Medium-chain triglycerides improve cognitive function in Alzheimer’s disease.

The brain relies heavily on glucose as its primary fuel, burning as much as 130 grams of glucose per day. However, glucose metabolism in the brain is impaired in Alzheimer’s disease, contributing to many of the disease’s symptoms. Findings from a recent study demonstrate that ketones derived from medium chain triglyceride metabolism may provide an alternative fuel source for the brain in the setting of Alzheimer’s disease.

Ketones are molecules produced by the liver during the breakdown of fatty acids. Ketone production occurs during periods of low food intake (such as during fasting), carbohydrate-restrictive diets, starvation, or prolonged intense exercise. Humans produce three types of ketones: acetoacetate, beta-hydroxybutyrate, and acetone. Ketones are readily used as energy by a diverse array of cell types, including neurons, and some evidence suggests that ketones improve cognitive function.

Medium-chain triglycerides (MCTs) are a class of saturated fats. They are composed of medium-length fatty acid chains (six to 12 carbons long) bound by a glycerol backbone. Medium-chain triglycerides occur naturally in coconut oil, palm oil, and butter, but they can also be synthesized in a laboratory or food processing setting and provided as dietary supplements.

The randomized, placebo-controlled trial involved 20 adults between the ages of 53 and 84 years who had been diagnosed with Alzheimer’s disease. The investigators used a crossover design, which allows all participants to receive the same treatment, at different times. In this trial, half of the participants received an average of two tablespoons of MCTs daily for three months, while the other half received a comparable amount of olive oil for the same duration. Then the participants switched to the opposite treatment. Participants underwent cognitive testing before, during, and after the intervention. After completing both forms of the intervention, all the participants received MCTs for six months. The investigators collected the participants' demographic and health data, which included measures of blood lipids, fasting insulin, body mass index, and body fat composition.

They found that 80 percent of the participants demonstrated improved or stable cognitive function while taking the MCTs. The greatest improvements were seen among participants who received MCTs last (providing them nine months of uninterrupted treatment) and among those who were older than 73 years.

These findings suggest that long-term MCT intake stabilizes cognitive function in adults with Alzheimer’s disease, especially in mild to moderate disease. This was a small study, however, so larger studies are needed to confirm these findings.

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