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Monteyne AJ, Falkenhain K, Whelehan G, Neudorf H, Abdelrahman DR, Murton AJ, Wall BT, Stephens FB, Little JP. A ketone monoester drink reduces postprandial blood glucose concentrations in adults with type 2 diabetes: a randomised controlled trial. Diabetologia 2024; 67:1107-1113. [PMID: 38483543 PMCID: PMC11058041 DOI: 10.1007/s00125-024-06122-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/28/2023] [Accepted: 02/01/2024] [Indexed: 04/07/2024]
Abstract
AIMS/HYPOTHESIS The aim of the present study was to conduct a randomised, placebo-controlled, double-blind, crossover trial to determine whether pre-meal ketone monoester ingestion reduces postprandial glucose concentrations in individuals with type 2 diabetes. METHODS In this double-blind, placebo-controlled, crossover design study, ten participants with type 2 diabetes (age 59±1.7 years, 50% female, BMI 32±1 kg/m2, HbA1c 54±2 mmol/mol [7.1±0.2%]) were randomised using computer-generated random numbers. The study took place at the Nutritional Physiology Research Unit, University of Exeter, Exeter, UK. Using a dual-glucose tracer approach, we assessed glucose kinetics after the ingestion of a 0.5 g/kg body mass ketone monoester (KME) or a taste-matched non-caloric placebo before a mixed-meal tolerance test. The primary outcome measure was endogenous glucose production. Secondary outcome measures were total glucose appearance rate and exogenous glucose appearance rate, glucose disappearance rate, blood glucose, serum insulin, β-OHB and NEFA levels, and energy expenditure. RESULTS Data for all ten participants were analysed. KME ingestion increased mean ± SEM plasma beta-hydroxybutyrate from 0.3±0.03 mmol/l to a peak of 4.3±1.2 mmol/l while reducing 2 h postprandial glucose concentrations by ~18% and 4 h postprandial glucose concentrations by ~12%, predominately as a result of a 28% decrease in the 2 h rate of glucose appearance following meal ingestion (all p<0.05). The reduction in blood glucose concentrations was associated with suppressed plasma NEFA concentrations after KME ingestion, with no difference in plasma insulin concentrations between the control and KME conditions. Postprandial endogenous glucose production was unaffected by KME ingestion (mean ± SEM 0.76±0.15 and 0.88±0.10 mg kg-1 min-1 for the control and KME, respectively). No adverse effects of KME ingestion were observed. CONCLUSIONS/INTERPRETATION KME ingestion appears to delay glucose absorption in adults with type 2 diabetes, thereby reducing postprandial glucose concentrations. Future work to explore the therapeutic potential of KME supplementation in type 2 diabetes is warranted. TRIAL REGISTRATION ClinicalTrials.gov NCT05518448. FUNDING This project was supported by a Canadian Institutes of Health Research (CIHR) Project Grant (PJT-169116) and a Natural Sciences and Engineering Research Council (NSERC) Discovery Grant (RGPIN-2019-05204) awarded to JPL and an Exeter-UBCO Sports Health Science Fund Project Grant awarded to FBS and JPL.
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Affiliation(s)
- Alistair J Monteyne
- Nutritional Physiology Research Group, Department of Public Health and Sport Sciences, University of Exeter, Exeter, UK
| | - Kaja Falkenhain
- School of Health and Exercise Sciences, University of British Columbia Okanagan, Kelowna, BC, Canada
| | - Gráinne Whelehan
- Nutritional Physiology Research Group, Department of Public Health and Sport Sciences, University of Exeter, Exeter, UK
| | - Helena Neudorf
- School of Health and Exercise Sciences, University of British Columbia Okanagan, Kelowna, BC, Canada
| | - Doaa R Abdelrahman
- Department of Surgery, University of Texas Medical Branch, Galveston, TX, USA
- Sealy Center on Aging, University of Texas Medical Branch, Galveston, TX, USA
| | - Andrew J Murton
- Department of Surgery, University of Texas Medical Branch, Galveston, TX, USA
- Sealy Center on Aging, University of Texas Medical Branch, Galveston, TX, USA
| | - Benjamin T Wall
- Nutritional Physiology Research Group, Department of Public Health and Sport Sciences, University of Exeter, Exeter, UK
| | - Francis B Stephens
- Nutritional Physiology Research Group, Department of Public Health and Sport Sciences, University of Exeter, Exeter, UK.
| | - Jonathan P Little
- School of Health and Exercise Sciences, University of British Columbia Okanagan, Kelowna, BC, Canada.
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Tsuruta H, Yamahara K, Yasuda-Yamahara M, Kume S. Emerging Pathophysiological Roles of Ketone Bodies. Physiology (Bethesda) 2024; 39:0. [PMID: 38260943 DOI: 10.1152/physiol.00031.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Revised: 01/15/2024] [Accepted: 01/18/2024] [Indexed: 01/24/2024] Open
Abstract
The discovery of insulin approximately a century ago greatly improved the management of diabetes, including many of its life-threatening acute complications like ketoacidosis. This breakthrough saved many lives and extended the healthy lifespan of many patients with diabetes. However, there is still a negative perception of ketone bodies stemming from ketoacidosis. Originally, ketone bodies were thought of as a vital source of energy during fasting and exercise. Furthermore, in recent years, research on calorie restriction and its potential impact on extending healthy lifespans, as well as studies on ketone bodies, have gradually led to a reevaluation of the significance of ketone bodies in promoting longevity. Thus, in this review, we discuss the emerging and hidden roles of ketone bodies in various organs, including the heart, kidneys, skeletal muscles, and brain, as well as their potential impact on malignancies and lifespan.
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Affiliation(s)
- Hiroaki Tsuruta
- Department of Medicine, Shiga University of Medical Science, Seta, Otsu, Shiga, Japan
| | - Kosuke Yamahara
- Department of Medicine, Shiga University of Medical Science, Seta, Otsu, Shiga, Japan
| | - Mako Yasuda-Yamahara
- Department of Medicine, Shiga University of Medical Science, Seta, Otsu, Shiga, Japan
| | - Shinji Kume
- Department of Medicine, Shiga University of Medical Science, Seta, Otsu, Shiga, Japan
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Dörner R, Hägele FA, Müller MJ, Seidel U, Rimbach G, Bosy-Westphal A. Effect of exogenous and endogenous ketones on respiratory exchange ratio and glucose metabolism in healthy subjects. Am J Physiol Cell Physiol 2024; 326:C1027-C1033. [PMID: 38314726 PMCID: PMC11193512 DOI: 10.1152/ajpcell.00429.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Revised: 01/31/2024] [Accepted: 01/31/2024] [Indexed: 02/07/2024]
Abstract
This study examined the effect of exogenous ketone bodies (KB) on oxygen consumption (V̇o2), carbon dioxide production (V̇co2), and glucose metabolism. The data were compared with the effects of endogenous ketonemia during both, a ketogenic diet or fasting. Eight healthy individuals [24.1 ± 2.5 yr, body mass index (BMI) 24.3 ± 3.1 kg/m2] participated in a crossover intervention study and were studied in a whole-room indirect calorimeter (WRIC) to assess macronutrient oxidation following four 24-h interventions: isocaloric controlled mixed diet (ISO), ISO supplemented with ketone salts (38.7 g of β-hydroxybutyrate/day, EXO), isocaloric ketogenic diet (KETO), and total fasting (FAST). A physical activity level of 1.65 was obtained. In addition to plasma KB, 24-h C-peptide and KB excretion rates in the urine and postprandial glucose and insulin levels were measured. Although 24-h KB excretion increased in response to KETO and FAST, there was a modest increase in response to EXO only (P < 0.05). When compared with ISO, V̇o2 significantly increased in KETO (P < 0.01) and EXO (P < 0.001), whereas there was no difference in FAST. V̇co2 increased in EXO but decreased in KETO (both P < 0.01) and FAST (P < 0.001), resulting in 24-h respiratory exchange ratios (RER) of 0.828 ± 0.024 (ISO) and 0.811 ± 0.024 (EXO) (P < 0.05). In response to EXO there were no differences in basal and postprandial glucose and insulin levels, as well as in insulin sensitivity. When compared with ISO, EXO, and KETO, FAST increased homeostatic model assessment β-cell function (HOMA-B) (all P < 0.05). In conclusion, at energy balance exogenous ketone salts decreased respiratory exchange ratio without affecting glucose tolerance.NEW & NOTEWORTHY Our findings revealed that during isocaloric nutrition, additional exogenous ketone salts increased V̇o2 and V̇co2 while lowering the respiratory exchange ratio (RER). Ketone salts had no effect on postprandial glucose metabolism.
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Affiliation(s)
- Rebecca Dörner
- Department of Human Nutrition, Institute of Human Nutrition and Food Sciences, Kiel University, Kiel, Germany
| | - Franziska A Hägele
- Department of Human Nutrition, Institute of Human Nutrition and Food Sciences, Kiel University, Kiel, Germany
| | - Manfred J Müller
- Department of Human Nutrition, Institute of Human Nutrition and Food Sciences, Kiel University, Kiel, Germany
| | - Ulrike Seidel
- Department of Food Sciences, Institute of Human Nutrition and Food Sciences, Kiel University, Kiel, Germany
| | - Gerald Rimbach
- Department of Food Sciences, Institute of Human Nutrition and Food Sciences, Kiel University, Kiel, Germany
| | - Anja Bosy-Westphal
- Department of Human Nutrition, Institute of Human Nutrition and Food Sciences, Kiel University, Kiel, Germany
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Falkenhain K, Oliveira BF, Islam H, Neudorf H, Cen HH, Johnson JD, Madden K, Singer J, Walsh JJ, Little JP. The effect of acute and 14-day exogenous ketone supplementation on glycemic control in adults with type 2 diabetes: two randomized controlled trials. Am J Physiol Endocrinol Metab 2024; 326:E61-E72. [PMID: 37991451 DOI: 10.1152/ajpendo.00332.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/09/2023] [Revised: 11/02/2023] [Accepted: 11/17/2023] [Indexed: 11/23/2023]
Abstract
Acute ingestion of the exogenous ketone monoester supplement [(R)-3-hydroxybutyl-(R)-3-hydroxybutyrate] lowers blood glucose, suggesting therapeutic potential in individuals with impaired glucose metabolism. However, it is unknown how acute or repeated ingestion of exogenous ketones affects blood glucose control in individuals with type 2 diabetes (T2D). We conducted two randomized, counterbalanced, double-blind, placebo-controlled crossover trials to determine if 1) acute exogenous ketone monoester (0.3 g/kg body mass; N = 18) or 2) 14-day thrice daily premeal exogenous ketone monoester (15 g; N = 15) supplementation could lower blood glucose in individuals living with T2D. A single dose of the ketone monoester supplement elevated blood β-OHB to ∼2 mM. There were no differences in the primary outcomes of plasma glucose concentration (acutely) or serum fructosamine (glycemic control across 14 days) between conditions. Ketone monoester ingestion acutely increased insulin and lowered nonesterified fatty acid concentrations; plasma metabolomics confirmed a reduction in multiple free fatty acids species and select gluconeogenic amino acids. In contrast, no changes were observed in fasting metabolic outcomes following 14 days of supplementation. In the context of these randomized controlled trials, acute or repeated ketone monoester ingestion in adults with T2D did not lower blood glucose when consumed acutely in a fasted state and did not improve glycemic control following thrice daily premeal ingestion across 14 days. Future studies exploring the mechanistic basis for the (lack of) glucose-lowering effect of exogenous ketone supplementation in T2D and other populations are warranted.NEW & NOTEWORTHY Exogenous ketone supplements can acutely lower blood glucose, suggesting therapeutic potential in individuals with impaired glucose metabolism. However, the effect of exogenous ketones on glucose metabolism in adults with type 2 diabetes has not been investigated in a controlled setting. In adults with type 2 diabetes, ketone monoester ingestion did not lower blood glucose acutely in a fasted state and did not improve glycemic control across thrice daily premeal ingestion across 14 days.
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Affiliation(s)
- Kaja Falkenhain
- Faculty of Health and Social Development, School of Health and Exercise Sciences, University of British Columbia, Kelowna, British Columbia, Canada
| | - Barbara F Oliveira
- Faculty of Health and Social Development, School of Health and Exercise Sciences, University of British Columbia, Kelowna, British Columbia, Canada
| | - Hashim Islam
- Faculty of Health and Social Development, School of Health and Exercise Sciences, University of British Columbia, Kelowna, British Columbia, Canada
| | - Helena Neudorf
- Faculty of Health and Social Development, School of Health and Exercise Sciences, University of British Columbia, Kelowna, British Columbia, Canada
| | - Haoning H Cen
- Department of Cellular & Physiological Sciences, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada
| | - James D Johnson
- Department of Cellular & Physiological Sciences, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada
| | - Kenneth Madden
- Department of Medicine, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada
| | - Joel Singer
- Faculty of Medicine, School of Population and Public Health, University of British Columbia, Vancouver, British Columbia, Canada
| | - Jeremy J Walsh
- Department of Kinesiology, Faculty of Science, McMaster University, Hamilton, Ontario, Canada
| | - Jonathan P Little
- Faculty of Health and Social Development, School of Health and Exercise Sciences, University of British Columbia, Kelowna, British Columbia, Canada
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Bolyard ML, Graziano CM, Fontaine KR, Sayer RD, Fisher G, Plaisance EP. Tolerability and Acceptability of an Exogenous Ketone Monoester and Ketone Monoester/Salt Formulation in Humans. Nutrients 2023; 15:4876. [PMID: 38068734 PMCID: PMC10708260 DOI: 10.3390/nu15234876] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2023] [Revised: 11/13/2023] [Accepted: 11/20/2023] [Indexed: 12/18/2023] Open
Abstract
Exogenous ketone ester and ketone ester mixed with ketone free acid formulations are rapidly entering the commercial marketspace. Short-term animal and human studies using these products suggest significant potential for primary or secondary prevention of a number of chronic disease conditions. However, a number of questions need to be addressed by the field for optimal use in humans, including variable responses among available exogenous ketones at different dosages; frequency of dosing; and their tolerability, acceptability, and efficacy in long-term clinical trials. The purpose of the current investigation was to examine the tolerability, acceptability, and circulating R-beta-hydroxybutyrate (R-βHB) and glucose responses to a ketone monoester (KME) and ketone monoester/salt (KMES) combination at 5 g and 10 g total R-βHB compared with placebo control (PC). Fourteen healthy young adults (age: 21 ± 2 years, weight: 69.7 ± 14.2 kg, percent fat: 28.1 ± 9.3%) completed each of the five study conditions: placebo control (PC), 5 g KME (KME5), 10 g KME (KME10), 5 g (KMES5), and 10 g KMES (KMES10) in a randomized crossover fashion. Circulating concentrations of R-βHB were measured at baseline (time 0) following an 8-12 h overnight fast and again at 15, 30, 60, and 120 min following drink ingestion. Participants also reported acceptability and tolerability during each condition. Concentrations of R-βHB rose to 2.4 ± 0.1 mM for KME10 after 15 min, whereas KMES10 similarly peaked (2.1 ± 0.1 mM) but at 30 min. KME5 and KMES5 achieved similar peak R-βHB concentrations (1.2 ± 0.7 vs. 1.1 ± 0.5 mM) at 15 min. Circulating R-βHB concentrations were similar to baseline for each condition by 120 min. Negative correlations were observed between R-βHB and glucose at the 30 min time point for each condition except KME10 and PC. Tolerability was similar among KME and KMES, although decreases in appetite were more frequently reported for KMES. Acceptability was slightly higher for KMES due to the more frequently reported aftertaste for KME. The results of this pilot investigation illustrate that the KME and KMES products used increase circulating R-βHB concentrations to a similar extent and time course in a dose-dependent fashion with slight differences in tolerability and acceptability. Future studies are needed to examine variable doses, frequency, and timing of exogenous ketone administration for individuals seeking to consume ketone products for health- or sport performance-related purposes.
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Affiliation(s)
- Mickey L. Bolyard
- Department of Human Studies, School of Education, University of Alabama at Birmingham, Birmingham, AL 35294, USA; (M.L.B.); (C.M.G.); (G.F.)
| | - Christina M. Graziano
- Department of Human Studies, School of Education, University of Alabama at Birmingham, Birmingham, AL 35294, USA; (M.L.B.); (C.M.G.); (G.F.)
| | - Kevin R. Fontaine
- Department of Health Behavior, School of Public Health, University of Alabama at Birmingham, Birmingham, AL 35294, USA;
| | - R. Drew Sayer
- Department of Family and Community Medicine, Heersink School of Medicine, University of Alabama at Birmingham, Birmingham, AL 35924, USA;
| | - Gordon Fisher
- Department of Human Studies, School of Education, University of Alabama at Birmingham, Birmingham, AL 35294, USA; (M.L.B.); (C.M.G.); (G.F.)
| | - Eric P. Plaisance
- Department of Nutrition Sciences, School of Health Professions, University of Alabama at Birmingham, Birmingham, AL 35924, USA
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Yu Q, Falkenhain K, Little JP, Wong KK, Nie J, Shi Q, Kong Z. Effects of ketone supplements on blood β-hydroxybutyrate, glucose and insulin: A systematic review and three-level meta-analysis. Complement Ther Clin Pract 2023; 52:101774. [PMID: 37327753 DOI: 10.1016/j.ctcp.2023.101774] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Accepted: 06/08/2023] [Indexed: 06/18/2023]
Abstract
BACKGROUND Effects of ketone supplements as well as relevant dose-response relationships and time effects on blood β-hydroxybutyrate (BHB), glucose and insulin are controversial. OBJECTIVE This study aimed to summarize the existing evidence and synthesize the results, and demonstrate underlying dose-response relationships as well as sustained time effects. METHODS Medline, Web of Science, Embase, and Cochrane Central Register of Controlled Trials were searched for relevant randomized crossover/parallel studies published until 25th November 2022. Three-level meta-analysis compared the acute effects of exogenous ketone supplementation and placebo in regulating blood parameters, with Hedge's g used as measure of effect size. Effects of potential moderators were explored through multilevel regression models. Dose-response and time-effect models were established via fractional polynomial regression. RESULTS The meta-analysis with 327 data points from 30 studies (408 participants) indicated that exogenous ketones led to a significant increase in blood BHB (Hedge's g = 1.4994, 95% CI [1.2648, 1.7340]), reduction in glucose (Hedge's g = -0.3796, 95% CI [-0.4550, -0.3041]), and elevation in insulin of non-athlete healthy population (Hedge's g = 0.1214, 95%CI [0.0582, 0.3011]), as well as insignificant change in insulin of obesity and prediabetes. Nonlinear dose-response relationship between ketone dosage and blood parameter change was observed in some time intervals for BHB (30-60 min; >120 min) and insulin (30-60 min; 90-120 min), with linear relationship observed for glucose (>120 min). Nonlinear associations between time and blood parameter change were found in BHB (>550 mg/kg) and glucose (450-550 mg/kg), with linear relationship observed in BHB (≤250 mg/kg) and insulin (350-550 mg/kg). CONCLUSION Dose-response relationships and sustained time effects were observed in BHB, glucose and insulin following ketone supplementation. Glucose-lowering effect without increasing insulin load among population of obesity and prediabetes was of remarkable clinical implication. REGISTRY AND REGISTRY NUMBER PROSPERO (CRD42022360620).
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Affiliation(s)
- Qian Yu
- Faculty of Education, University of Macau, Macao, China
| | - Kaja Falkenhain
- School of Health and Exercise Sciences, University of British Columbia Okanagan, Kelowna, British Columbia, Canada
| | - Jonathan P Little
- School of Health and Exercise Sciences, University of British Columbia Okanagan, Kelowna, British Columbia, Canada
| | - Ka Kit Wong
- Faculty of Education, University of Macau, Macao, China
| | - Jinlei Nie
- Faculty of Health Sciences and Sports, Macao Polytechnic University, Macao, China
| | - Qingde Shi
- Faculty of Health Sciences and Sports, Macao Polytechnic University, Macao, China
| | - Zhaowei Kong
- Faculty of Education, University of Macau, Macao, China.
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Høgild ML, Hjelholt AJ, Hansen J, Pedersen SB, Møller N, Wojtaszewski JFP, Johannsen M, Jessen N, Jørgensen JOL. Ketone Body Infusion Abrogates Growth Hormone-Induced Lipolysis and Insulin Resistance. J Clin Endocrinol Metab 2023; 108:653-664. [PMID: 36240323 DOI: 10.1210/clinem/dgac595] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Revised: 10/10/2022] [Indexed: 11/19/2022]
Abstract
CONTEXT Exogenous ketone body administration lowers circulating glucose levels but the underlying mechanisms are uncertain. OBJECTIVE We tested the hypothesis that administration of the ketone body β-hydroxybutyrate (βOHB) acutely increases insulin sensitivity via feedback suppression of circulating free fatty acid (FFA) levels. METHODS In a randomized, single-blinded crossover design, 8 healthy men were studied twice with a growth hormone (GH) infusion to induce lipolysis in combination with infusion of either βOHB or saline. Each study day comprised a basal period and a hyperinsulinemic-euglycemic clamp combined with a glucose tracer and adipose tissue and skeletal muscle biopsies. RESULTS βOHB administration profoundly suppressed FFA levels concomitantly with a significant increase in glucose disposal and energy expenditure. This was accompanied by a many-fold increase in skeletal muscle content of both βOHB and its derivative acetoacetate. CONCLUSION Our data unravel an insulin-sensitizing effect of βOHB, which we suggest is mediated by concomitant suppression of lipolysis.
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Affiliation(s)
- Morten Lyng Høgild
- Medical Research Laboratory, Department of Clinical Medicine, Endocrinology and Internal Medicine, Aarhus University Hospital, Aarhus N, Region Midtjylland 8200, Denmark
| | - Astrid Johannesson Hjelholt
- Medical Research Laboratory, Department of Clinical Medicine, Endocrinology and Internal Medicine, Aarhus University Hospital, Aarhus N, Region Midtjylland 8200, Denmark
- Department of Clinical Pharmacology, Aarhus University Hospital, Aarhus N, Region Midtjylland 8200, Denmark
| | - Jakob Hansen
- Department of Forensic Medicine, Aarhus University, Aarhus N 8200, Denmark
| | - Steen Bønløkke Pedersen
- Steno Diabetes Centre Aarhus, Aarhus University Hospital, Aarhus N, Region Midtjylland 8200, Denmark
| | - Niels Møller
- Medical Research Laboratory, Department of Clinical Medicine, Endocrinology and Internal Medicine, Aarhus University Hospital, Aarhus N, Region Midtjylland 8200, Denmark
- Department of Forensic Medicine, Aarhus University, Aarhus N 8200, Denmark
| | - Jørgen F P Wojtaszewski
- August Krogh Section for Molecular Physiology, University of Copenhagen, Copenhagen 2100, Denmark
| | - Mogens Johannsen
- Department of Forensic Medicine, Aarhus University, Aarhus N 8200, Denmark
| | - Niels Jessen
- Department of Clinical Pharmacology, Aarhus University Hospital, Aarhus N, Region Midtjylland 8200, Denmark
- Steno Diabetes Centre Aarhus, Aarhus University Hospital, Aarhus N, Region Midtjylland 8200, Denmark
- Department of Biomedicine, Aarhus University, Aarhus 8000, Denmark
| | - Jens Otto Lunde Jørgensen
- Medical Research Laboratory, Department of Clinical Medicine, Endocrinology and Internal Medicine, Aarhus University Hospital, Aarhus N, Region Midtjylland 8200, Denmark
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Falkenhain K, Islam H, Little JP. Exogenous ketone supplementation: an emerging tool for physiologists with potential as a metabolic therapy. Exp Physiol 2023; 108:177-187. [PMID: 36533967 PMCID: PMC10103874 DOI: 10.1113/ep090430] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Accepted: 11/28/2022] [Indexed: 12/23/2022]
Abstract
NEW FINDINGS What is the topic of this review? The integrative physiological response to exogenous ketone supplementation. What advances does it highlight? The physiological effects and therapeutic potential of exogenous ketones on metabolic health, cardiovascular function, cognitive processing, and modulation of inflammatory pathways and immune function. Also highlighted are current challenges and future directions of the field. ABSTRACT Exogenous oral ketone supplements, primarily in form of ketone salts or esters, have emerged as a useful research tool for manipulating metabolism with potential therapeutic application targeting various aspects of several common chronic diseases. Recent literature has investigated the effects of exogenously induced ketosis on metabolic health, cardiovascular function, cognitive processing, and modulation of inflammatory pathways and immune function. This narrative review provides an overview of the integrative physiological effects of exogenous ketone supplementation and highlights current challenges and future research directions. Much of the existing research on therapeutic applications - particularly mechanistic studies - has involved pre-clinical rodent and/or cellular models, requiring further validation in human clinical studies. Existing human studies report that exogenous ketones can lower blood glucose and improve some aspects of cognitive function, highlighting the potential therapeutic application of exogenous ketones for type 2 diabetes and neurological diseases. There is also support for the ability of exogenous ketosis to improve cardiac metabolism in rodent models of heart failure with supporting human studies emerging; long-terms effects of exogenous ketone supplementation on the human cardiovascular system and lipid profiles are needed. An important avenue for future work is provided by research accelerating technologies that enable continuous ketone monitoring and/or the development of more palatable ketone mixtures that optimize plasma ketone kinetics to enable sustained ketosis. Lastly, research exploring the physiological interactions between exogenous ketones and varying metabolic states (e.g., exercise, fasting, metabolic disease) should yield important insights that can be used to maximize the health benefits of exogenous ketosis.
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Affiliation(s)
- Kaja Falkenhain
- School of Health and Exercise SciencesUniversity of British Columbia OkanaganKelownaBritish ColumbiaCanada
| | - Hashim Islam
- School of Health and Exercise SciencesUniversity of British Columbia OkanaganKelownaBritish ColumbiaCanada
| | - Jonathan P. Little
- School of Health and Exercise SciencesUniversity of British Columbia OkanaganKelownaBritish ColumbiaCanada
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Falkenhain K, Daraei A, Forbes SC, Little JP. Effects of Exogenous Ketone Supplementation on Blood Glucose: A Systematic Review and Meta-analysis. Adv Nutr 2022; 13:1697-1714. [PMID: 35380602 PMCID: PMC9526861 DOI: 10.1093/advances/nmac036] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2022] [Revised: 03/04/2022] [Accepted: 04/01/2022] [Indexed: 01/28/2023] Open
Abstract
Recently developed ketone (monoester or salt) supplements acutely elevate blood β-hydroxybutyrate (BHB) exogenously without prolonged periods of fasting or carbohydrate restriction. Previous (small-scale) studies have found a blood glucose-lowering effect of exogenous ketones. This study aimed to systematically review available evidence and conduct meta-analyses of studies reporting on exogenous ketones and blood glucose. We searched 6 electronic databases on 13 December 2021 for randomized and nonrandomized trials of any length that reported on the use of exogenous ketones. We calculated raw mean differences (MDs) in blood BHB and glucose in 2 main analyses: 1) after compared with before acute ingestion of exogenous ketones and 2) following acute ingestion of exogenous ketones compared with a comparator supplement. We pooled effect sizes using random-effects models and performed prespecified subgroup analyses to examine the effect of potential explanatory factors, including study population, exercise, blood BHB, and supplement type, dosing, and timing. Risk of bias was examined using Cochrane's risk-of-bias tools. Studies that could not be meta-analyzed were summarized narratively. Forty-three trials including 586 participants are summarized in this review. Following ingestion, exogenous ketones increased blood BHB (MD = 1.73 mM; 95% CI: 1.26, 2.21 mM; P < 0.001) and decreased mean blood glucose (MD = -0.54 mM; 95% CI: -0.68, -0.40 mM; P < 0.001). Similarly, when compared with placebo, blood BHB increased (MD = 1.98 mM; 95% CI: 1.52, 2.45 mM; P < 0.001) and blood glucose decreased (MD = -0.47 mM; 95% CI: -0.57, -0.36 mM; P < 0.001). Across both analyses, significantly greater effects were seen with ketone monoesters compared with salts (P < 0.001). The available evidence indicates that acute ingestion of exogenous ketones leads to increased blood BHB and decreased blood glucose. Limited evidence on prolonged ketone supplementation was found.
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Affiliation(s)
| | - Ali Daraei
- School of Health and Exercise Sciences, University of British Columbia Okanagan, Kelowna, British Columbia, Canada
| | - Scott C Forbes
- Department of Physical Education Studies, Faculty of Education, Brandon University, Brandon, Manitoba, Canada
| | - Jonathan P Little
- School of Health and Exercise Sciences, University of British Columbia Okanagan, Kelowna, British Columbia, Canada
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