Use of ketogenic diets in the treatment of central nervous system diseases: a systematic review

Association between Mediterranean diet adherence and Parkinson's disease: a systematic review and meta-analysis

BACKGROUND AND AIMS

Parkinson's disease (PD) is a chronic neurodegenerative disorder, and past research suggests that adherence to the Mediterranean diet (MD) may influence the risk of PD. However, there are varying conclusions among different studies regarding the correlation between long-term adherence to the MD and the occurrence of PD. This meta-analysis aimed to investigate the association between MD adherence and PD incidence.

METHODS

This meta-analysis was registered on PROSPERO (CRD42024520410). We searched PubMed, Embase, Web of Science, and Cochrane databases to identify observational studies, including prospective cohorts, case-control, and cross-sectional studies, up to February 2024. Studies reported on MD adherence were included, with MD adherence categorized through a quantifying score or index. The pool odds ratios (ORs) and 95% confidence intervals (CIs) were calculated for the highest versus the lowest categories of MD score in relation to PD risk, using random-effects models. Additionally, bias assessment, heterogeneity assessment, sensitivity analysis, and subgroup analysis were performed. A total of 12 studies were included in the meta-analysis.

RESULTS

The overall effect size of PD risk was as follows: compared to the lowest adherence to the MD, the highest adherence to MD showed a significant negative correlation with the incidence of PD, with an overall OR of 0.75 (95% CI: 0.66, 0.84). Specifically, in studies diagnosing PD, the overall OR was 0.83 (95% CI: 0.74, 0.94), while in studies diagnosing prodromal Parkinson's disease (pPD), the overall OR was 0.67 (95%CI: 0.59, 0.76). For individuals aged <60 years, the overall OR was 0.70 (95%CI: 0.62, 0.78), whereas, for those aged ≥60 years, the overall OR was 0.86 (95%CI: 0.74, 0.99).

CONCLUSIONS

The evidence from this meta-analysis demonstrates a significant negative correlation between adherence to MD patterns and the risk of PD, suggesting that the MD may serve as a protective factor for PD. This dietary pattern may be particularly beneficial in reducing the risk of pPD.

Illuminating the Safety, Tolerability, and Efficacy of Different Ketogenic Diets for Individuals with Epilepsy: A Scoping Meta-Review

BACKGROUND

Diet therapies for epilepsy, including the ketogenic diets (KDs), have been used as a treatment for both pediatric and adult populations. Recent studies have focused on the safety, efficacy, and tolerability of various diet therapies for epilepsy. The objective of this scoping meta- review was to evaluate the evidence regarding different ketogenic diets for epilepsy.

METHODS

This study followed the Arksey and O'Malley framework and adhered to the Preferred Reporting Items for Systematic Reviews and Meta-analysis extension for scoping reviews (PRISMA-ScR) reporting standards. The research question was formulated using the Population, Concept, Context (PCC) framework. A comprehensive literature search was conducted across PubMed, Scopus, and Web of Science up to August 14, 2024.

RESULTS

Out of the 152 papers identified, 38 systematic reviews and meta-analyses were included. The review examined the safety, tolerability, and efficacy of diet therapies for epilepsy, particularly in drug-resistant cases. The findings underscore the significant benefits of classic ketogenic diet (CKD) in reducing seizure frequency. The Modified Atkins Diet (MAD) and Medium-Chain Triglyceride (MCT) KD were found to be effective with improved tolerability. The Low Glycemic Index Diet (LGID) may be less effective. Further research is needed to refine these dietary approaches.

CONCLUSION

The KDs are effective in reducing seizure frequency in epilepsy, especially in drug-resistant cases. The results highlight the valuable advantages of the CKD in decreasing the frequency of seizures. The MCT KD and the MAD are also effective options and are generally better tolerated. The LGID shows potential but may be less effective. Further research is needed to enhance these dietary treatments and investigate their long-term impact.

Lost and found: dynamics of relationship and employment status over time in people with affective and psychotic spectrum disorders

BACKGROUND

Employment and relationship are crucial for social integration. However, individuals with major psychiatric disorders often face challenges in these domains.

AIMS

We investigated employment and relationship status changes among patients across the affective and psychotic spectrum - in comparison with healthy controls, examining whether diagnostic groups or functional levels influence these transitions.

METHOD

The sample from the longitudinal multicentric PsyCourse Study comprised 1260 patients with affective and psychotic spectrum disorders and 441 controls (mean age ± s.d., 39.91 ± 12.65 years; 48.9% female). Multistate models (Markov) were used to analyse transitions in employment and relationship status, focusing on transition intensities. Analyses contained multiple multistate models adjusted for age, gender, job or partner, diagnostic group and Global Assessment of Functioning (GAF) in different combinations to analyse the impact of the covariates on the hazard ratio of changing employment or relationship status.

RESULTS

The clinical group had a higher hazard ratio of losing partner (hazard ratio 1.46, P < 0.001) and job (hazard ratio 4.18, P < 0.001) than the control group (corrected for age/gender). Compared with controls, clinical groups had a higher hazard of losing partner (affective group, hazard ratio 2.69, P = 0.003; psychotic group, hazard ratio 3.06, P = 0.001) and job (affective group, hazard ratio 3.43, P < 0.001; psychotic group, hazard ratio 4.11, P < 0.001). Adjusting for GAF, the hazard ratio of losing partner and job decreased in both clinical groups compared with controls.

CONCLUSION

Patients face an increased hazard of job loss and relationship dissolution compared with healthy controls, and this is partially conditioned by the diagnosis and functional level. These findings underscore a high demand for destigmatisation and support for individuals in managing their functional limitations.

Nutrient analysis of three low-carbohydrate diets differing in carbohydrate content

Introduction

Low-carbohydrate diets are increasing in popularity. Despite clinical evidence demonstrating their safety and efficacy, concerns regarding the nutrient adequacy of low-carbohydrate diets persist. The aims of this study were to assess the nutrient adequacy of three 7-day meal plans that delivered 20 (VLCD20), 40 (VLCD40), and 100 (LCD100) grams of net carbohydrate per day respectively.

Methods

Nutrient analyses were conducted using USDA Food Data Central.

Results

All three low-carbohydrate meal plans exceeded recommendations for vitamins A, C, D, E, K, thiamin, riboflavin, niacin, B6, folate and B12 in males and females 31-70 years and exceeded calcium recommendations for adults 31-50 years but remained below the Tolerable Upper Intake Level. VLCD40 and LCD100 met or exceeded fiber recommendations for females ages 31-70 years and were adequate for males 51-70 years. None of the meal plans contributed meaningful amounts of added sugar. The plans exceeded the Recommended Dietary Allowance for protein for adults ages 31-70 years of age but were within the Acceptable Macronutrient Distribution Range of 10-35% of energy. The plans slightly exceeded recommendations for saturated fat and sodium but were lower in these nutrients than the average American diet and had more favorable omega-6 to omega-3 and sodium to potassium ratios than is typical. All three meals plans met or exceeded the Estimated Average Requirement for micronutrients in females ages 31-50 years, the population group most likely to consume low-carbohydrate diets.

Discussion

Well-constructed low-carbohydrate meal plans can be nutritionally adequate in adults.

The use of ketogenic diets in children living with drug-resistant epilepsy, glucose transporter 1 deficiency syndrome and pyruvate dehydrogenase deficiency: A scoping review

BACKGROUND

The ketogenic diet (KD) is a high fat, moderate protein and very low carbohydrate diet. It can be used as a medical treatment for drug-resistant epilepsy (DRE), glucose transporter 1 deficiency syndrome and pyruvate dehydrogenase deficiency. The aim of this scoping review was to map the KD literature, with a focus on epilepsy and associated metabolic conditions, to summarise the current evidence-base and identify any gaps.

METHODS

This review was conducted using JBI scoping review methodological guidance and the PRISMA extension for scoping reviews reporting guidance. A comprehensive literature search was conducted in September 2021 and updated in February 2024 using MEDLINE, CINAHL, AMED, EmBASE, CAB Abstracts, Scopus and Food Science Source databases.

RESULTS

The initial search yielded 2721 studies and ultimately, data were extracted from 320 studies that fulfilled inclusion criteria for the review. There were five qualitative studies, and the remainder were quantitative, including 23 randomised controlled trials (RCTs) and seven quasi-experimental studies. The USA published the highest number of KD studies followed by China, South Korea and the UK. Most studies focused on the classical KD and DRE. The studies key findings suggest that the KD is efficacious, safe and tolerable.

CONCLUSIONS

There are opportunities available to expand the scope of future KD research, particularly to conduct high-quality RCTs and further qualitative research focused on the child's needs and family support to improve the effectiveness of KDs.

Impact of a keto diet on symptoms of Parkinson's disease, biomarkers, depression, anxiety and quality of life: a longitudinal study

Aim: Evidence suggests low-carbohydrate diets (LCHF) may assist in treating neurodegenerative diseases such as Parkinson's disease (PD); however, gaps exist in the literature.Patients & methods: We conducted a small 24-week pilot study to investigate the effects of an LCHF diet on motor and nonmotor symptoms, health biomarkers, anxiety, and depression in seven people with PD. We also captured patient experiences during the process (quality of life [QoL]).Results: Participants reported improved biomarkers, enhanced cognition, mood, motor and nonmotor symptoms, and reduced pain and anxiety. Participants felt improvements enhanced their QoL.Conclusion: We conclude that an LCHF intervention is safe, feasible, and potentially effective in mitigating the symptoms of this disorder. However, more extensive randomized controlled studies are needed to create generalizable recommendations.

ESPEN guideline on nutrition and hydration in dementia - Update 2024

BACKGROUND & AIMS

Dementia is accompanied by a variety of changes that result in an increased risk of malnutrition and low-intake dehydration. This guideline update aims to give evidence-based recommendations for nutritional care of persons with dementia in order to prevent and treat these syndromes.

METHODS

The previous guideline version was reviewed and expanded in accordance with the standard operating procedure for ESPEN guidelines. Based on a systematic search in three databases, strength of evidence of appropriate literature was graded by use of the SIGN system. The original recommendations were reviewed and reformulated, and new recommendations were added, which all then underwent a consensus process.

RESULTS

40 recommendations for nutritional care of older persons with dementia were developed and agreed, seven at institutional level and 33 at individual level. As a prerequisite for good nutritional care, organizations caring for persons with dementia are recommended to employ sufficient qualified staff and offer attractive food and drinks with choice in a functional and appealing environment. Nutritional care should be based on a written care concept with standardized operating procedures. At the individual level, routine screening for malnutrition and dehydration, nutritional assessment and close monitoring are unquestionable. Oral nutrition may be supported by eliminating potential causes of malnutrition and dehydration, and adequate social and nursing support (including assistance, utensils, training and oral care). Oral nutritional supplements are recommended to improve nutritional status but not to correct cognitive impairment or prevent cognitive decline. Routine use of dementia-specific ONS, ketogenic diet, omega-3 fatty acid supplementation and appetite stimulating agents is not recommended. Enteral and parenteral nutrition and hydration are temporary options in patients with mild or moderate dementia, but not in severe dementia or in the terminal phase of life. In all stages of the disease, supporting food and drink intake and maintaining or improving nutrition and hydration status requires an individualized, comprehensive approach. Due to a lack of appropriate studies, most recommendations are good practice points.

CONCLUSION

Nutritional care should be an integral part of dementia management. Numerous interventions are available that should be implemented in daily practice. Future high-quality studies are needed to clarify the evidence.

A comprehensive examination of the evidence for whole of diet patterns in Parkinson's disease: a scoping review

Both motor and non-motor symptoms of Parkinson's disease (PD), a progressive neurological condition, have broad-ranging impacts on nutritional intake and dietary behaviour. Historically studies focused on individual dietary components, but evidence demonstrating ameliorative outcomes with whole-of-diet patterns such as Mediterranean and Mediterranean-DASH Intervention for Neurodegenerative Delay (MIND) is emerging. These diets provide plenty of antioxidant rich fruits, vegetables, nuts, wholegrains and healthy fats. Paradoxically, the ketogenic diet, high fat and very low carbohydrate, is also proving to be beneficial. Within the PD community, it is well advertised that nutritional intake is associated with disease progression and symptom severity but understandably, the messaging is inconsistent. With projected prevalence estimated to rise to 1.6 million by 2037, more data regarding the impact of whole-of-diet patterns is needed to develop diet-behaviour change programmes and provide clear advice for PD management. Objectives and Methods: Objectives of this scoping review of both peer-reviewed academic and grey literatures are to determine the current evidence-based consensus for best dietary practice in PD and to ascertain whether the grey literature aligns. Results and Discussion: The consensus from the academic literature was that a MeDi/MIND whole of diet pattern (fresh fruit, vegetables, wholegrains, omega-3 fish and olive oil) is the best practice for improving PD outcomes. Support for the KD is emerging, but further research is needed to determine long-term effects. Encouragingly, the grey literature mostly aligned but nutrition advice was rarely forefront. The importance of nutrition needs greater emphasis in the grey literature, with positive messaging on dietary approaches for management of day-to-day symptoms.

Effect of the ketogenic diet as a treatment for refractory epilepsy in children and adolescents: a systematic review of reviews

CONTEXT

Epilepsy is one of the most prevalent neurological disorders in childhood. Antiepileptic drugs are the preferred treatment. However, 30% of children continue suffering seizures. A ketogenic diet (KD) is one of the emerging alternative treatments.

OBJECTIVE

This review aims to analyze the current evidence regarding the use of a KD for the treatment of refractory epilepsy (RE) in childhood.

DATA SOURCES

A systematic review of reviews was performed, based on MEDLINE (PubMed) as at January 2021.

DATA EXTRACTION

The data extracted included the first author's last name; the year of publication; the country; the study design; the population; the diagnosis, concept, and description of KD types; and major outcome.

RESULTS

Twenty-one reviews were included, 8 with systematic methodology (2 of them included a meta-analysis) and 13 with unsystematic methodology. The main difference between the 2 types of reviews is the reproducibility of their methodology. Therefore, the results of each type of review were analyzed separately. Each type of review described 4 categories of KD: classic KD, modified Atkins diet (MAD), use of medium-chain triglycerides (MCTs), and low glycemic index treatment (LGIT). In terms of effectiveness, the considered systematic reviews reported reductions in the frequency of seizures greater than 50% in about half of the patients. Reviews without systematic methodology reported that 30%-60% of the children showed a 50% or greater reduction in seizures. The most frequently described adverse effects in the 8 systematic reviews were: vomiting (6/8), constipation (6/8), and diarrhea (6/8); and in the unsystematic reviews: vomiting and nausea (10/13), constipation (10/13), and acidosis (9/13).

CONCLUSION

KD can be an effective treatment for RE, with a more than 50% reduction in the frequency of seizures and cognitive improvement being achieved in half of the pediatric patients. The effectiveness of the various types of KD is comparable, and the KD can be adapted to the needs of the patient.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration no. CRD42021244142.

A qualitative study of the implementation and organization of the national Greenlandic addiction treatment service

Background

Alcohol and cannabis use constitutes the major public health problems in Greenland. Thus, it is important to assess if Allorfik, a new national outpatient addiction treatment service introduced in 2016, was implemented successfully and how it is perceived. Allorfik introduced local treatment centers offering a treatment methodology (motivational interviewing and cognitive therapy) new to addiction treatment in Greenland with limited evidence from Indigenous populations such as the Greenlandic. The present study investigates the implementation of Allorfik from the perspective of those engaged in the process and the field.

Methods

Data consisted of transcribed interviews with 23 individuals from both Allorfik and organizations collaborating with or supposed to collaborate with Allorfik. The theme of the interviews was their perspectives on the implementation process, enablers, and obstacles in the process and how Allorfik was performing at the time of the interview. The interview guide was informed by implementation theory. The transcribed material was analyzed using a general inductive approach.

Results

The analysis resulted in three overall and interconnected themes, namely, implementation, collaborations, and challenges. The implementation was overall considered a success by the interviewees as all components were implemented as planned with a few adaptions, e.g., a treatment guideline update. The collaborations are considered challenging but important to all interviewees. Collaborations seem to rely on personal commitment as opposed to well-defined structures, making it unstable and vulnerable to changes in staff. One of the main challenges highlighted by the interviewees is the number of problems other than addiction among people in treatment, which makes addiction treatment and recovery difficult to achieve. Nevertheless, the high levels of other problems being treated in Allorfik highlights the need for easily accessible therapy as many find that Allorfik is the only place to turn to in times of crisis.

Conclusion

Allorfik seems to have been implemented in accordance with original intentions and plans for addiction treatment service but has also become more than just a service for addiction treatment with easy access in a country with vast distances and limited resources.

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.

Effect of low-carbohydrate diet on depression and anxiety: A systematic review and meta-analysis of controlled trials

BACKGROUND

Despite considerable advances in pharmacological and non-pharmacological treatments, mental health illnesses carry many economic and social burdens. Depression and anxiety are known as mental disorders which are highly prevalent worldwide. Previous studies have shown different results. This diet has attracted enormous interest.

OBJECTIVE

This is the first meta-analysis conducted to review systematically all trials to evaluating the effect of a low carbohydrate diet (LCD) on depression, and anxiety.

METHODS

PubMed, Web of Science, and Scopus have been searched until 9 September 2021. In total, 8 RCTs (n = 590) were carried out for evaluation the effects of LCDs on depression and anxiety were included. All the trials included in the analyses evaluated patients without a mood disorder. Random model effects meta-analysis was conducted. To evaluate the heterogeneity among the included studies. The egger test was used. Subgroup analyses performed based on regions, assessment methods, carbohydrate intake and duration of studies.

RESULTS

This study did not show any significant association between a low carbohydrate diet and the of anxiety (SMD = 0.19, 95 % CI -0.10, 0.47; P = 0.20) and also depression (SMD = 0.06, 95 % CI -0.11, 0.24; P = 0.49). If one of the studies is excluded, this diet significantly increases anxiety (SMD = 0.33, 95 % CI 0.12, 0.54; P ≤ 0.001). This study showed that this diet increases anxiety in studies with <26 % carbohydrate intake (SMD = 0.31; 95%CI 0.10, 0.52; P ≤ 0.001; I² = 0.00, P = 0.52), in the Australia (SMD = 0.29; 95%CI 0.08, 0.49; P = 0.01; I² = 0.00, P = 0.42), and in studies that used the Spielberger State Anxiety Inventory (SAI) to assess anxiety (SMD = 0.33; 95%CI 0.11, 0.54; P ≤ 0.001; I² = 0.00, P = 0.54).

LIMITATIONS

One of the limitations of intervention studies examining the effect of diet is that it is difficult to blind people under intervention.

CONCLUSION

The present study did not demonstrate significant association between a low carbohydrate diet and improvement of depression and anxiety. More accurate studies are needed to reach definitive conclusions.

REDD-PAC Cohort Description: Researching Dual Diagnosis - Prognosis and Characteristics

OBJECTIVE

Evidence from real-world integrated dual diagnosis treatment programs is limited. In 2017 we decided to establish the REDD-PAC cohort with the aim to provide more in-depth information regarding the effect of integrated treatment.

METHODS

The REDD-PAC cohort includes more than 2,500 patients with dual diagnosis that have been treated at an in-patient department specializing in the integrated treatment of both psychiatric illness and substance use disorder in Denmark in the period from 2002 to 2017. The collected data included information on diagnosis as well as patient-completed questionnaires regarding anxiety, depression, self-worth, and use of substances. Data regarding medications prescribed and administered, weight, height, and blood pressure were also included.

RESULTS

The primary diagnosis was psychosis spectrum disorder (37.0%), followed by affective disorders (18.8%). More than two-thirds of the patients were male, and most patients had a weak connection to the labor market and basic schooling. Patients were generally very motivated for treatment.

CONCLUSIONS

Further linking the data to Danish national register data makes it possible to follow individual trajectories pre- and post-admission as well as to access complete follow-up data regarding long-term outcomes, e.g., use of health services, mortality, morbidity, crime, and social circumstances. This article describes both the overarching aims of the REDD-PAC cohort and the basic diagnostic and sociodemographic characteristics of the cohort.

The Potential Role of Gut Microbiota in Alzheimer’s Disease: from Diagnosis to Treatment

Gut microbiota is emerging as a key regulator of many disease conditions and its dysregulation is implicated in the pathogenesis of several gastrointestinal and extraintestinal disorders. More recently, gut microbiome alterations have been linked to neurodegeneration through the increasingly defined gut microbiota brain axis, opening the possibility for new microbiota-based therapeutic options. Although several studies have been conducted to unravel the possible relationship between Alzheimer’s Disease (AD) pathogenesis and progression, the diagnostic and therapeutic potential of approaches aiming at restoring gut microbiota eubiosis remain to be fully addressed. In this narrative review, we briefly summarize the role of gut microbiota homeostasis in brain health and disease, and we present evidence for its dysregulation in AD patients. Based on these observations, we then discuss how dysbiosis might be exploited as a new diagnostic tool in early and advanced disease stages, and we examine the potential of prebiotics, probiotics, fecal microbiota transplantation, and diets as complementary therapeutic interventions on disease pathogenesis and progression, thus offering new insights into the diagnosis and treatment of this devastating and progressive disease.

Ketogenic diet for epilepsy: an overview of systematic review and meta-analysis

Ketogenic diet therapy (KDT) is an established nonpharmacologic treatment in various types of epilepsy. We aim to evaluate the quality of the systematic reviews and meta-analyses (SRMAs) of KDT for epilepsy and summarize the evidence on their effects. We conducted an overview on MEDLINE, EMBASE, Cochrane Database of Systematic Review, and Web of Science from database inception to 3 September 2020. Two investigators independently performed study selection to include SRMAs, extracted data and assessed the quality of SRMAs with the AMSTAR-2 and PRISMA statement. Twenty-four SRMAs were selected which encompassed a total of 255 original studies. Four reviews assessed the effects of KDT on infant patients; thirteen reviews reported on children and adolescent patients; eight reviews focused on adults or all patients; four assessed cognitive and behavior outcomes; three assessed quality of life; two assessed growth and development outcomes; seventeen reported on adverse effects; seven reported on retention; ten reported on attrition and reasons; and four reported on death outcomes. Overall, positive effects of KDT for epilepsy on seizure frequency reduction, as well as cognition and behavior were observed. In contrast, the effects of KDT on quality of life, growth and development were more controversial. The present overview indicates that KDT is safe. The most prevalent adverse events were GI, weight loss, and metabolic disorders, while the most common reasons for discontinuance were the lack of observed efficacy and dietary intolerance.

Experience of participants with chronic pain in a pilot randomized clinical trial using a ketogenic diet

Aim: To report the experience of chronic pain participants after a well-formulated ketogenic diet (WFKD) or whole-food diet (WFD). The quantitative outcomes for this trial have been published separately (clinical trial registration number ACTRN12620000946910). Patients & methods: The experience of 24 participants was evaluated after 12 and 24 weeks of dietary intervention using survey responses and open questions. Results & conclusion: Retention rates for the WFKD and WFD groups were 93 and 89%, respectively. Average adherence to the WFKD was 82% and to the WFD was 87%. The WFKD enjoyment was rated at 66 and 81% for the WFD group. The ease of adhering to the diet varied more widely for the WFKD group. Barriers included knowledge integration, time management, navigating social food environments and emotional attachment to eliminated foods. Facilitators included structured support and coaching, and comprehensive learning materials. The WFKD was shown to be a feasible and effective treatment option for chronic pain.

[The ketogenic diet: history, mechanism of action, indications and contraindications]

Low-carb diets have been successfully used to alleviate a number of severe neurological diseases for about 100 years. The publication of the results of new studies suggesting that this type of diet may play a therapeutic role in other pathologies such as diabetes, obesity, polycystic ovary syndrome, and oncology is of particular interest for both doctors and the public. However, the long-term safety of using a low-carb or ketogenic diet, as well as its impact, primarily on the risks of developing cardiovascular diseases, remains poorly studied. This article presents the results of observation of patients against the background of a low-carbohydrate diet, both in the short-term perspective as well as provides an assessment of its long-term consequences.

Effects of a low-carbohydrate ketogenic diet on reported pain, blood biomarkers and quality of life in patients with chronic pain: A pilot randomised clinical trial

BACKGROUND

A low-carbohydrate ketogenic diet has been reported to improve chronic pain by reducing inflammation, oxidative stress, and sensitivity within the nervous system. The main aim of this trial is to evaluate the effects of a ketogenic diet on reported pain, blood biomarkers and quality of life in patients with chronic pain.

METHODS

Participants with chronic musculoskeletal pain were recruited for a 12-week diet intervention that commenced with a 3-week run-in diet removing ultra-processed foods, followed by randomisation to either a whole-food/well-formulated ketogenic diet (WFKD) or to continue with the minimally processed whole-food diet (WFD). Outcome measures included: average pain (visual analogue scale VAS), blood biomarkers, anthropometrics, adherence, depression, anxiety, sleep, ketones, quality of life, diet satisfaction and macronutrient intake.

RESULTS

Average weekly pain improved for both groups. WFKD group VAS reduced by 17.9 ± 5.2 mm (p = 0.004) and the WFD group VAS reduced 11.0 ± 9.0 mm (p = 0.006). Both groups also reported improved quality of life (WFKD = 11.5 ± 2.8%, p = 0.001 and WFD = 11.0 ± 3.5%, p = 0.014). The WFKD group also demonstrated significant improvements in pain interference (p = 0.013), weight (p < 0.005), depression (p = 0.015), anxiety (p = 0.013), and inflammation (hsCRP) (p = 0.009). Significant average pain reduction remained at three-month follow-up for both groups (WFKD p = 0.031, WFD p = 0.011).

CONCLUSION

The implementation of a whole-food diet that restricts ultra-processed foods is a valid pain management tool, however a low-carbohydrate ketogenic diets may have potentially greater pain reduction, weight loss and mood improvements.

Increased Beta-Hydroxybutyrate Level Is Not Sufficient for the Neuroprotective Effect of Long-Term Ketogenic Diet in an Animal Model of Early Parkinson's Disease. Exploration of Brain and Liver Energy Metabolism Markers

The benefits of a ketogenic diet in childhood epilepsy steered up hope for neuroprotective effects of hyperketonemia in Parkinson’s disease (PD). There are multiple theoretical reasons but very little actual experimental proof or clinical trials. We examined the long-term effects of the ketogenic diet in an animal model of early PD. A progressive, selective dopaminergic medium size lesion was induced by 6-OHDA injection into the medial forebrain bundle. Animals were kept on the stringent ketogenic diet (1% carbohydrates, 8% protein, 70% fat) for 3 weeks prior and 4 weeks after the brain operation. Locomotor activity, neuron count, dopaminergic terminal density, dopamine level, and turnover were analyzed at three time-points post-lesion, up to 4 weeks after the operation. Energy metabolism parameters (glycogen, mitochondrial complex I and IV, lactate, beta-hydroxybutyrate, glucose) were analyzed in the brain and liver or plasma. Protein expression of enzymes essential for gluconeogenesis (PEPCK, G6PC) and glucose utilization (GCK) was analyzed in the liver. Despite long-term hyperketonemia pre- and post-lesion, the ketogenic diet did not protect against 6-OHDA-induced dopaminergic neuron lesions. The ketogenic diet only tended to improve locomotor activity and normalize DA turnover in the striatum. Rats fed 7 weeks in total with a restrictive ketogenic diet maintained normoglycemia, and neither gluconeogenesis nor glycogenolysis in the liver was responsible for this effect. Therefore, potentially, the ketogenic diet could be therapeutically helpful to support the late compensatory mechanisms active via glial cells but does not necessarily act against the oxidative stress-induced parkinsonian neurodegeneration itself. A word of caution is required as the stringent ketogenic diet itself also carries the risk of unwanted side effects, so it is important to study the long-term effects of such treatments. More detailed metabolic long-term studies using unified diet parameters are required, and human vs. animal differences should be taken under consideration.