Ketone Dose and Cerebral Blood Flow Study
- Conditions
- CognitionCerebrovascular Function
- Interventions
- Dietary Supplement: Low Dose β-OHBDietary Supplement: High Dose β-OHBOther: Placebo
- Registration Number
- NCT06032156
- Lead Sponsor
- McMaster University
- Brief Summary
Ketone bodies are produced by the liver during periods of food scarcity or severe carbohydrate restriction. Blood ketones are an alternative fuel source used by the brain, heart, and skeletal muscle during periods of fasting. Further, ketones bodies act as a signalling molecule that have pleiotropic effects that upregulate cellular stress-resistance pathways throughout the body.
Oral supplements containing exogenous ketones have recently become available and represent a novel tool for increasing plasma ketone bodies without the need for dietary restriction. Early evidence suggests that oral ketone supplements may enhance cerebral blood flow and improve cognition. However, the dose-dependent effects of a single ketone supplement on cerebral blood flow and cognition in young adults is currently unknown.
The purpose of this study is to characterize the effects of ingesting a high versus low dose of an oral ketone monoester on cerebral blood flow, circulating blood markers, and cognition in young adults.
As an exploratory aim, this study will investigate how oxygen uptake kinetics during submaximal exercise are impacted 2 hours after ingestion of a ketone supplement. Recent findings indicate that ketone supplementation may impair exercise performance due to the physiological stress (i.e., pH disturbances) imposed by an acute ketone dose. Delaying exercise onset by 2 hours after ingestion of a ketone supplement may enhance oxygen kinetics in a dose-dependent manner.
- Detailed Description
Not available
Recruitment & Eligibility
- Status
- RECRUITING
- Sex
- All
- Target Recruitment
- 20
- Between the ages of 18 and 35
- Presence of obesity (body mass index > 30 kg/m^2)
- Presence of known cardiovascular disease
- Presence of type 2 diabetes
- History of cardiovascular events requiring hospitalization (i.e., heart attack)
- History of concussion(s) with persistent symptoms
- Currently following a ketogenic diet and/or taking ketone body supplements
Study & Design
- Study Type
- INTERVENTIONAL
- Study Design
- CROSSOVER
- Arm && Interventions
Group Intervention Description Low Dose β-OHB Low Dose β-OHB Single dose of a ketone monoester (\[R\]-3-hydroxybutyl \[R\]-3-hydroxybutyrate; 0.3 g β-OHB/kg body weight) High Dose β-OHB High Dose β-OHB Single dose of a ketone monoester (\[R\]-3-hydroxybutyl \[R\]-3-hydroxybutyrate; 0.6 g β-OHB/kg body weight) Placebo Placebo Single dose of a taste-matched calorie-free placebo
- Primary Outcome Measures
Name Time Method Resting cerebral blood flow (CBF) 2-hour Measured via duplex ultrasound of the extra-cranial arteries (internal carotid and vertebral arteries).
- Secondary Outcome Measures
Name Time Method Plasma beta-hydroxybutyrate area under the curve 2-hour Venous blood samples will be obtained via intravenous catheter
Brain-derived neurotrophic factor (BDNF) 2-hour, then following completion of submaximal exercise bout Serum and plasma BDNF measured in venous blood samples will be obtained via intravenous catheter
Oxygen uptake (VO2) 2-hour, then during submaximal exercise (performed after 2-hour rest period) Breath-by-breath analysis performed via metabolic cart
Mean arterial pressure (MAP) 2-hour Automated blood pressure cuff measurement of brachial artery pressure in mmHg.
Cognitive Function 2-hour The MST (Mnemonic Similarity Task) will be used to assess hippocampal-dependent memory and pattern separation.
End-tidal CO2 2-hour, then during submaximal exercise (performed after 2-hour rest period) Breath-by-breath analysis performed via PowerLab Gas Analyzer (AD Instruments)
Trial Locations
- Locations (1)
McMaster University
🇨🇦Hamilton, Ontario, Canada