
Modern Healthspan|13. Mai
A 40% Energy Rescue for the Aging Brain in Clinical Trial | Dr Stephen Cunnane
The BENEFIC Trial: A Rescue for the Aging Brain?
Study Design and Objective
- The Theory: In mild cognitive impairment (MCI), a brain "energy gap" exists because glucose uptake is impaired. This study investigates whether ketones can fill this gap.
- The Intervention: 30 g of medium-chain triglycerides (MCTs) per day, split into two doses (15 g at breakfast, 15 g at dinner) as an emulsion in low-fat milk.
- Duration: Six months.
- Participants: People with MCI (age >55, subjective memory complaints, and objective deficits in at least one of five cognitive domains). 19-20 people per group (placebo vs. active).
- Primary Goal: Improving brain metabolism (measured by PET scans for glucose and ketone uptake). Cognitive tests were a secondary goal, as the study was not designed to detect changes related to Alzheimer's disease.
Key Results
- The energy gap was reduced by 30-40% – but only transiently (around 15-20 minutes) after taking the MCT drink. Over a 24-hour period, the reduction was likely less than 10%.
- Ketone uptake into the brain varied significantly between participants.
- Cognitive improvements (memory, executive function, language) were positively correlated with the reduction of the energy gap.
Background on MCT Composition
- The MCT used consisted of 55% C8 (caprylic acid, more ketogenic) and 35% C10 (capric acid).
- MCT was chosen because it was already approved in Canada and a placebo could be produced – unlike with ketone esters or salts.
- The dose was chosen for tolerability reasons; at higher doses, many participants dropped out of the study.
Conclusion
- The BENEFIC trial provided proof-of-concept that MCTs can close the energy gap in the aging brain.
- However, the duration of the correction is short, limiting the effect over the day.
- Future studies could be more effective with pure C8, more frequent dosing, or more stable ketone sources.






