Fortier · Alzheimer's & dementia : the journal of the Alzheimer's Association 2019 · randomized controlled trial · n=52

A ketogenic drink improves brain energy and some measures of cognition in mild cognitive impairment.

Cited 214 times in the scientific literature.

Level 2 - randomized trial

Individual randomized controlled trial

PubMed 31027873 · doi:10.1016/j.jalz.2018.12.017 · record verified 2026-08-26

What was done

Fifty-two participants with mild cognitive impairment (MCI) were blindly randomized to receive either 30 g/day of ketogenic medium-chain triglycerides (kMCT) or a matching placebo for 6 months. Brain ketone and glucose metabolism were quantified using positron emission tomography (PET) as the primary outcome, and cognitive performance was assessed across multiple domains as a secondary outcome at baseline and 6 months.

What was found

Brain ketone metabolism increased by 230% in the kMCT group (P < .001), while brain glucose uptake remained unchanged. Within the kMCT group, episodic memory, language, executive function, and processing speed improved relative to baseline, and increased ketone uptake positively correlated with several cognitive measures. Seventy-five percent of participants completed the intervention. Specific numerical cognitive scores and between-group statistical comparisons were not reported in the abstract.

Why it matters

This study provides evidence that oral ketogenic supplementation can bypass impaired brain glucose uptake by significantly boosting brain ketone availability, accompanied by gains in several cognitive domains in mild cognitive impairment.

Limits

The sample size was small (n = 52), and there was a 25% dropout rate over the 6-month trial. The abstract omits numerical values, effect sizes, and between-group significance testing versus placebo for the cognitive outcomes.

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