Ketogenic diets and pain

Effects of nutritional interventions on cognitive function in adult cancer survivors: A systematic review

AIM

To evaluate the effectiveness and safety of nutritional interventions (i.e. nutritional support, dietary patterns and dietary supplements) on cognitive function in cancer survivors.

DESIGN

Systematic review.

METHODS

A systematic and comprehensive search of PubMed, Web of Science, the Cochrane Library, Embase, and CINAHL was conducted from the inception until March 10, 2023. The last search was conducted on December 10, 2023.

REPORTING METHOD

PRISMA.

RESULTS

A total of 59 randomized controlled trials were included for analysis. Nutritional support, dietary patterns and dietary supplements improved cognitive function in cancer survivors with no apparent safety concerns. The anti-inflammatory diet, the fasting-mimicking diet and the web-based diet significantly improved cognitive function. Whereas the ketogenic diet or dietary advice to consume more soluble dietary fibres and less insoluble dietary fibres and lactose could not. There was evidence from dietary supplements to support the beneficial effects of polyunsaturated fatty acid supplements, traditional herbal medicines and other supplements.

CONCLUSIONS

Nutritional interventions have great promise for improving cognitive function in adult cancer survivors. Further validation of the nutritional interventions supported in this study in other survivors and exploration of more effective nutritional interventions are needed.

IMPLICATIONS FOR THE PROFESSION AND/OR PATIENT CARE

This work can support the construction of nutritional support interventions and dietary guidance programs to prevent cancer-related cognitive decline.

IMPACT

This work filled a gap in preventive strategies for cancer-related cognitive decline from a nutritional perspective. Nutritional support, dietary patterns, and dietary supplements can prevent cancer-related cognitive decline without serious safety concerns. This work highlighted nutritional interventions that have the potential to improve cognitive function in cancer survivors, benefiting the further construction of evidence-based nutritional intervention programs.

PROTOCOL REGISTRATION

PROSPERO.

PATIENT OR PUBLIC CONTRIBUTION

No patient or public contribution.

Incidence of emergence delirium after homeostasis-guided pediatric anesthesia for ear-nose-throat surgery

BACKGROUND

Emergence delirium is a complication of pediatric anesthesia during the early recovery period. Children undergoing ear, nose, and throat surgery are at high risk. The Pediatric Assessment of Emergence Delirium (PAED) scale is used for diagnosis and founded to specify the degree of emergence delirium. However, there is no consensus regarding a threshold value for emergence delirium diagnosis. Homeostasis-guided pediatric general anesthesia aims to maintain physiological parameters within normal ranges. In this prospective, observational study we evaluated the incidence of emergence delirium in children undergoing elective ear, nose, and throat surgery under standardized homeostasis-guided general anesthesia. Secondarily, we identified risk factors associated with an increased PAED score.

METHODS

In children aged 0-6 years, we collected data from standard monitoring, depth of anesthesia, and preoperative glucose and ketone body levels. These variables were studied as risk or protective factors for increased PAED >0 scores using multivariate logistic regression.

RESULTS

Of the 105 children analyzed, only five children (4.7%) had emergence delirium according to a threshold PAED score ≥10, while 37 children (35%) had PAED scores >0. Statistical analysis of the PAED outcome identified two significant positive associations with pain (P<0.001) and preoperative blood glucose levels (P=0.006) and one negative association with preoperative ketone body levels (P<0.001).

CONCLUSIONS

Our cohort observed a lower incidence of emergence delirium than in the literature. Higher pain intensity and lower blood glucose levels were risk factors for PAED > 0, whereas preoperative ketone body levels were protective.

Time-restricted ketogenic diet in amyotrophic lateral sclerosis: a case study

Amyotrophic lateral sclerosis (ALS) is an incurable neurodegenerative disorder. The most devastating variant is bulbar-onset ALS, which portends a median survival of 24 months from the onset of symptoms. Abundant evidence indicates that neuron metabolism and mitochondrial function are impaired in ALS. Metabolic strategies, particularly fasting and ketogenic diet protocols, alter neuron metabolism and mitochondria function in a manner that may mitigate the symptoms of this disorder. We report the case of a 64-year-old man with a 21-month history of progressive, deteriorating bulbar-onset ALS, with an associated pseudobulbar affect, who implemented a time-restricted ketogenic diet (TRKD) for 18 months. During this time, he improved in ALS-related function (7% improvement from baseline), forced expiratory volume (17% improvement), forced vital capacity (13% improvement), depression (normalized), stress levels (normalized), and quality of life (19% improvement), particularly fatigue (23% improvement). His swallowing impairment and neurocognitive status remained stable. Declines were measured in physical function, maximal inspiratory pressure, and maximal expiratory pressure. Weight loss was attenuated and no significant adverse effects occurred. This case study represents the first documented occurrence of a patient with ALS managed with either a fasting or ketogenic diet protocol, co-administered as a TRKD. We measured improved or stabilized ALS-related function, forced expiratory volume, forced vital capacity, swallowing, neurocognitive status, mood, and quality of life. Measurable declines were restricted to physical function, maximal inspiratory pressure, and maximal expiratory pressure. Now over 45 months since symptom onset, our patient remains functionally independent and dedicated to his TRKD.

Low-carbohydrate and ketogenic diets: a scoping review of neurological and inflammatory outcomes in human studies and their relevance to chronic pain

Dietary restriction of carbohydrate has been demonstrated to be beneficial for nervous system dysfunction in animal models and may be beneficial for human chronic pain. The purpose of this review is to assess the impact of a low-carbohydrate/ketogenic diet on the adult nervous system function and inflammatory biomarkers to inform nutritional research for chronic pain. An electronic database search was carried out in May 2021. Publications were screened for prospective research with dietary carbohydrate intake <130 g per day and duration of ≥2 weeks. Studies were categorised into those reporting adult neurological outcomes to be extracted for analysis and those reporting other adult research outcomes. Both groups were screened again for reported inflammatory biomarkers. From 1548 studies, there were 847 studies included. Sixty-four reported neurological outcomes with 83% showing improvement. Five hundred and twenty-three studies had a different research focus (metabolic n = 394, sport/performance n = 51, cancer n = 33, general n = 30, neurological with non-neuro outcomes n = 12, or gastrointestinal n = 4). The second screen identified sixty-three studies reporting on inflammatory biomarkers, with 71% reporting a reduction in inflammation. The overall results suggest a favourable outcome on the nervous system and inflammatory biomarkers from a reduction in dietary carbohydrates. Both nervous system sensitisation and inflammation occur in chronic pain, and the results from this review indicate it may be improved by low-carbohydrate nutritional therapy. More clinical trials within this population are required to build on the few human trials that have been done.

Protocol for a randomized controlled trial comparing a very low-carbohydrate diet or moderate-carbohydrate plate-method diet for type 2 diabetes: the LEGEND (Lifestyle Education about Nutrition for Diabetes) trial

BACKGROUND

Optimal carbohydrate intake is an important and controversial area in the nutritional management of type 2 diabetes. Some evidence indicates that reducing overall carbohydrate intake with a low- or very low-carbohydrate eating plan can improve glycemic control compared to following eating plans that involve greater carbohydrate intake. However, critical knowledge gaps currently prevent clear recommendations about carbohydrate intake levels.

METHODS

The LEGEND (Lifestyle Education about Nutrition for Diabetes) Trial aims to compare a very low-carbohydrate diet to a moderate-carbohydrate plate-method diet for glycemic control in adults with type 2 diabetes. This two-site trial plans to recruit 180 adults with type 2 diabetes. We will randomize participants to either a 20-session group-based diet and lifestyle intervention that teaches either a very low-carbohydrate diet or a moderate-carbohydrate plate-method diet. We will assess participants at study entry and 4 and 12 months later. The primary outcome is HbA1c, and secondary outcomes include inflammation (high sensitivity C-reactive protein), body weight, changes in diabetes medications, lipids (small particle LDL, HDL, triglycerides), skeletal metabolism (bone mineral density from dual-energy x-ray absorptiometry and bone turnover markers serum procollagen type I N propeptide and serum C-terminal telopeptide of type I collagen), and body composition (percent body fat, percent lean body mass).

DISCUSSION

The LEGEND trial is a randomized controlled trial to assess optimal carbohydrate intake in type 2 diabetes by evaluating the effects of a very low-carbohydrate diet vs. a moderate-carbohydrate plate-method diet over a year-long period. The research addresses important gaps in the evidence base for the nutritional management of type 2 diabetes by providing data on potential benefits and adverse effects of different levels of carbohydrate intake.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05237128. Registered on February 11, 2022.

Efficacy, safety and tolerability of very low-calorie ketogenic diet in obese women with fibromyalgia: a pilot interventional study

Introduction

Obesity can worsen fibromyalgia (FM) and very low-calorie ketogenic diet (VLCKD) is a potential therapeutic option for diseases that share clinical and pathophysiological features with FM. In this pilot interventional study, we investigated the effects of VLCKD in obese women with FM.

Methods

Female patients with FM and a body mass index (BMI) ≥ 30  kg/m² were eligible for VLCKD. The ketogenic phase (T0 to T8) was followed by progressive reintroduction of carbohydrates (T8 to T20). Changes in BMI, Fibromyalgia Impact Questionnaire (FIQ), Hospital Anxiety and Depression Scale (HADS), EuroQol 5D (EQ-5D) and 36-item Short Form Health Survey (SF-36) were evaluated. A change of 14% in FIQ was considered clinically relevant. The longitudinal association between BMI and patient-reported outcomes (PROs) was assessed using generalized estimating equations.

Results

Twenty women were enrolled. Two discontinued the intervention. The mean age of the 18 patients who reached T20 was 51.3  years and mean BMI was 37.2  kg/m². All patients lost weight during the first period of VLCKD and this achievement was maintained at T20. Mean BMI decreased from 37.2  kg/m² at T0 to 34.8  kg/m² at T4, 33.5  kg/m² at T8 and 32.1  kg/m² at T20 (p < 0.001). A significant reduction of mean FIQ from 61.7 at T0 to 37.0 at T4 and to 38.7 at T8 (p < 0.001) was observed and it was maintained at T20 with a mean FIQ of 39.1 (p = 0.002). Similar results were obtained for HADS, EQ-5D and SF-36. Analysing each participant, the reduction of FIQ was clinically meaningful in 16 patients (89%) at T4, in 13 (72%) at T8 and in 14 (78%) at T20. No significant association was observed between change in BMI and improvement of the PROs over time. Adverse effects were mild and transient. No major safety concerns emerged.

Conclusion

These are the first data on the efficacy of VLCKD in FM. All patients achieved improvement in different domains of the disease, which was maintained also after carbohydrate reintroduction. Our results suggest that ketosis might exert beneficial effects in FM beyond the rapid weight loss.

Clinical trial registration

This trial is registered on ClinicalTrials.gov, number NCT05848544.

Habituation to Pain in Patients with Chronic Pain: Clinical Implications and Future Directions

In this review, the latest insights into habituation to pain in chronic pain are summarized. Using a systematic search, results of studies on the evidence of habituation to (experimental) pain in migraine, chronic low back pain, fibromyalgia, and a variety of chronic pain indications are presented. In migraine, reduced habituation based on self-report and the EEG-based N1 and N2-P2 amplitude is reported, but the presence of contradictory results demands further replication in larger, well-designed studies. Habituation to pain in chronic low back pain seems not to differ from controls, with the exception of EEG measures. In fibromyalgia patients, there is some evidence for reduced habituation of the N2-P2 amplitude. Our analysis shows that the variability between outcomes of studies on habituation to pain is high. As the mechanisms underlying habituation to pain are still not fully understood and likely involve several pathways, it is now too early to conclude that habituation to pain is related to clinical outcomes and can be used as a diagnostic marker. The review ends with a discussion on future directions for research including the use of standard outcome measures to improve comparisons of habituation to pain in patients and controls, as well as a focus on individual differences.

Nummular headache: a case report of remission following ketogenic diet and botulinum toxin type A injections

Nummular headache is an unusual facial pain disorder with no evidence-based therapy recommendations. The ketogenic diet is an alternative therapy that demonstrated to be effective in migraineurs, but it was never used in the setting of nummular headache. We describe a 58-years old female patient with nummular headache successfully treated with a 6-months ketogenic diet and botulinum toxin type A injections. Ketogenic diet could be an effective alternative/complementary therapy in nummular headache patients although more studies are needed to confirm our results.

Ketogenic diet enhances the effects of oxycodone in mice

Opioids have been used to manage pain for thousands of years, but they have significant potential for abuse. Prescription opioids, like oxycodone, are associated with 32% of overdoses, that have reached a total of 75,673 deaths in 2021. A major challenge is maximizing their therapeutic potential while minimizing the negative side effects including opioid use disorder (OUD). The Ketogenic Diet (KD) has been reported to reduce pain and decrease the severity of alcohol use disorder, yet its effects on oxycodone responses remain unknown. KD mice displayed increased oxycodone-induced locomotor activity and enhanced antinociceptive effects of oxycodone, suggesting a dietary effect on opiate sensitivity. Male KD mice exposed to chronic oxycodone exhibited increased naloxone-induced jumps, suggesting a sex-specific effect of diet on opioid withdrawal. Consistent with this, male KD mice self-administered less oxycodone while female KD mice did not differ from controls. Finally, no effect of KD on motivation to obtain oxycodone was observed during a progressive ratio schedule. These data suggest sex-biased effects of KD on responses to opioids that should be considered and potentially leveraged in both clinical pain management and treatment of OUD.

Pharmacological and non-pharmacological therapeutic interventions for the treatment of spinal cord injury-induced pain

Spinal cord injury (SCI) is a complex neurophysiological disorder, which can result in many long-term complications including changes in mobility, bowel and bladder function, cardiovascular function, and metabolism. In addition, most individuals with SCI experience some form of chronic pain, with one-third of these individuals rating their pain as severe and unrelenting. SCI-induced chronic pain is considered to be "high impact" and broadly affects a number of outcome measures, including daily activity, physical and cognitive function, mood, sleep, and overall quality of life. The majority of SCI pain patients suffer from pain that emanates from regions located below the level of injury. This pain is often rated as the most severe and the underlying mechanisms involve injury-induced plasticity along the entire neuraxis and within the peripheral nervous system. Unfortunately, current therapies for SCI-induced chronic pain lack universal efficacy. Pharmacological treatments, such as opioids, anticonvulsants, and antidepressants, have been shown to have limited success in promoting pain relief. In addition, these treatments are accompanied by many adverse events and safety issues that compound existing functional deficits in the spinally injured, such as gastrointestinal motility and respiration. Non-pharmacological treatments are safer alternatives that can be specifically tailored to the individual and used in tandem with pharmacological therapies if needed. This review describes existing non-pharmacological therapies that have been used to treat SCI-induced pain in both preclinical models and clinical populations. These include physical (i.e., exercise, acupuncture, and hyper- or hypothermia treatments), psychological (i.e., meditation and cognitive behavioral therapy), and dietary interventions (i.e., ketogenic and anti-inflammatory diet). Findings on the effectiveness of these interventions in reducing SCI-induced pain and improving quality of life are discussed. Overall, although studies suggest non-pharmacological treatments could be beneficial in reducing SCI-induced chronic pain, further research is needed. Additionally, because chronic pain, including SCI pain, is complex and has both emotional and physiological components, treatment should be multidisciplinary in nature and ideally tailored specifically to the patient.

The Effectiveness of Intermittent Fasting, Time Restricted Feeding, Caloric Restriction, a Ketogenic Diet and the Mediterranean Diet as Part of the Treatment Plan to Improve Health and Chronic Musculoskeletal Pain: A Systematic Review

Food strategies are currently used to improve inflammation and oxidative stress conditions in chronic pain which contributes to a better quality of life for patients. The main purpose of this systematic review is to analyze the effectiveness of different dietary strategies as part of the treatment plan for patients suffering from chronic pain and decreased health. PubMed, Web of Science, ProQuest, Scopus, Cumulative Index to Nursing & Allied Health Literature (CINAHL), Cambridge Core, and Oxford Academy databases were used to review and to appraise the literature. Randomized clinical trials (RCT), observational studies, and systematic reviews published within the last 6 years were included. The Physiotherapy Evidence Database (PEDro) scale, the PEDro Internal Validity (PVI), the Standard Quality Assessment Criteria for Evaluating Primary Research Papers from a variety of fields (QUALSYT), and the Quality Assessment Tool of Systematic Reviews scale were used to evaluate the risk of bias of the included studies. A total of 16 articles were included, of which 11 were RCTs and 5 were observational studies. Six of them showed an improvement in pain assessment, while two studies showed the opposite. Inflammation was shown to be decreased in four studies, while one did not show a decrease. The quality of life was shown to have improved in five studies. All of the selected studies obtained good methodological quality in their assessment scales. In the PVI, one RCT showed good internal validity, five RCTs showed moderate internal quality, while five of them were limited. Current research shows that consensus on the effects of an IF diet on pain improvement, in either the short or the long term, is lacking. A caloric restriction diet may be a good long term treatment option for people suffering from pain. Time restricted food and ketogenic diets may improve the quality of life in chronic conditions. However, more studies analyzing the effects of different nutritional strategies, not only in isolation but in combination with other therapies in the short and the long term, are needed.

A Molecular Approach to Understanding the Role of Diet in Cancer-Related Fatigue: Challenges and Future Opportunities

Cancer-related fatigue (CRF) is considered one of the most frequent and distressing symptoms for cancer survivors. Despite its high prevalence, factors that predispose, precipitate, and perpetuate CRF are poorly understood. Emerging research focuses on cancer and treatment-related nutritional complications, changes in body composition, and nutritional deficiencies that can compound CRF. Nutritional metabolomics, the novel study of diet-related metabolites in cells, tissues, and biofluids, offers a promising tool to further address these research gaps. In this position paper, we examine CRF risk factors, summarize metabolomics studies of CRF, outline dietary recommendations for the prevention and management of CRF in cancer survivorship, and identify knowledge gaps and challenges in applying nutritional metabolomics to understand dietary contributions to CRF over the cancer survivorship trajectory.

Continuous care intervention with carbohydrate restriction improves physical function of the knees among patients with type 2 diabetes: a non-randomized study

Background

In a previous study, we assessed a novel, remotely monitored carbohydrate restricted diet regimen including nutritional ketosis in patients with type 2 diabetes and reported significant improvements in weight, glycemic control, abdominal fat and inflammation from baseline to 2 years. Knee outcome measures were collected as a secondary outcome in the trial. This study aims to assess the effect of this intervention on knee functional scores and to identify if changes in weight, central abdominal fat (CAF), glycemic status and high sensitivity C-reactive protein (hsCRP) were associated with its improvement.

Methods

This prospective analysis included continuous care intervention (CCI, n = 173) and usual care (UC, n = 69) trial participants with type 2 diabetes that reported knee pain at baseline. Knee outcome measures included the Knee injury and Osteoarthritis Outcome Score (KOOS) pain, symptoms, activities of daily living (ADL), sports and recreation function, and knee-related quality of life subscales, and total KOOS score were assessed from baseline to 2 years. Missing data at each time point were replaced with multiple imputation under the assumption of missing at random. To assess if the primary analysis of the knee scores changed under plausible missing not at random assumptions, sensitivity analysis was also performed using pattern mixture models. In CCI, we also assessed factors associated with the improvement of knee scores.

Results

In the primary analysis, CCI participants demonstrated a statistically significant improvement in total KOOS and all KOOS individual subscale scores at 1 year and maintained through 2 years as opposed to UC patients who showed no significant changes from baseline to 2 years. The significant improvement in total KOOS and its individual subscale scores from baseline to 2 years remained relatively stable in CCI in the sensitivity analysis under different missing not at random scenarios confirming the robustness of the findings from the primary analysis. Approximately 46% of the CCI participants met the 10 points minimal clinically important change at 2 years. A reduction in CAF was associated with improvement in total KOOS and KOOS ADL, while a decrease in hsCRP was associated with improvement in KOOS symptoms scores.

Conclusion

A very low carbohydrate intervention including nutritional ketosis resulted in significant improvements in knee pain and function among patients with T2D. The improvements in knee function were likely secondary to a reduction in central adiposity and inflammation. Future research on the applicability of this intervention in radiographically confirmed OA patients is important.

Trial registration

Clinical trial registration: NCT02519309 (10/08/2015).

Supplementary Information

The online version contains supplementary material available at 10.1186/s12891-022-05258-0.

Effect of Ketogenic Diet on Quality of Life in Adults with Chronic Disease: A Systematic Review of Randomized Controlled Trials

Background: Chronic diseases adversely affect quality of life (QOL). The ketogenic diet (KD) may improve the QOL. Objective: The aim of this systematic review was to summarize the available evidence of randomized controlled trials (RCTs) to establish the effect of KD on the QOL in adults with chronic diseases. Methods: Reporting followed PRISMA guidelines. We included randomized controlled trials (RCTs) conducted on adults with chronic disease including an intervention group that received KD and a control group, and where QOL was reported as outcome. We searched PubMed, APA PsycInfo, EMBASE, the Cumulative Index to Nursing and Allied Health Literature (CINAHL), the Cochrane Library, and Clinicaltrials.gov, and the references of the included articles and previous relevant reviews, without language or time restrictions. We critically appraised included studies and narratively synthesized their findings. Results: Nine RCTs were included. The risk of bias was low, except of allocation concealment and blinding. In patients with cancer: one RCT found an improvement in overall QOL, another reported improved physical component summary, and one found no superiority of KD in all QOL domains. In patients with neurological disorders: improved QOL was reported in Alzheimer’s disease patients, whereas no difference in mental and physical health QOL was noted in patients with multiple sclerosis. In patients with obesity and type II diabetes: one RCT reported superiority of energy-restricted KD in improving role functioning, mental health, health perceptions, and pain compared with guideline-based diet, whereas in another RCT, high and low carbohydrate diets achieved comparable improvements. Among patients with knee osteoarthritis, no differences between KD and low-fat groups were noted. Dietary compliance with the KD, reported in three studies, was shown to be high. Side effects were mostly noted during the first weeks of intervention, and adverse events were not markedly different with KD and the comparison diet. Conclusions: The evidence from RCTs investigating the effect of KD on QOL in adults with chronic disease is inconclusive. The promising effect noted in some included studies and the low rates of adverse events and side effects encourage future investigations in this regard.

Effect of Anti-Inflammatory Diets on Pain in Rheumatoid Arthritis: A Systematic Review and Meta-Analysis

Various nutritional therapies have been proposed in rheumatoid arthritis, particularly diets rich in ω-3 fatty acids, which may lead to eicosanoid reduction. Our aim was to investigate the effect of potentially anti-inflammatory diets (Mediterranean, vegetarian, vegan, ketogenic) on pain. The primary outcome was pain on a 10 cm visual analogue scale. Secondary outcomes were C-reactive protein levels, erythrocyte sedimentation rate, health assessment questionnaire, disease activity score 28, tender/swollen joint counts, weight, and body mass index. We searched MEDLINE (OVID), Embase (Elsevier), and CINAHL for studies published from database inception to 12 November 2021. Two authors independently assessed studies for inclusion, extracted study data, and assessed the risk of bias. We performed a meta-analysis with all eligible randomized controlled trials using RevMan 5. We used mean differences or standardized mean differences and the inverse variance method of pooling using a random-effects model. The search retrieved 564 unique publications, of which we included 12 in the systematic review and 7 in the meta-analysis. All studies had a high risk of bias and the evidence was very low. The main conclusion is that anti-inflammatory diets resulted in significantly lower pain than ordinary diets (-9.22 mm; 95% CI -14.15 to -4.29; p = 0.0002; 7 RCTs, 326 participants).

Ketogenic diet prevents paclitaxel-induced neuropathic nociception through activation of PPARγ signalling pathway and inhibition of neuroinflammation in rat dorsal root ganglion

Chemotherapy-induced peripheral neuropathy (CIPN) is a common side effect during the course of cancer treatment, which is mainly manifested as a series of sensory abnormalities. At present, there are no recommended prevention or treatment strategies, and the underlying mechanisms are unclear. The ketogenic diet (KD), a special diet that is high in fat and low in carbohydrate intake, shows good therapeutic potential in children with epilepsy. In this study, it was found that KD significantly prevented paclitaxel-induced neuropathic nociception. Using the GSE113941 database, 281 differentially expressed genes (DEGs) were found in an animal model of CIPN and controls. The DEGs were mainly enriched in peroxisome proliferator activated receptor (PPAR) and oxidative phosphorylation signalling pathways. As a main regulatory pathway of lipid metabolism, the PPARγ signalling pathway was significantly upregulated in the KD model. In addition, KD also inhibited the expression of pro-inflammatory cytokines and the TLR4/NF-κB signalling pathway in the dorsal root ganglion (DRG) in paclitaxel-treated rats. In vitro, rat primary DRG neurons were used to investigate the role of PPARγ in paclitaxel-induced neurotoxicity. It was found that PPARγ agonist rosiglitazone significantly protected DRG neurons against cell apoptosis and reactive oxygen species generation induced by paclitaxel administration. Therefore, KD is a prospective treatment option when applied as a dietary intervention in the prevention and treatment of paclitaxel-induced neuropathic nociception, possibly through the activation of PPARγ and its neuroprotective functions.

Microecological preparation combined with an modified low-carbon diet improves glucolipid metabolism and cardiovascular complication in obese patients

OBJECTIVE

To investigate the impact of microecological preparation combined with modified low-carbon diet on the glucolipid metabolism and cardiovascular complication in obese patients.

METHODS

From August 2017 to July 2020, 66 obese patients were recruited, and administrated with an modified low-carbon diet with (group A) or without (Group B) microecology preparation and a balanced diet in control group (group C) for 6 months. Meanwhile, 20 volunteers administrated with a balanced diet were recruited as the healthy control group (group D).

RESULTS

After 6-month intervention, obese subjects in group A and B showed significant improvement of body and liver fat mass, reduction of serum lipid levels, intestinal barrier function markers, insulin resistance index (IRI), high blood pressure (HBP) and carotid intima thickness, as compared with subjects in group C. More importantly, subjects in group A had better improvement of vascular endothelial elasticity and intimal thickness than subjects in group B. However, these intervention had no effect on carotid atherosclerotic plaque.

CONCLUSION

Administration of microecological preparation combined with modified low-carbon diet had better improvement of intestinal barrier function, glucose and lipid metabolism, and cardiovascular complications than low-carbon diet in obese patients, but the effect of a simple low-carb diet on carotid atherosclerotic plaque need to be further addressed.

Ketogenic diets and the nervous system: a scoping review of neurological outcomes from nutritional ketosis in animal studies

OBJECTIVES

Ketogenic diets have reported efficacy for neurological dysfunctions; however, there are limited published human clinical trials elucidating the mechanisms by which nutritional ketosis produces therapeutic effects. The purpose of this present study was to investigate animal models that report variations in nervous system function by changing from a standard animal diet to a ketogenic diet, synthesise these into broad themes, and compare these with mechanisms reported as targets in pain neuroscience to inform human chronic pain trials.

METHODS

An electronic search of seven databases was conducted in July 2020. Two independent reviewers screened studies for eligibility, and descriptive outcomes relating to nervous system function were extracted for a thematic analysis, then synthesised into broad themes.

RESULTS

In total, 170 studies from eighteen different disease models were identified and grouped into fourteen broad themes: alterations in cellular energetics and metabolism, biochemical, cortical excitability, epigenetic regulation, mitochondrial function, neuroinflammation, neuroplasticity, neuroprotection, neurotransmitter function, nociception, redox balance, signalling pathways, synaptic transmission and vascular supply.

DISCUSSION

The mechanisms presented centred around the reduction of inflammation and oxidative stress as well as a reduction in nervous system excitability. Given the multiple potential mechanisms presented, it is likely that many of these are involved synergistically and undergo adaptive processes within the human body, and controlled animal models that limit the investigation to a particular pathway in isolation may reach differing conclusions. Attention is required when translating this information to human chronic pain populations owing to the limitations outlined from the animal research.

Ketogenic diets consumed during radio-chemotherapy have beneficial effects on quality of life and metabolic health in patients with rectal cancer

PURPOSE

Interest in ketogenic diets (KDs) as complementary nutritional treatments for cancer patients is rising, although some skepticism about their safety exists. We, therefore, studied the effects of KDs on quality of life and blood parameters in rectal cancer patients undergoing radio-chemotherapy.

METHODS

EORTC-QLQ30 questionnaire scores and different metabolic and hormonal blood parameters were obtained prior to, in the middle of and at the end of radiotherapy within the KETOCOMP study (ClinicalTrials.gov Identifier: NCT02516501). A total of 18 patients consuming a KD were compared to 23 patients consuming their standard diet (SD). Baseline-end differences were measured using Wilcoxon tests, and repeated measures analysis was performed using linear mixed effects models.

RESULTS

Eighty-nine percent of patients on the KD reported subjectively feeling good or very good, but roughly half of them rated the daily routine implementation as difficult. Only the SD group experienced significant declines in physical and role functioning, while the KD group improved in role (p = 0.045), emotional (p = 0.018) and social functioning (p = 0.009).Urinary frequency, buttock pain and fatigue significantly increased in the SD group, but to a much lesser extent in the KD group. Several biomarkers of metabolic health (gamma-glutamyl-transpeptidase, triglyceride-glucose index, HDL cholesterol/triglyceride ratio, and free T3) improved in the KD, but not the SD group.

CONCLUSIONS

Despite being perceived as difficult to implement by ≈50% of patients, KDs are feasible as complementary therapies alongside radio-chemotherapy and associated with subjective well-being. The hypothesis that they exert beneficial effects on quality of life and metabolic health in rectal cancer patients is supported by our data.

TRIAL REGISTRATION

ClinicalTrials.gov identifier NCT02516501, registered Aug 6th 2015.

Poor diet quality is associated with self-reported knee pain in community-dwelling women aged 50 years and older

In the current study, we aimed to examine the association between knee pain and diet quality in women aged ≥ 50 years using data from the Korea National Health and Nutrition Examination Survey. This was a population-based, cross-sectional study. Diet quality was assessed using the Diet Quality Index-International (DQI-I), and knee pain and osteoarthritis were self-reported. A multivariate logistic regression model was used to adjust for age, body mass index, household income, marital status, education, occupation, smoking status, hazardous alcohol use, regular physical activity, menopause, and chronic diseases, including hypertension, diabetes, dyslipidemia, osteoarthritis, and depression. A total of 3,881 women were included in this study, and the prevalence of knee pain was 25.4%. The intakes of total energy, protein, and fat were lower in women with knee pain than in those without (all P < 0.01), while the carbohydrate intake was higher (P = 0.01). No significant differences were noted in the scores for variety, overall balance, and moderation components, except for the item of total fat intake, between the DQI-I scores for women with and without knee pain, after adjusting for age. Women without knee pain showed higher scores in several items of the adequacy component (P < 0.05) than did women with knee pain. The total DQI-I scores were lower in women with knee pain than in women without knee pain, after adjusting for covariates, including osteoarthritis (OR = 0.985, 95% CI = 0.973–0.997, P = 0.01). Knee pain independent of osteoarthritis was associated with poor diet quality in community-dwelling women aged ≥ 50 years.

Effect of the ketogenic diet in excitable tissues

In the past decade, ketogenic diet (KD) has gained some popularity as a potential treatment for a wide range of diseases, including neurological and metabolic disorders, thanks to a beneficial role mainly related to its anti-inflammatory properties. The high-fat and carbohydrate-restricted regimen causes changes in the metabolism, leading, through the β-oxidation of fatty acids, to the hepatic production of ketone bodies (KBs), which are used by many extrahepatic tissues as energy fuels. Once synthetized, KBs are delivered through the systemic circulation to all the tissues of the organism, where they play pleiotropic roles acting directly and indirectly on various targets, and among them ion channels and neurotransmitters. Moreover, they can operate as signaling metabolites and epigenetic modulators. Therefore, it is inappropriate to consider that the KD regimen can improve the patients' clinical condition simply by means of specific and localized effects; rather, it is more correct to think that KBs affect the organism as a whole. In this review, we tried to summarize the recent knowledge of the effects of KBs on various tissues, with a particular attention on the excitable ones, namely the nervous system, heart, and muscles.

Ketogenic diet effects on inflammatory allodynia and ongoing pain in rodents

Ketogenic diets are very low carbohydrate, high fat, moderate protein diets used to treat medication-resistant epilepsy. Growing evidence suggests that one of the ketogenic diet’s main mechanisms of action is reducing inflammation. Here, we examined the diet’s effects on experimental inflammatory pain in rodent models. Young adult rats and mice were placed on the ketogenic diet or maintained on control diet. After 3–4 weeks on their respective diets, complete Freund’s adjuvant (CFA) was injected in one hindpaw to induce inflammation; the contralateral paw was used as the control. Tactile sensitivity (von Frey) and indicators of spontaneous pain were quantified before and after CFA injection. Ketogenic diet treatment significantly reduced tactile allodynia in both rats and mice, though with a species-specific time course. There was a strong trend to reduced spontaneous pain in rats but not mice. These data suggest that ketogenic diets or other ketogenic treatments might be useful treatments for conditions involving inflammatory pain.

Ketogenic diet as a potential intervention for lipedema

Lipedema (LI) is a common yet misdiagnosed condition, often misconstrued with obesity. LI affects women almost exclusively, and its painful and life-changing symptoms have long been thought to be resistant to the lifestyle interventions such as diet and exercise. In this paper, we discuss possible mechanisms by which patients adopting a ketogenic diet (KD) can alleviate many of the unwanted clinical features of LI. This paper is also an effort to provide evidence for the hypothesis of the potency of this dietary intervention for addressing the symptoms of LI. Specifically, we examine the scientific evidence of effectiveness of adopting a KD by patients to alleviate clinical features associated with LI, including excessive and disproportionate lower body adipose tissue (AT) deposition, pain, and reduction in quality of life (QoL). We also explore several clinical features of LI currently under debate, including the potential existence and nature of edema, metabolic and hormonal dysfunction, inflammation, and fibrosis. The effectiveness of a KD on addressing clinical features of LI has been demonstrated in human studies, and shows promise as an intervention for LI. We hope this paper leads to an improved understanding of optimal nutritional management for patients with LI and stimulates future research in this area of study.

Impact of a Ketogenic Diet on Sporadic Inclusion Body Myositis: A Case Study

Sporadic inclusion body myositis (IBM) is a chronic inflammatory and degenerative muscle disease with limited treatment options; no therapy can alter its natural course. Ketogenic diets are theoretically capable of suppressing inflammation, enhancing cell bioenergetics, alleviating mitochondria dysfunction, and stimulating autophagy, which may be beneficial in IBM. We report the case of a 52-year-old woman with worsening IBM who pursued a modified ketogenic diet for 1 year. Adverse effects were mild and resolved 3 weeks into the diet. Prior to starting her ketogenic diet, despite the use of a walking stick at all times, she was experiencing one to two falls per week as well as swallowing difficulties, musculoskeletal pain, and depression. Moreover, magnetic resonance imaging (MRI) of the bilateral thighs during the year prior to the diet indicated worsening muscle inflammation and a 14% decrease in thigh muscle volume, which corresponded to a 4% decrease in the ratio of thigh muscle to thigh total volume. After 1 year on her ketogenic diet, our patient regained independent walking, and her swallowing difficulties, pain, and depression resolved. She maintained her strength, improved in every test of function, enhanced her quality of life, and lowered her blood creatine kinase. MRI of the bilateral thighs during the year of the diet indicated stabilized muscle inflammation and a 2.9% decrease in thigh muscle volume, which in the context of diet-induced fat loss corresponded to a sustained 1% increase in the ratio of thigh muscle to thigh total volume. This case is unique in that a ketogenic diet was utilized as the primary treatment strategy for a patient with confirmed IBM, culminating in substantial clinical improvement, stabilized muscle inflammation, and a slowed rate of muscle atrophy. Our patient has remained on her ketogenic diet for over 2 years now and continues to enjoy a full and independent life.

Preclinical testing of the ketogenic diet in fragile X mice

The ketogenic diet is highly effective at attenuating seizures in refractory epilepsy, and accumulating evidence in the literature suggests that it may be beneficial in autism. To our knowledge, no one has studied the ketogenic diet in any fragile X syndrome (FXS) model. FXS is the leading known genetic cause of autism. Herein, we tested the effects of chronic ketogenic diet treatment on seizures, body weight, ketone and glucose levels, diurnal activity levels, learning and memory, and anxiety behaviors in Fmr1^KO and littermate control mice as a function of age. The ketogenic diet selectively attenuates seizures in male but not female Fmr1^KO mice and differentially affects weight gain and diurnal activity levels dependent on Fmr1 genotype, sex and age.

Potential Protective Mechanisms of Ketone Bodies in Migraine Prevention

An increasing amount of evidence suggests that migraines are a response to a cerebral energy deficiency or oxidative stress levels that exceed antioxidant capacity. The ketogenic diet (KD), a diet mimicking fasting that leads to the elevation of ketone bodies (KBs), is a therapeutic intervention targeting cerebral metabolism that has recently shown great promise in the prevention of migraines. KBs are an alternative fuel source for the brain, and are thus likely able to circumvent some of the abnormalities in glucose metabolism and transport found in migraines. Recent research has shown that KBs-D-β-hydroxybutyrate in particular-are more than metabolites. As signalling molecules, they have the potential to positively influence other pathways commonly believed to be part of migraine pathophysiology, namely: mitochondrial functioning, oxidative stress, cerebral excitability, inflammation and the gut microbiome. This review will describe the mechanisms by which the presence of KBs, D-BHB in particular, could influence those migraine pathophysiological mechanisms. To this end, common abnormalities in migraines are summarised with a particular focus on clinical data, including phenotypic, biochemical, genetic and therapeutic studies. Experimental animal data will be discussed to elaborate on the potential therapeutic mechanisms of elevated KBs in migraine pathophysiology, with a particular focus on the actions of D-BHB. In complex diseases such as migraines, a therapy that can target multiple possible pathogenic pathways seems advantageous. Further research is needed to establish whether the absence/restriction of dietary carbohydrates, the presence of KBs, or both, are of primary importance for the migraine protective effects of the KD.

Nutritional Interventions for Treating Cancer-Related Fatigue: A Qualitative Review

Cancer-related fatigue (CRF) is a debilitating syndrome that persists for many cancer survivors for years after treatment. Symptoms include early and persistent fatigue, functional decline, depression, and cognitive difficulties. Inflammation, assessed using pro-inflammatory biomarkers, is increased in cancer survivors with fatigue and treatments for fatigue are often aimed at reducing inflammation. Additionally, cancer and its treatment lead to nutritional complications, changes in body composition, and nutritional deficiencies that potentially weaken the cancer survivor and impact CRF. We conducted a qualitative review of clinical trials that assessed nutritional interventions for preventing and treating CRF. Further studies were examined that used nutritional interventions to address inflammation and fatigue, due to the dearth of nutrition research directly related to CRF. Dietary intake prior to, during, and after cancer treatment appears to affect fatigue levels. Increased protein intake may help preserve lean mass and body composition. Dietary patterns that reduce inflammation, such as the Mediterranean diet and other plant-based diets, appear tolerable to cancer survivors and may reduce fatigue. Supplementation with ginseng, ginger, or probiotics may improve cancer survivors' energy levels. Nutritional interventions, alone or in combination with other interventions should be considered as therapy for fatigue in cancer survivors.

When pain gets stuck: the evolution of pain chronification and treatment resistance

It is well-recognized that, despite similar pain characteristics, some people with chronic pain recover, whereas others do not. In this review, we discuss possible contributions and interactions of biological, social, and psychological perturbations that underlie the evolution of treatment-resistant chronic pain. Behavior and brain are intimately implicated in the production and maintenance of perception. Our understandings of potential mechanisms that produce or exacerbate persistent pain remain relatively unclear. We provide an overview of these interactions and how differences in relative contribution of dimensions such as stress, age, genetics, environment, and immune responsivity may produce different risk profiles for disease development, pain severity, and chronicity. We propose the concept of "stickiness" as a soubriquet for capturing the multiple influences on the persistence of pain and pain behavior, and their stubborn resistance to therapeutic intervention. We then focus on the neurobiology of reward and aversion to address how alterations in synaptic complexity, neural networks, and systems (eg, opioidergic and dopaminergic) may contribute to pain stickiness. Finally, we propose an integration of the neurobiological with what is known about environmental and social demands on pain behavior and explore treatment approaches based on the nature of the individual's vulnerability to or protection from allostatic load.

A fatal case of Fournier's gangrene during neoadjuvant radiotherapy for rectal cancer

PURPOSE

To report the development of an ultimately fatal occurrence of Fournier's gangrene in a rectal cancer patient undergoing neoadjuvant radiotherapy without chemotherapy.

METHODS

A 53-year-old male patient with G2 cT3 cN1a cM0 stage IIIB adenocarcinoma of the lower rectum and several comorbidities including ulcerative colitis was treated with 56 Gy to the primary tumor in 28 fractions because he declined the recommended simultaneous chemotherapy. He was also enrolled in the ketogenic diet arm of our KETOCOMP study, so that prospective measurements of blood parameters, quality of life, and body composition were made.

RESULTS

The patient died 6 days after completion of radiotherapy due to septic shock associated with Fournier's gangrene reaching from the right buttock into the gluteal muscles and descending into the scrotum. In retrospect, there were several signs probably indicating the development of the gangrene: (i) a decline in bioelectrical phase angle; (ii) an accelerated weight and fat-free mass loss starting in the third week of radiotherapy; (iii) an increase in C-reactive protein (CRP) and concurrent drop in high-density lipoprotein (HDL) cholesterol and insulin-like growth factor(IGF)-1 concentrations; and (iv) the occurrence of a sharp pain in the perianal region reported in the fifth week of radiotherapy. Notably, his self-reported quality of life score was the same at the end of as before radiotherapy.

CONCLUSIONS

This case highlights the occurrence of Fournier's gangrene as an extremely rare but life-threatening complication during neoadjuvant radiotherapy for rectal cancer which should be refreshed in the awareness of radiation oncologists and radiologists.

Wilhelm Brünings' forgotten contribution to the metabolic treatment of cancer utilizing hypoglycemia and a very low carbohydrate (ketogenic) diet

The growing interest in the alterations of tumor cell metabolism and their possible therapeutic exploitation also spurred new complementary and integrative approaches such as treating patients with a ketogenic diet (KD). KDs aim at inhibiting glycolytic tumor metabolism and growth, and have therefore been proposed as adjuncts not only to standard-of-care, but also to other therapies targeting tumor metabolism. Here I describe the life and forgotten work of one of the earliest researchers who realized the importance of altered tumor cell metabolism and its possible exploitation through metabolic modifications: Wilhelm Brünings. Brünings was a German natural scientist and physician famous for his innovative contributions to the fields of physiology and otorhinolaryngology. Based on the findings of Otto Warburg and his physiological reasoning he started to experiment with insulin administration and KDs in his patients with head and neck cancers, aiming to maximally lower blood glucose concentrations. He obtained encouraging short-term results, although most tumors became refractory to treatment after several weeks. His pioneering work is worth revisiting, especially for an international readership that may be unaware of his efforts, as hypoglycemic treatments, including the use of insulin injections and KDs, are currently being re-investigated as complementary and integrative cancer treatments.

Functional Nutrition Treatment of Vulvodynia, Irritable Bowel Syndrome, and Depression: A Case Report

A 34-y-old pregnant woman previously diagnosed with vulvodynia, irritable bowel syndrome (IBS), and depression used an elimination diet and nutritional supplementation-from 15 wk pregnant to 22 wk postpartum-to resolve her vulvodynia and IBS, and to reduce her use of antidepressant medication. This case demonstrates the potential usefulness of incorporating a customized functional nutritional approach to evaluate potential proinflammatory foods and nutritional insufficiencies in perinatal patients and postnatal patients.

A ketogenic diet reduces metabolic syndrome-induced allodynia and promotes peripheral nerve growth in mice

Current experiments investigated whether a ketogenic diet impacts neuropathy associated with obesity and prediabetes. Mice challenged with a ketogenic diet were compared to mice fed a high-fat diet or a high-fat diet plus exercise. Additionally, an intervention switching to a ketogenic diet following 8 weeks of high-fat diet was performed to compare how a control diet, exercise, or a ketogenic diet affects metabolic syndrome-induced neural complications. When challenged with a ketogenic diet, mice had reduced bodyweight and fat mass compared to high-fat-fed mice, and were similar to exercised, high-fat-fed mice. High-fat-fed, exercised and ketogenic-fed mice had mildly elevated blood glucose; conversely, ketogenic diet-fed mice were unique in having reduced serum insulin levels. Ketogenic diet-fed mice never developed mechanical allodynia contrary to mice fed a high-fat diet. Ketogenic diet fed mice also had increased epidermal axon density compared all other groups. When a ketogenic diet was used as an intervention, a ketogenic diet was unable to reverse high-fat fed-induced metabolic changes but was able to significantly reverse a high-fat diet-induced mechanical allodynia. As an intervention, a ketogenic diet also increased epidermal axon density. In vitro studies revealed increased neurite outgrowth in sensory neurons from mice fed a ketogenic diet and in neurons from normal diet-fed mice given ketone bodies in the culture medium. These results suggest a ketogenic diet can prevent certain complications of prediabetes and provides significant benefits to peripheral axons and sensory dysfunction.

Effects of the Ketogenic diet in overweight divers breathing Enriched Air Nitrox

Central Nervous System Oxygen Toxicity (CNS-OT) is one of the most harmful effects of Enriched Air Nitrox (EAN) diving. Protective factors of the Ketogenic Diet (KD) are antioxidant activity, the prevention of mitochondrial damage and anti-inflammatory mechanisms. We aimed to investigate if a short-term KD may reduce oxidative stress and inflammation during an hyperoxic dive. Samples from six overweight divers (mean ± SD, age: 55.2 ± 4.96 years; BMI: 26.7 ± 0.86 kg/m²) were obtained a) before and after a dive breathing Enriched Air Nitrox and performing 20-minute mild underwater exercise, b) after a dive (same conditions) performed after 7 days of KD. We measured urinary 8-isoprostane and 8-OH-2-deoxyguanosine and plasmatic IL-1β, IL-6 and TNF-α levels. The KD was successful in causing weight loss (3.20 ± 1.31 Kgs, p < 0.01) and in limiting lipid peroxidation (3.63 ± 1.16 vs. 1.11 ± 0.22; p < 0.01) and inflammatory response (IL-1β = 105.7 ± 25.52 vs. 57.03 ± 16.32, p < 0.05; IL-6 = 28.91 ± 4.351 vs. 14.08 ± 1.74, p < 0.001; TNF-α = 78.01 ± 7.69 vs. 64.68 ± 14.56, p < 0.05). A short-term KD seems to be effective in weight loss, in decreasing inflammation and protective towards lipid peroxidation during hyperoxic diving.

A low-carbohydrate survey: Evidence for sustainable metabolic syndrome reversal

Background: Metabolic syndrome has become a significant problem, with the American Diabetes Association estimating the cost of diabetes and pre-diabetes in the United States alone to be $322 billion per year. Numerous clinical trials have demonstrated the efficacy of low-carbohydrate diets in reversing metabolic syndrome and its associated disorders.Aim: This study was designed to examine how voluntary adherents to a low-carbohydrate diet rate its effectiveness and sustainability using an online survey.Setting and methods: The 57-question survey was administered online and shared internationally via social media and ‘low-carb’ communities. Where appropriate, chi-squared tests and paired t-tests were used to analyse the responses.Results: There were 1580 respondents. The majority of respondents had consumed less than 100 g of carbohydrates per day for over a year, typically for reasons of weight loss or disease management. There was a reported decrease in waist circumference and weight with a simultaneous decrease in hunger and increase in energy level. Of those who provided laboratory values, the majority saw improvements in their HbA1c, blood glucose measurements, and lipid panel results. There was a reduction in usage of various medications, and 25% reported medication cost savings, with average monthly savings of $288 for those respondents. In particular, the usage of pain relievers and anti-inflammatories dropped with a simultaneous decreased rating of pain and increase in mobility.Conclusion: We conclude that low-carbohydrate diets are a sustainable method of metabolic syndrome reversal in a community setting.

Ketogenic Diets and Cancer: Emerging Evidence

Combining a ketogenic diet with standard chemotherapeutic and radiotherapeutic options may help improve tumor response, although more research is needed.

Tumor Metabolism, the Ketogenic Diet and β-Hydroxybutyrate: Novel Approaches to Adjuvant Brain Tumor Therapy

Malignant brain tumors are devastating despite aggressive treatments such as surgical resection, chemotherapy and radiation therapy. The average life expectancy of patients with newly diagnosed glioblastoma is approximately ~18 months. It is clear that increased survival of brain tumor patients requires the design of new therapeutic modalities, especially those that enhance currently available treatments and/or limit tumor growth. One novel therapeutic arena is the metabolic dysregulation that results in an increased need for glucose in tumor cells. This phenomenon suggests that a reduction in tumor growth could be achieved by decreasing glucose availability, which can be accomplished through pharmacological means or through the use of a high-fat, low-carbohydrate ketogenic diet (KD). The KD, as the name implies, also provides increased blood ketones to support the energy needs of normal tissues. Preclinical work from a number of laboratories has shown that the KD does indeed reduce tumor growth in vivo. In addition, the KD has been shown to reduce angiogenesis, inflammation, peri-tumoral edema, migration and invasion. Furthermore, this diet can enhance the activity of radiation and chemotherapy in a mouse model of glioma, thus increasing survival. Additional studies in vitro have indicated that increasing ketones such as β-hydroxybutyrate (βHB) in the absence of glucose reduction can also inhibit cell growth and potentiate the effects of chemotherapy and radiation. Thus, while we are only beginning to understand the pluripotent mechanisms through which the KD affects tumor growth and response to conventional therapies, the emerging data provide strong support for the use of a KD in the treatment of malignant gliomas. This has led to a limited number of clinical trials investigating the use of a KD in patients with primary and recurrent glioma.

How effective is the ketogenic diet for electrical status epilepticus of sleep?

Electrical status epilepticus of sleep (ESES), with the activation of profuse amounts of epileptiform discharges in sleep, may lead to intractable epilepsy and neurocognitive decline in children. Numerous varied treatments including antiseizure medications, steroids, and surgery have been investigated as possible treatment options. The ketogenic diet (KD) is an additional treatment option which may add to our treatment armamentarium for ESES. The KD may theoretically improve ESES by affecting GABA systems and reducing inflammation. Clinical reports of the KD for ESES have been heterogeneous, but to date 38 children have been described in six publications. Overall, 53% had EEG improvement, 41% had>50% seizure reduction, 45% had cognitive improvement, but only 9% had EEG normalization. This review will assess the efficacy of the KD in the treatment of ESES based on known data as well as possible mechanisms of action and the need for future study.

The effect of ketogenic diet in an animal model of autism induced by prenatal exposure to valproic acid

OBJECTIVES

Autism spectrum disorder (ASD) is characterized by impairments in social interaction and communication, and by restricted repetitive behaviors and interests. Its etiology is still unknown, but different environmental factors during pregnancy, such as exposure to valproic acid (VPA), are associated with high incidence of ASD in children. In this context, prenatal exposure to VPA in rodents has been used as a reliable model of ASD. Ketogenic diet (KD) is an alternative therapeutic option for refractory epilepsy; however, the effects of this approach in ASD-like behavior need to be evaluated. We conducted a behavioral assessment of the effects of KD in the VPA model of autism.

METHODS

Pregnant animals received a single-intraperitoneal injection of 600 mg/kg VPA, and their offspring were separated into four groups: (1) control group with standard diet (C-SD), (2) control group with ketogenic diet (C-KD), (3) VPA group with standard diet (VPA-SD), and (4) VPA group with ketogenic diet (VPA-KD).

RESULTS

When compared with the control group, VPA animals presented increased social impairment, repetitive behavior and higher nociceptive threshold. Interestingly, the VPA group fed with KD presented improvements in social behavior. These mice displayed higher scores in sociability index and social novelty index when compared with the SD-fed VPA mice.

DISCUSSION

VPA mice chronically exposed to a KD presented behavioral improvements; however, the mechanism by which KD improves ASD-like features needs to be further investigated. In conclusion, the present study reinforces the potential use of KD as a treatment for the core deficits of ASD.

Mitoprotective dietary approaches for Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: Caloric restriction, fasting, and ketogenic diets

Myalgic Encephalomyelitis/Chronic Fatigue Syndrome is an idiopathic illness characterized by debilitating fatigue and neuro-immune abnormalities. A growing body of evidence proposes mitochondrial dysfunction as a central perpetrator of the illness due to activation of immune-inflammatory pathways that burden the mitochondria. Under a model of mitochondrial dysfunction, this paper explores dietary strategies that are mitoprotective. Studied for decades, the cellular mechanisms of ketogenic diets, fasting, and caloric restriction now reveal mitochondria-specific mechanisms which could play a role in symptom reduction in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome. Future research should examine the physiological effects of these dietary strategies in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome.

Drivers of age-related inflammation and strategies for healthspan extension

Aging is the greatest risk factor for the development of chronic diseases such as arthritis, type 2 diabetes, cardiovascular disease, kidney disease, Alzheimer's disease, macular degeneration, frailty, and certain forms of cancers. It is widely regarded that chronic inflammation may be a common link in all these age-related diseases. This raises the question, can one alter the course of aging and potentially slow the development of all chronic diseases by manipulating the mechanisms that cause age-related inflammation? Emerging evidence suggests that pro-inflammatory cytokines interleukin-1 (IL-1) and IL-18 show an age-dependent regulation implicating inflammasome-mediated caspase-1 activation in the aging process. The Nod-like receptor (NLR) family of innate immune cell sensors, such as the nucleotide-binding domain, leucine-rich-containing family, pyrin domain-containing-3 (NLRP3) inflammasome controls the caspase-1 activation in myeloid-lineage cells in several organs during aging. The NLRP3 inflammasome is especially relevant to aging as it can get activated in response to structurally diverse damage-associated molecular patterns (DAMPs) such as extracellular ATP, excess glucose, ceramides, amyloids, urate, and cholesterol crystals, all of which increase with age. Interestingly, reduction in NLRP3-mediated inflammation prevents age-related insulin resistance, bone loss, cognitive decline, and frailty. NLRP3 is a major driver of age-related inflammation and therefore dietary or pharmacological approaches to lower aberrant inflammasome activation holds promise in reducing multiple chronic diseases of age and may enhance healthspan.

Ketogenic diets, mitochondria, and neurological diseases

The ketogenic diet (KD) is a broad-spectrum therapy for medically intractable epilepsy and is receiving growing attention as a potential treatment for neurological disorders arising in part from bioenergetic dysregulation. The high-fat/low-carbohydrate "classic KD", as well as dietary variations such as the medium-chain triglyceride diet, the modified Atkins diet, the low-glycemic index treatment, and caloric restriction, enhance cellular metabolic and mitochondrial function. Hence, the broad neuroprotective properties of such therapies may stem from improved cellular metabolism. Data from clinical and preclinical studies indicate that these diets restrict glycolysis and increase fatty acid oxidation, actions which result in ketosis, replenishment of the TCA cycle (i.e., anaplerosis), restoration of neurotransmitter and ion channel function, and enhanced mitochondrial respiration. Further, there is mounting evidence that the KD and its variants can impact key signaling pathways that evolved to sense the energetic state of the cell, and that help maintain cellular homeostasis. These pathways, which include PPARs, AMP-activated kinase, mammalian target of rapamycin, and the sirtuins, have all been recently implicated in the neuroprotective effects of the KD. Further research in this area may lead to future therapeutic strategies aimed at mimicking the pleiotropic neuroprotective effects of the KD.