Plain language summary
Brain energy rescue is emerging as a potential strategy to reduce cognitive decline in mild cognitive impairment (MCI) and Alzheimer’s disease (AD). The main aim of this study was to report the complete cognitive outcomes of the BENEFIC (Brain Energy, Functional Imaging, and Cognition) trial. The secondary objectives are to report plasma ketones (free caprylic and capric acids) levels; as well as the metabolic response, safety, and tolerability after the 6-month intervention. This study is a 6-month randomised, placebo-controlled trial. A total of 122 participants were enrolled and randomised into one of the two arms: ketogenic medium chain triglyceride (kMCT) or placebo arm. Results show that performance on widely used tests of episodic memory, executive function, and language improved over 6 months in MCI when consuming 30g/day of a kMCT drink relative to a matching placebo. Moderate to large effect sizes were observed on four cognitive tests in the kMCT group. Furthermore, it is safe and feasible for an MCI population to consume a 15g kMCT supplement twice daily for 6 months. Authors conclude that formulation of a kMCT drink improved four cognitive outcomes in MCI by increasing blood ketone levels.
Expert Review
Conflicts of interest:
None
Take Home Message:
- MCT supplementation is a promising strategy to rescue energy metabolism in the brain for those with MCIs by providing an alternative energy source
- Improvements in cognition were associated with increased blood ketone levels from MCT supplementation
- Practitioners should be mindful that higher intakes of MCTs (>30g/d) may lead to negative GI effects in some individuals.
Evidence Category:
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X
A: Meta-analyses, position-stands, randomized-controlled trials (RCTs)
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B: Systematic reviews including RCTs of limited number
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C: Non-randomized trials, observational studies, narrative reviews
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D: Case-reports, evidence-based clinical findings
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E: Opinion piece, other
Summary Review:
This randomized controlled trial demonstrates that supplementation of a ketogenic drink containing medium-chain triglycerides (MCTs) is both safe and effective in improving cognitive outcomes in individuals with mild cognitive impairments (MCI), and does so through supporting energy metabolism in the brain.
Clinical practice applications:
These findings might be useful for Nutritional Therapists and Clinical Practitioners as follows:
- The results of this randomised controlled trial demonstrate that MCT supplementation (at 30g per day, split between two doses) is a viable strategy to support brain metabolism in individuals experiencing MCIs
- There was a dose-dependant response on elevated ketones and selected cognitive improvements which may have pertinent applications to therapeutic practice (either dietary or supplemental)
- The paper highlighted the involvement of energy metabolism in cognitive decline; this has potential therapeutic applications in terms of targeted nutritional support for mitochondrial function or energy signalling
- Some individuals experienced negative gastrointestinal effects when consuming MCTs at 30g/d for prolonged periods; practitioners should be mindful of this.
Considerations for future research:
Future research should consider:
- Whether dietary-induced ketosis can therapeutically impact MCI and support patient well-being
- Use of MCTs in those with severe cognitive impairments or those taking medication such as cholinesterase inhibitors
the role of glucose hypometabolism to determine alternative strategies for those who have GI issues with MCTs
- Whether APOE4 status has any impact on therapeutic outcomes to MCT supplementation
- Whether adjunct nutritional support for mitochondrial function alongside MCT could further impact on MCIs.
Abstract
INTRODUCTION Counteracting impaired brain glucose metabolism with ketones may improve cognition in mild cognitive impairment (MCI). METHODS Cognition, plasma ketone response, and metabolic profile were assessed before and 6 months after supplementation with a ketogenic drink containing medium chain triglyceride (ketogenic medium chain triglyceride [kMCT]; 15 g twice/day; n = 39) or placebo (n = 44). RESULTS Free and cued recall (Trial 1; P = .047), verbal fluency (categories; P = .024), Boston Naming Test (total correct answers; P = .033), and the Trail-Making Test (total errors; P = .017) improved significantly in the kMCT group compared to placebo (analysis of covariance; pre-intervention score, sex, age, education, and apolipoprotein E4 as covariates). Some cognitive outcomes also correlated positively with plasma ketones. Plasma metabolic profile and ketone response were unchanged. CONCLUSIONS This kMCT drink improved cognitive outcomes in MCI, at least in part by increasing blood ketone level. These data support further assessment of MCI progression to Alzheimer's disease.
Lifestyle medicine
Functional Laboratory Testing
:
Blood
Methodological quality
Jadad score
:
3
Allocation concealment
:
Yes
