A Dietary Ketone Ester Normalizes Abnormal Behavior in a Mouse Model of Alzheimer's Disease

Therapeutic Potential of the Ketogenic Diet: A Metabolic Switch with Implications for Neurological Disorders, the Gut-Brain Axis, and Cardiovascular Diseases

The Ketogenic Diet (KD) is a dietary regimen that is low in carbohydrates, high in fats, and contains adequate protein. It is designed to mimic the metabolic state of fasting. This diet triggers the production of ketone bodies through a process known as ketosis. The primary objective of KD is to induce and sustain ketosis, which has been associated with numerous health benefits. Recent research has uncovered promising therapeutic potential for KD in the treatment of various diseases. This includes evidence of its effectiveness as a dietary strategy for managing intractable epilepsy, a form of epilepsy that is resistant to medication. We are currently assessing the efficacy and safety of KD through laboratory and clinical studies. This review focuses on the anti-inflammatory properties of the KD and its potential benefits for neurological disorders and the gut-brain axis. We also explore the existing literature on the potential effects of KD on cardiac health. Our aim is to provide a comprehensive overview of the current knowledge in these areas. Given the encouraging preliminary evidence of its therapeutic effects and the growing understanding of its mechanisms of action, randomized controlled trials are warranted to further explore the rationale behind the clinical use of KD. These trials will ultimately enhance our understanding of how KD functions and its potential benefits for various health conditions. We hope that our research will contribute to the body of knowledge in this field and provide valuable insights for future studies.

Molecular mechanisms of aging and anti-aging strategies

Aging is a complex and multifaceted process involving a variety of interrelated molecular mechanisms and cellular systems. Phenotypically, the biological aging process is accompanied by a gradual loss of cellular function and the systemic deterioration of multiple tissues, resulting in susceptibility to aging-related diseases. Emerging evidence suggests that aging is closely associated with telomere attrition, DNA damage, mitochondrial dysfunction, loss of nicotinamide adenine dinucleotide levels, impaired macro-autophagy, stem cell exhaustion, inflammation, loss of protein balance, deregulated nutrient sensing, altered intercellular communication, and dysbiosis. These age-related changes may be alleviated by intervention strategies, such as calorie restriction, improved sleep quality, enhanced physical activity, and targeted longevity genes. In this review, we summarise the key historical progress in the exploration of important causes of aging and anti-aging strategies in recent decades, which provides a basis for further understanding of the reversibility of aging phenotypes, the application prospect of synthetic biotechnology in anti-aging therapy is also prospected.

The interplay between glucose and ketone bodies in neural stem cell metabolism

Glucose is the primary energy source for neural stem cells (NSCs), supporting their proliferation, differentiation, and quiescence. However, the high demand for glucose during brain development often exceeds its supply, leading to the utilization of alternative energy sources including ketone bodies. Ketone bodies, including β-hydroxybutyrate, are short-chain fatty acids produced through hepatic ketogenesis and play a crucial role in providing energy and the biosynthetic components for NSCs when required. The interplay between glucose and ketone metabolism influences NSC behavior and fate decisions, and disruptions in these metabolic pathways have been linked to neurodevelopmental, neuropsychiatric, and neurodegenerative disorders. Additionally, ketone bodies exert neuroprotective effects on NSCs and modulate cellular responses to oxidative stress, energy maintenance, deacetylation, and inflammation. As such, understanding the interdependence of glucose and ketone metabolism in NSCs is crucial to understanding their roles in NSC function and their implications for neurological conditions. This article reviews the mechanisms of glucose and ketone utilization in NSCs, their impact on NSC function, and the therapeutic potential of targeting these metabolic pathways in neurological disorders.

Adenosine deficiency facilitates CA1 synaptic hyperexcitability in the presymptomatic phase of a knock in mouse model of Alzheimer's disease

The disease's trajectory of Alzheimer's disease (AD) is associated with and worsened by hippocampal hyperexcitability. Here we show that during the asymptomatic stage in a knock in mouse model of Alzheimer's disease (APPNL-G-F/NL-G-F; APPKI), hippocampal hyperactivity occurs at the synaptic compartment, propagates to the soma and is manifesting at low frequencies of stimulation. We show that this aberrant excitability is associated with a deficient adenosine tone, an inhibitory neuromodulator, driven by reduced levels of CD39/73 enzymes, responsible for the extracellular ATP-to-adenosine conversion. Both pharmacologic (adenosine kinase inhibitor) and non-pharmacologic (ketogenic diet) restorations of the adenosine tone successfully normalize hippocampal neuronal activity. Our results demonstrated that neuronal hyperexcitability during the asymptomatic stage of a KI model of Alzheimer's disease originated at the synaptic compartment and is associated with adenosine deficient tone. These results extend our comprehension of the hippocampal vulnerability associated with the asymptomatic stage of Alzheimer's disease.

Role of ketogenic diet in neurodegenerative diseases focusing on Alzheimer diseases: The guardian angle

The ketogenic diet (KD) is a low-carbohydrate, adequate protein and high-fat diet. KD is primarily used to treat refractory epilepsy. KD was shown to be effective in treating different neurodegenerative diseases. Alzheimer disease (AD) is the first common neurodegenerative disease in the world characterized by memory and cognitive impairment. However, the underlying mechanism of KD in controlling of AD and other neurodegenerative diseases are not discussed widely. Therefore, this review aims to revise the fundamental mechanism of KD in different neurodegenerative diseases focusing on the AD. KD induces a fasting-like which modulates the central and peripheral metabolism by regulating mitochondrial dysfunction, oxidative stress, inflammation, gut-flora, and autophagy in different neurodegenerative diseases. Different studies highlighted that KD improves AD neuropathology by regulating synaptic neurotransmission and inhibiting of neuroinflammation and oxidative stress. In conclusion, KD improves cognitive function and attenuates the progression of AD neuropathology by reducing oxidative stress, mitochondrial dysfunction, and enhancing neuronal autophagy and brain BDNF.

Ketogenic therapy towards precision medicine for brain diseases

Precision nutrition and nutrigenomics are emerging in the development of therapies for multiple diseases. The ketogenic diet (KD) is the most widely used clinical diet, providing high fat, low carbohydrate, and adequate protein. KD produces ketones and alters the metabolism of patients. Growing evidence suggests that KD has therapeutic effects in a wide range of neuronal diseases including epilepsy, neurodegeneration, cancer, and metabolic disorders. Although KD is considered to be a low-side-effect diet treatment, its therapeutic mechanism has not yet been fully elucidated. Also, its induced keto-response among different populations has not been elucidated. Understanding the ketone metabolism in health and disease is critical for the development of KD-associated therapeutics and synergistic therapy under any physiological background. Here, we review the current advances and known heterogeneity of the KD response and discuss the prospects for KD therapy from a precision nutrition perspective.

Molecular Mechanisms of Neuroprotection by Ketone Bodies and Ketogenic Diet in Cerebral Ischemia and Neurodegenerative Diseases

Ketone bodies (KBs), such as acetoacetate and β-hydroxybutyrate, serve as crucial alternative energy sources during glucose deficiency. KBs, generated through ketogenesis in the liver, are metabolized into acetyl-CoA in extrahepatic tissues, entering the tricarboxylic acid cycle and electron transport chain for ATP production. Reduced glucose metabolism and mitochondrial dysfunction correlate with increased neuronal death and brain damage during cerebral ischemia and neurodegeneration. Both KBs and the ketogenic diet (KD) demonstrate neuroprotective effects by orchestrating various cellular processes through metabolic and signaling functions. They enhance mitochondrial function, mitigate oxidative stress and apoptosis, and regulate epigenetic and post-translational modifications of histones and non-histone proteins. Additionally, KBs and KD contribute to reducing neuroinflammation and modulating autophagy, neurotransmission systems, and gut microbiome. This review aims to explore the current understanding of the molecular mechanisms underpinning the neuroprotective effects of KBs and KD against brain damage in cerebral ischemia and neurodegenerative diseases, including Alzheimer's disease and Parkinson's disease.

(R,R)-BD-AcAc2 Mitigates Chronic Colitis in Rats: A Promising Multi-Pronged Approach Modulating Inflammasome Activity, Autophagy, and Pyroptosis

Ulcerative colitis is a chronic and incurable form of inflammatory bowel disease that can increase the risk of colitis-associated cancer and mortality. Limited treatment options are available for this condition, and the existing ones often come with non-tolerable adverse effects. This study is the first to examine the potential benefits of consuming (R,R)-BD-AcAc2, a type of ketone ester (KE), and intermittent fasting in treating chronic colitis induced by dextran sodium sulfate (DSS) in rats. We selected both protocols to enhance the levels of β-hydroxybutyrate, mimicking a state of nutritional ketosis and early ketosis, respectively. Our findings revealed that only the former protocol, consuming the KE, improved disease activity and the macroscopic and microscopic features of the colon while reducing inflammation scores. Additionally, the KE counteracted the DSS-induced decrease in the percentage of weight change, reduced the colonic weight-to-length ratio, and increased the survival rate of DSS-insulted rats. KE also showed potential antioxidant activities and improved the gut microbiome composition. Moreover, consuming KE increased the levels of tight junction proteins that protect against leaky gut and exhibited anti-inflammatory properties by reducing proinflammatory cytokine production. These effects were attributed to inhibiting NFκB and NLRP3 inflammasome activation and restraining pyroptosis and apoptosis while enhancing autophagy as revealed by reduced p62 and increased BECN1. Furthermore, the KE may have a positive impact on maintaining a healthy microbiome. To conclude, the potential clinical implications of our findings are promising, as (R,R)-BD-AcAc2 has a greater safety profile and can be easily translated to human subjects.

Ketogenic Diet as a Promising Non-Drug Intervention for Alzheimer’s Disease: Mechanisms and Clinical Implications

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.

A Novel Ketone-Supplemented Diet Improves Recognition Memory and Hippocampal Mitochondrial Efficiency in Healthy Adult Mice

Mitochondrial dysfunction and cognitive impairment are common symptoms in many neurologic and psychiatric disorders, as well as nonpathological aging. Ketones have been suggested as therapeutic for their efficacy in epilepsy and other brain pathologies such as Alzheimer's disease and major depressive disorder. However, their effects on cognitive function in healthy individuals is less established. Here, we explored the mitochondrial and performative outcomes of a novel eight-week ketone-supplemented ketogenic (KETO) diet in healthy adult male and female mice. In a novel object recognition test, KETO mice spent more time with the novel, compared to familiar, object, indicating an improvement in recognition memory. High-resolution respirometry on permeabilized hippocampal tissue returned significant reductions in mitochondrial O2 consumption. No changes in ATP production were observed, yielding a significantly higher ATP:O2 ratio, a measure of mitochondrial efficiency. Together, these findings demonstrate the KETO diet improves hippocampal mitochondrial efficiency. They add to a growing body of evidence that suggests ketones and ketogenic diets are neuroprotective and metabolically and cognitively relevant, even in healthy adults. They also suggest that ketogenic lifestyle changes may be effective strategies for protecting against cognitive decline associated with aging and disease.

Nutrition, longevity and disease: From molecular mechanisms to interventions

Diet as a whole, encompassing food composition, calorie intake, and the length and frequency of fasting periods, affects the time span in which health and functional capacity are maintained. Here, we analyze aging and nutrition studies in simple organisms, rodents, monkeys, and humans to link longevity to conserved growth and metabolic pathways and outline their role in aging and age-related disease. We focus on feasible nutritional strategies shown to delay aging and/or prevent diseases through epidemiological, model organism, clinical, and centenarian studies and underline the need to avoid malnourishment and frailty. These findings are integrated to define a longevity diet based on a multi-pillar approach adjusted for age and health status to optimize lifespan and healthspan in humans.

Can dietary patterns prevent cognitive impairment and reduce Alzheimer's disease risk: exploring the underlying mechanisms of effects

Alzheimer's disease (AD) is one of the fastest growing cognitive decline-related neurological diseases. To date, effective curative strategies have remained elusive. A growing body of evidence indicates that dietary patterns have significant effects on cognitive function and the risk of developing AD. Previous studies on the association between diet and AD risk have mainly focused on individual food components and specific nutrients, and the mechanisms responsible for the beneficial effects of dietary patterns on AD are not well understood. This article provides a comprehensive overview of the effects of dietary patterns, including the Mediterranean diet (MedDiet), dietary approaches to stop hypertension (DASH) diet, Mediterranean-DASH diet intervention for neurological delay (MIND), ketogenic diet, caloric restriction, intermittent fasting, methionine restriction, and low-protein and high-carbohydrate diet, on cognitive impairment and summarizes the underlying mechanisms by which dietary patterns attenuate cognitive impairment, especially highlighting the modulation of dietary patterns on cognitive impairment through gut microbiota. Furthermore, considering the variability in individual metabolic responses to dietary intake, we put forward a framework to develop personalized dietary patterns for people with cognitive disorders or AD based on individual gut microbiome compositions.

Ketone Supplementation: Meeting the Needs of the Brain in an Energy Crisis

Diverse neurological disorders are associated with a deficit in brain energy metabolism, often characterized by acute or chronic glucose hypometabolism. Ketones serve as the brain's only significant alternative fuel and can even become the primary fuel in conditions of limited glucose availability. Thus, dietary supplementation with exogenous ketones represents a promising novel therapeutic strategy to help meet the energetic needs of the brain in an energy crisis. Preliminary evidence suggests ketosis induced by exogenous ketones may attenuate damage or improve cognitive and motor performance in neurological conditions such as seizure disorders, mild cognitive impairment, Alzheimer's disease, and neurotrauma.

Studies on the mechanism of Panax Ginseng in the treatment of deficiency of vital energy dementia rats based on urine metabolomics

Panax Ginseng (PG) has been used to strengthen memory and physique for thousands of years, because its main components ginsenosides (GS) and ginseng polysaccharides (GP) play a major role, but its mechanism is not clear. In this study, a rat model of dementia with vital energy deficiency (DED) was established through intraperitoneal injection with D-galactose and AlCl₃ and combined with exhaustive swimming. Pharmacological studies and the urine metabolomics based on ultra-high-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS) were employed for evaluation the efficacy of PG and exploring this treatment mechanism. Through urine metabolic profiling, it can be seen that DED rats after PG administration are close to normal group (NG) rats, and PG can regulate the in vivo status of DED rats which tend to NG. The results of behavioral, biochemical indicators and immunohistochemistry further verified the above results, and the mechanism of action of each component is refined. Ultimately, we believe that the mechanism of PG in the treatment of DED is that ginsenosides (GS) intervenes in phenylalanine tryptophan and tyrosine metabolism, stimulates dopamine production, inhibits Aβ deposition and neuroinflammation; and that ginseng polysaccharides (GP) provides energy to strengthen the TCA cycle and improve immune capacity.

Ketone Ester Effects on Biomarkers of Brain Metabolism and Cognitive Performance in Cognitively Intact Adults ≥ 55 Years Old. A Study Protocol for a Double-Blinded Randomized Controlled Clinical Trial

BACKGROUND

Ketone bodies have been proposed as an "energy rescue" for the Alzheimer's disease (AD) brain, which underutilizes glucose. Prior research has shown that oral ketone monoester (KME) safely induces robust ketosis in humans and has demonstrated cognitive-enhancing and pathology-reducing properties in animal models of AD. However, human evidence that KME may enhance brain ketone metabolism, improve cognitive performance and engage AD pathogenic cascades is scarce.

OBJECTIVES

To investigate the effects of ketone monoester (KME) on brain metabolism, cognitive performance and AD pathogenic cascades in cognitively normal older adults with metabolic syndrome and therefore at higher risk for AD.

DESIGN

Double-blinded randomized placebo-controlled clinical trial.

SETTING

Clinical Unit of the National Institute on Aging, Baltimore, US.

PARTICIPANTS

Fifty cognitively intact adults ≥ 55 years old, with metabolic syndrome.

INTERVENTION

Drinks containing 25 g of KME or isocaloric placebo consumed three times daily for 28 days.

OUTCOMES

Primary: concentration of beta-hydroxybutyrate (BHB) in precuneus measured with Magnetic Resonance Spectroscopy (MRS). Exploratory: plasma and urine BHB, multiple brain and muscle metabolites detected with MRS, cognition assessed with the PACC and NIH toolbox, biomarkers of AD and metabolic mediators in plasma extracellular vesicles, and stool microbiome.

DISCUSSION

This is the first study to investigate the AD-biomarker and cognitive effects of KME in humans. Ketone monoester is safe, tolerable, induces robust ketosis, and animal studies indicate that it can modify AD pathology. By conducting a study of KME in a population at risk for AD, we hope to bridge the existing gap between pre-clinical evidence and the potential for brain-metabolic, pro-cognitive, and anti-Alzheimer's effects in humans.

Can Ketogenic Diet Improve Alzheimer's Disease? Association With Anxiety, Depression, and Glutamate System

Background: Alzheimer's disease is the most common neurodegenerative disorder in our society, mainly characterized by loss of cognitive function. However, other symptoms such as anxiety and depression have been described in patients. The process is mediated by alterations in the synaptic and extrasynaptic activity of the neurotransmitter glutamate, which are linked to a hypometabolism of glucose as the main source of brain energy. In that respect, Ketogenic diet (KD) has been proposed as a non-pharmacological treatment serving as an alternative energy source to the neurons increasing the fat percentage and reducing the carbohydrates percentage, showing promising results to improve the cognitive symptoms associated with different neurodegenerative disorders, including AD. However, the association of this type of diet with emotional symptoms and the modulation of glutamate neurotransmission systems after this dietary reduction of carbohydrates are unknown.

Objective: The aim of this short review is to provide update studies and discuss about the relationship between KD, anxiety, depression, and glutamate activity in AD patients.

Discussion: The main results suggest that the KD is an alternative energy source for neurons in AD with positive consequences for the brain at different levels such as epigenetic, metabolic and signaling, and that the substitution of carbohydrates for fats is also associated with emotional symptoms and glutamate activity in AD.

Conditional Knockout of Pdha1 in Mouse Hippocampus Impairs Cognitive Function: The Possible Involvement of Lactate

Background and Purpose: Neurodegenerative diseases are associated with metabolic disturbances. Pyruvate dehydrogenase E1 component subunit alpha (PDHA1) is an essential component in the process of glucose metabolism, and its deficiency exists in various diseases such as Alzheimer’s disease (AD), epilepsy, Leigh’s syndrome, and diabetes-associated cognitive decline. However, the exact role of PDHA1 deficiency in neurodegenerative diseases remains to be elucidated. In this study, we explored the effect of PDHA1 deficiency on cognitive function and its molecular mechanism.

Methods: A hippocampus-specific Pdha1 knockout (Pdha1^–/–) mouse model was established, and behavioral tests were used to evaluate the cognitive function of mice. Transmission electron microscopy (TEM) was performed to observe the morphological changes of the hippocampus. The lactate level in the hippocampus was measured. Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and western blotting were used to explore the possible mechanism of the effect of PDHA1 on cognition.

Results:Pdha1 knockout damaged the spatial memory of mice and led to the ultrastructural disorder of hippocampal neurons. Lactate accumulation and abnormal lactate transport occurred in Pdha1^–/– mice, and the cyclic AMP-protein kinase A-cAMP response element-binding protein (cAMP/PKA/CREB) pathway was inhibited.

Conclusion: Lactate accumulation caused by PDHA1 deficiency in the hippocampus may impair cognitive function by inhibiting the cAMP/PKA/CREB pathway.

Exogenous ketone ester delays CNS oxygen toxicity without impairing cognitive and motor performance in male Sprague-Dawley rats

Hyperbaric oxygen (HBO2) is breathing >1 atmosphere absolute (ATA; 101.3 kPa) O2 and is used in HBO2 therapy and undersea medicine. What limits the use of HBO2 is the risk of developing central nervous system (CNS) oxygen toxicity (CNS-OT). A promising therapy for delaying CNS-OT is ketone metabolic therapy either through diet or exogenous ketone ester (KE) supplement. Previous studies indicate that KE induces ketosis and delays the onset of CNS-OT; however, the effects of exogeneous KE on cognition and performance are understudied. Accordingly, we tested the hypothesis that oral gavage with 7.5 g/kg induces ketosis and increases the latency time to seizure (LSz) without impairing cognition and performance. A single oral dose of 7.5 g/kg KE increases systemic β-hydroxybutyrate (BHB) levels within 0.5 h and remains elevated for 4 h. Male rats were separated into three groups: control (no gavage), water-gavage, or KE-gavage, and were subjected to behavioral testing while breathing 1 ATA (101.3 kPa) of air. Testing included the following: DigiGait (DG), light/dark (LD), open field (OF), and novel object recognition (NOR). There were no adverse effects of KE on gait or motor performance (DG), cognition (NOR), and anxiety (LD, OF). In fact, KE had an anxiolytic effect (OF, LD). The LSz during exposure to 5 ATA (506.6 kPa) O2 (≤90 min) increased 307% in KE-treated rats compared with control rats. In addition, KE prevented seizures in some animals. We conclude that 7.5 g/kg is an optimal dose of KE in the male Sprague-Dawley rat model of CNS-OT.

The possibility of use of the ketogenic diet and medium chain triglycerides supplementation in the support therapy of Alzheimer disease

PURPOSE OF REVIEW

Diet-induced ketosis has a fasting-like effect and brings the body to increase the production of ketone bodies (KB). Works over the last decades have provided evidence of the therapeutic potential of the ketogenic diet (KD). This review focus on mainly clinical research on the effectiveness of the KD and medium-chain triglycerides (MCT) supplementation in ameliorating the severity of symptoms in Alzheimer disease (AD).

RECENT FINDINGS

A limited number of clinical studies (short-time and with a small number of participants) evaluated the role of the KD and MCT supplementation in AD as a potential dietary intervention in the therapy of this disease. These studies report that the application of KD or/and MCT supplements to older people reduces symptoms of AD. MCT supplements allow achieving an increased level of KBs in the blood even with a greater supply of carbohydrates in the diet and without any drastic changes in the habitual diet of patients.

SUMMARY

The recent literature highlights the potential benefit of using diet-induced ketosis as an additional element of therapy in AD. Since persons with AD are at risk of malnutrition, the use of KD raises certain concerns due to side effects, especially for long periods of time. MCT supplements to obtain similar clinical results without the need for drastic changes in the diet of patients.

Ketogenic diet therapy in Alzheimer's disease: an updated review

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.

Beneficial Effects of Exogenous Ketogenic Supplements on Aging Processes and Age-Related Neurodegenerative Diseases

Life expectancy of humans has increased continuously up to the present days, but their health status (healthspan) was not enhanced by similar extent. To decrease enormous medical, economical and psychological burden that arise from this discrepancy, improvement of healthspan is needed that leads to delaying both aging processes and development of age-related diseases, thereby extending lifespan. Thus, development of new therapeutic tools to alleviate aging processes and related diseases and to increase life expectancy is a topic of increasing interest. It is widely accepted that ketosis (increased blood ketone body levels, e.g., β-hydroxybutyrate) can generate neuroprotective effects. Ketosis-evoked neuroprotective effects may lead to improvement in health status and delay both aging and the development of related diseases through improving mitochondrial function, antioxidant and anti-inflammatory effects, histone and non-histone acetylation, β-hydroxybutyrylation of histones, modulation of neurotransmitter systems and RNA functions. Administration of exogenous ketogenic supplements was proven to be an effective method to induce and maintain a healthy state of nutritional ketosis. Consequently, exogenous ketogenic supplements, such as ketone salts and ketone esters, may mitigate aging processes, delay the onset of age-associated diseases and extend lifespan through ketosis. The aim of this review is to summarize the main hallmarks of aging processes and certain signaling pathways in association with (putative) beneficial influences of exogenous ketogenic supplements-evoked ketosis on lifespan, aging processes, the most common age-related neurodegenerative diseases (Alzheimer’s disease, Parkinson’s disease and amyotrophic lateral sclerosis), as well as impaired learning and memory functions.

Ketogenic diet reduces alcohol withdrawal symptoms in humans and alcohol intake in rodents

Individuals with alcohol use disorder (AUD) show elevated brain metabolism of acetate at the expense of glucose. We hypothesized that a shift in energy substrates during withdrawal may contribute to withdrawal severity and neurotoxicity in AUD and that a ketogenic diet (KD) may mitigate these effects. We found that inpatients with AUD randomized to receive KD (n = 19) required fewer benzodiazepines during the first week of detoxification, in comparison to those receiving a standard American (SA) diet (n = 14). Over a 3-week treatment, KD compared to SA showed lower "wanting" and increased dorsal anterior cingulate cortex (dACC) reactivity to alcohol cues and altered dACC bioenergetics (i.e., elevated ketones and glutamate and lower neuroinflammatory markers). In a rat model of alcohol dependence, a history of KD reduced alcohol consumption. We provide clinical and preclinical evidence for beneficial effects of KD on managing alcohol withdrawal and on reducing alcohol drinking.

An Alternative Enzymatic Route to the Ergogenic Ketone Body Ester (R)-3-Hydroxybutyl (R)-3-Hydroxybutyrate

Recent studies have highlighted the therapeutic and ergogenic potential of the ketone body ester, (R)-3-hydroxybutyl-(R)-3-hydroxybutyrate. In the present work, the enzymatic synthesis of this biological active compound is reported. The (R)-3-hydroxybutyl-(R)-3-hydroxybutyrate has been produced through the transesterification of racemic ethyl 3-hydroxybutyrate with (R)-1,3-butanediol by exploiting the selectivity of Candida antarctica lipase B (CAL-B). The needed (R)-1,3-butanediol was in turn obtained from the kinetic resolution of the racemate achieved by acetylation with vinyl acetate, also in this case, thanks to the enantioselectivity of the CAL-B used as catalyst. Finally, the stereochemical inversion of the unreacted (S) enantiomers of the ethyl 3-hydroxybutyate and 1,3-butanediol accomplished by known procedure allowed to increase the overall yield of the synthetic pathway by incorporating up to 70% of the starting racemic reagents into the final product.

Ketogenic regimens for acute neurotraumatic events

Dietary modification would be the most translatable, cost-efficient, and, likely, the safest approach available that can reduce the reliance on pharmaceutical treatments for treating acute or chronic neurological disorders. A wide variety of evidence suggests that the ketogenic diet (KD) could have beneficial effects in acute traumatic events, such as spinal cord injury and traumatic brain injury. Review of existing human and animal studies revealed that KD can improve motor neuro-recovery, gray matter sparing, pain thresholds, and neuroinflammation and decrease depression. Although the exact mechanism by which the KD provides neuroprotection is not fully understood, its effects on cellular energetics, mitochondria function and inflammation are likely to have a role.

Nutritional Ketosis as a Potential Treatment for Alcohol Use Disorder

Alcohol use disorder (AUD) is a chronic, relapsing brain disorder, characterized by compulsive alcohol seeking and disrupted brain function. In individuals with AUD, abstinence from alcohol often precipitates withdrawal symptoms than can be life threatening. Here, we review evidence for nutritional ketosis as a potential means to reduce withdrawal and alcohol craving. We also review the underlying mechanisms of action of ketosis. Several findings suggest that during alcohol intoxication there is a shift from glucose to acetate metabolism that is enhanced in individuals with AUD. During withdrawal, there is a decline in acetate levels that can result in an energy deficit and could contribute to neurotoxicity. A ketogenic diet or ingestion of a ketone ester elevates ketone bodies (acetoacetate, β-hydroxybutyrate and acetone) in plasma and brain, resulting in nutritional ketosis. These effects have been shown to reduce alcohol withdrawal symptoms, alcohol craving, and alcohol consumption in both preclinical and clinical studies. Thus, nutritional ketosis may represent a unique treatment option for AUD: namely, a nutritional intervention that could be used alone or to augment the effects of medications.