Ketone Dose and Cerebral Blood Flow Study

Cognition Clinical Trial

— kCBF  

Official title:

The Acute Effects of a High Versus Low Dose of a Ketone Monoester Supplement on Cerebral Blood Flow and Cognition

Clinical Trial Details — Status: Recruiting

Administrative data

• NCT number: NCT06032156
• Other study ID #: kCBF
• Status: Recruiting
• Phase: N/A
• Start date: November 8, 2023
• Est. completion date: August 2024

Study information

• Verified date: December 2023
• Source: McMaster University
• Contact: Jeremy J Walsh, PhD
• Phone: 905-525-9140
• Email: walshj18[@]mcmaster.ca
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial 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.

Recruitment information / eligibility

• Status: Recruiting
• Enrollment: 20
• Est. completion date: August 2024
• Est. primary completion date: May 2024
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: All
• Age group: 18 Years to 35 Years

Eligibility

Inclusion Criteria:

• Between the ages of 18 and 35

Exclusion Criteria:

• 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

Related Conditions & MeSH terms

• Cerebrovascular Function
• Cognition

Intervention

Dietary Supplement:
• Low Dose ß-OHB
Ingestion of a low dose [R]-3-hydroxybutyl [R]-3-hydroxybutyrate (0.3 g ß-OHB/kg body weight) followed by 2-hours of rest. Submaximal exercise to be performed following 2-hour resting measures.
• High Dose ß-OHB
Ingestion of a high dose [R]-3-hydroxybutyl [R]-3-hydroxybutyrate (0.6 g ß-OHB/kg body weight) followed by 2-hours of rest. Submaximal exercise to be performed following 2-hour resting measures.

Other:
• Placebo
Ingestion of a taste-matched calorie-free placebo drink followed by 2-hours of rest. Submaximal exercise to be performed following 2-hour resting measures.

Locations

Country	Name	City	State
Canada	McMaster University	Hamilton	Ontario

Sponsors (1)

Lead Sponsor	Collaborator
McMaster University

Country where clinical trial is conducted

Canada, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Resting cerebral blood flow (CBF)	Measured via duplex ultrasound of the extra-cranial arteries (internal carotid and vertebral arteries).	2-hour
Secondary	Cognitive Function	The MST (Mnemonic Similarity Task) will be used to assess hippocampal-dependent memory and pattern separation.	2-hour
Secondary	Plasma beta-hydroxybutyrate area under the curve	Venous blood samples will be obtained via intravenous catheter	2-hour
Secondary	Brain-derived neurotrophic factor (BDNF)	Serum and plasma BDNF measured in venous blood samples will be obtained via intravenous catheter	2-hour, then following completion of submaximal exercise bout
Secondary	Oxygen uptake (VO2)	Breath-by-breath analysis performed via metabolic cart	2-hour, then during submaximal exercise (performed after 2-hour rest period)
Secondary	End-tidal CO2	Breath-by-breath analysis performed via PowerLab Gas Analyzer (AD Instruments)	2-hour, then during submaximal exercise (performed after 2-hour rest period)
Secondary	Mean arterial pressure (MAP)	Automated blood pressure cuff measurement of brachial artery pressure in mmHg.	2-hour