The ketogenic diet 2011: how it works

Does Ketogenic Diet Used in Pregnancy Affect the Nervous System Development in Offspring?─FTIR Microspectroscopy Study

Anti-seizure medications used during pregnancy may have transient or long-lasting impact on the nervous system of the offspring. Therefore, there is a great need to search for alternative therapies for pregnant women suffering from seizures. One of the solutions may be the use of the ketogenic diet (KD), which has been successfully applied as a treatment of drug-resistant epilepsy in children and adults. However, the risks associated with the use of this dietary therapy during pregnancy are unknown and more investigation in this area is needed. To shed some light on this problem, we attempted to determine the potential abnormalities in brain biomolecular composition that may occur in the offspring after the prenatal exposure to KD. To achieve this, the female Wistar rats were, during pregnancy, fed with either ketogenic or standard laboratory diet, and for further studies, their male offspring at 2, 6, or 14 days of age were used. Fourier transform infrared microspectroscopy was applied for topographic and quantitative analysis of main biological macromolecules (proteins, lipids, compounds containing phosphate and carbonyl groups, and cholesterol) in brain samples. Performed chemical mapping and further semi-quantitative and statistical analysis showed that the use of the KD during pregnancy, in general, does not lead to the brain biochemical anomalies in 2 and 6 days old rats. The exception from this rule was increased relative (comparing to proteins) content of compounds containing phosphate groups in white matter and cortex of 2 days old rats exposed prenatally to KD. Greater number of abnormalities was found in brains of the 14 days old offspring of KD-fed mothers. They included the increase of the relative level of compounds containing carbonyl groups (in cortex as well as multiform and molecular cells of the hippocampal formation) as well as the decrease of the relative content of lipids and their structural changes (in white matter). What is more, the surface of the internal capsule (structure of the white matter) determined for this age group was smaller in animals subjected to prenatal KD exposure. The observed changes seem to arise from the elevated exposition to ketone bodies during a fetus life and the disturbance of lipid metabolism after prenatal exposure to the KD. These changes may be also associated with the processes of compensation of mother organism, which slowly began to make up for the deficiencies in carbohydrates postpartum.

The Role of Ketogenic Diet in the Treatment of Neuroblastoma

The ketogenic diet (KD) was initially used in 1920 for drug-resistant epileptic patients. From this point onward, ketogenic diets became a pivotal part of nutritional therapy research. To date, KD has shown therapeutic potential in many pathologies such as Alzheimer's disease, Parkinson's disease, autism, brain cancers, and multiple sclerosis. Although KD is now an adjuvant therapy for certain diseases, its effectiveness as an antitumor nutritional therapy is still an ongoing debate, especially in Neuroblastoma. Neuroblastoma is the most common extra-cranial solid tumor in children and is metastatic at initial presentation in more than half of the cases. Although Neuroblastoma can be managed by surgery, chemotherapy, immunotherapy, and radiotherapy, its 5-year survival rate in children remains below 40%. Earlier studies have proposed the ketogenic diet as a possible adjuvant therapy for patients undergoing treatment for Neuroblastoma. In this study, we seek to review the possible roles of KD in the treatment of Neuroblastoma.

Cognitive profile of male mice exposed to a Ketogenic Diet

In recent years, nutritional interventions for different psychiatric diseases have gained increasing attention, such as the ketogenic diet (KD). This has led to positive effects in neurological disorders such as Parkinson's disease, addiction, autism or epilepsy. The neurobiological mechanisms through which these effects are induced and the effects in cognition still warrant investigation, and considering that other high-fat diets (HFD) can lead to cognitive disturbances that may affect the results achieved, the main aim of the present work was to evaluate the effects of a KD to determine whether it can induce such cognitive effects. A total of 30 OF1 male mice were employed to establish the behavioral profile of mice fed a KD by testing anxiety behavior (Elevated Plus Maze), locomotor activity (Open Field), learning (Hebb Williams Maze), and memory (Passive Avoidance Test). The results revealed that the KD did not affect locomotor activity, memory or hippocampal-dependent learning, as similar results were obtained with mice on a standard diet, albeit with increased anxiety behavior. We conclude that a KD is a promising nutritional approach to apply in research studies, given that it does not cause cognitive alterations.

Effects of ketosis on cocaine-induced reinstatement in male mice

In recent years, the benefits of the ketogenic diet (KD) on different psychiatric disorders have been gaining attention, but the substance abuse field is still unexplored. Some studies have reported that palatable food can modulate the rewarding effects of cocaine, but the negative metabolic consequences rule out the recommendation of using it as a complementary treatment. Thus, the main aim of this study was to evaluate the effects of the KD on cocaine conditioned place preference (CPP) during acquisition, extinction, and reinstatement. 41 OF1 male mice were employed to assess the effects of the KD on a 10 mg/kg cocaine-induced CPP. Animals were divided into three groups: SD, KD, and KD after the Post-Conditioning test. The results revealed that, while access to the KD did not block CPP acquisition, it did significantly reduce the number of sessions required to extinguish the drug-associated memories and it blocked the priming-induced reinstatement.

A combination of ketogenic diet and voluntary exercise ameliorates anxiety and depression-like behaviors in Balb/c mice

The positive effects of both ketogenic diet (KD) and regular voluntary exercise on anxiety and depression behavior have been recently reported in rodent animals, but the effects of pairing a KD with exercise on depression and anxiety are unknown. In this study, we aimed to investigate the effects of combination of KD and regular voluntary exercise on anxiety and depression-like behavior in Balb/c mice. We've demostrated that anxiety and depression levels decreased in KD-exercised (KD-Ex) mice. β-hydroxybutyrate (BHB) levels increased while glucose, insulin levels and LDL/HDL ratio decreased in KD-Ex mice. There was a negative correlation between BHB and the time spent in the closed arms of elevated plus maze (EPM) or the time spent in periphery walls of open field test (OFT) and the immobility time in forced swim test (FST) which all of them are indicators of low depression and anxiety levels. There was a positive correlation between LDL/HDL ratio and the time spent in the closed arms of EPM or the immobility time in FST. The immobility time in FST was positively correlated with insulin while the mobility time in FST was negatively correlated with glucose. In conclusion, these results suggest that decline in anxiety and depression-like behaviors resulted from KD with regular voluntary exercise may be associated with increased BHB levels and decreased LDL/HDL ratio and insulin or glucose levels. Further research is necessary for our understanding of the mechanisms by which pairing a KD with voluntary exercise influences brain and behavior.

Ketogenic Diet Decreases Alcohol Intake in Adult Male Mice

The classic ketogenic diet is a diet high in fat, low in carbohydrates, and well-adjusted proteins. The reduction in glucose levels induces changes in the body’s metabolism, since the main energy source happens to be ketone bodies. Recent studies have suggested that nutritional interventions may modulate drug addiction. The present work aimed to study the potential effects of a classic ketogenic diet in modulating alcohol consumption and its rewarding effects. Two groups of adult male mice were employed in this study, one exposed to a standard diet (SD, n = 15) and the other to a ketogenic diet (KD, n = 16). When a ketotic state was stable for 7 days, animals were exposed to the oral self-administration paradigm to evaluate the reinforcing and motivating effects of ethanol. Rt-PCR analyses were performed evaluating dopamine, adenosine, CB1, and Oprm gene expression. Our results showed that animals in a ketotic state displayed an overall decrease in ethanol consumption without changes in their motivation to drink. Gene expression analyses point to several alterations in the dopamine, adenosine, and cannabinoid systems. Our results suggest that nutritional interventions may be a useful complementary tool in treating alcohol-use disorders.

Overall cognitive profiles in patients with GLUT1 Deficiency Syndrome

INTRODUCTION

Glucose Transporter Type I Deficiency Syndrome (GLUT1DS) classical symptoms are seizures, involuntary movements, and cognitive impairment but so far the literature has not devoted much attention to the last.

METHODS

In our retrospective study involving 25 patients with established GLUT1DS diagnosis, we describe the cognitive impairment of these patients in detail and their response to the ketogenic diet in terms of cognitive improvement.

RESULTS

We outlined a specific cognitive profile where performance skills were more affected than verbal ones, with prominent deficiencies in visuospatial and visuomotor abilities. We demonstrated the efficacy of ketogenic diet (KD) on cognitive outcome, with particular improvement tin total and verbal IQ; we found that timing of KD introduction was inversely related to IQ outcome: the later the starting of KD, the lower the IQ, more notable nonverbal scale (verbal IQ correlation coefficient -0.634, p-value = 0.015). We found a significant direct correlation between cognition and CSF/blood glucose ratio values: the higher the ratio, the better the cognitive improvement in response to diet (from T0-baseline evaluation to T1 on average 18 months after introduction of KD-: TIQ correlation coefficient 0.592, p-value = 0.26; VIQ correlation coefficient 0.555, p-value = 0.039). Finally, we demonstrated that a longer duration of treatment is necessary to find an improvement in patients with "severely low ratio."

CONCLUSION

Our results were consistent with the hypothesis that timing of the diet introduction is a predictive factor of cognitive outcome in these patients, confirming that earlier initiation of the diet may prevent the onset of all GLUT1DS symptoms: epilepsy, movement disorders, and cognitive impairment.

The modification of the ketogenic diet mitigates its stunting effects in rodents

The high-fat and low-carbohydrate ketogenic diet (HFKD) is extensively studied within the fields of numerous diseases, including cancer and neurological disorders. Since most studies incorporate animal models, ensuring the quality of ketogenic rodent diets is important, both in the context of laboratory animal welfare as well as for the accuracy of the obtained results. In this study we implemented a modification to a commonly used ketogenic rodent chow by replacing non-resorbable cellulose with wheat bran. We assessed the effects of month-long treatment with either the unmodified or the modified HFKD on the growth and development of young male rats. Daily body weight, functional performance, and brain morphometric parameters were assessed to evaluate the influence of both applied diets on rodent development. Our results revealed that the unmodified ketogenic chow induced strong side effects that included weakness, emaciation, and brain undergrowth concomitant to growth inhibition. However, application of the ketogenic chow supplemented with wheat bran suppressed these adverse side effects, which was associated with the restoration of insulin-like growth factor 1 and a decrease in corticosterone levels. We have also shown that the advantageous results of the modified HFKD are not species- or sex-specific. Our data indicate that the proposed HFKD modification even allows for its application in young animals, without causing detrimental side effects.

Ketotic hypercalcemia: a case series and description of a novel entity

CONTEXT

The ketogenic diet is increasingly used in refractory epilepsy and is associated with clinically significant effects on bone and mineral metabolism. Although hypercalciuria and loss of bone mineral density are common in patients on the ketogenic diet, hypercalcemia has not previously been described.

OBJECTIVE

The aim of the study was to describe three children who developed hypercalcemia while on the ketogenic diet.

DESIGN

A retrospective chart review of three children on the ketogenic with severe hypercalcemia was conducted.

RESULTS

We describe three children on the ketogenic diet for refractory seizures who presented with hypercalcemia. Case 1 was a 5.5-year-old male with an undiagnosed, rapidly progressive seizure disorder associated with developmental regression. Case 2 was a 2.5-year-old male with a chromosomal deletion of 2q24.3, and case 3 was a 4.6-year-old male with cerebral cortex dysplasia. Patients had been on a ketogenic diet for 6 to 12 months before presentation. Daily intake of calcium and vitamin D was not excessive, and all three patients were not acidotic because they were taking supplemental bicarbonate. Each child had elevated serum levels of calcium and normal serum phosphate levels, moderately elevated urinary calcium excretion, and low levels of serum alkaline phosphatase, PTH, and 1,25-dihydroxyvitamin D. All patients responded to calcitonin.

CONCLUSIONS

Hypercalcemia is an uncommon complication of the ketogenic diet, and these children may represent the severe end of a clinical spectrum of disordered mineral metabolism. The mechanism for hypercalcemia is unknown but is consistent with excess bone resorption and impaired calcium excretion.

Fructose-1,6-diphosphate protects against epileptogenesis by modifying cation-chloride co-transporters in a model of amygdaloid-kindling temporal epilepticus

Fructose-1,6-diphosphate (FDP) shifts the metabolism of glucose from glycolysis to the pentose phosphate pathway and has anticonvulsant activity in several acute seizure animal models. In the present study, we investigated the anti-epileptogenic effects of FDP in an amygdaloid-kindling seizure model, which is an animal model of the most common form of human temporal lobe epilepsy. We found that 1.0 g/kg FDP slowed seizure progression and shortened the corresponding after-discharge duration (ADD). FDP increased the number of stimulations needed to reach seizure stages 2-5 and prolonged the cumulative ADD prior to reaching stages 3-5. It also shortened staying days and cumulative ADD in stages 4-5. However, it demonstrated no significant protective effect when administered after the animals were fully kindled. In hippocampal neurons, cation-chloride co-transporters (CCCs) are suggested to play interesting roles in epilepsy by modulating γ-aminobutyric acid (GABA)ergic activity through controlling GABAA receptor-mediated reversal potential. We examined the potential link between FDP and the hippocampal expression of two main members of the CCCs: the neuron-specific K(+)-Cl(-)co-transporter 2 (KCC2) and Na(+)-K(+)-Cl(-)co-transporter 1 (NKCC1). FDP inhibited the kindling-induced downregulation of KCC2 expression and decreased NKCC1 expression during the kindling session. Taken together, our data reveal that FDP may have protective activity against epileptogenesis, from partial to generalized tonic-clonic seizures. Furthermore, our findings suggest that the FDP-induced imbalance between KCC2 and NKCC1 expression may be involved in the neuroprotective effect.