The effect of an MCT-based ketogenic drink on brain ketone metabolism Original paper

In people with mild cognitive impairment, a medium-chain triglycerides–based ketogenic drink increased ketone levels and the metabolism of ketones in the gray matter of the brain.

This Study Summary was published on January 4, 2022.


Many forms of cognitive impairment might be related to the brain’s reduced ability to generate energy from glucose. As a way of rectifying this energy deficit, it has been suggested that increasing ketone bodies may provide additional energy to the brain, potentially benefiting cognition. This study tested whether a ketogenic drink high in medium-chain triglycerides (MCTs) would impact ketone body metabolism in the gray matter of people with mild cognitive impairment (MCI).

The study

This 6-month randomized controlled trial examined the effect of an MCT-based ketogenic supplement on people with MCI. In total, 33 people over age 55 with MCI were randomly assigned to consume a drink containing 30 grams of either MCTs (60% capric acid and 40% caprylic acid) or high-oleic sunflower oil daily. In both groups the oil was mixed with lactose-free skim milk. The primary outcomes were ketone metabolism in gray matter, assessed via PET (positron emission tomography) scan as acetoacetate uptake, and plasma ketone levels.

The results

Compared with the sunflower oil group, the MCT group experienced an increase in both plasma ketones and gray matter ketone metabolism.


Changes in cognitive outcomes were reported in a previously published paper, with most cognitive outcomes the same between groups.

In the MCT group, researchers increased the dose slowly over the first two weeks. This was done in an attempt to minimize the gastrointestinal side effects that frequently occur from consuming high amounts of MCTs.

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This Study Summary was published on January 4, 2022.