Ketogenic Diet Research Articles

Exploring Consumption of Ultra‐Processed Foods and Diet Quality in the Context of Popular Low Carbohydrate and Plant‐Based Dietary Approaches

ABSTRACTThis study investigates diet quality across four popular dietary patterns: Ketogenic Diet, Low‐Carbohydrate Healthy‐Fat, Vegetarian, and Vegan, employing the NOVA and Human Interference Scoring System (HISS) classification systems. Utilizing a modified Food Frequency Questionnaire (FFQ) and analyzing 168 participants' dietary habits, the research identifies notable differences in dietary quality among the dietary patterns. While all groups reported lower consumption of UPFs than the general population, plant‐based diets demonstrated higher UPF consumption than ketogenic and low carbohydrate diets. The study reveals that both NOVA and HISS effectively identify UPFs, with significant differences observed at various processing levels, except for UPFs where both systems showed similarity. This research contributes to the detailed understanding of diet quality within popular dietary patterns, highlighting the importance of considering food processing in dietary choices and the need for ongoing research to further elucidate the health implications of different types of UPFs.

The hydroxycarboxylic acid receptor HCA2 is required for the protective effect of ketogenic diet in epilepsy.

One third of epilepsy patients are resistant to treatment with current anti-seizure medications. The ketogenic diet is used to treat some forms of refractory epilepsy, but the mechanism of its action has not yet been elucidated. In this study, we aimed to investigate whether the hydroxycarboxylic acid receptor 2 (HCA2), a known immunomodulatory receptor, plays a role in mediating the protective effect of this diet. We demonstrate for the first time that selective agonists at this receptor can directly reduce seizures in animal models. Agonists also reduce network activity in rodent and human brain slices. Ketogenic diet is known to increase circulating levels of endogenous HCA2 agonists, and we show that the effect of ketogenic diet in reducing seizures in the 6 Hz seizure model is negated in HCA2-deficient mice. Our data support the potential of HCA2 as a target for the treatment of epilepsy and potentially for neurodegenerative diseases.

Ketone Esters Partially and Selectively Rescue Mitochondrial Bioenergetics After Acute Cervical Spinal Cord Injury in Rats: A Time-Course.

Spinal cord injury (SCI) pathology and pathophysiology can be attributed to both primary physical injury and secondary injury cascades. Secondary injury cascades involve dysregulated metabolism and energetic deficits directly linked to compromised mitochondrial bioenergetics. Rescuing mitochondrial function and reducing oxidative stress are associated with neuroprotection. In this regard, ketosis after traumatic brain injury (TBI), or after SCI, improves secondary neuropathology by decreasing oxidative stress, increasing antioxidants, reducing inflammation, and improving mitochondrial bioenergetics. Here, we follow up on our previous study and have used an exogenous ketone monoester, (R)-3-hydroxybutyl (R)-3-hydroxybutyrate (KE), as an alternative to a ketogenic diet, focusing on mitochondrial function between 1 and 14 days after injury. Starting 3 h following a cervical level 5 (C5) hemi-contusion injury, animals were fed either a standard control diet (SD) or a ketone ester diet (KED) combined with KE administered orally (OKE). We found that mitochondrial function was reduced after SCI at all times post-SCI, accompanied by reduced expression of most of the components of the electron transport chain (ETC). The KE rescued some of the bioenergetic parameters 1 day after SCI when D-β-Hydroxybutyrate (BHB) concentrations were ~2 mM. Still, most of the beneficial effects were observed 14 days after injury, with BHB concentrations reaching values of 4-6 mM. To our knowledge, this is the first report to show the beneficial effects of KE in rescuing mitochondrial function after SCI and demonstrates the suitability of KE in ameliorating the metabolic dysregulation that occurs after traumatic SCI without requiring a restrictive dietary regime.

The impact of 3 different dietary interventions on overweight or obese adults: A network meta-analysis.

This network meta-analysis aims to investigate and compare the effectiveness of 3 dietary interventions - Mediterranean, ketogenic, and low-fat diet - on overweight and obese adults, with a comparison to traditional low-calorie diet. A systematic review was conducted in both Chinese and English databases, including the China National Knowledge Infrastructure (CNKI), Wanfang Database, China Science and Technology Journal Database (VIP), SinoMed, PubMed, Web of Science, Cochrane Library and Embase to identify relevant randomized controlled trials (RCTs) up to January 31, 2024. Two researchers independently screened and extracted data from the identified literature. The quality of these studies was assessed using the Cochrane bias risk assessment tool. A random-effects network meta-analysis was performed using Review Manager 5.4.1 and Stata 16.0 software. A total of 17 randomized controlled trials involving 5802 subjects were included in this study. The network meta-analysis revealed a descending order of effectiveness for reducing body weight (BW), body mass index (BMI), and waist circumference (WC): ketogenic diet > low-fat diet > low-calorie diet > Mediterranean diet. The ketogenic diet was identified as the most effective intervention for reducing BW, BMI, and WC in the studied dietary comparisons. It consistently showed superior outcomes, ranking highest in effectiveness among the 4 evaluated dietary approaches. Nevertheless, additional high-quality randomized controlled trials are necessary to validate these findings.

The ketone body β-hydroxybutyrate ameliorates neurodevelopmental deficits in the GABAergic system of daf-18/PTEN Caenorhabditis elegans mutants.

A finely tuned balance between excitation and inhibition (E/I) is essential for proper brain function. Disruptions in the GABAergic system, which alter this equilibrium, are a common feature in various types of neurological disorders, including autism spectrum disorders (ASDs). Mutations in Phosphatase and Tensin Homolog (PTEN), the main negative regulator of the phosphatidylinositol 3-phosphate kinase/Akt pathway, are strongly associated with ASD. However, it is unclear whether PTEN deficiencies can differentially affect inhibitory and excitatory signaling. Using the Caenorhabditis elegans neuromuscular system, where both excitatory (cholinergic) and inhibitory (GABAergic) inputs regulate muscle activity, we found that daf-18/PTEN mutations impact GABAergic (but not cholinergic) neurodevelopment and function. This selective impact results in a deficiency in inhibitory signaling. The defects observed in the GABAergic system in daf-18/PTEN mutants are due to reduced activity of DAF-16/FOXO during development. Ketogenic diets (KGDs) have proven effective for disorders associated with E/I imbalances. However, the mechanisms underlying their action remain largely elusive. We found that a diet enriched with the ketone body β-hydroxybutyrate during early development induces DAF-16/FOXO activity, therefore improving GABAergic neurodevelopment and function in daf-18/PTEN mutants. Our study provides valuable insights into the link between PTEN mutations and neurodevelopmental defects and delves into the mechanisms underlying the potential therapeutic effects of KGDs.

Effects of a Carbohydrate Meal on Lipolysis

Background: Due to the increasing prevalence of obesity and type 2 diabetes, effective dietary recommendations are needed. Previously, we developed the low-insulin method: by avoiding insulinogenic, i.e., insulin-release-triggering foods, insulin secretion becomes reduced, lipolysis is stimulated, and energy production is shifted to ketosis with excess ketone bodies exhaled in the form of acetone. Now, we investigate how quickly stable ketosis (defined as fasting breath acetone concentration ≥ 7.0 ppm) is achieved, whether and for how long a carbohydrate meal inhibits ketosis, and whether the responses differ in healthy adults with different insulin levels. Methods: An oral glucose tolerance test was conducted, and body composition and fasting insulin were determined at the beginning and end of the 14-day study. Participants (n = 10) followed a ketogenic diet and performed continuous glucose monitoring. Ketosis levels were determined by measuring breath acetone concentrations. On day 8, two white bread rolls with jam (72 g carbohydrates) were consumed for breakfast. Results: After seven days, all participants achieved stable ketosis (defined as fasting breath acetone concentration ≥ 7.0 ppm), which dropped from 8.2 to 5.7 ppm (p = 0.0014) after the carbohydrate meal. It took five days to achieve stable ketosis again. The stratification of participants into tertiles according to their fasting insulin levels demonstrated that individuals with low fasting insulin levels achieved stable ketosis again after two days and those with medium insulin levels after five days, while those with high baseline values did not reach stable ketosis by the end of the study. Conclusions: By carbohydrate restriction, stable ketosis can be achieved within one week. However, a single carbohydrate meal inhibits ketosis for several days. This effect is pronounced in individuals with elevated fasting insulin levels.

The ketone body β-hydroxybutyrate ameliorates neurodevelopmental deficits in the GABAergic system of daf-18/PTEN Caenorhabditis elegans mutants

A finely tuned balance between excitation and inhibition (E/I) is essential for proper brain function. Disruptions in the GABAergic system, which alter this equilibrium, are a common feature in various types of neurological disorders, including autism spectrum disorders (ASDs). Mutations in Phosphatase and Tensin Homolog (PTEN), the main negative regulator of the phosphatidylinositol 3-phosphate kinase/Akt pathway, are strongly associated with ASD. However, it is unclear whether PTEN deficiencies can differentially affect inhibitory and excitatory signaling. Using the Caenorhabditis elegans neuromuscular system, where both excitatory (cholinergic) and inhibitory (GABAergic) inputs regulate muscle activity, we found that daf-18/PTEN mutations impact GABAergic (but not cholinergic) neurodevelopment and function. This selective impact results in a deficiency in inhibitory signaling. The defects observed in the GABAergic system in daf-18/PTEN mutants are due to reduced activity of DAF-16/FOXO during development. Ketogenic diets (KGDs) have proven effective for disorders associated with E/I imbalances. However, the mechanisms underlying their action remain largely elusive. We found that a diet enriched with the ketone body β-hydroxybutyrate during early development induces DAF-16/FOXO activity, therefore improving GABAergic neurodevelopment and function in daf-18/PTEN mutants. Our study provides valuable insights into the link between PTEN mutations and neurodevelopmental defects and delves into the mechanisms underlying the potential therapeutic effects of KGDs.

Oral Administration of a Novel, Synthetic Ketogenic Compound Elevates Blood β-Hydroxybutyrate Levels in Mice in Both Fasted and Fed Conditions.

Elevating ketone levels with therapeutic nutritional ketosis can help to metabolically manage disease processes associated with epilepsy, diabetes, obesity, cancer, and neurodegenerative disease. Nutritional ketosis can be achieved with various dieting strategies such as the classical ketogenic diet, the modified Atkins diet, caloric restriction, periodic fasting, or the consumption of exogenous ketogenic supplements such as medium-chain triglycerides (MCTs). However, these various strategies can be unpleasant and difficult to follow, so that achieving and sustaining nutritional ketosis can be a major challenge. Thus, investigators continue to explore the science and applications of exogenous ketone supplementation as a means to further augment the therapeutic efficacy of this metabolic therapy. Here, we describe a structurally new synthetic triglyceride, glycerol tri-acetoacetate (Gly-3AcAc), that we prepared from glycerol and an acetoacetate precursor that produces hyperketonemia in the therapeutic range (2-3 mM) when administered to mice under both fasting and non-fasting conditions. Animal studies were undertaken to evaluate the potential effects of eliciting a ketogenic response systemically. Acute effects (24 h or less) were determined in male VM/Dk mice in both fasted and unfasted dietary states. Concentration levels of β-hydroxybutyrate in blood were elevated (βHB; 2-3 mM) under both conditions. Levels of glucose were reduced only in the fasted state. No detrimental side effects were observed. Pending further study, this novel compound could potentially add to the repertoire of methods for inducing therapeutic nutritional ketosis.

Ketogenic Approaches for the Treatment of Alzheimer's Disease.

Dementia represents one of the largest and most urgent public health problems across the globe. Modeling projections have estimated that delaying the onset of Alzheimer's disease (AD) by 6 months would reduce the prevalence by 5%, while a delay of 12 months would reduce the prevalence by 10%. One approach to achieving a delay in the onset of AD is to investigate lifestyle interventions that could be widely implemented with a favorable risk-benefit relationship and socioeconomic profile. Amongst such interventions, there is increasing evidence to support the use of ketogenic interventions in AD. Indeed, it is well known that cerebral glucose metabolism is impaired in AD, even at a preclinical stage, and a growing body of literature suggests that these findings may represent a primary pathogenic mechanism leading to neurodegeneration. Ketones are readily taken up by the brain and can serve as an alternative energy source for neurons and glia, hypothetically bypassing the glucose uptake deficit in AD. In this invited review we discuss the preclinical as well as clinical work aiming to increase ketones as a primary intervention in AD, including variations of the ketogenic diet, medium chain triglyceride supplementation, and newer, more experimental approaches.

Investigating the impact of ketogenic diets.

Exposure to ketone bodies in early development can reduce neurological impairments in a strain of the nematode C. elegans with PTEN defects.

Role of the ketogenic diet in the treatment of epilepsy

role of the ketogenic diet in the treatment of epilepsy

Exploring the role of ketogenic diet in ADPKD treatment: A promising avenue.

Dear Editor, This letter intends to highlight the importance of the keto diet in the treatment and slowing the progression of Autosomal Dominant Polycystic Kidney Disease (ADPKD). We aim to increase awareness about this newly advertised nutrition plan for ADPKD patients. Autosomal Dominant Polycystic Kidney Disease (ADPKD) is a disease that continuously expands multiple cysts in both kidneys. Clinical symptoms (Flanks pain, haematuria, hypertension) mostly develop in the fourth decade of life and around 50% of almost 12 million worldwide affected people will go into end-stage renal disease (ESRD) in their sixth decade of life.1 In 2015, EMA approved the use of Vasopressin receptor antagonists, i.e., tolvaptan, for the treatment of ADPKD in adults with CKD stages 1-3 and with rapidly progressive disease.2 However, these drugs are associated with side effects such as transient extracellular volume reduction and continuous symptoms of increased aquaresis, liver toxicity, avoiding pregnancy and breastfeeding and drug interactions.2 Moreover, strict criteria for patient selection such as GFR values, changes in GFR, patient age and cost-effectiveness needed to be fulfilled before commencing this particular therapy.2 The ongoing advancements in medical sciences have recently provided evidence that introducing the keto diet in patients with ADPKD can lead to a decline in the reduction rate of GFR and to a reduced rate of increasing kidney volume.3,4 A small study published in November 2023 compared the effects of the keto diet (KD) with control and water fasting groups.5 KD group surprisingly showed a decrease in height-adjusted total kidney volume by 0.55% and height-adjusted total liver volume by 4.7%.5 The most important observed effect was an increase in eGFR by 5.5% compared to the other groups, which showed a decrease in eGFR.5 Serum levels of Beta Hydroxy Butyrate were used to evaluate the ketosis state.5 The most commonly reported side effect was transiently occurring keto flu. However, one patient developed appendicitis and one patient also had nephrolithiasis.5 This three-month duration study overall shows good outcomes in ADPKD patients. We encourage physicians and the broader community of nephrologists to prioritise and carry out larger-scale randomised controlled trials based on the previously mentioned study using the keto diet in the management of ADPKD patients. This will require not only the aggressive participation of physicians in carrying out the research study but also the active education of the general public about this newly introduced nutrition plan. ---Continue

Ketogenic β-hydroxybutyrate regulates β-hydroxybutyrylation of TCA cycle-associated enzymes and attenuates disease-associated pathologies in Alzheimer's mice.

Lysine β-hydroxybutyrylation (Kbhb) is a post-translational modification that has recently been found to regulate protein functions. However, whether and how protein Kbhb modification participates in Alzheimer's disease (AD) remains unknown. Herein, we carried out 4D label-free β-hydroxybutylation quantitative proteomics using brain samples of 8-month-old and 2-month-old APP/PS1 AD model mice and wild-type (WT) controls. We identified a series of tricarboxylic acid (TCA) cycle-associated enzymes including citrate synthase (CS) and succinate-CoA ligase subunit alpha (SUCLG1), whose Kbhb modifications were decreased in APP/PS1 mice at pathological stages. Sodium β-hydroxybutyrate (Na-β-OHB) treatment markedly increased Kbhb modifications of CS and SUCLG1 and their enzymatic activities, leading to elevated ATP production. We further found that Kbhb modifications at lysine 393 site in CS and at lysine 81 site in SUCLG1 were crucial for their enzymatic activities. Finally, we found that β-OHB levels were decreased in the brain of APP/PS1 mice at pathological stages. While ketogenic diet not only significantly increased β-OHB levels, Kbhb modifications and enzymatic activities of CS and SUCLG1, and ATP production, but also dramatically attenuated β-amyloid plaque pathologies and microgliosis in APP/PS1 mice. Together, our findings indicate the importance of protein Kbhb modification for maintaining normal TCA cycle and ATP production and provide a novel molecular mechanism underlying the beneficial effects of ketogenic diet on energy metabolism and AD intervention.

Mapping the evolution and impact of ketogenic diet research on diabetes management: a comprehensive bibliometric analysis from 2005 to 2024.

The ketogenic diet (KD) has been explored for diabetes management; however, a quantitative synthesis of its specific effects on diabetes has not yet been conducted. This study aims to examine the current status and research hotspots of KD in diabetes management from 2005 to 2024, providing a reference for future research. We retrieved articles published between 2005 and 2024 from the Web of Science database and analyzed them using R software, VOSviewer, and CiteSpace. This study includes 432 relevant publications. From 2005 to 2024, the volume of literature in this field has shown a steady upward trend, with a notable increase from 2017 to 2021, and a slight decline observed from 2021 to 2023. The United States is the leading country in terms of the number of publications, followed by China, Australia, and Canada. The United States not only leads in publication volume but also maintains a broader international collaboration network. Nutrients and the American Journal of Clinical Nutrition are the most frequently published and cited journals. Current research hotspots primarily focus on the impact of KD on blood glucose control, insulin resistance, and lipid metabolism in diabetic patients. Mechanistic studies on KD in diabetes management concentrate on aspects such as the "regulation of genes by β-hydroxybutyrate," "anti-inflammatory effects," and "oxidative stress." The role of the gut microbiome is also emerging as an important research area. Currently, exploring the application of KD in managing different age groups and types of diabetes has become a significant research trend. As an emerging dietary intervention, KD is gradually attracting widespread attention from researchers around the world and is expected to become a major research focus in the future for diabetes management and control. This paper provides a systematic review and analysis of the current research status and hotspots of KD in diabetes management, offering important references and insights for future research in related fields.

CHARACTERISATION OF THE RESPONSE OF PRE-CLINICAL MODELS OF GLIOMA TO METABOLIC THERAPIES USING IN VIVO MAGNETIC RESONANCE SPECTROSCOPY

Abstract AIMS Magnetic resonance imaging (MRI) is routinely used to diagnose and monitor brain tumours. Magnetic resonance spectroscopy (MRS) allows us to record the metabolic profile of tumours in situ. This provides a non-invasive method to monitor the response of tumours to metabolic therapies. We aimed to characterise the response of pre-clinical models of glioma to metabolic therapies such as arginine deprivation and the ketogenic diet (KD) by MRS, to better understand what metabolic changes are occurring in the tumour. METHOD We performed orthotopic injection of three different cell lines, including the syngeneic models GL261 and CT2A, as well as a primary GBM cell line, into the striatum of C57BL/6 and athymic nude mice respectively. Mice were randomised to either arginine deprivation treatment using pegylated arginine deiminase (ADI), or KD, plus controls. In each animal, we collected single voxel MRS data using STEAM on both the tumour itself, and healthy brain. MRS data was exported in jMRUI format and analysed in R using the spant package, followed by PCA and OPLS-DA. RESULTS PCA showed that there is clear distinction between healthy and tumour spectra across all models. OPLS-DA indicated that the lipid and choline spectral regions were significantly associated with tumour, whereas the NAA and glutamine/glutamate regions were significantly associated with healthy brain. Integration of specific peaks associated with these metabolites confirmed these results. Subset analysis indicated distinct metabolic signatures between the syngeneic models and the primary GBM model. Furthermore, there is evidence to suggest that tumours in animals treated with arginine deprivation have a unique metabolic signature. CONCLUSION This data indicates that the tumour specific response to metabolic therapies can be measured by routine MRS screening. This would allow a non-invasive method by which clinicians could monitor the effectiveness of metabolic therapies in patients with gliomas.

Correction: Toivio et al. Ketogenic Diet High in Saturated Fat Promotes Colonic Claudin Expression without Changes in Intestinal Permeability to Iohexol in Healthy Mice. Nutrients 2024, 16, 18

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Unveiling the Potential of Gut Microbiota: Promising Approaches to Treat Drug-Resistant Epilepsy

Introduction: Epilepsy is a chronic, non-infectious disease of the brain. Data shows that even 70 million people worldwide suffer from it and one-third of them fail to control it with anti-epileptic drugs. The gut microbiota has an impact on the course of the disease. The microbiota mediates between the gastrointestinal system and the central nervous system.Purpose: The aim of the work is to analyse how modification of the gut microbiota affects patients with drug-resistant epilepsy.Material and method: In December 2023, an extensive search was conducted and articles found in the Medline (PubMed) databases were selected by using the following keywords: drug-resistant epilepsy, gut microbiota, gut-brain axis, ketogenic diet, probiotics, faecal microbiota transplantation, to focus on recent developments and advancements in the field, the search was limited to articles published between 2017 and 2023.Conclusions: The intestinal microbiota in drug-resistant epilepsy (DRE) patients differs from that of healthy individuals or drug-sensitive epilepsy patients. Acknowledging the presence of the gut-brain axis and its impact on the central nervous system, we can view altering the flora as a potential therapeutic approach for DRE patients. The ways in which microbiota changes have been confirmed by research include: ketogenic diet, antibiotics, probiotics and fecal microbiota transplantation (FMT). Modifying the microbiota through these mentioned methods is all promising for treating DRE.

Nutritional aspects in neuroendocrine neoplasms. bridging the gap between dietary interventions and cancer care strategies: a scoping review.

Neuroendocrine neoplasms (NENs) represent heterogeneous tumors arising from neuroendocrine cells in different organs. Despite growing interest in the nutritional aspects of NEN management, research in this area is limited. Aim of this review is to summarize the current state of knowledge, highlight research gaps, and underscore the significance of nutrition in the comprehensive care of NEN patients. We conducted an extensive bibliographic search focusing on studies (including retrospective and prospective studies, systematic reviews, case series, and guidelines) exploring the relationship between nutritional assessments, dietary interventions, micronutrient deficiencies, and their impact on NEN outcomes. Significant gaps exist in current research, particularly in understanding the specific nutritional needs of NEN patients and how tailored nutritional interventions can improve clinical outcomes. Evidence suggests that a high-fat Western diet may promote the growth of NEN, while a Mediterranean diet may help lower insulin levels and strengthen the immune system, potentially preventing tumor development. The ketogenic diet and intermittent fasting may also have positive impacts. Addressing common micronutrient deficiencies, such as vitamin D and niacin, is crucial to mitigate disease progression. There's a crucial need for future studies to include a comprehensive nutritional assessment incorporating patient-reported outcomes, to fully capture the impact of nutritional strategies. Nutritional management, an important but under-researched facet of NEN treatment, significantly improves patients' quality of life and survival. Integrating nutrition into personalized cancer care is essential, highlighting the role of nutritional strategies in optimizing patient outcomes.

Impact of Ketogenic Diet in Metabolic & Brain Health

Abstract Not Available Journal of Monno Medical College December, 2023;9(2):34-36

Is a Meta-Analysis of Clinical Trial Outcomes for Ketogenic Diets Justifiable? A Critical Assessment Based on Systematic Research.

While the macronutrient content of a ketogenic diet specifically utilized for childhood epilepsy is clearly defined in the literature, variations among other ketogenic diets exhibit substantial heterogeneity. Furthermore, studies utilizing ketogenic diets contain several confounders with notable impacts on outcomes, thereby rendering both their findings and those of the meta-analyses less reliable. The objective of this meta-epidemiological assessment was to scrutinize existing clinical trials that investigated the effects of ketogenic diets on patients with obesity and diabetes, thereby determining the feasibility of conducting a meta-analysis. The Ovid Medline, Scopus, Cochrane Central Register of Controlled Trials (CENTRAL), and Embase databases were searched from 1946 to 24 September 2024. Of the studies reviewed, none met the predefined inclusion criteria. However, seven articles met these criteria very closely. In the future, studies investigating the effects of ketogenic diets containing significant confounding factors should adopt a single definition of a ketogenic diet. Additionally, accurate measurement of actual macronutrient and caloric intake, along with regularly monitored nutritional ketosis, will be essential to highlight the true effects of a ketogenic diet.