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1.
Proc Natl Acad Sci U S A ; 121(36): e2321874121, 2024 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-39207736

RESUMO

Medium chain fatty acids are commonly consumed as part of diets for endurance sports and as medical treatment in ketogenic diets where these diets regulate energy metabolism and increase adenosine levels. However, the role of the equilibrative nucleoside transporter 1 (ENT1), which is responsible for adenosine transport across membranes in this process, is not well understood. Here, we investigate ENT1 activity in controlling the effects of two dietary medium chain fatty acids (decanoic and octanoic acid), employing the tractable model system Dictyostelium. We show that genetic ablation of three ENT1 orthologues unexpectedly improves cell proliferation specifically following decanoic acid treatment. This effect is not caused by increased adenosine levels triggered by both fatty acids in the presence of ENT1 activity. Instead, we show that decanoic acid increases expression of energy-related genes relevant for fatty acid ß-oxidation, and that pharmacological inhibition of ENT1 activity leads to an enhanced effect of decanoic acid to increase expression of tricarboxylicacid cycle and oxidative phosphorylation components. Importantly, similar transcriptional changes have been shown in the rat hippocampus during ketogenic diet treatment. We validated these changes by showing enhanced mitochondria load and reduced lipid droplets. Thus, our data show that ENT1 regulates the medium chain fatty acid-induced increase in cellular adenosine levels and the decanoic acid-induced expression of important metabolic enzymes in energy provision, identifying a key role for ENT1 proteins in metabolic effects of medium chain fatty acids.


Assuntos
Metabolismo Energético , Transportador Equilibrativo 1 de Nucleosídeo , Adenosina/metabolismo , Adenosina/farmacologia , Caprilatos/farmacologia , Proliferação de Células/efeitos dos fármacos , Dictyostelium/metabolismo , Dictyostelium/genética , Dictyostelium/efeitos dos fármacos , Dieta Cetogênica , Gorduras na Dieta/farmacologia , Gorduras na Dieta/metabolismo , Metabolismo Energético/efeitos dos fármacos , Transportador Equilibrativo 1 de Nucleosídeo/metabolismo , Transportador Equilibrativo 1 de Nucleosídeo/genética , Regulação da Expressão Gênica/efeitos dos fármacos , Mitocôndrias/metabolismo , Mitocôndrias/efeitos dos fármacos
2.
J Nutr ; 153(7): 1944-1949, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-37182692

RESUMO

BACKGROUND: Early studies show that ketogenic diets (KDs) lead to preferential loss of fat mass (FM), whereas preserving fat-free mass (FFM). Additionally, animal data support the anticatabolic effects of DL-3-hydroxybutyrate. From our knowledge, a potential association between ß-hydroxybutyrate (ßHB) plasma concentrations and changes in body composition has never been explored. OBJECTIVES: The main aim of this analysis was to determine if ßHB plasma concentrations, following hypocaloric KDs, were associated with FM and FFM changes in men and women with obesity. METHODS: Data from 199 individuals (BMI = 36.6 ± 4.3 kg/m2; age = 43.6 ± 9.8 y; 82 men) were collated from 3 weight loss studies employing common measures of body composition (air displacement plethysmography) and ßHB plasma concentration (ELISA). The association between ßHB and weight, FM and FFM loss (kg), and %FFM loss (%FFML) was investigated with Spearman correlation. Multivariable linear regression was used to determine if ßHB was a significant predictor of the changes in anthropometric variables, after adjusting for confounding factors. RESULTS: ßHB was not associated with FFML (% or kg), but a weak positive association was seen with FM loss (r = 0.182, P = 0.01, n = 199) and a trend with weight loss (r = 0.128, P = 0.072, n = 199). ßHB was a significant predictor of both weight and FM loss (kg), after adjusting for age, sex, baseline BMI, and intervention study. CONCLUSIONS: The magnitude of ketosis is not associated with FFM preservation. However, the higher the level of ketosis, the greater the weight and FM loss. Further studies are needed to confirm these findings and to explore the mechanisms involved. This trial was registered at clinicaltrials.gov identifier as NCT01834859, NCT04051190, NCT02944253.


Assuntos
Dieta Cetogênica , Feminino , Humanos , Composição Corporal , Índice de Massa Corporal , Obesidade , Redução de Peso
3.
Microb Pathog ; 155: 104899, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33894293

RESUMO

OBJECTIVE: The aim of this study was to investigate the composition of the intestinal microbiota and its association with fecal short chain fatty acids (SCFAs) in children with drug refractory epilepsy (DRE) before and after treatment with a ketogenic diet (KD). METHODS: Herein, we conducted a cross-sectional study of 12 children with DRE and 12 matched healthy controls to compare the changes in fecal microbiomes and SCFAs. Disease cohort also underwent analysis before and after 6 months of KD treatment. RESULTS: A higher microbial alpha diversity and a significant increase in Actinobacteria at the phylum level and Enterococcus, Anaerostipes, Bifidobacterium, Bacteroides, and Blautia at the genus level were observed in the children with DRE. The abundance of the eight epileptic-associated genera was reversed after six months of KD treatment with decreases in Bifidobacterium, Akkermansia, Enterococcaceae and Actinomyces and increases in Subdoligranulum, Dialister, Alloprevotella (p < 0.05). In particular, we identified some taxa that were more prevalent in patients with an inadequate response to KD than in those with an adequate response. Further, a significant correlation was observed between the change in the microbiome genera after KD treatment. The SCFA content in the fecal after 6 months of KD treatment increased and was highly correlated with the gut bacteria. SIGNIFICANCES: Dysbiosis of the microbiome could be involved in the pathogenesis of DRE in children, which can be relieved by a KD to a large extent. Gut microbiota and microbial metabolism could contribute to the antiseizure effect of KD.


Assuntos
Dieta Cetogênica , Epilepsia , Microbioma Gastrointestinal , Criança , Estudos Transversais , Disbiose , Fezes , Humanos
4.
Epilepsia ; 62(8): 1790-1806, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34169513

RESUMO

Many studies show that glucose metabolism in epileptic brain areas can be impaired. Energy is crucial to maintain normal brain function, including ion and neurotransmitter balances. Energy deficits can lead to disruption of ion gradients, which can trigger neuronal depolarization and generation of seizures. Thus, perturbed metabolic processing of glucose in epileptogenic brain areas indicates a specific nutritional need for people and animals with epilepsy, as they are likely to benefit from auxiliary brain fuels other than glucose. Ketogenic diets provide the ketone bodies acetoacetate and ß-hydroxybutyrate, which can be used as auxiliary fuel by the brain. In approximately 50% children and adults with certain types of epilepsy, who can tolerate and maintain these dietary regimens, seizure frequency can be effectively reduced. More recent data demonstrate that addition of medium chain triglycerides (MCTs), which provide the medium chain fatty acids octanoic and decanoic acid, as well as ketone bodies as auxiliary brain energy, can be beneficial in rodent seizure models, and dogs and humans with epilepsy. Here, this evidence is reviewed, including tolerance in 65% of humans, efficacy studies in dogs, possible anticonvulsant mechanisms of actions of MCTs, and specifically decanoic acid as well as metabolic and antioxidant mechanisms. In conclusion, MCTs are a promising adjunct to standard pharmacological treatment for both humans and dogs with epilepsy, as they lack central nervous system side effects found with current antiepileptic drugs. There is now a need for larger clinical trials in children, adults, and dogs to find the ideal composition and doses of MCTs and the types of epilepsy that respond best.


Assuntos
Epilepsia , Animais , Anticonvulsivantes/uso terapêutico , Ácidos Decanoicos , Dieta Cetogênica , Cães , Epilepsia/dietoterapia , Epilepsia/tratamento farmacológico , Glucose , Humanos , Corpos Cetônicos , Roedores , Convulsões , Triglicerídeos
5.
Int J Mol Sci ; 22(1)2021 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-33406758

RESUMO

The existence of a common mesenchymal cell progenitor shared by bone, skeletal muscle, and adipocytes cell progenitors, makes the role of the skeleton in energy metabolism no longer surprising. Thus, bone fragility could also be seen as a consequence of a "poor" quality in nutrition. Ketogenic diet was originally proven to be effective in epilepsy, and long-term follow-up studies on epileptic children undergoing a ketogenic diet reported an increased incidence of bone fractures and decreased bone mineral density. However, the causes of such negative impacts on bone health have to be better defined. In these subjects, the concomitant use of antiepileptic drugs and the reduced mobilization may partly explain the negative effects on bone health, but little is known about the effects of diet itself, and/or generic alterations in vitamin D and/or impaired growth factor production. Despite these remarks, clinical studies were adequately designed to investigate bone health are scarce and bone health related aspects are not included among the various metabolic pathologies positively influenced by ketogenic diets. Here, we provide not only a narrative review on this issue, but also practical advice to design and implement clinical studies on ketogenic nutritional regimens and bone health outcomes. Perspectives on ketogenic regimens, microbiota, microRNAs, and bone health are also included.


Assuntos
Desenvolvimento Ósseo , Dieta Cetogênica/estatística & dados numéricos , Metabolismo Energético , Fraturas Ósseas/prevenção & controle , Projetos de Pesquisa/estatística & dados numéricos , Animais , Ensaios Clínicos como Assunto , Humanos , Estudos Prospectivos
6.
Nutr Res Rev ; 33(2): 260-270, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-32102704

RESUMO

The purpose of the present review is to describe how human physiology at very low carbohydrate intakes relates to the criteria for nutritional essentiality. Although we did not limit ourselves to one particular type or function of carbohydrates, we did primarily focus on glucose utilisation as that function was used to determine the recommended daily allowance. In the general population, the human body is able to endogenously synthesise carbohydrates, and does not show signs of deficiency in the absence of dietary carbohydrates. However, in certain genetic defects, such as glycogen storage disease type I, absence of dietary carbohydrates causes abnormalities that are resolved with dietary supplementation of carbohydrates. Therefore, dietary carbohydrates may be defined as conditionally essential nutrients because they are nutrients that are not required in the diet for the general population but are required for specific subpopulations. Ketosis may be considered a physiological normal state due to its occurrence in infants in addition to at very low carbohydrate intakes. Although sources of dietary carbohydrates can provide beneficial micronutrients, no signs of micronutrient deficiencies have been reported in clinical trials of low-carbohydrate ketogenic diets. Nonetheless, more research is needed on how micronutrient requirements can change depending on the dietary and metabolic context. More research is also needed on the role of dietary fibre during a low-carbohydrate ketogenic diet as the beneficial effects of dietary fibre were determined on a standard diet and several studies have shown beneficial effects of decreasing non-digestible carbohydrates.


Assuntos
Dieta , Carboidratos da Dieta , Desnutrição , Necessidades Nutricionais , Dieta Cetogênica , Fibras na Dieta , Humanos , Cetose , Desnutrição/etiologia , Micronutrientes/deficiência , Recomendações Nutricionais
7.
Rev Endocr Metab Disord ; 20(4): 415-425, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31720986

RESUMO

Gut microbiota (GM) is a key contributor to host metabolism and physiology. Data generated on comparing diseased and healthy subjects have reported changes in the GM profile between both health states, suggesting certain bacterial composition could be involved in pathogenesis. Moreover, studies reported that reshaping of GM could contribute actively to disease recovery. Interestingly, ketogenic diets (KD) have emerged recently as new economic dietotherapeutic strategy to combat a myriad of diseases (refractory epilepsy, obesity, cancer, neurodegenerative diseases…). KD, understood in a broad sense, refers to whatever dietetic approximation, which causes physiological ketosis. Therefore, high fat-low carbs diets, fasting periods or caloric restriction constitute different strategies to produce an increase of main ketones bodies, acetoacetate and ß-hydroxybutyrate, in blood. Involved biological mechanisms in ketotherapeutic effects are still to be unravelled. However, it has been pointed out that GM remodelling by KD, from now on "keto microbiota", may play a crucial role in patient response to KD treatment. In fact, germ-free animals were resistant to ketotherapeutic effects; reinforcing keto microbiota may be a powerful contributor to host disease recovery. In this review, we will comment the influence of gut microbiota on host, as well as, therapeutic potential of ketogenic diets and keto microbiota to restore health status. Current progress and limitations will be argued too. In spite of few studies have defined applicability and mechanisms of KD, in the light of results, keto microbiota might be a new useful therapeutic agent.


Assuntos
Microbioma Gastrointestinal/fisiologia , Animais , Dieta Cetogênica , Disbiose/microbiologia , Humanos , Cetose/microbiologia
8.
Br J Nutr ; 120(5): 484-490, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-30001753

RESUMO

Consumption of diets containing medium-chain TAG (MCT) has been shown to confer neuroprotective effects. We aim to identify the global metabolic perturbations associated with consumption of a ketogenic diet (medium-chain TAG diet (MCTD)) in dogs with idiopathic epilepsy. We used ultra-performance liquid chromatography-MS (UPLC-MS) to generate metabolic and lipidomic profiles of fasted canine serum and made comparisons between the MCTD and standardised placebo diet phases. We identified metabolites that differed significantly between diet phases using metabolite fragmentation profiles generated by tandem MS (UPLC-MS/MS). Consumption of the MCTD resulted in significant differences in serum metabolic profiles when compared with the placebo diet, where sixteen altered lipid metabolites were identified. Consumption of the MCTD resulted in reduced abundances of palmitoylcarnitine, octadecenoylcarnitine, stearoylcarnitine and significant changes, both reduced and increased abundances, of phosphatidylcholine (PC) metabolites. There was a significant increase in abundance of the saturated C17 : 0 fatty acyl moieties during the MCTD phase. Lysophosphatidylcholine (17 : 0) (P=0·01) and PC (17:0/20:4) (P=0·03) were both significantly higher in abundance during the MCTD. The data presented in this study highlight global changes in lipid metabolism, and, of particular interest, in the C17 : 0 moieties, as a result of MCT consumption. Elucidating the global metabolic response of MCT consumption will not only improve the administration of current ketogenic diets for neurological disease models but also provides new avenues for research to develop better diet therapies with improved neuroprotective efficacies. Future studies should clarify the involvement and importance of C17 : 0 moieties in endogenous MCT metabolic pathways.


Assuntos
Dieta Cetogênica/efeitos adversos , Doenças do Cão/dietoterapia , Epilepsia/veterinária , Lipídeos/sangue , Triglicerídeos/administração & dosagem , Animais , Anticonvulsivantes , Carnitina/análogos & derivados , Carnitina/sangue , Cromatografia Líquida , Estudos Cross-Over , Dieta/veterinária , Doenças do Cão/sangue , Cães , Epilepsia/dietoterapia , Jejum , Ácidos Graxos/administração & dosagem , Ácidos Graxos/sangue , Feminino , Metabolismo dos Lipídeos/efeitos dos fármacos , Masculino , Espectrometria de Massas , Metaboloma , Fosfatidilcolinas/sangue , Placebos
9.
Headache ; 56(9): 1553-1562, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27699772

RESUMO

BACKGROUND: Comprehensive diets do not require the exclusion of a specific provocative food or ingredient, but regulate the quantities of core components of foods such as vitamins, ions, proteins, carbohydrates, and fats. OBJECTIVES: To review the evidence supporting the use of comprehensive diets in the prevention of migraine and other headache disorders and to discuss the mechanisms through which food, and ingredients within foods and beverages might trigger attacks of headache METHODS: This represents Part 2 of a narrative review of the role of diet in the prevention of migraine and other headache disorders. A PubMed search was performed with the following search terms: "folate," "vitamin D," "low fat diet," "omega-3 and omega-6 fatty acid diet," "ketogenic diet," "Atkins diet," and "sodium." Each of these search terms was then crossreferenced with "headache" and "migraine" to identify relevant studies. Only studies that were written in English were included in this review. RESULTS: Low fat and high omega-3/low omega-6 fatty diets decrease the frequency of attacks of migraine and/or other headache disorders as demonstrated in two separate randomized controlled trials. A ketogenic diet was more effective than a standard diet in reducing the frequency of migraine in a single nonrandomized clinical study. An observation study found that dietary consumption of folate was inversely associated with the frequency of migraine attacks in persons with migraine with aura that have the C variant of the methylene tetrahydrofolate reductase gene. The mechanisms though which diets may precipitate headache include their effects on neuropeptides, neuro-receptors and ion channels, inflammation, sympathetic nervous system, release of nitric oxide, vasodilation, and cerebral glucose metabolism. CONCLUSIONS: Evidence exists to support the use of comprehensive diets in the prevention of migraine and other headache disorders. However, the results of these studies should be considered preliminary until replicated in larger randomized controlled clinical trials.


Assuntos
Dietoterapia , Transtornos da Cefaleia/dietoterapia , Transtornos da Cefaleia/prevenção & controle , Cefaleia/dietoterapia , Cefaleia/prevenção & controle , Dieta/efeitos adversos , Dietoterapia/métodos , Cefaleia/fisiopatologia , Transtornos da Cefaleia/fisiopatologia , Humanos
10.
Diabetologia ; 58(10): 2414-23, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26099854

RESUMO

AIMS/HYPOTHESIS: Ketogenic diets (KDs) have increasingly gained attention as effective means for weight loss and potential adjunctive treatment of cancer. The metabolic benefits of KDs are regularly ascribed to enhanced hepatic secretion of fibroblast growth factor 21 (FGF21) and its systemic effects on fatty-acid oxidation, energy expenditure (EE) and body weight. Ambiguous data from Fgf21-knockout animal strains and low FGF21 concentrations reported in humans with ketosis have nevertheless cast doubt regarding the endogenous function of FGF21. We here aimed to elucidate the causal role of FGF21 in mediating the therapeutic benefits of KDs on metabolism and cancer. METHODS: We established a dietary model of increased vs decreased FGF21 by feeding C57BL/6J mice with KDs, either depleted of protein or enriched with protein. We furthermore used wild-type and Fgf21-knockout mice that were subjected to the respective diets, and monitored energy and glucose homeostasis as well as tumour growth after transplantation of Lewis lung carcinoma cells. RESULTS: Hepatic and circulating, but not adipose tissue, FGF21 levels were profoundly increased by protein starvation, independent of the state of ketosis. We demonstrate that endogenous FGF21 is not essential for the maintenance of normoglycaemia upon protein and carbohydrate starvation and is therefore not needed for the effects of KDs on EE. Furthermore, the tumour-suppressing effects of KDs were independent of FGF21 and, rather, driven by concomitant protein and carbohydrate starvation. CONCLUSIONS/INTERPRETATION: Our data indicate that the multiple systemic effects of KD exposure in mice, previously ascribed to increased FGF21 secretion, are rather a consequence of protein malnutrition.


Assuntos
Dieta Cetogênica , Fatores de Crescimento de Fibroblastos/genética , Glucose/metabolismo , Homeostase/genética , Cetose/genética , Neoplasias/genética , Deficiência de Proteína/genética , Tecido Adiposo/metabolismo , Animais , Fatores de Crescimento de Fibroblastos/metabolismo , Cetose/metabolismo , Fígado/metabolismo , Camundongos , Camundongos Knockout , Neoplasias/dietoterapia , Neoplasias/metabolismo , Deficiência de Proteína/metabolismo
11.
Br J Nutr ; 114(9): 1438-47, 2015 11 14.
Artigo em Inglês | MEDLINE | ID: mdl-26337751

RESUMO

Despite appropriate antiepileptic drug treatment, approximately one-third of humans and dogs with epilepsy continue experiencing seizures, emphasising the importance for new treatment strategies to improve the quality of life of people or dogs with epilepsy. A 6-month prospective, randomised, double-blinded, placebo-controlled cross-over dietary trial was designed to compare a ketogenic medium-chain TAG diet (MCTD) with a standardised placebo diet in chronically antiepileptic drug-treated dogs with idiopathic epilepsy. Dogs were fed either MCTD or placebo diet for 3 months followed by a subsequent respective switch of diet for a further 3 months. Seizure frequency, clinical and laboratory data were collected and evaluated for twenty-one dogs completing the study. Seizure frequency was significantly lower when dogs were fed the MCTD (2·31/month, 0-9·89/month) in comparison with the placebo diet (2·67/month, 0·33-22·92/month, P=0·020); three dogs achieved seizure freedom, seven additional dogs had ≥50 % reduction in seizure frequency, five had an overall <50 % reduction in seizures (38·87 %, 35·68-43·27 %) and six showed no response. Seizure day frequency were also significantly lower when dogs were fed the MCTD (1·63/month, 0-7·58/month) in comparison with the placebo diet (1·69/month, 0·33-13·82/month, P=0·022). Consumption of the MCTD also resulted in significant elevation of blood ß-hydroxybutyrate concentrations in comparison with placebo diet (0·071 (sd 0·035) v. 0·053 (sd 0·028) mmol/l, P=0·028). There were no significant changes in serum concentrations of glucose (P=0·903), phenobarbital (P=0·422), potassium bromide (P=0·404) and weight (P=0·300) between diet groups. In conclusion, the data show antiepileptic properties associated with ketogenic diets and provide evidence for the efficacy of the MCTD used in this study as a therapeutic option for epilepsy treatment.


Assuntos
Dieta Cetogênica/veterinária , Epilepsia/dietoterapia , Epilepsia/veterinária , Convulsões/dietoterapia , Convulsões/veterinária , Triglicerídeos/administração & dosagem , Ácido 3-Hidroxibutírico/sangue , Animais , Anticonvulsivantes/administração & dosagem , Glicemia/metabolismo , Brometos/sangue , Estudos Cross-Over , Cães , Método Duplo-Cego , Feminino , Masculino , Fenobarbital/sangue , Compostos de Potássio/sangue , Estudos Prospectivos , Qualidade de Vida , Resultado do Tratamento
12.
Biomed J ; 47(1): 100677, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37940045

RESUMO

Overactivation of the NLRP3 inflammasome is implicated in chronic low-grade inflammation associated with various disease states, including obesity, type 2 diabetes, atherosclerosis, Alzheimer's disease, and Parkinson's disease. Emerging evidence, mostly from cell and animal models of disease, supports a role for ketosis in general, and the main circulating ketone body beta-hydroxybutyrate (BHB) in particular, in reducing NLRP3 inflammasome activation to improve chronic inflammation. As a result, interventions that can induce ketosis (e.g., fasting, intermittent fasting, time-restricted feeding/eating, very low-carbohydrate high-fat ketogenic diets) and/or increase circulating BHB (e.g., exogenous ketone supplementation) have garnered increasing interest for their therapeutic potential. The purpose of the present review is to summarize our current understanding of the literature on how ketogenic interventions impact the NLRP3 inflammasome across human, rodent and cell models. Overall, there is convincing evidence that ketogenic interventions, likely acting through multiple interacting mechanisms in a cell-, disease- and context-specific manner, can reduce NLRP3 inflammasome activation. The evidence supports a direct effect of BHB, although it is important to consider the myriad of other metabolic responses to fasting or ketogenic diet interventions (e.g., elevated lipolysis, low insulin, stable glucose, negative energy balance) that may also impact innate immune responses. Future research is needed to translate promising findings from discovery science to clinical application.


Assuntos
Diabetes Mellitus Tipo 2 , Dieta Cetogênica , Cetose , Animais , Humanos , Inflamassomos , Proteína 3 que Contém Domínio de Pirina da Família NLR , Corpos Cetônicos , Cetonas , Jejum , Ácido 3-Hidroxibutírico/metabolismo , Ácido 3-Hidroxibutírico/farmacologia , Inflamação
13.
Sports Health ; : 19417381241271547, 2024 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-39233399

RESUMO

CONTEXT: Ketogenic diets and ketone supplements have gained popularity among endurance runners given their purported effects: potentially delaying the onset of fatigue by enabling the increased utilization of the body's fat reserve or external ketone bodies during prolonged running. OBJECTIVE: This systematic review was conducted to evaluate the effects of ketogenic diets (>60% fat and <10% carbohydrates/<50 g carbohydrates per day) or ketone supplements (ketone esters or ketone salts, medium-chain triglycerides or 1,3-butadiol) on the aerobic performance of endurance runners. DATA SOURCES: A systematic search was conducted in PubMed, Web of Science, Pro Quest, and Science Direct for publications up to October 2023. STUDY SELECTION: Human studies on the effects of ketogenic diets or ketone supplements on the aerobic performance of adult endurance runners were included after independent screening by 2 reviewers. STUDY DESIGN: Systematic review. LEVEL OF EVIDENCE: Level 3. DATA EXTRACTION: Primary outcomes were markers of aerobic performance (maximal oxygen uptake [VO2max], race time, time to exhaustion and rate of perceived exertion). RESULTS: VO2max was assessed by incremental test to exhaustion. Endurance performance was assessed by time trials, 180-minute running trials, or run-to-exhaustion trials; 5 studies on ketogenic diets and 7 studies on ketone supplements involving a total of 132 endurance runners were included. Despite the heterogeneity in study design and protocol, none reported benefits of ketogenic diets or ketone supplements on selected markers of aerobic performance compared with controls. Reduction in bodyweight and fat while preserving lean mass and improved glycemic control were reported in some included studies on ketogenic diets. CONCLUSION: This review did not identify any significant advantages or disadvantages of ketogenic diets or ketone supplements for the aerobic performance of endurance runners. Further trials with larger sample sizes, more gender-balanced participants, longer ketogenic diet interventions, and follow-up on metabolic health are warranted.

14.
Diabetes Ther ; 15(1): 77-97, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37966583

RESUMO

Carbohydrate restriction has gained increasing popularity as an adjunctive nutritional therapy for diabetes management. However, controversy remains regarding the long-term suitability, safety, efficacy and potential superiority of a very low carbohydrate, ketogenic diet compared to current recommended nutritional approaches for diabetes management. Recommendations with respect to a ketogenic diet in clinical practice are often hindered by the lack of established definition, which prevents its capacity to be most appropriately prescribed as a therapeutic option for diabetes. Furthermore, with conflicted evidence, this has led to uncertainty amongst clinicians on how best to support and advise their patients. This review will explore whether a ketogenic diet has a place within clinical practice by reviewing current evidence and controversies.

15.
Acta Physiol (Oxf) ; 240(3): e14104, 2024 03.
Artigo em Inglês | MEDLINE | ID: mdl-38314929

RESUMO

AIM: Drug-resistant epilepsy (DRE) is a neurological disorder characterized by uncontrolled seizures. It affects between 10%-40% of the patients with epilepsy worldwide. Drug-resistant patients have been reported to have a different microbiota composition compared to drug-sensitive patients and healthy controls. Importantly, fecal microbiota transplantations (FMTs), probiotic and dietary interventions have been shown to be able to reduce seizure frequency and improve the quality of life in drug-resistant patients. The classic ketogenic diet (KD) and its modifications may reduce seizures in DRE in some patients, whereas in others they do not. The mechanisms mediating the dietary effects remain elusive, although it is known that gut microbes play an important role in transmitting dietary effects to the host. Indeed, specific commensal microbes differ even between responders and non-responders to KD treatment. METHODS: In this narrative mini-review, we summarize what is known about the gut microbiota changes and ketogenic diets with special focus on patients with DRE. RESULTS AND CONCLUSIONS: By highlighting unanswered questions and by suggesting future research directions, we map the route towards future improvement of successful DRE therapy.


Assuntos
Dieta Cetogênica , Microbioma Gastrointestinal , Microbiota , Humanos , Qualidade de Vida , Convulsões , Resultado do Tratamento
16.
Nutr Metab (Lond) ; 21(1): 50, 2024 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-39030553

RESUMO

OBJECTIVE: This study was designed to evaluate the impact of VLCKD on cardiovascular risk factors in patients with T2DM. METHODS: Until March 2024, extensive searches were conducted on PubMed, Scopus, Web of Science, Embase, and other relevant databases. The purpose was to identify clinical trials examining the impact of VLCKD on glycemic control, lipid profile, and blood pressure. The GRADE (Grading of Recommendations Assessment, Development, and Evaluation) method was used to assess the evidence's degree of certainty. RESULTS: Our initial search found a total of 2568 records and finally 29 trials were included in final analysis. Our results showed that adherence from VLCKD led to significant reduction in fasting blood sugar (WMD= -11.68 mg/dl; 95% CI: -18.79, -4.56; P = 0.001), HbA1c (WMD= -0.29; 95% CI: -0.44, -0.14; P < 0.001), HOMA-IR(WMD= -0.71; 95% CI: -1.14, -0.29; P = 0.001), insulin (WMD= -1.45; 95% CI: -2.54, -0.36; P = 0.009), triglyceride (WMD= -17.95; 95% CI: -26.82, -9.07; P < 0.001), systolic blood pressure (WMD= -2.85, 95% CI: -4.99, -0.71; P = 0.009) and diastolic blood pressure (WMD= -1.40; 95% CI: -2.66, -0.13; P = 0.03). We also found a significant increase in high-density lipoprotein (HDL) level after adherence from VLCKD diet (WMD = 3.93, 95% CI: 2.03, 5.84; P = 0.000). We couldn't find any significant differences between groups in term of LDL and total cholesterol levels. CONCLUSION: People following a VLCKD experience a more significant improvement in cardiovascular risk factors when compared to individuals on control diets.

17.
Curr Nutr Rep ; 13(3): 552-556, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39039372

RESUMO

PURPOSE OF REVIEW: In an attempt to clarify the most appropriate nomenclature for the very low-calorie ketogenic diets (VLCKD), we propose to change the nomenclature and acronym of this medical nutrition therapy. The new definition and acronym proposed by the "KetoNut" panel of experts of the Italian Society of Nutraceuticals (SINut) and the Italian Association of Dietetics and Clinical Nutrition (ADI) is Very Low-Energy Ketogenic Therapy (VLEKT). RECENT FINDINGS: In the last few years, different authors have focused on the issue of confusion in the nomenclature of ketogenic diets. In detail, have been differentiated the VLCKD that provides < 800 kcal per day, which is intended for the weight loss in the medical treatment of obesity, and a eucaloric ketogenic diet, which contains more calories from fat (predominantly unsaturated) and with specific ketogenic ratios, for allow growth in children while helping, at the same time, to establish epileptic seizure control. In recent years, ketogenic diets have attracted great interest for their efficacy in the treatment of epilepsy and other neurological diseases but also in patients with overweight and obesity-related metabolic disorders. Nevertheless, although ketogenic diets are a dietary intervention designed to induce nutritional ketosis, different diets with different macronutrients' composition have been called with this name. The confusion in the nomenclature of ketogenic diets may result in significant bias and mistakes in the interpretation of the current scientific evidence.


Assuntos
Dieta Cetogênica , Terminologia como Assunto , Humanos , Itália , Obesidade/dietoterapia , Restrição Calórica , Epilepsia/dietoterapia , Suplementos Nutricionais , Redução de Peso , Ingestão de Energia
18.
J Nutr Biochem ; 126: 109562, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38176626

RESUMO

Ketogenic diets (KDs) are very high-fat low-carbohydrate diets that promote nutritional ketosis and are widely used for weight loss, although concerns about potential adverse cardiovascular effects remain. We investigated a very high-fat KD's vascular impact and plasma metabolic signature compared to a non-ketogenic high-fat diet (HFD). Apolipoprotein E deficient (ApoE -/-) mice were fed a KD (%kcal:81:1:18, fat/carbohydrate/protein), a non-ketogenic high-fat diet with half of the fat content (HFD) (%kcal:40:42:18, fat/carbohydrate/protein) for 12 weeks. Plasma samples were used to quantify the major ketone body beta-hydroxybutyrate (BHB) and several pro-inflammatory cytokines (IL-6, MCP-1, MIP-1alpha, and TNF alpha), and to targeted metabolomic profiling by mass spectrometry. In addition, aortic atherosclerotic lesions were quantified ex-vivo by magnetic resonance imaging (MRI) on a 14-tesla system. KD was atherogenic when compared to the control diet, but KD mice, when compared to the HFD group (1) had markedly higher levels of BHB and lower levels of cytokines, confirming the presence of ketosis that alleviated the well-established fat-induced systemic inflammation; (2) displayed significant changes in the plasma metabolome that included a decrease in lipophilic metabolites and an increase in hydrophilic metabolites; (3) had significantly lower levels of several atherogenic lipid metabolites, including phosphatidylcholines, cholesterol esters, sphingomyelins, and ceramides; and (4) presented significantly lower aortic plaque burden. KD was atherogenic and was associated with specific metabolic changes but alleviated the fat-induced inflammation and lessened the progression of atherosclerosis when compared to the HFD.


Assuntos
Aterosclerose , Cetose , Camundongos , Animais , Dieta Hiperlipídica/efeitos adversos , Aterosclerose/etiologia , Aterosclerose/patologia , Inflamação/metabolismo , Citocinas/metabolismo , Fator de Necrose Tumoral alfa/metabolismo , Metaboloma
19.
Nutrients ; 16(14)2024 Jul 13.
Artigo em Inglês | MEDLINE | ID: mdl-39064705

RESUMO

There is currently a growing interest in diets and physical activity patterns that may be beneficial in preventing and treating breast cancer (BC). Mounting evidence indicates that indeed, the so-called Mediterranean diet (MedDiet) and regular physical activity likely both help reduce the risk of developing BC. For those who have already received a BC diagnosis, these interventions may decrease the risk of tumor recurrence after treatment and improve quality of life. Studies also show the potential of other dietary interventions, including fasting or modified fasting, calorie restriction, ketogenic diets, and vegan or plant-based diets, to enhance the efficacy of BC therapies. In this review article, we discuss the biological rationale for utilizing these dietary interventions and physical activity in BC prevention and treatment. We highlight published and ongoing clinical studies that have applied these lifestyle interventions to BC patients. This review offers valuable insights into the potential application of these dietary interventions and physical activity as complimentary therapies in BC management.


Assuntos
Neoplasias da Mama , Dieta Cetogênica , Dieta Mediterrânea , Exercício Físico , Humanos , Neoplasias da Mama/prevenção & controle , Neoplasias da Mama/terapia , Feminino , Restrição Calórica , Qualidade de Vida , Dieta
20.
Cureus ; 16(5): e61045, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38800782

RESUMO

Diabetes mellitus is a collection of metabolic disorders marked by elevated levels of glucose in the blood due to irregularities in the generation or functioning of insulin. Medical nutrition therapy and weight loss are crucial elements in the management of diabetes and the prevention of complications. Several diets have become popular over time for the goal of achieving weight loss, but their popularity has declined due to a lack of reliable scientific evidence. This study classifies popular diets into three categories: diets that manage the composition of macronutrients, diets that restrict specific foods or food groups, and diets that manipulate meal timing. The review includes research studies that investigated the effects of popular diets on the prevention, management, and complications of diabetes. It is clear that different popular diets can have positive effects on both preventing and treating diabetes and preventing and treating complications related to diabetes. However, it is not practical to determine which diet is the most effective option for preventing or controlling diabetes. Thus, the main focus should be on common underlying factors that support well-being, such as decreasing the intake of refined grains and added sugar, choosing non-starchy vegetables, and giving priority to whole foods over processed foods whenever possible, until there is stronger evidence supporting the specific benefits of different dietary patterns.

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