MCTs in coconuts

Medium Chain Triglycerides

  • Vitamins & Supplements
  • Updated April 28, 2016

Medium-chain triglycerides (MCTs) are a naturally occurring source of dietary fats that are abundant in coconut oil. Our bodies rapidly convert them into ketones, which can be used as an energy source by the brain. No studies have yet found that MCTs can prevent dementia, but some evidence suggests that patients with dementia might find short-term benefit using MCTs. While they are generally considered safe, some gastrointestinal side effects are common.

Evidence

Only two small clinical trials have studied the impact of MCTs on cognition. They were in different patient populations and reported contradictory results.

• Two randomized controlled trials, one in elderly individuals with age-related cognitive decline and one in diabetic patients
• 0 observation studies
• Multiple preclinical studies

Potential Benefit

In healthy individuals, glucose supplies almost all of the brain's energy. However, in certain patient populations (e.g. those with or developing Alzheimer's disease, type II diabetics) the ability of the brain to use glucose is impaired. Ketones are an alternative energy source for the brain and might be able to compensate for this impairment [1][2].

One clinical trial in elderly individuals with age-related cognitive decline reported no cognitive improvement with an MCT supplement (here). However, another small clinical trial in diabetic patients reported that MCT supplements preserved cognitive function in conditions of artificial hypoglycemia (where glucose levels were held low) [3]. No human studies have examined whether MCTs can prevent or delay dementia.

Although some laboratory studies provide a biological rationale of how MCTs might benefit brain health such as improving brain cell function, preventing Alzheimer's-like pathology, and enhancing learning in older animals [4][5], there exists no clinical data that MCTs promote long-term brain health.

APOE4 Carriers:

Two clinical trials reported that MCT supplements improved cognitive function in mild cognitive impairment (MCI) and Alzheimer's disease patients who do not carry the APOE4 genotype but were ineffective for APOE4 carriers [6][7]. For more information on what the APOE4 gene allele means for your health, read our APOE4 information page.

For Dementia Patients

Two clinical trials suggest that an MCT supplement (Axona®) may provide an acute benefit in patients with MCI and Alzheimer's disease. However, these improvements were short-lived and disappeared 14 days after the supplement was stopped [6][7]. Both trials were funded by Accera, the company that sells Axona®. No studies have tested the effects of MCTs in patients with severe dementia. Some preclinical laboratory studies suggest that MCTs may improve some measures of cognition and prevent amyloid plaque formation in animals, but these results have not been confirmed in humans [5][8].

Safety

Strong evidence suggests that MCTs are low risk when used by healthy adults. Foods high in MCTs such as coconut oil are used widely with few adverse events reported. For some people, though, MCTs can increase plasma triglyceride levels, which might be harmful for cardiovascular health [3][9]. And mild gastrointestinal side effects are common in individuals taking MCTs. The side effects may be reduced by taking MCTs with food and by slowly incorporating them into the diet.

NOTE: This is not a comprehensive safety evaluation or complete list of potentially harmful drug interactions. It is important to discuss safety issues with your physician before taking any new supplement or medication.

How to Use

MCTs can be found in certain foods, as supplements, and as medical foods. Coconut oil has the highest naturally occurring percentage of MCTs, which make up nearly 60 percent of its total fat content. Palm oil and butter also contain significant amounts of MCTs. In most studies, individuals have taken 10-40g of MCTs per day.

Learn More

Additional information on MCTs is available at WebMD.

References

  1. Cunnane SC, Courchesne-Loyer A, St-Pierre V et al. (2016) Can ketones compensate for deteriorating brain glucose uptake during aging? Implications for the risk and treatment of Alzheimer's disease. Annals of the New York Academy of Sciences 1367, 12-20.
  2. Castellano CA, Nugent S, Paquet N et al. (2015) Lower brain 18F-fluorodeoxyglucose uptake but normal 11C-acetoacetate metabolism in mild Alzheimer's disease dementia. Journal of Alzheimer's disease : JAD 43, 1343-1353.
  3. Page KA, Williamson A, Yu N et al. (2009) Medium-chain fatty acids improve cognitive function in intensively treated type 1 diabetic patients and support in vitro synaptic transmission during acute hypoglycemia. Diabetes 58, 1237-1244.
  4. Pan Y, Larson B, Araujo JA et al. (2010) Dietary supplementation with medium-chain TAG has long-lasting cognition-enhancing effects in aged dogs. The British journal of nutrition 103, 1746-1754.
  5. Kashiwaya Y, Bergman C, Lee JH et al. (2013) A ketone ester diet exhibits anxiolytic and cognition-sparing properties, and lessens amyloid and tau pathologies in a mouse model of Alzheimer's disease. Neurobiology of aging 34, 1530-1539.
  6. Henderson ST, Vogel JL, Barr LJ et al. (2009) Study of the ketogenic agent AC-1202 in mild to moderate Alzheimer's disease: a randomized, double-blind, placebo-controlled, multicenter trial. Nutrition & metabolism 6, 31.
  7. Reger MA, Henderson ST, Hale C et al. (2004) Effects of beta-hydroxybutyrate on cognition in memory-impaired adults. Neurobiology of aging 25, 311-314.
  8. Yin JX, Maalouf M, Han P et al. (2016) Ketones block amyloid entry and improve cognition in an Alzheimer's model. Neurobiology of aging 39, 25-37.
  9. Nosaka N, Kasai M, Nakamura M et al. (2002) Effects of dietary medium-chain triacylglycerols on serum lipoproteins and biochemical parameters in healthy men. Biosci Biotechnol Biochem 66, 1713-1718.