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Kumar M, Bhatt B, Gusain C, Mahajan N, Bishnoi M. Sex-specific effects of ketogenic diet on anxiety-like behavior and neuroimmune response in C57Bl/6J mice. J Nutr Biochem 2024; 127:109591. [PMID: 38311044 DOI: 10.1016/j.jnutbio.2024.109591] [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: 11/15/2023] [Revised: 01/27/2024] [Accepted: 01/29/2024] [Indexed: 02/06/2024]
Abstract
The ketogenic diet (KD) has been shown to reduce anxiety and enhance cognitive functions in neurological diseases. However, the sex-specific effects of KD on anxiety-like behavior in healthy individuals and the underlying molecular mechanisms contributing to these effects, including neuroinflammation, are unelucidated. This study investigated the sex-specific effects of KD on anxiety-like behavior and the neuroimmune response in the prefrontal cortex (PFC) and hippocampus of healthy C57BL/6J male and female mice. Animals were fed either a control diet (CD- 17% fat, 65% carb, 18% protein) or a KD (80% fat, 5% carb, 15% protein) for 4 weeks. KD increased the levels of circulating β-hydroxybutyrate (BHB) both in males and females. However, PFC BHB levels were found to be elevated only in KD males. Moreover, KD did not affect the behavior of females but improved motor abilities and reduced anxiety levels in males. KD suppressed the mRNA expression of the pan microglial markers (Cd68, P2ry12) and induced morphological changes in the male PFC microglia. A sex-specific decrease in IL1β and an increase in IL-10 levels was found in the PFC of KD males. A similar trend was observed in the hippocampus of males where KD reduced the mRNA expression of P2ry12, Il1β, and cFos. Additionally, BHB increased the production of IL-10 whereas it decreased the production of IL1β from human microglia in in-vitro conditions. In summary, these results demonstrate that the anxiolytic and motor function enhancement abilities of KD are male-specific. Reduced pro-inflammatory and improved anti-inflammatory factors in the male PFC and hippocampus may underlie these effects.
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Affiliation(s)
- Mohit Kumar
- Centre for Excellence in Functional Foods, Food & Nutrition Biotechnology Division, National Agri-Food Biotechnology Institute, S.A.S Nagar, Sector 81 (Knowledge City), Punjab, India; Adjunct faculty, Regional Centre for Biotechnology, Faridabad, Haryana, India.
| | - Babita Bhatt
- Centre for Excellence in Functional Foods, Food & Nutrition Biotechnology Division, National Agri-Food Biotechnology Institute, S.A.S Nagar, Sector 81 (Knowledge City), Punjab, India
| | - Chitralekha Gusain
- Centre for Excellence in Functional Foods, Food & Nutrition Biotechnology Division, National Agri-Food Biotechnology Institute, S.A.S Nagar, Sector 81 (Knowledge City), Punjab, India
| | - Nayan Mahajan
- Centre for Excellence in Functional Foods, Food & Nutrition Biotechnology Division, National Agri-Food Biotechnology Institute, S.A.S Nagar, Sector 81 (Knowledge City), Punjab, India
| | - Mahendra Bishnoi
- Centre for Excellence in Functional Foods, Food & Nutrition Biotechnology Division, National Agri-Food Biotechnology Institute, S.A.S Nagar, Sector 81 (Knowledge City), Punjab, India
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Ramezani M, Fernando M, Eslick S, Asih PR, Shadfar S, Bandara EMS, Hillebrandt H, Meghwar S, Shahriari M, Chatterjee P, Thota R, Dias CB, Garg ML, Martins RN. Ketone bodies mediate alterations in brain energy metabolism and biomarkers of Alzheimer's disease. Front Neurosci 2023; 17:1297984. [PMID: 38033541 PMCID: PMC10687427 DOI: 10.3389/fnins.2023.1297984] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2023] [Accepted: 10/30/2023] [Indexed: 12/02/2023] Open
Abstract
Alzheimer's disease (AD) is the most common form of dementia. AD is a progressive neurodegenerative disorder characterized by cognitive dysfunction, including learning and memory deficits, and behavioral changes. Neuropathology hallmarks of AD such as amyloid beta (Aβ) plaques and neurofibrillary tangles containing the neuron-specific protein tau is associated with changes in fluid biomarkers including Aβ, phosphorylated tau (p-tau)-181, p-tau 231, p-tau 217, glial fibrillary acidic protein (GFAP), and neurofilament light (NFL). Another pathological feature of AD is neural damage and hyperactivation of astrocytes, that can cause increased pro-inflammatory mediators and oxidative stress. In addition, reduced brain glucose metabolism and mitochondrial dysfunction appears up to 15 years before the onset of clinical AD symptoms. As glucose utilization is compromised in the brain of patients with AD, ketone bodies (KBs) may serve as an alternative source of energy. KBs are generated from the β-oxidation of fatty acids, which are enhanced following consumption of ketogenic diets with high fat, moderate protein, and low carbohydrate. KBs have been shown to cross the blood brain barrier to improve brain energy metabolism. This review comprehensively summarizes the current literature on how increasing KBs support brain energy metabolism. In addition, for the first time, this review discusses the effects of ketogenic diet on the putative AD biomarkers such as Aβ, tau (mainly p-tau 181), GFAP, and NFL, and discusses the role of KBs on neuroinflammation, oxidative stress, and mitochondrial metabolism.
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Affiliation(s)
- Matin Ramezani
- Macquarie Medical School, Faculty of Medicine, Health and Human Sciences, Macquarie University, Macquarie, NSW, Australia
| | - Malika Fernando
- Macquarie Medical School, Faculty of Medicine, Health and Human Sciences, Macquarie University, Macquarie, NSW, Australia
| | - Shaun Eslick
- Macquarie Medical School, Faculty of Medicine, Health and Human Sciences, Macquarie University, Macquarie, NSW, Australia
| | - Prita R. Asih
- Macquarie Medical School, Faculty of Medicine, Health and Human Sciences, Macquarie University, Macquarie, NSW, Australia
- Flinders Health and Medical Research Institute, College of Medicine and Public Health, Flinders University, Adelaide, SA, Australia
| | - Sina Shadfar
- Motor Neuron Disease Research Centre, Macquarie Medical School, Faculty of Medicine, Health and Human Sciences, Macquarie University, Sydney, NSW, Australia
| | | | - Heidi Hillebrandt
- Macquarie Medical School, Faculty of Medicine, Health and Human Sciences, Macquarie University, Macquarie, NSW, Australia
| | - Silochna Meghwar
- Macquarie Medical School, Faculty of Medicine, Health and Human Sciences, Macquarie University, Macquarie, NSW, Australia
| | - Maryam Shahriari
- Macquarie Medical School, Faculty of Medicine, Health and Human Sciences, Macquarie University, Macquarie, NSW, Australia
| | - Pratishtha Chatterjee
- Macquarie Medical School, Faculty of Medicine, Health and Human Sciences, Macquarie University, Macquarie, NSW, Australia
| | - Rohith Thota
- Macquarie Medical School, Faculty of Medicine, Health and Human Sciences, Macquarie University, Macquarie, NSW, Australia
| | - Cintia B. Dias
- Macquarie Medical School, Faculty of Medicine, Health and Human Sciences, Macquarie University, Macquarie, NSW, Australia
| | - Manohar L. Garg
- Macquarie Medical School, Faculty of Medicine, Health and Human Sciences, Macquarie University, Macquarie, NSW, Australia
| | - Ralph N. Martins
- Macquarie Medical School, Faculty of Medicine, Health and Human Sciences, Macquarie University, Macquarie, NSW, Australia
- School of Medical and Health Sciences, Edith Cowan University, Joondalup, WA, Australia
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Ashton JS, Roberts JW, Wakefield CJ, MacLaren DPM, Marwood S, Malone JJ. Medium chain triglycerides with a C8:C10 ratio of 30:70 enhances cognitive performance and mitigates the cognitive decline associated with prolonged exercise in young and healthy adults. Physiol Behav 2023; 269:114284. [PMID: 37394051 DOI: 10.1016/j.physbeh.2023.114284] [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: 10/19/2022] [Revised: 06/09/2023] [Accepted: 06/27/2023] [Indexed: 07/04/2023]
Abstract
INTRODUCTION Prolonged exercise has been linked to a decline in cognitive function due to a variety of factors, such as a drop in oxygen in the prefrontal cortex and an increase in stress hormones and neurotransmitters. Medium chain triglycerides (MCTs) may possibly offset this decline as they provide energy for the brain via both direct and indirect pathways, alongside promoting chronic physiological adaptations within the brain. METHODS Participants were divided into two groups; MCT (n = 9) and Placebo (n = 10). The MCT gels contained 6 g of MCT with a C8:C10 ratio of 30:70, whereas the placebo gels contained carbohydrates of similar calorific value to the MCT gels. Participants visited the laboratory on three occasions (familiarisation/fitness test, pre-supplementation, post-supplementation), during which they performed a battery of cognitive tasks assessing domains such as processing speed, working memory, selective attention, decision making and coordination, before and after a prolonged bout of exercise (60 mins at 90% gas exchange threshold (GET). A 2-week supplementation period between visits 2 and 3 involved the ingestion of 2 gels per day. RESULTS Exercise resulted in detriments in most cognitive tasks pre-supplementation for both groups, and post-supplementation for the Placebo group (main effect ps< 0.05). Post-supplementation, the effect of exercise was mediated in the MCT group for all cognitive tasks (main effect ps< 0.05), except for the Digit and Spatial Span Backwards test phases (main effect ps> 0.05). Furthermore, MCT supplementation enhanced before-exercise cognitive performance and in some measures, such as working memory, this was maintained after-exercise (interaction effect ps> 0.05). CONCLUSIONS Chronic MCT supplementation enhanced before-exercise cognitive performance and offset the cognitive decline caused by a prolonged bout of exercise. In some cases, improvements in before-exercise cognitive performance were maintained after-exercise.
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Affiliation(s)
- Jake S Ashton
- School of Health and Sport Sciences, Liverpool Hope University, Liverpool, UK.
| | - James W Roberts
- School of Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, UK
| | | | - Don P M MacLaren
- School of Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, UK
| | - Simon Marwood
- School of Health and Sport Sciences, Liverpool Hope University, Liverpool, UK
| | - James J Malone
- School of Health and Sport Sciences, Liverpool Hope University, Liverpool, UK
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González Ibáñez F, Halvorson T, Sharma K, McKee C, Carrier M, Picard K, Vernoux N, Bisht K, Deslauriers J, Lalowski M, Tremblay MÈ. Ketogenic diet alters microglial morphology and changes the hippocampal lipidomic profile distinctively in stress susceptible versus resistant male mice upon repeated social defeat. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.28.555135. [PMID: 37693370 PMCID: PMC10491121 DOI: 10.1101/2023.08.28.555135] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/12/2023]
Abstract
Psychological stress confers an increased risk for several diseases including psychiatric conditions. The susceptibility to psychological stress is modulated by various factors, many of them being modifiable lifestyle choices. The ketogenic diet (KD) has emerged as a dietary regime that offers positive outcomes on mood and health status. Psychological stress and elevated inflammation are common features of neuropsychiatric disorders such as certain types of major depressive disorder. KD has been attributed anti-inflammatory properties that could underlie its beneficial consequences on the brain and behavior. Microglia are the main drivers of inflammation in the central nervous system. They are known to respond to both dietary changes and psychological stress, notably by modifying their production of cytokines and relationships among the brain parenchyma. To assess the interactions between KD and the stress response, including effects on microglia, we examined adult male mice on control diet (CD) versus KD that underwent 10 days of repeated social defeat (RSD) or remained non-stressed (controls; CTRLs). Through a social interaction test, stressed mice were classified as susceptible (SUS) or resistant (RES) to RSD. The mouse population fed a KD tended to have a higher proportion of individuals classified as RES following RSD. Microglial morphology and ultrastructure were then analyzed in the ventral hippocampus CA1, a brain region known to present structural alterations as a response to psychological stress. Distinct changes in microglial soma and arborization linked to the KD, SUS and RES phenotypes were revealed. Ultrastructural analysis by electron microscopy showed a clear reduction of cellular stress markers in microglia from KD fed animals. Furthermore, ultrastructural analysis showed that microglial contacts with synaptic elements were reduced in the SUS compared to the RES and CTRL groups. Hippocampal lipidomic analyses lastly identified a distinct lipid profile in SUS animals compared to CTRLs. These key differences, combined with the distinct microglial responses to diet and stress, indicate that unique metabolic changes may underlie the stress susceptibility phenotypes. Altogether, our results reveal novel mechanisms by which a KD might improve the resistance to psychological stress.
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Affiliation(s)
- Fernando González Ibáñez
- Axe neurosciences, Centre de recherche du CHU de Québec-Université Laval, Québec, QC, Canada
- Département de médecine moléculaire, Université Laval, Québec City, QC, Canada
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada
| | - Torin Halvorson
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada
- Department of Medicine, University of British Columbia, Vancouver, BC, Canada
| | - Kaushik Sharma
- Axe neurosciences, Centre de recherche du CHU de Québec-Université Laval, Québec, QC, Canada
- Département de médecine moléculaire, Université Laval, Québec City, QC, Canada
- Department of Chemistry, Purdue University, West Lafayette, IN, United States of America
| | - Chloe McKee
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada
| | - Micaël Carrier
- Axe neurosciences, Centre de recherche du CHU de Québec-Université Laval, Québec, QC, Canada
- Département de médecine moléculaire, Université Laval, Québec City, QC, Canada
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada
| | - Katherine Picard
- Axe neurosciences, Centre de recherche du CHU de Québec-Université Laval, Québec, QC, Canada
- Département de médecine moléculaire, Université Laval, Québec City, QC, Canada
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada
| | - Nathalie Vernoux
- Axe neurosciences, Centre de recherche du CHU de Québec-Université Laval, Québec, QC, Canada
| | - Kanchan Bisht
- Axe neurosciences, Centre de recherche du CHU de Québec-Université Laval, Québec, QC, Canada
- Département de médecine moléculaire, Université Laval, Québec City, QC, Canada
- Department of Chemistry, Purdue University, West Lafayette, IN, United States of America
| | | | - Maciej Lalowski
- Department of Gene Expression, Institute of Molecular Biology and Biotechnology, Faculty of Biology, Adam Mickiewicz University, Poznań, Poland
- Biochemistry/Developmental Biology, Meilahti Clinical Proteomics Core Facility, University of Helsinki, Finland
| | - Marie-Ève Tremblay
- Axe neurosciences, Centre de recherche du CHU de Québec-Université Laval, Québec, QC, Canada
- Département de médecine moléculaire, Université Laval, Québec City, QC, Canada
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada
- Neurology and Neurosurgery Department, McGill University, Montréal, QC, Canada
- Department of Biochemistry and Molecular Biology, The University of British Columbia, Vancouver, BC, Canada
- Centre for Advanced Materials and Related Technology (CAMTEC), University of Victoria, BC, Canada
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Xu Y, Zheng F, Zhong Q, Zhu Y. Ketogenic Diet as a Promising Non-Drug Intervention for Alzheimer’s Disease: Mechanisms and Clinical Implications. J Alzheimers Dis 2023; 92:1173-1198. [PMID: 37038820 DOI: 10.3233/jad-230002] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/07/2023]
Abstract
Alzheimer’s disease (AD) is a progressive neurodegenerative disorder that is mainly characterized by cognitive deficits. Although many studies have been devoted to developing disease-modifying therapies, there has been no effective therapy until now. However, dietary interventions may be a potential strategy to treat AD. The ketogenic diet (KD) is a high-fat and low-carbohydrate diet with adequate protein. KD increases the levels of ketone bodies, providing an alternative energy source when there is not sufficient energy supply because of impaired glucose metabolism. Accumulating preclinical and clinical studies have shown that a KD is beneficial to AD. The potential underlying mechanisms include improved mitochondrial function, optimization of gut microbiota composition, and reduced neuroinflammation and oxidative stress. The review provides an update on clinical and preclinical research on the effects of KD or medium-chain triglyceride supplementation on symptoms and pathophysiology in AD. We also detail the potential mechanisms of KD, involving amyloid and tau proteins, neuroinflammation, gut microbiota, oxidative stress, and brain metabolism. We aimed to determine the function of the KD in AD and outline important aspects of the mechanism, providing a reference for the implementation of the KD as a potential therapeutic strategy for AD.
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Affiliation(s)
- Yunlong Xu
- Shenzhen Key Laboratory of Drug Addiction, Shenzhen Neher Neural Plasticity Laboratory, the Brain Cognition and Brain Disease Institute (BCBDI), Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences (CAS), Shenzhen-Hong Kong Institute of Brain Science-Shenzhen Fundamental Research Institutions, Shenzhen, China
- University of Chinese Academy of Sciences, Beijing, China
- Department of Neonatology, Shenzhen Maternity & Child Healthcare Hospital, The First School of Clinical Medicine, Southern Medical University, Shenzhen, China
| | - Fuxiang Zheng
- Department of Clinical Laboratory, Shenzhen Traditional Chinese Medicine Hospital, Shenzhen, Guangdong, China
| | - Qi Zhong
- Department of Neurology, Shenzhen Luohu People’s Hospital; The Third Affiliated Hospital of Shenzhen University, Shenzhen, China
| | - Yingjie Zhu
- Shenzhen Key Laboratory of Drug Addiction, Shenzhen Neher Neural Plasticity Laboratory, the Brain Cognition and Brain Disease Institute (BCBDI), Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences (CAS), Shenzhen-Hong Kong Institute of Brain Science-Shenzhen Fundamental Research Institutions, Shenzhen, China
- University of Chinese Academy of Sciences, Beijing, China
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Heidt C, Fobker M, Newport M, Feldmann R, Fischer T, Marquardt T. Beta-Hydroxybutyrate (BHB), Glucose, Insulin, Octanoate (C8), and Decanoate (C10) Responses to a Medium-Chain Triglyceride (MCT) Oil with and without Glucose: A Single-Center Study in Healthy Adults. Nutrients 2023; 15:nu15051148. [PMID: 36904147 PMCID: PMC10005646 DOI: 10.3390/nu15051148] [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: 02/04/2023] [Revised: 02/16/2023] [Accepted: 02/22/2023] [Indexed: 03/02/2023] Open
Abstract
MCTs are increasingly being used to promote ketogenesis by patients on ketogenic diet therapy, but also by people with other conditions and by the general public for the perceived potential benefits. However, consumption of carbohydrates with MCTs and untoward gastrointestinal side effects, especially at higher doses, could decrease the sustainability of the ketogenic response. This single-center study investigated the impact of consuming carbohydrate as glucose with MCT oil compared to MCT alone on the BHB response. The effects of MCT oil versus MCT oil plus glucose on blood glucose, insulin response, levels of C8, C10, BHB, and cognitive function were determined, and side effects were monitored. A significant plasma BHB increase with a peak at 60 min was observed in 19 healthy participants (24.4 ± 3.9 years) after consuming MCT oil alone, and a more delayed but slightly higher peak was observed after consuming MCT oil plus glucose. A significant increase in blood glucose and insulin levels occurred only after MCT oil plus glucose intake. The overall mean plasma levels of C8 and C10 were higher with the intake of MCT oil alone. MCT oil plus glucose consumption showed improved scores for the arithmetic and vocabulary subtests.
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Affiliation(s)
- Christina Heidt
- Department of Pediatrics, University Hospital Muenster, 48149 Muenster, Germany
- Correspondence: (C.H.); (T.M.)
| | - Manfred Fobker
- Centre of Laboratory Medicine, University Hospital Muenster, 48149 Muenster, Germany
| | - Mary Newport
- Spring Hill Neonatology, Inc., Spring Hill, FL 34610, USA
| | - Reinhold Feldmann
- Department of Pediatrics, University Hospital Muenster, 48149 Muenster, Germany
| | - Tobias Fischer
- Department of Food, Nutrition and Facilities, FH Muenster, University of Applied Sciences, 48149 Muenster, Germany
| | - Thorsten Marquardt
- Department of Pediatrics, University Hospital Muenster, 48149 Muenster, Germany
- Correspondence: (C.H.); (T.M.)
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Shcherbakova K, Schwarz A, Ivleva I, Nikitina V, Krytskaya D, Apryatin S, Karpenko M, Trofimov A. Short- and long-term cognitive and metabolic effects of medium-chain triglyceride supplementation in rats. Heliyon 2023; 9:e13446. [PMID: 36825166 PMCID: PMC9941952 DOI: 10.1016/j.heliyon.2023.e13446] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Revised: 12/19/2022] [Accepted: 01/30/2023] [Indexed: 02/08/2023] Open
Abstract
Medium-chain triglycerides (MCT) possess neuroprotective properties. However, the long-term metabolic consequences of supplementing a regular diet with cognition-enhancing doses of MCT are largely unknown. We studied the effects of chronic (28 days) supplementation of regular diet with different doses of MCT oil (1, 3, or 6 g/kg/day) or water (control) on working memory (Y-maze), behavior in the Open Field, spatial learning (Morris water maze), and weight of internal organs in male Wistar 2.5-m.o. Rats. In a separate experiment, we evaluated acute (single gavage) and chronic (28 days) effects of MCT or lard supplementation (3 g/kg) on blood biochemical parameters. MCT-1 and MCT-3 doses improved working memory in YM. In MWM, MCT-6 treatment improved spatial memory. Chronic MCT-1 or MCT-3 treatment did not affect internal organ weight, while MCT-6 dose increased liver weight and the brown/white adipose tissue ratio. Acutely, MCT administration elevated blood β-hydroxybutyrate and malondialdehyde levels. Chronic MCT administration (3 g/kg) did not affect the blood levels of glucose, lactate, pyruvate, acetoacetate, β-hydroxybutyrate, total and HDL cholesterol, triglycerides, malondialdehyde, and aspartate transaminase and alanine transaminase activities. Therefore, daily supplementation of standard feed with MCT resulted in mild intermittent ketosis. It improved working memory at lower concentrations without significant adverse side effects. At higher concentrations, it improved long-term spatial memory but also resulted in organ weight changes and is likely unsafe. These results highlight the importance of monitoring the metabolic effects of MCT supplementation alongside cognitive assessment in future studies of MCT's neuroprotective properties.
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Affiliation(s)
- Ksenia Shcherbakova
- Laboratory of Neurobiology of the Brain Integrative Functions, I.P. Pavlov Department of Physiology, Institute of Experimental Medicine, 12 Akad. Pavlova St., 197022, St. Petersburg, Russia
- Corresponding author.
| | - Alexander Schwarz
- Laboratory of Molecular Mechanisms of Neuronal Interactions, I. M. Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, 44 Thorez Avenue, 194223, St. Petersburg, Russia
| | - Irina Ivleva
- Laboratory of Neurochemistry, I.P. Pavlov Department of Physiology, Institute of Experimental Medicine, 12 Akad. Pavlova St., 197022, St. Petersburg, Russia
| | - Veronika Nikitina
- Laboratory of Neurobiology of the Brain Integrative Functions, I.P. Pavlov Department of Physiology, Institute of Experimental Medicine, 12 Akad. Pavlova St., 197022, St. Petersburg, Russia
| | - Darya Krytskaya
- Laboratory of Neurobiology of the Brain Integrative Functions, I.P. Pavlov Department of Physiology, Institute of Experimental Medicine, 12 Akad. Pavlova St., 197022, St. Petersburg, Russia
| | - Sergey Apryatin
- Laboratory of Neurobiology of the Brain Integrative Functions, I.P. Pavlov Department of Physiology, Institute of Experimental Medicine, 12 Akad. Pavlova St., 197022, St. Petersburg, Russia
| | - Marina Karpenko
- Laboratory of Neurochemistry, I.P. Pavlov Department of Physiology, Institute of Experimental Medicine, 12 Akad. Pavlova St., 197022, St. Petersburg, Russia
| | - Alexander Trofimov
- Laboratory of Neurobiology of the Brain Integrative Functions, I.P. Pavlov Department of Physiology, Institute of Experimental Medicine, 12 Akad. Pavlova St., 197022, St. Petersburg, Russia
- Corresponding author.
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Giannos P, Prokopidis K, Lidoriki I, Triantafyllidis KK, Kechagias KS, Celoch K, Candow DG, Ostojic SM, Forbes SC. Medium-chain triglycerides may improve memory in non-demented older adults: a systematic review of randomized controlled trials. BMC Geriatr 2022; 22:817. [PMID: 36273115 PMCID: PMC9588230 DOI: 10.1186/s12877-022-03521-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2022] [Accepted: 10/10/2022] [Indexed: 11/24/2022] Open
Abstract
BACKGROUND Ketosis has been exploited for its neuroprotective impact and treatment of neurological conditions via ketone production. Exogenous medium-chain triglyceride (MCT) supplementation may induce nutritional ketosis. The aim of this systematic review is to explore the effects of MCTs on memory function in older adults without cognitive impairment. METHODS A systematic literature search of PubMed, Cochrane Library, Scopus, and Web of Science was employed from inception until April 2022 for randomized controlled trials (RCTs) in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, investigating the impact of MCT oils on components of memory. Risk of bias (RoB2) tool was utilized for quality assessment. RESULTS Six trials were included for qualitative synthesis, in which two studies examined the effect of MCTs through a ketogenic meal. MCT supplementation compared to controls was associated with improved indices of memory function in 4 out of 6 studies, particularly working memory. A meta-analysis was not employed due to the low number of studies, therefore, a true effect measure of MCT supplementation was not explored. CONCLUSIONS MCT supplementation may enhance working memory in non-demented older adults. These effects may be more prominent in individuals with lower baseline scores, from short and long-term supplementation. Further studies are warranted to confirm these findings in terms of optimal dose and MCTs composition, which may protect from memory decline during aging.
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Affiliation(s)
- Panagiotis Giannos
- Society of Meta-Research and Biomedical Innovation, London, UK.
- Department of Life Sciences, Faculty of Natural Sciences, Imperial College London, London, UK.
| | - Konstantinos Prokopidis
- Society of Meta-Research and Biomedical Innovation, London, UK
- Department of Musculoskeletal Biology, Institute of Life Course and Medical Sciences, University of Liverpool, Liverpool, UK
| | - Irene Lidoriki
- First Department of Surgery, National and Kapodistrian University of Athens, Laikon General Hospital, Athens, Greece
| | - Konstantinos K Triantafyllidis
- Society of Meta-Research and Biomedical Innovation, London, UK
- Department of Nutrition and Dietetics, Musgrove Park Hospital, Taunton and Somerset NHS Foundation Trust, Taunton, UK
| | - Konstantinos S Kechagias
- Society of Meta-Research and Biomedical Innovation, London, UK
- Department of Metabolism, Digestion and Reproduction, Faculty of Medicine, Imperial College London, London, UK
- Department of Obstetrics and Gynaecology, Chelsea and Westminster Hospital NHS Foundation Trust, London, UK
| | - Kamil Celoch
- Department of Psychology and Neuroscience, Nova Southeastern University, Davie, USA
| | - Darren G Candow
- Faculty of Kinesiology and Health Studies, University of Regina, Regina, Saskatchewan, Canada
| | - Sergej M Ostojic
- Department of Nutrition and Public Health, University of Agder, Kristiansand, Norway
| | - Scott C Forbes
- Department of Physical Education Studies, Faculty of Education, Brandon University, Brandon, Manitoba, Canada
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Shcherbakova K, Schwarz A, Apryatin S, Karpenko M, Trofimov A. Supplementation of Regular Diet With Medium-Chain Triglycerides for Procognitive Effects: A Narrative Review. Front Nutr 2022; 9:934497. [PMID: 35911092 PMCID: PMC9334743 DOI: 10.3389/fnut.2022.934497] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2022] [Accepted: 06/15/2022] [Indexed: 01/09/2023] Open
Abstract
It is now widely accepted that ketosis (a physiological state characterized by elevated plasma ketone body levels) possesses a wide range of neuroprotective effects. There is a growing interest in the use of ketogenic supplements, including medium-chain triglycerides (MCT), to achieve intermittent ketosis without adhering to a strict ketogenic diet. MCT supplementation is an inexpensive and simple ketogenic intervention, proven to benefit both individuals with normal cognition and those suffering from mild cognitive impairment, Alzheimer's disease, and other cognitive disorders. The commonly accepted paradigm underlying MCT supplementation trials is that the benefits stem from ketogenesis and that MCT supplementation is safe. However, medium-chain fatty acids (MCFAs) may also exert effects in the brain directly. Moreover, MCFAs, long-chain fatty acids, and glucose participate in mutually intertwined metabolic pathways. Therefore, the metabolic effects must be considered if the desired procognitive effects require administering MCT in doses larger than 1 g/kg. This review summarizes currently available research on the procognitive effects of using MCTs as a supplement to regular feed/diet without concomitant reduction of carbohydrate intake and focuses on the revealed mechanisms linked to particular MCT metabolites (ketone bodies, MCFAs), highlighting open questions and potential considerations.
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Affiliation(s)
- Ksenia Shcherbakova
- I.P. Pavlov Department of Physiology, Institute of Experimental Medicine, Saint Petersburg, Russia,*Correspondence: Ksenia Shcherbakova
| | - Alexander Schwarz
- Laboratory of the Molecular Mechanisms of Neuronal Interactions, Institute of Evolutionary Physiology and Biochemistry (RAS), Saint Petersburg, Russia
| | - Sergey Apryatin
- I.P. Pavlov Department of Physiology, Institute of Experimental Medicine, Saint Petersburg, Russia
| | - Marina Karpenko
- I.P. Pavlov Department of Physiology, Institute of Experimental Medicine, Saint Petersburg, Russia
| | - Alexander Trofimov
- I.P. Pavlov Department of Physiology, Institute of Experimental Medicine, Saint Petersburg, Russia
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Triglycerides of medium-chain fatty acids: a concise review. JOURNAL OF FOOD SCIENCE AND TECHNOLOGY 2022:1-10. [PMID: 35761969 PMCID: PMC9217113 DOI: 10.1007/s13197-022-05499-w] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Revised: 04/19/2022] [Accepted: 05/21/2022] [Indexed: 10/25/2022]
Abstract
Medium-chain triglycerides contain medium-chain fatty acid esterified to the glycerol backbone. These MCFA have a shorter chain length and are quickly metabolized in the body serving as an immediate energy source. They are known to have good physiological as well as functional characteristics which help in treating various health disorders. Naturally, they are found in coconut oil, milk fat, and palm kernel oil, and they are synthetically produced by esterification and interesterification reactions. Due to their numerous health benefits, MCT is used as a functional or nutraceutical oil in various food and pharmaceutical formulations. To increase their nutraceutical benefits and food applications MCFA can be used along with polyunsaturated fatty acids in the synthesis of structured lipids. This review aims to provide information about triglycerides of MCFA, structure, metabolism, properties, synthetic routes, intensified synthesis approaches, health benefits, application, and safety of use of MCT in the diet.
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Watanabe S, Tsujino S. Applications of Medium-Chain Triglycerides in Foods. Front Nutr 2022; 9:802805. [PMID: 35719157 PMCID: PMC9203050 DOI: 10.3389/fnut.2022.802805] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Accepted: 05/06/2022] [Indexed: 11/17/2022] Open
Abstract
In the 1950s, the production of processed fats and oils from coconut oil was popular in the United States. It became necessary to find uses for the medium-chain fatty acids (MCFAs) that were byproducts of the process, and a production method for medium-chain triglycerides (MCTs) was established. At the time of this development, its use as a non-fattening fat was being studied. In the early days MCFAs included fatty acids ranging from hexanoic acid (C6:0) to dodecanoic acid (C12:0), but today their compositions vary among manufacturers and there seems to be no clear definition. MCFAs are more polar than long-chain fatty acids (LCFAs) because of their shorter chain length, and their hydrolysis and absorption properties differ greatly. These differences in physical properties have led, since the 1960s, to the use of MCTs to improve various lipid absorption disorders and malnutrition. More than half a century has passed since MCTs were first used in the medical field. It has been reported that they not only have properties as an energy source, but also have various physiological effects, such as effects on fat and protein metabolism. The enhancement of fat oxidation through ingestion of MCTs has led to interest in the study of body fat reduction and improvement of endurance during exercise. Recently, MCTs have also been shown to promote protein anabolism and inhibit catabolism, and applied research has been conducted into the prevention of frailty in the elderly. In addition, a relatively large ingestion of MCTs can be partially converted into ketone bodies, which can be used as a component of "ketone diets" in the dietary treatment of patients with intractable epilepsy, or in the nutritional support of terminally ill cancer patients. The possibility of improving cognitive function in dementia patients and mild cognitive impairment is also being studied. Obesity due to over-nutrition and lack of exercise, and frailty due to under-nutrition and aging, are major health issues in today's society. MCTs have been studied in relation to these concerns. In this paper we will introduce the results of applied research into the use of MCTs by healthy subjects.
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Altayyar M, Nasser JA, Thomopoulos D, Bruneau M. The Implication of Physiological Ketosis on The Cognitive Brain: A Narrative Review. Nutrients 2022; 14:nu14030513. [PMID: 35276871 PMCID: PMC8840718 DOI: 10.3390/nu14030513] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2021] [Revised: 01/21/2022] [Accepted: 01/23/2022] [Indexed: 01/27/2023] Open
Abstract
Optimal cognitive functions are necessary for activities of daily living and self-independence. Cognitive abilities are acquired during early childhood as part of progressive neurodevelopmental milestones; unfortunately, regressive changes can occur as part of physiological aging, or more ominously, pathological diseases, such as Alzheimer’s disease (AD). Cases of AD and its milder subset, mild cognitive impairment (MCI), are rising and would impose a burdensome impact beyond the individual level. Various dietary and nutritional approaches have potential for promising results in managing cognitive deterioration. Glucose is the core source of bioenergy in the body; however, glucose brain metabolism could be affected in aging cells or due to disease development. Ketone bodies are an efficient alternate fuel source that could compensate for the deficient glycolytic metabolism upon their supra-physiologic availability in the blood (ketosis), which, in turn, could promote cognitive benefits and tackle disease progression. In this review, we describe the potential of ketogenic approaches to produce cognitive benefits in healthy individuals, as well as those with MCI and AD. Neurophysiological changes of the cognitive brain in response to ketosis through neuroimaging modalities are also described in this review to provide insight into the ketogenic effect on the brain outside the framework of purely molecular explanations.
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Affiliation(s)
- Mansour Altayyar
- Department of Nutrition Sciences, Drexel University, 1601 Cherry Street, Philadelphia, PA 19102, USA; (J.A.N.); (D.T.)
- Correspondence:
| | - Jennifer A. Nasser
- Department of Nutrition Sciences, Drexel University, 1601 Cherry Street, Philadelphia, PA 19102, USA; (J.A.N.); (D.T.)
| | - Dimitra Thomopoulos
- Department of Nutrition Sciences, Drexel University, 1601 Cherry Street, Philadelphia, PA 19102, USA; (J.A.N.); (D.T.)
| | - Michael Bruneau
- Department of Health Science, Drexel University, 1601 Cherry Street, Philadelphia, PA 19102, USA;
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Lilamand M, Mouton-Liger F, Di Valentin E, Sànchez Ortiz M, Paquet C. Efficacy and Safety of Ketone Supplementation or Ketogenic Diets for Alzheimer's Disease: A Mini Review. Front Nutr 2022; 8:807970. [PMID: 35111799 PMCID: PMC8803132 DOI: 10.3389/fnut.2021.807970] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Accepted: 12/27/2021] [Indexed: 12/27/2022] Open
Abstract
Alzheimer's disease (AD) is the most frequent age-related neurodegenerative disorder, with no curative treatment available so far. Alongside the brain deposition of β-amyloid peptide and hyperphosphorylated tau, neuroinflammation triggered by the innate immune response in the central nervous system, plays a central role in the pathogenesis of AD. Glucose usually represents the main fuel for the brain. Glucose metabolism has been related to neuroinflammation, but also with AD lesions. Hyperglycemia promotes oxidative stress and neurodegeneration. Insulinoresistance (e.g., in type 2 diabetes) or low IGF-1 levels are associated with increased β-amyloid production. However, in the absence of glucose, the brain may use another fuel: ketone bodies (KB) produced by oxidation of fatty acids. Over the last decade, ketogenic interventions i.e., ketogenic diets (KD) with very low carbohydrate intake or ketogenic supplementation (KS) based on medium-chain triglycerides (MCT) consumption, have been studied in AD animal models, as well as in AD patients. These interventional studies reported interesting clinical improvements in animals and decrease in neuroinflammation, β-amyloid and tau accumulation. In clinical studies, KS and KD were associated with better cognition, but also improved brain metabolism and AD biomarkers. This review summarizes the available evidence regarding KS/KD as therapeutic options for individuals with AD. We also discuss the current issues and potential adverse effects associated with these nutritional interventions. Finally, we propose an overview of ongoing and future registered trials in this promising field.
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Affiliation(s)
- Matthieu Lilamand
- Groupe Hospitalier Lariboisiere FW Saint-Louis, Cognitive Neurology Center Paris Nord Ile de France, AP-HP.Nord, Paris, France
- Department of Geriatrics, Bichat and Bretonneau University Hospitals, AP-HP.Nord, Paris, France
- INSERM UMR-S1144, Université de Paris, Paris, France
- *Correspondence: Matthieu Lilamand
| | - François Mouton-Liger
- Groupe Hospitalier Lariboisiere FW Saint-Louis, Cognitive Neurology Center Paris Nord Ile de France, AP-HP.Nord, Paris, France
- Department of Histology and Biology of Aging, Groupe Hospitalier Lariboisiere FW Saint Louis, AP-HP.Nord, Paris, France
| | - Emmanuelle Di Valentin
- Department of Geriatrics, Bichat and Bretonneau University Hospitals, AP-HP.Nord, Paris, France
| | - Marta Sànchez Ortiz
- Groupe Hospitalier Lariboisiere FW Saint-Louis, Cognitive Neurology Center Paris Nord Ile de France, AP-HP.Nord, Paris, France
| | - Claire Paquet
- Groupe Hospitalier Lariboisiere FW Saint-Louis, Cognitive Neurology Center Paris Nord Ile de France, AP-HP.Nord, Paris, France
- INSERM UMR-S1144, Université de Paris, Paris, France
- Department of Histology and Biology of Aging, Groupe Hospitalier Lariboisiere FW Saint Louis, AP-HP.Nord, Paris, France
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Lilamand M, Mouton-Liger F, Paquet C. Ketogenic diet therapy in Alzheimer's disease: an updated review. Curr Opin Clin Nutr Metab Care 2021; 24:372-378. [PMID: 33871419 DOI: 10.1097/mco.0000000000000759] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
PURPOSE OF REVIEW Ketogenic diets (KD) are validated treatments of pharmacoresistant epilepsy. Their interest in neurodegenerative diseases such as Alzheimer's disease (AD) has been suggested, because ketone bodies may reduce neuroinflammation, improve neurotransmitters transport pathway, synaptic maintenance, and reduce brain β-amyloid deposition. In this updated review, we aimed at critically examining the evidence of the past 2 years regarding KD or ketogenic supplements (KS) on cognitive and biological/neuropathological outcomes. We conducted our search in preclinical studies (animal models of AD) or in humans with or without cognitive impairment. RECENT FINDINGS Overall, 12 studies were included: four in animal models of AD and eight in humans. In preclinical studies, we found additional evidence for a decrease in cerebral inflammation as well as in specific features of AD: β-amyloid, aggregates of tau protein under KD/KS. Several AD mouse models experienced clinical improvements. Human studies reported significant cognitive benefits, improved brain metabolism and biomarkers change under KD/KS, despite rather short-term interventions. Adherence to KD or KS was acceptable with frequent, but minor gastrointestinal adverse effects. SUMMARY The present review gathered additional evidence for both pathophysiological and clinical benefits of KS/KD in AD. Further studies are warranted with a biomarker-based selection of AD participants and long-term follow-up.
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Affiliation(s)
- Matthieu Lilamand
- Université de Paris
- INSERM UMRS1144 Optimisation Thérapeutique en Neuropsychopharmacologie
- Centre de Neurologie Cognitive/CMRR Paris Nord Ile de France, APHP Nord Université de Paris, Lariboisière Hospital, Paris, France
| | - François Mouton-Liger
- Université de Paris
- INSERM UMRS1144 Optimisation Thérapeutique en Neuropsychopharmacologie
- Centre de Neurologie Cognitive/CMRR Paris Nord Ile de France, APHP Nord Université de Paris, Lariboisière Hospital, Paris, France
| | - Claire Paquet
- Université de Paris
- INSERM UMRS1144 Optimisation Thérapeutique en Neuropsychopharmacologie
- Centre de Neurologie Cognitive/CMRR Paris Nord Ile de France, APHP Nord Université de Paris, Lariboisière Hospital, Paris, France
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