oils like olive oil and vegetable oil are stored as body fat, making weight loss more difficult. Third, it’s been shown that the fats in MCT oil increase feelings of satiety. To translate that into English, they make you feel fuller than LCTs do. Finally, when you eliminate most of the carbs from your diet, they have to be replaced with something else. In the case of the keto diet, carbs are replaced with healthy fats. It should now be clear why MCT oil is an excellent tool when you’re using the keto diet to lose weight.
Benefits of MCT Oil
Here are science-backed benefits of adding MCT oil to your diet.
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Weight Management
MCT oil has about 10% fewer calories than long-chain triglycerides (LCTs), which are found in foods such as olive oil, nuts, and avocados. A 2020 analysis of 17 studies found an association between MCTs and lower calorie intake. People consuming MCTs had a moderately lower calorie intake than people consuming LCTs. A 2014 review of older research suggests that MCT oil could promote the release of two hormones that help people feel full when eating: peptide YY and leptin. However, the 2020 analysis found no link between MCT and appetite-related hormones. However, a 2017 study found that people taking 2 tablespoons of MCT oil as part of their breakfast ended up eating less food for lunch than those taking coconut oil. The reason for this potential effect isn’t clear. Some people believe that MCT oil can help you feel fuller or reduce your appetite, which could lead to eating less. However, studies show little evidence that taking MCTs reduces appetite. Future studies may help to reveal the relationship between MCT and calorie reduction.
A 2015 review of 13 randomized controlled trials found that MCTs supported modest weight loss, fat loss, and reduced body size. However, the authors commented that many of the studies were of questionable quality, and industry funding may influence the results. Another 2015 review of 11 trials made very similar conclusions, including regarding study quality.
Part of the equation is the satiety, or feeling of fullness, we’ve already discussed. But it also appears that MCTs encourage the body to use them right away, which means they’re not stored in the body as fat.
Energy Source
Your body can convert MCTs into ketones, which provide a fat-based energy source when carbohydrate intake is low. Since MCT oil is quickly metabolized in your liver, it raises your ketone levels immediately. Studies show that supplementing with MCTs results in higher beta-hydroxybutyrate (BHB) levels compared to LCT supplements.
Researchers have examined whether MCT oil could help burn fat instead of carbs during exercise. One older 2009 study found that athletes who took 6 grams or about 1.5 teaspoons of MCTs with food before cycling used more fat than carbs for energy, compared to those taking LCTs. However, the difference was not significant. Overall, most studies have not shown significant changes in the body’s use of fat after taking MCTs. Study results are also mixed as to whether MCT oil can help you exercise better. A 2011 animal study suggests that an MCT-rich diet may not impair exercise performance, unlike an LCT-rich diet, which may worsen it. However, a 2022 review of 13 human studies found that MCT offered minimal or no benefits for exercise. MCT supplementation had no significant effects on energy use in the body or other markers of exercise performance.
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MCT oil may enhance exercise performance by providing a quick and efficient energy source. Unlike long-chain fats, MCTs are rapidly absorbed and converted into ketones, which can fuel both endurance and high-intensity workouts with more efficient energy expenditure. This boosts stamina and delays fatigue, especially if your preferred exercise is aerobic activity. MCT oil may also help preserve glycogen stores in your muscles during exercise for those on low-carb diets.
You hear a lot about athletes and workout warriors using dietary supplements or illegal substances to boost their performance and endurance levels. There’s a good reason for that. When you exercise, your muscles produce lactic acid. Research has shown that MCTs are able to decrease or prevent that lactic acid buildup, apparently because the body uses the medium-chain fatty acids for energy.
Managing Medical Conditions
Some studies suggest MCT oil and a ketogenic diet may help manage conditions such as cancer and insulin resistance in type 2 diabetes. It’s important to remember that MCTs are not a replacement for prescription medications or medical treatments. It’s best to talk with a doctor before taking any new supplements. They can have side effects and potentially interact with certain medications you may be taking.
Epilepsy
While the ketogenic diet has gained popularity among people wishing to lose weight, it was first introduced as a way of managing epilepsy. Epilepsy is a neurological condition that causes epileptic seizures. Researchers found that fasting increases ketone production and that this may reduce the frequency of epileptic seizures. Since the body may convert MCTs into ketones, they may be beneficial in managing epilepsy. While few human studies examine MCTs and epilepsy, test-tube and animal studies suggest promising results, according to a 2021 review of research. One small 2022 study included adults with epilepsy who did not respond well to medication. On average, the participants had 42% fewer seizures when supplementing with MCT oil for 3 months. However, the authors caution that more studies are needed. The type of MCT may also be important. A 2013 test tube study suggests that the MCT oil may have more potent effects on seizure control than a widespread anti-epileptic drug. Another older 2015 study in rats found that the same MCT blocked receptors in the brain that cause seizures, though more human studies are needed. If you’re considering a ketogenic diet or MCT oil to help manage your epilepsy, be sure to talk with your doctor first. In addition, it’s important to note that a ketogenic diet is not for everyone and can be challenging to follow long term. Keto has long been used as a treatment for some types of epilepsy, particularly forms of childhood epilepsy, and a meta-analysis of the research clearly shows its effectiveness.
Alzheimer’s Disease
Alzheimer’s disease impairs your brain’s ability to use glucose, a form of energy. A ketogenic diet may offer an alternative energy source in the form of ketones. According to 2018 research, in the absence of glucose, ketones may help fuel the brain, allowing brain cells to survive better with Alzheimer’s. Researchers found that prioritizing MCTs as the source of fat in a ketogenic diet may allow people to eat more carbs than a standard ketogenic diet while still effectively producing ketones. Eating more carbs can make the diet easier to follow over time. One 2020 study found that taking MCTs for 30 days improved cognition in people with Alzheimer’s disease with a specific gene type, specifically APOE ɛ4-negative. In another 2018 study, people with mild to moderate Alzheimer’s disease saw increased ketone use in their brains when they took 30 grams of MCT supplements daily. Their brains used ketones at a similar rate to healthy young adults taking MCTs. Other researchers have proposed that 20 to 70 grams of supplemental MCTs that include caprylic and capric acid could modestly improve the symptoms of mild to moderate Alzheimer’s. A 2019 meta-analysis of 12 studies indicated that MCTs may promote improved cognition in Alzheimer’s disease, but stronger evidence is needed. Overall, using MCT oil in Alzheimer’s disease shows some promise, but longer and larger-scale studies are needed. Related research has found that MCTs seem to improve cognitive function in patients with Alzheimer’s disease,
Glucose is the brain’s primary fuel source, but ketones can replace glucose when its supply is inadequate. Unlike glucose, ketones are a more efficient fuel for the brain, especially during periods of fasting or low carb intake. Research suggests MCT oil may improve memory, focus, and overall brain function, particularly in individuals with mild cognitive impairment or Alzheimer’s disease.
Autism
Limited evidence suggests that MCT oil may help children manage autistic characteristics. When considering this research, it’s important to keep in mind that many autistic people do not support therapies aimed at making people appear “less autistic.” One preliminary 2018 study found that a ketogenic and gluten-free diet with MCTs substantially lowered behaviors associated with autism in 6 of the 15 children involved in the study. Other small studies discussed in a 2017 review of research have suggested some potential for ketogenic diets with or without MCTs to lower autistic behaviors. However, more research is needed. It’s currently not known if this type of diet is safe or has any therapeutic benefits for autistic children. What is known is that placing a child on a restrictive diet carries risks, including malnutrition and delayed growth. Plus, sensory issues can cause some autistic people to eat a limited diet of preferred foods. Adding further dietary restrictions may be inappropriate and could lead to nutritional deficiencies. If you’re considering dietary changes or supplements for your child, always talk with your doctor first. and that a keto diet supplemented with MCT oil may help some children who are on the autism spectrum.
Antimicrobial and Antifungal Effects
MCTs may have antimicrobial and antifungal effects. Some researchers suggest it may have specific anti-inflammatory effects, which could contribute to this outcome, but more studies are needed. According to a 2019 study, formula and breast milk supplementation with MCT oil significantly reduced the growth of Candida albicans in the digestive tracts of premature infants. This common yeast can cause thrush and various skin infections. A 2013 test-tube study also showed that coconut oil reduced the growth of Clostridium difficile, a disease-causing bacterium. Coconut oil’s ability to reduce yeast and bacterial growth may be due to the caprylic, capric, and lauric acid in MCTs. In a 2019 test-tube study, virgin coconut oil slowed the growth of Staphylococcus aureus and helped immune cells destroy the bacteria. Staphylococcus aureus causes skin infections and other potentially serious conditions. However, most of the research on MCTs and immune support has been conducted through in vitro or animal studies. High-quality human studies are needed before stronger conclusions can be drawn. It’s clear from research that MCTs have both antibacterial and anti-fungal properties. Among the microbes that have been shown to respond to these fatty acids are C. albicans and C.
MCT oil promotes a balanced microbiome, and a healthy gut is essential to overall health. (5) Its antimicrobial properties may also combat harmful bacteria in your digestive tract, potentially reducing issues like candida overgrowth. This could reduce symptoms of uncomfortable conditions like ulcerative colitis and Crohn’s disease, which worsen when your microbiome is out of balance. It’s also interesting to note that your body can digest MCTs better than most foods, even in those with gut conditions. MCTs may boost your immune system defenses. Among the medium-chain fatty acids, lauric acid and monolaurin (the derivative of lauric acid) are considered the most effective antimicrobial agents. Research shows they can help combat harmful bacteria, viruses, and fungi in the body, reducing your risk of infections.
Blood Sugar Control
One small 2007 study followed 40 people with diabetes. Those who consumed MCT oil daily saw reductions in body weight, waist circumference, and insulin resistance compared to participants who consumed corn oil containing LCTs. Newer studies on MCTs and blood sugar have shown mixed results. A 2022 review of 18 studies examined the effects of coconut oil, which is high in MCTs. Eating a meal containing coconut oil may promote a slight improvement in after-meal blood sugar regulation. However, the review’s authors found long-term use of coconut oil had the opposite effect. It may increase insulin resistance, which means your body can’t manage blood sugar as it should. A 2021 randomized controlled trial followed people with metabolic syndrome after 4 weeks of daily coconut oil consumption. Participants had significantly lower fasting blood sugar and triglycerides and higher “good” HDL cholesterol. However, they also had higher “bad” LDL and total cholesterol. While MCTs may benefit blood sugar under some circumstances, more evidence is needed to draw firm conclusions. Those with prediabetes or active diabetes may benefit from taking MCTs for insulin resistance. Studies suggest that MCTs are well-tolerated in individuals with type 2 diabetes and that MCTs may increase insulin sensitivity. It comes down to the effect of MCTs on fat metabolism. Doctors always suggest that people who have diabetes or whose blood sugar levels are regularly high should lose weight. In one study, half of the diabetic participants took MCT oil with their food for 90 days, while the other half took LCT-loaded corn oil. Those using MCT oil saw reductions in both insulin resistance and body weight; the LCT oil users did not. A different project followed ten people who took insulin to treat their diabetes.
Improved Cholesterol Levels.
In one important study, overweight subjects were given diets that were high in either MCTs or olive oil (high in LCTs). Those consuming high levels of MCTs showed a better lipid profile, with greatly improved HDL, LDL, and overall cholesterol levels.
Potential Drawbacks of MCT Oil
Although MCTs are a popular supplement, they may have some disadvantages.
Heart Disease Risk
Your diet can affect your heart health. The foods you eat can change the type and amount of fats, or lipids, that circulate in your bloodstream. High levels of certain fats in your blood are often associated with a higher risk for cardiovascular disease. MCTs are saturated fats. Research indicates that MCT slightly increases triglycerides, and coconut oil is associated with increased LDL (bad cholesterol). A second 2020 analysis of 12 studies found a similar effect. Compared with liquid (non-tropical) plant oils, coconut oil may increase LDL cholesterol. In both of these studies, “good” HDL cholesterol also increased. In many cases, this can be beneficial. However, when HDL becomes very high, it’s associated with heart health risks. Fewer studies have examined MCT oil specifically. High blood triglycerides are associated with heart, stroke, and liver conditions. However, consuming MCTs and coconut oil may promote a healthier blood lipid profile than animal-sourced fats. Plus, MCT oil may support weight and fat loss, which may, in turn, help reduce the risk of heart disease. It may be too soon to say whether MCTs are a negative or positive choice for heart health. However, if you want to include heart-healthy fat in your diet, other plant oils such as olive oil have stronger evidence for their benefits.
Increased Hunger Hormones
If your goal is to lose weight, you’re probably not looking for ways to increase your appetite. While some people believe that MCTs can help you feel fuller longer, they may also stimulate the release of hunger hormones in some people. A 2017 study involving people with anorexia found that MCTs increased the release of two hormones that stimulate appetite: ghrelin and neuropeptide Y. People who took more than 6 grams of MCTs daily produced more of these hormones than those who took less than 1 gram daily. This could provide a therapeutic benefit to people seeking to increase their calorie intake, but it’s unclear whether the increase in these hormones causes people to eat more.
Liver Fat Buildup and Other Side Effects
High doses of MCT oil may increase the fat in your liver in the long term. One older 2017 12-week study in mice found that a diet in which 50% of the fats were MCTs increased liver fat. The same study also found that MCTs reduced total body fat and improved insulin resistance. Remember that high doses of MCT oil, such as those in the study above, are not recommended. Overall, more research is needed on the long-term effects of MCT oil. MCT oil has no defined tolerable upper intake level (UL). However, researchers have suggested a safe upper limit of 4 to 7 tablespoons (60-100 mL) daily. Even in lower amounts, consuming too much MCT oil can lead to digestive side effects for some people. These include abdominal cramping, diarrhea, and bloating. Some people may need to start with smaller amounts and slowly increase their MCT intake over time to reduce side effects. The other potential issue: too much MCT oil can cause a buildup of fat in the liver.
Calorie Density
MCTs are saturated fats, and they are high in calories. The American Heart Association recommends getting 5% to 6% of your calories from saturated fat to protect heart health. In a 2000-calorie diet, that’s about 13 grams of saturated fat daily. In most cases, you should consume MCT oil as part of your total fat intake, not as an additional amount. It’s important to note that high-fat MCT oil adds extra calories to your diet. Your use of MCT oil should be considered alongside the meat, olive oil, fatty fish, avocados, and nuts you already consume.
How to Use MCT Oil
MCT oil is available as a dietary supplement, which can be taken orally or added to foods and beverages.
The most common dose of MCT oil is 1 tablespoon or 15 ml at least once daily. If you’re new to MCT oil, it’s best to start off slowly, especially if you have a sensitive stomach.
Here are some ways to incorporate MCT oil into your diet:
- Add it to your coffee. Instead of drinking your coffee black, add a tablespoon of MCT oil. Bulletproof coffee, also known as keto coffee or butter coffee, is loaded with fat, and fat is an important replacement for carbohydrates in the ketogenic diet. There are drawbacks, though. Bulletproof coffee is extremely high in calories and saturated fat, so it can quickly become quite unhealthy for people who drink it more than once a day. And the temptation to drink keto coffee in place of a healthy breakfast can deprive the body of important nutrients.
- Use it as a pre- or post-workout supplement.
- Jazz up your salad dressings.
- Add it to baked goods. Substitute oils in your recipes with MCT oil.
- Make a healthy shake.
- Incorporate it into intermittent fasting routines.
MCT Oil vs. MCT Powder
Both MCT oil and MCT powder can be used as good source of MCTs and ingredients for keto foods and drinks. MCT powder can be taken with you anywhere you go without having to deal with spills. MCT powders can be easier to digest than MCT oil. We love our versatile MCT Oil Powder for smoothies and shakes, but if you’re looking for cognitive function support, too, try our Grass-Fed Collagen Peptides & MCT Brain Boost.
Considerations
People with heart disease or liver disease who are considering using MCT oil should first discuss it with a healthcare professional, as MCT oil could potentially worsen both conditions.
To avoid adverse effects of MCT oil, start slow with MCT oil supplements. Studies show MCT oil may also affect triglycerides and fat buildup on your liver, although it doesn’t affect total cholesterol levels.
The time it takes to see benefits from MCT oil can vary depending on your current diet and overall health. Many people notice an energy boost within hours of consumption. Compared to other fats, MCT oil is more rapidly absorbed and converted into energy, bypassing the digestive processes that longer-chain fats may undergo.