By Dr. Mercola
Medium-chain triglycerides (MCTs) have become increasingly popular as people are learning more about the health benefits of nutritional ketosis, which is achieved by replacing net carbohydrates (total carbs minus fiber) with high amounts of healthy fats and moderate amounts of high-quality protein.
Some of the health benefits of coconut oil relate to the MCTs in the oil. But MCT oil is a more concentrated source, so it tends to be more appropriate for clinical uses, which include:1
•Appetite reduction and weight loss2,3
•Improved cognitive and neurological function with possible implications in neurodegenerative diseases
•Increased energy levels and improved athletic performance
•Improved mitochondrial function and subsequent reduced risk for diseases such as atherosclerosis, diabetes, cancer, cardiovascular disease, autoimmune diseases and epilepsy4
•As part of a specialized dietary therapy for the treatment of epilepsy
•Prevention of non-alcoholic fatty liver disease (NAFLD)5
Short-, Medium- and Long-Chain Triglycerides
The disastrous "low-fat diet" dogma of the last half-century has led to a devastating drop in most people's intake of healthy saturated fats, including MCTs, as most people have bought into the erroneous assumption that saturated fats are unhealthy and will raise their risk of heart disease.
Besides coconuts, coconut oil and palm kernel oil, small amounts of MCT can be found in butter and other high-fat dairy products from grass-fed cows and goats.
Be sure not to confuse the extremely unhealthy industrial versions of coconut and palm oils (which are historically used as hydrogenated oils in industrial baked goods) with organic, virgin and unrefined oils available as "health foods."
MCTs get their name from their chemical structure. Fats consist of chains of carbon molecules connected to hydrogen atoms. Short-chain fats have six carbons or less.
Medium-chain fats contain between six and 12 carbons, while long-chained fats, such as the omega-3 fats docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), have 13 to 21 carbons.
Four Types of MCTs
MCTs can be divided into four groups based on their carbon length:6
•6 carbons (C6), caproic acid
•8 carbons (C8), caprylic acid
•10 carbons (C10), capric acid
•12 carbons (C12), lauric acid
As a general rule, the shorter the carbon chain, the more efficiently the MCT will be turned into ketones, which are an excellent source of energy for your body — far preferable to glucose, as ketones produce far less reactive oxygen species (ROS) when they are metabolized to produce ATP.
I recently wrote about how a novel ketone ester drink may help boost performance in professional athletes, but while ketone supplements are still in development, your best bet at the moment is to use MCTs found in foods and supplements, which your body will then convert to ketones.
Most commercial brands of MCT oil contain close to a 50/50 combination of C8 and C10 fats. My personal preference, even though it is more expensive, is straight C8 (caprylic acid), as it converts to ketones far more rapidly than do C10 fats, and may be easier on your digestion.
Coconut oil provides a mix of all the medium-chain fats, including C6, C8, C10 and C12 fats, the latter of which (lauric acid) makes up over 40 percent of the fat in coconut oil. (The exception is FRACTIONATED coconut oil, which contains primarily C8 and C10.7)
There are benefits to all of these fatty acids. However, caprylic and capric fatty acids increase ketone levels far more efficiently.
Also, while lauric acid is technically an MCT, its longer carbon chain means it does not always have the same biological activity as the shorter chained ones. In fact, C12 can behave more like long-chain fatty acids (LCTs), which are less efficiently broken down into ketones.
As a result, C12 is less potent when it comes to curbing hunger and promoting brain health. For these benefits, you want C8 and C10. Lauric acid is most well-known for its antibacterial, antimicrobial and antiviral properties.
The shorter-chained MCTs, on the other hand, are more readily converted into ketones, which are an excellent mitochondrial fuel. Ketones also help suppress ghrelin (a.k.a. the hunger hormone) and enhance another hormone that signals your brain when you're full.
Why Take MCT Oil?
Your body processes MCTs differently from the long-chain fats in your diet. Normally, a fat taken into your body must be mixed with bile released from your gallbladder and acted on by pancreatic enzymes to break it down in your digestive system.
MCTs don't need bile or pancreatic enzymes. Once they reach your intestine, they diffuse through your intestinal membrane into your bloodstream and are transported directly to your liver, which naturally converts the oil into ketones.
Your liver then releases the ketones back into your bloodstream, where they are transported throughout your body. They can even pass the blood-brain barrier to supply your brain with energy. MCTs also have a thermogenic effect, which has a positive effect on your metabolism.8
For these reasons, MCTs are readily used by your body for energy rather than being stored as fat. MCTs are also helpful for ridding your gut of harmful microorganisms like pathogenic bacteria, viruses, fungi and parasites. Like coconut oil, MCTs also have antioxidant and anti-inflammatory properties.
MCT oil (either straight MCT or coconut oil) may be consumed every day. One of the challenges with MCT oils is that if you consume high amounts initially before you develop tolerance to them, they can cause loose stools and gastrointestinal (GI) side effects.
I recommend taking no more than 1 teaspoon of MCT oil to start. Have it at the same time as another fat, for example, with a handful of nuts, with ghee in your coffee or as one of the oils in your salad dressing. Once your tolerance increases, you can slowly increase that amount to 4 tablespoons of MCT oil per day.
If you stop taking MCT oil for a while and then restart, begin with a small amount again to allow your digestive system to readjust. That said, MCT oil is often more easily digested by those struggling to digest other types of fat, such as those with malabsorption, leaky gut, Crohn's disease or gallbladder impairment (such as an infection or if you had your gallbladder removed).
One of the ways you can improve your tolerance is by using the powdered form in shakes or home-baked keto muffins or bread.