A simple Internet search yields copious amounts of web pages declaring the health benefits of MCT oil, from therapeutic use in hospitals, weight loss and improved body composition to improved blood lipid and glucose profiles, and even treating Alzheimer’s disease.
Medium-chain triglycerides are found in coconut or palm oil, human breast milk and in full-fat cow and goat milk. But despite its wide availability online, in vitamin or supplement retailers and in the natural health section of grocery stores, MCT oil doesn’t occur in nature. Pure MCT oil is hydrolyzed from coconut or palm oil, then fractionated, esterified and deodorized to create a colorless, flavorless and odorless semi-synthetic liquid devoid of long-chain triglycerides, or LCTs.
While many people confuse MCT oil with coconut oil, they are not the same. Coconut oil is a whole food with a variety of saturated fats, including a combination of MCTs and LCTs, so it is solid at room temperature.
Pure MCT oil is not a culinary oil, and due to its low smoke point (284 degrees Fahrenheit — far lower than most commonly used oils), it is most often taken as a dietary supplement or MCT oil used in salad dressings or smoothies.
Dietary intake of MCT oil can cause significant gastrointestinal distress, such as diarrhea, vomiting, bloating and cramping, because it is metabolized differently than LCTs. (For this reason, MCT oil is not appropriate for people with liver damage or disease.) Whereas most studies reporting these symptoms found they were experienced by individuals with very high-fat diets (90 percent of daily calories) or who took MCT oil on an empty stomach, others studies indicated MCT oil was well-tolerated.
Some research shows potential effectiveness of therapeutic MCT oil used both orally and intravenously in children and adults for conditions ranging from cystic fibrosis, seizures including epilepsy, cachexia and for treating diarrhea. Because of the unique absorption of MCTs, they have been used to reduce intestinal irritation in patients with irritable bowel disease, short bowel syndrome, celiac disease or post-gastrectomy. And although small studies show promise for Alzheimer’s disease treatment with the use of MCT oil and diet-induced ketosis, much more research is needed.
When it comes to weight-loss claims, some research suggests replacing other dietary fats, such as vegetable or olive oils, with MCT oil may be beneficial due to the unique metabolism of these fats. A review of 25 clinical studies concluded that MCT oil consumption ranging from 5 grams to 48 grams, most often replacing corn, olive, soybean, canola or animal saturated fats, may lead to enhanced diet-induced thermogenesis and fat oxidation and also preserve insulin sensitivity in participants with Type 2 diabetes. However, excessive consumption could cause weight gain, especially if consumed in addition to the regular diet, rather than as a replacement.
Other uses by consumers, including detoxification and improved athletic performance, are supported by little, mixed or no evidence. The popular “Bulletproof Diet” suggests adding MCT oil to coffee each morning for a 400-calorie beverage that is said to improve satiety and lead to weight loss. Butter or coconut oil also are used in this practice. When discussing MCT oil with clients, it is important to differentiate pure MCT oil from coconut oil, and to discuss potential adverse effects, including avoidance for those with hepatic disease, potential for weight gain with excessive intake and gastrointestinal upset. The use of MCT oil should not replace dietary and lifestyle interventions for blood lipid, weight management or diabetic needs, particularly given current limitations in research.