Study of the ketogenic agent AC-1202 in mild to moderate Alzheimer's disease: a randomized, double-blind, placebo-controlled, multicenter trial

The role of dietary coconut for the prevention and treatment of Alzheimer's disease: potential mechanisms of action

Coconut, Cocos nucifera L., is a tree that is cultivated to provide a large number of products, although it is mainly grown for its nutritional and medicinal values. Coconut oil, derived from the coconut fruit, has been recognised historically as containing high levels of saturated fat; however, closer scrutiny suggests that coconut should be regarded more favourably. Unlike most other dietary fats that are high in long-chain fatty acids, coconut oil comprises medium-chain fatty acids (MCFA). MCFA are unique in that they are easily absorbed and metabolised by the liver, and can be converted to ketones. Ketone bodies are an important alternative energy source in the brain, and may be beneficial to people developing or already with memory impairment, as in Alzheimer's disease (AD). Coconut is classified as a highly nutritious 'functional food'. It is rich in dietary fibre, vitamins and minerals; however, notably, evidence is mounting to support the concept that coconut may be beneficial in the treatment of obesity, dyslipidaemia, elevated LDL, insulin resistance and hypertension - these are the risk factors for CVD and type 2 diabetes, and also for AD. In addition, phenolic compounds and hormones (cytokinins) found in coconut may assist in preventing the aggregation of amyloid-β peptide, potentially inhibiting a key step in the pathogenesis of AD. The purpose of the present review was to explore the literature related to coconut, outlining the known mechanistic physiology, and to discuss the potential role of coconut supplementation as a therapeutic option in the prevention and management of AD.

Effects of ketone bodies in Alzheimer's disease in relation to neural hypometabolism, β-amyloid toxicity, and astrocyte function

Diet supplementation with ketone bodies (acetoacetate and β-hydroxybuturate) or medium-length fatty acids generating ketone bodies has consistently been found to cause modest improvement of mental function in Alzheimer's patients. It was suggested that the therapeutic effect might be more pronounced if treatment was begun at a pre-clinical stage of the disease instead of well after its manifestation. The pre-clinical stage is characterized by decade-long glucose hypometabolism in brain, but ketone body metabolism is intact even initially after disease manifestation. One reason for the impaired glucose metabolism may be early destruction of the noradrenergic brain stem nucleus, locus coeruleus, which stimulates glucose metabolism, at least in astrocytes. These glial cells are essential in Alzheimer pathogenesis. The β-amyloid peptide Aβ interferes with their cholinergic innervation, which impairs synaptic function because of diminished astrocytic glutamate release. Aβ also reduces glucose metabolism and causes hyperexcitability. Ketone bodies are similarly used against seizures, but the effectively used concentrations are so high that they must interfere with glucose metabolism and de novo synthesis of neurotransmitter glutamate, reducing neuronal glutamatergic signaling. The lower ketone body concentrations used in Alzheimer's disease may owe their effect to support of energy metabolism, but might also inhibit release of gliotransmitter glutamate. Alzheimer's disease is a panglial-neuronal disorder with long-standing brain hypometabolism, aberrations in both neuronal and astrocytic glucose metabolism, inflammation, hyperexcitability, and dementia. Relatively low doses of β-hydroxybutyrate can have an ameliorating effect on cognitive function. This could be because of metabolic supplementation or inhibition of Aβ-induced release of glutamate as gliotransmitter, which is likely to reduce hyperexcitability and inflammation. The therapeutic β-hydroxybutyrate doses are too low to reduce neuronally released glutamate.

Brain and behavioral perturbations in rats following Western diet access

Energy dense "Western" diets (WD) are known to cause obesity as well as learning and memory impairments, blood-brain barrier damage, and psychological disturbances. Impaired glucose (GLUT1) and monocarboxylate (MCT1) transport may play a role in diet-induced dementia development. In contrast, ketogenic diets (KD) have been shown to be neuroprotective. We assessed the effect of 10, 40 and 90 days WD, KD and Chow maintenance on spontaneous alternation (SA) and vicarious trial and error (VTE) behaviors in male rats, then analyzed blood glucose, insulin, and ketone levels; and hippocampal GLUT1 and MCT1 mRNA. Compared to Chow and KD, rats fed WD had increased 90 day insulin levels. SA was decreased in WD rats at 10, but not 40 or 90 days. VTE was perturbed in WD-fed rats, particularly at 10 and 90 days, indicating hippocampal deficits. WD rats had lower hippocampal GLUT1 and MCT1 expression compared to Chow and KD, and KD rats had increased 90 day MCT1 expression compared to Chow and WD. These data suggest that WD reduces glucose and monocarboxylate transport at the hippocampus, which may result in learning and memory deficits. Further, KD consumption may be useful for MCT1 transporter recovery, which may benefit cognition.

Nutritional or pharmacological activation of HCA(2) ameliorates neuroinflammation

Neuroinflammation is a pathology common to many neurological diseases, including multiple sclerosis (MS) and stroke. However, therapeutic attempts to modulate neuroinflammation have proved difficult. Neuroinflammatory cells express HCA2, a receptor for the endogenous neuroprotective ketone body β-hydroxybutyrate (BHB) as well as for the drugs dimethyl fumarate (DMF) and nicotinic acid, which have established efficacy in the treatment of MS and experimental stroke, respectively. This review summarizes the evidence that HCA2 is involved in the therapeutic effects of DMF, nicotinic acid, and ketone bodies in reducing neuroinflammation. Furthermore, we discuss the mechanisms underlying the beneficial effects of HCA2 activation in neuroinflammatory diseases and the therapeutic potential of recently developed synthetic ligands of HCA2.

Evaluation and management of the elderly patient presenting with cognitive complaints

Cognitive complaints are common in the geriatric population. Older adults should routinely be asked about any concerns about their memory or thinking, and any cognitive complaint from the patient or an informant should be evaluated rather than be attributed to aging. Several screening instruments are available to document objective impairments and guide further evaluation. Management goals for patients with cognitive impairment are focused on maintaining function and independence, providing caregiver support, and advance care planning. There are currently no treatments to effectively prevent or treat dementia. Increasing appreciation of the heterogeneity of Alzheimer disease may lead to novel treatment approaches.

Biomarkers, ketone bodies, and the prevention of Alzheimer's disease

Sporadic Alzheimer's disease (spAD) has three successive phases: preclinical, mild cognitive impairment, and dementia. Individuals in the preclinical phase are cognitively normal. Diagnosis of preclinical spAD requires evidence of pathologic brain changes provided by established biomarkers. Histopathologic features of spAD include (i) extra-cellular cerebral amyloid plaques and intracellular neurofibrillary tangles that embody hyperphosphorylated tau; and (ii) neuronal and synaptic loss. Amyloid-PET brain scans conducted during spAD's preclinical phase have disclosed abnormal accumulations of amyloid-beta (Aβ) in cognitively normal, high-risk individuals. However, this measure correlates poorly with changes in cognitive status. In contrast, MRI measures of brain atrophy consistently parallel cognitive deterioration. By the time dementia appears, amyloid deposition has already slowed or ceased. When a new treatment offers promise of arresting or delaying progression of preclinical spAD, its effectiveness must be inferred from intervention-correlated changes in biomarkers. Herein, differing tenets of the amyloid cascade hypothesis (ACH) and the mitochondrial cascade hypothesis (MCH) are compared. Adoption of the ACH suggests therapeutic research continue to focus on aspects of the amyloid pathways. Adoption of the MCH suggests research emphasis be placed on restoration and stabilization of mitochondrial function. Ketone ester (KE)-induced elevation of plasma ketone body (KB) levels improves mitochondrial metabolism and prevents or delays progression of AD-like pathologic changes in several AD animal models. Thus, as a first step, it is imperative to determine whether KE-caused hyperketonemia can bring about favorable changes in biomarkers of AD pathology in individuals who are in an early stage of AD's preclinical phase.

A practical algorithm for managing Alzheimer's disease: what, when, and why?

Alzheimer's disease (AD) is the most common form of dementia and its prevalence is increasing. Recent developments in AD management provide improved ways of supporting patients and their caregivers throughout the disease continuum. Managing cardiovascular risk factors, maintaining an active lifestyle (with regular physical, mental and social activity) and following a Mediterranean diet appear to reduce AD risk and may slow cognitive decline. Pharmacologic therapy for AD should be initiated upon diagnosis. All of the currently available cholinesterase inhibitors (ChEIs; donepezil, galantamine, and rivastigmine) are indicated for mild-to-moderate AD. Donepezil (10 and 23 mg/day) and rivastigmine transdermal patch (13.3 mg/24 h) are indicated for moderate-to-severe AD. Memantine, an N-methyl-d-aspartate receptor antagonist, is approved for moderate-to-severe AD. ChEIs have been shown to improve cognitive function, global clinical status and patients' ability to perform activities of daily living. There is also evidence for reduction in emergence of behavioral symptoms with ChEI therapy. Treatment choice (e.g., oral vs. transdermal) should be based on patient or caregiver preference, ease of use, tolerability, and cost. Treatment should be individualized; patients can be switched from one ChEI to another if the initial agent is poorly tolerated or ineffective. Memantine may be introduced in moderate-to-severe disease stages. Clinicians will regularly monitor symptoms and behaviors, manage comorbidities, assess function, educate and help caregivers access information and support, evaluate patients' fitness to drive or own firearms, and provide advice about the need for legal and financial planning. Review of caregiver well-being and prompt referral for support is vital.

Pilot feasibility and safety study examining the effect of medium chain triglyceride supplementation in subjects with mild cognitive impairment: A randomized controlled trial

BACKGROUND

Impaired brain glucose metabolism appears to be a potential pathogenic feature of mild cognitive impairment (MCI). This study examined the potential for increasing circulating ketone bodies through medium chain triglyceride (MCT) supplementation, as a means to beneficially modulate brain homeostasis in subjects with MCI.

METHODS

Six participants with MCI were enrolled in a randomized placebo-controlled trial. Participants received 56 g/day of either medium chain triglycerides (MCTs) or placebo for 24 weeks. Serum β-hydroxybutyrate concentrations, apolipoprotein-E4 status, and cognitive assessments were carried out. Due to the small number of participants only the raw scores were examined.

RESULTS

Intake of MCT oil increased serum ketone bodies and improved memory, while intake of placebo did not show improvement in any of the cognitive measures tested.

CONCLUSIONS

Consumption of 56 g/day of MCTs for 24 weeks increases serum ketone concentrations and appears to be a candidate for larger randomized control trials in the future that quantify the modulation of cognitive function through supplementation with ketone precursors, in patients with MCI.

Targeting the prodromal stage of Alzheimer's disease: bioenergetic and mitochondrial opportunities

Alzheimer's disease (AD) has a complex and progressive neurodegenerative phenotype, with hypometabolism and impaired mitochondrial bioenergetics among the earliest pathogenic events. Bioenergetic deficits are well documented in preclinical models of mammalian aging and AD, emerge early in the prodromal phase of AD, and in those at risk for AD. This review discusses the importance of early therapeutic intervention during the prodromal stage that precedes irreversible degeneration in AD. Mechanisms of action for current mitochondrial and bioenergetic therapeutics for AD broadly fall into the following categories: 1) glucose metabolism and substrate supply; 2) mitochondrial enhancers to potentiate energy production; 3) antioxidants to scavenge reactive oxygen species and reduce oxidative damage; 4) candidates that target apoptotic and mitophagy pathways to either remove damaged mitochondria or prevent neuronal death. Thus far, mitochondrial therapeutic strategies have shown promise at the preclinical stage but have had little-to-no success in clinical trials. Lessons learned from preclinical and clinical therapeutic studies are discussed. Understanding the bioenergetic adaptations that occur during aging and AD led us to focus on a systems biology approach that targets the bioenergetic system rather than a single component of this system. Bioenergetic system-level therapeutics personalized to bioenergetic phenotype would target bioenergetic deficits across the prodromal and clinical stages to prevent and delay progression of AD.

The benefit of docosahexaenoic acid for the adult brain in aging and dementia

A brief overview of the evidence for omega-3 fatty acids and, in particular, of docosahexaenoic acid (DHA), involvement in cognition and in dementia is given. Two studies are presented in this regard in which the key intervention is a DHA supplement. The fist, the MIDAS Study demonstrated that DHA can be of benefit for episodic memory in healthy adults with a mild memory complaint. The second, the ADCS AD trial found no benefit of DHA in the primary outcomes but found an intriguing benefit for cognitive score in ApoE4 negative allele patients. This leads to a consideration of the mechanisms of action and role of ApoE and its modulation by DHA. Given the fundamental role of ApoE in cellular lipid transport and metabolism in the brain and periphery, it is no surprise that ApoE affects n-3 PUFA brain function as well. It remains to be seen to what extent ApoE4 deleterious effect in AD is associated with n-3 PUFA-related cellular mechanisms in the brain and, more specifically, whether ApoE4 directly impairs the transport of DHA into the brain, as has been suggested.

Seizure control by derivatives of medium chain fatty acids associated with the ketogenic diet show novel branching-point structure for enhanced potency

The medium chain triglyceride (MCT) ketogenic diet is a major treatment of drug-resistant epilepsy but is problematic, particularly in adults, because of poor tolerability. Branched derivatives of octanoic acid (OA), a medium chain fat provided in the diet have been suggested as potential new treatments for drug-resistant epilepsy, but the structural basis of this functionality has not been determined. Here we investigate structural variants of branched medium chain fatty acids as new seizure-control treatments. We initially employ a series of methyl-branched OA derivatives, and using the GABAA receptor antagonist pentylenetetrazol to induce seizure-like activity in rat hippocampal slices, we show a strong, branch-point-specific activity that improves upon the related epilepsy treatment valproic acid. Using low magnesium conditions to induce glutamate excitotoxicity in rat primary hippocampal neuronal cultures for the assessment of neuroprotection, we also show a structural dependence identical to that for seizure control, suggesting a related mechanism of action for these compounds in both seizure control and neuroprotection. In contrast, the effect of these compounds on histone deacetylase (HDAC) inhibition, associated with teratogenicity, shows no correlation with therapeutic efficacy. Furthermore, small structural modifications of the starting compounds provide active compounds without HDAC inhibitory effects. Finally, using multiple in vivo seizure models, we identify potent lead candidates for the treatment of epilepsy. This study therefore identifies a novel family of fatty acids, related to the MCT ketogenic diet, that show promise as new treatments for epilepsy control and possibly other MCT ketogenic diet-responding conditions, such as Alzheimer disease.

Bioenergetic medicine

Here we discuss a specific therapeutic strategy we call 'bioenergetic medicine'. Bioenergetic medicine refers to the manipulation of bioenergetic fluxes to positively affect health. Bioenergetic medicine approaches rely heavily on the law of mass action, and impact systems that monitor and respond to the manipulated flux. Since classically defined energy metabolism pathways intersect and intertwine, targeting one flux also tends to change other fluxes, which complicates treatment design. Such indirect effects, fortunately, are to some extent predictable, and from a therapeutic perspective may also be desirable. Bioenergetic medicine-based interventions already exist for some diseases, and because bioenergetic medicine interventions are presently feasible, new approaches to treat certain conditions, including some neurodegenerative conditions and cancers, are beginning to transition from the laboratory to the clinic.

Altered coupling of regional cerebral blood flow and brain temperature in schizophrenia compared with bipolar disorder and healthy subjects

Previous studies have suggested that schizophrenia patients have dysfunctional thermoregulation. The aim of this study was to examine whether brain temperature (BT) in schizophrenia patients differs from that in patients with bipolar disorder and healthy subjects by using magnetic resonance imaging. We also evaluated the possible relationship between BT and cerebral blood flow (CBF). We analyzed the temperature of lateral ventricles as the mean BT using diffusion-weighted imaging (DWI) thermometry, and evaluated the relationships between the BT and the CBF using pseudo-continuous arterial spin labeling (pCASL) among 3 diagnostic groups, 22 male patients with schizophrenia, 19 male patients with bipolar disorder, and 23 healthy male subjects. There were significant positive correlations between BT in the lateral ventricles and CBF in both the patients with bipolar disorder and healthy subjects. By contrast, there were significant negative correlations in patients with schizophrenia. We could not detect the significant difference in the surrogates of BT among three diagnostic groups. We showed that patients with schizophrenia, but not those with bipolar disorder, have dysfunctional thermoregulation in the brain. Brain temperature is highly dependent on cerebral metabolism and CBF, and thus uncoupling of cerebral metabolism and CBF may occur in schizophrenics.

Nutrition and prevention of Alzheimer's dementia

A nutritional approach to prevent, slow, or halt the progression of disease is a promising strategy that has been widely investigated. Much epidemiologic data suggests that nutritional intake may influence the development and progression of Alzheimer’s dementia (AD). Modifiable, environmental causes of AD include potential metabolic derangements caused by dietary insufficiency and or excess that may be corrected by nutritional supplementation and or dietary modification. Many nutritional supplements contain a myriad of health promoting constituents (anti-oxidants, vitamins, trace minerals, flavonoids, lipids, …etc.) that may have novel mechanisms of action affecting cellular health and regeneration, the aging process itself, or may specifically disrupt pathogenic pathways in the development of AD. Nutritional modifications have the advantage of being cost effective, easy to implement, socially acceptable and generally safe and devoid of significant adverse events in most cases. Many nutritional interventions have been studied and continue to be evaluated in hopes of finding a successful agent, combination of agents, or dietary modifications that can be used for the prevention and or treatment of AD. The current review focuses on several key nutritional compounds and dietary modifications that have been studied in humans, and further discusses the rationale underlying their potential utility for the prevention and treatment of AD.

A new way to produce hyperketonemia: use of ketone ester in a case of Alzheimer's disease

BACKGROUND

Providing ketone bodies to the brain can bypass metabolic blocks to glucose utilization and improve function in energy-starved neurons. For this, plasma ketones must be elevated well above the ≤ 0.2 mM default concentrations normally prevalent. Limitations of dietary methods currently used to produce therapeutic hyperketonemia have stimulated the search for better approaches.

METHOD

Described herein is a new way to produce therapeutic hyperketonemia, entailing prolonged oral administration of a potent ketogenic agent--ketone monoester (KME)--to a patient with Alzheimer's disease dementia and a pretreatment Mini-Mental State Examination score of 12.

RESULTS

The patient improved markedly in mood, affect, self-care, and cognitive and daily activity performance. The KME was well tolerated throughout the 20-month treatment period. Cognitive performance tracked plasma β-hydroxybutyrate concentrations, with noticeable improvements in conversation and interaction at the higher levels, compared with predose levels.

CONCLUSION

KME-induced hyperketonemia is robust, convenient, and safe, and the ester can be taken as an oral supplement without changing the habitual diet.

Reversal of cognitive decline: a novel therapeutic program

This report describes a novel, comprehensive, and personalized therapeutic program that is based on the underlying pathogenesis of Alzheimer's disease, and which involves multiple modalities designed to achieve metabolic enhancement for neurodegeneration (MEND). The first 10 patients who have utilized this program include patients with memory loss associated with Alzheimer's disease (AD), amnestic mild cognitive impairment (aMCI), or subjective cognitive impairment (SCI). Nine of the 10 displayed subjective or objective improvement in cognition beginning within 3-6 months, with the one failure being a patient with very late stage AD. Six of the patients had had to discontinue working or were struggling with their jobs at the time of presentation, and all were able to return to work or continue working with improved performance. Improvements have been sustained, and at this time the longest patient follow-up is two and one-half years from initial treatment, with sustained and marked improvement. These results suggest that a larger, more extensive trial of this therapeutic program is warranted. The results also suggest that, at least early in the course, cognitive decline may be driven in large part by metabolic processes. Furthermore, given the failure of monotherapeutics in AD to date, the results raise the possibility that such a therapeutic system may be useful as a platform on which drugs that would fail as monotherapeutics may succeed as key components of a therapeutic system.

Natural products and supplements for geriatric depression and cognitive disorders: an evaluation of the research

Numerous geriatric patients are using Complementary and Alternative Medicine (CAM) for late-life mood and cognitive disorders. Natural products and supplements are a common CAM intervention which have risks and benefits of which patients should be appropriately advised. The data for omega-3 fatty acids, ginkgo biloba, SAMe, St John's wort, B vitamins and vitamin D, huperzine, caprylidene, and coconut oil will be evaluated. Since the evidence basis for natural products and supplements is limited, especially for the geriatric population, studies involving the general adult population are included to infer effects in the aging population. Despite the data available, more rigorous studies with larger sample sizes over longer periods of time are still needed. Regardless of a physician's preference to recommend various natural supplements and products, a physician could protect their patients by having an understanding of the side effects and indications for various natural products.

Role of Medium Chain Triglycerides (Axona®) in the Treatment of Mild to Moderate Alzheimer's Disease

Treatment of Alzheimer's disease (AD) with acetylcholinesterase inhibitors or N-methyl-D-aspartate (NMDA) receptor antagonists provides symptomatic relief but do not prevent its progression. Thus, additional approaches aimed at slowing the progression of the disease have been investigated. Reports detailing reduced brain glucose metabolism in the early stages of AD led to the hypothesis that alternate energy sources aimed at increasing neuronal metabolism may protect neurons and thus benefit patients with AD. Medium-chain triglycerides (MCTs) are metabolized to ketone bodies that serve as an alternative source of energy for neurons. Data from clinical trials suggest that MCTs improve cognition in patients with mild to moderate AD in apolipoprotein E4-negative patients. Adverse events observed were mild and included minor gastrointestinal problems such as diarrhea, dyspepsia, and flatulence. However, since genomic profiles are not routinely conducted in patients with AD in a clinical setting, the role of MCTs in clinical practice seems to be minimal.

Effects of caprylic triglyceride on cognitive performance and cerebral glucose metabolism in mild Alzheimer's disease: a single-case observation

Objective: To examine the effect of 109 days of caprylic triglyceride (CT) in a 70-year-old male with mild Alzheimer’s disease (AD).

Background: Cerebral metabolism is limited to glucose under most conditions, and diminished cerebral glucose metabolism is a characteristic feature of AD. Another substrate available for cerebral metabolism is ketone bodies. Ketone bodies (KB) are normally derived from fat stores under conditions of low glucose availability as an alternative energy substrate to glucose. KB can also be produced by oral administration of CT. Prior studies suggest that the alternative energy source of CT may improve cognitive function due to mild to moderate AD, by circumventing the diminished glucose metabolism.

Method: The effect of CT was analyzed in a single-case of mild AD with cognitive alterations in an open label study. Study outcomes included the Montreal cognitive assessment (MoCA), mini mental state exam (MMSE), and 18-fluorodeoxyglucose (18F) positron emission tomography (FDG PET) scans.

Results: After 109 days of CT, MoCA scores changed from a baseline value of 24–28, and MMSE scores changed from 23 to 28. No changes were observed on FDG PET scans.

Conclusion: The results suggest that, in a case of mild AD, CT may have affected cognitive function, assessed by means of MMSE and MoCA, although glucose uptake and metabolism remained unchanged.

Oxaloacetate activates brain mitochondrial biogenesis, enhances the insulin pathway, reduces inflammation and stimulates neurogenesis

Brain bioenergetic function declines in some neurodegenerative diseases, this may influence other pathologies and administering bioenergetic intermediates could have therapeutic value. To test how one intermediate, oxaloacetate (OAA) affects brain bioenergetics, insulin signaling, inflammation and neurogenesis, we administered intraperitoneal OAA, 1-2 g/kg once per day for 1-2 weeks, to C57Bl/6 mice. OAA altered levels, distributions or post-translational modifications of mRNA and proteins (proliferator-activated receptor-gamma coactivator 1α, PGC1 related co-activator, nuclear respiratory factor 1, transcription factor A of the mitochondria, cytochrome oxidase subunit 4 isoform 1, cAMP-response element binding, p38 MAPK and adenosine monophosphate-activated protein kinase) in ways that should promote mitochondrial biogenesis. OAA increased Akt, mammalian target of rapamycin and P70S6K phosphorylation. OAA lowered nuclear factor κB nucleus-to-cytoplasm ratios and CCL11 mRNA. Hippocampal vascular endothelial growth factor mRNA, doublecortin mRNA, doublecortin protein, doublecortin-positive neuron counts and neurite length increased in OAA-treated mice. (1)H-MRS showed OAA increased brain lactate, GABA and glutathione thereby demonstrating metabolic changes are detectable in vivo. In mice, OAA promotes brain mitochondrial biogenesis, activates the insulin signaling pathway, reduces neuroinflammation and activates hippocampal neurogenesis.

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.

Health economics evidence for medical nutrition: are these interventions value for money in integrated care?

BACKGROUND

Health care decision-makers have begun to realize that medical nutrition plays an important role in the delivery of care, and it needs to be seen as a sole category within the overall health care reimbursement system to establish the value for money. Indeed, improving health through improving patients' nutrition may contribute to the cost-effectiveness and financial sustainability of health care systems. Medical nutrition is regulated by a specific bill either in Europe or in the United States, which offers specific legislations and guidelines (as provided to patients with special nutritional needs) and indications for nutritional support. Given that the efficacy of medical nutrition has been proven, one can wonder whether the heterogeneous nature of its coverage/reimbursement across countries might be due to the lack of health-related economic evidence or value-for-money of nutritional interventions. This paper aims to address this knowledge gap by performing a systematic literature review on health economics evidence regarding medical nutrition, and by summarizing the results of these publications related to the value for money of medical nutrition interventions.

METHODS

A systematic literature search was initiated and executed based on a predefined search protocol following the population, intervention, comparison, and outcomes (PICO) criteria. Following the systematic literature search of recently published literature on health economics evidence regarding medical nutrition, this study aims to summarize the results of those publications that are related to the value for money of medical nutrition interventions. The evaluations were conducted by analyzing different medical nutrition according to their indications, the economic methodology or perspective adopted, the cost source and utility measures, selected efficiency measures, as well as the incremental cost-effectiveness ratio.

RESULTS

A total of 225 abstracts were identified for the detailed review, and the data were entered into a data extraction sheet. For the abstracts that finally met the predefined inclusion criteria (n=53), full-text publications were obtained via PubMed, subito, or directly via each journal's Webpage for further assessment. After a detailed review of the full text articles, 34 publications have been qualified for a thorough data extraction procedure. When differentiating the resulting articles in terms of their settings, 20 studies covered inpatients, whereas 14 articles covered outpatients, including patients in community centers. When reviewing the value-for-money evaluations, the indications showed that the different results were mostly impacted by the different perspectives adopted and the comparisons that were made. In order to draw comprehensive conclusions, the results were split according to the main indications and diseases.

DISCUSSION

The systematic literature search has shown that there is not only an interest in health economics and its application in medical nutrition, but that there is a lot of ongoing research in this area. Based on the underlying systematic analysis, it has been shown that medical nutrition interventions offer value for money in the different health care settings, particularly for the specific disease areas that have been pointed out.

CONCLUSION

Based on the systematic literature search that was performed, it was shown that medical nutrition interventions offer value for money in the different health care settings. Although medical nutrition has been the topic of some health economic analyses, the usual willingness to pay threshold used in health care rarely was applied. Often, these products are either directly part of a lump sum in the financing system (for example, diagnosis-related groups), or they are covered as out-of-pocket payments by patients directly. More research would be necessary to better understand how medical nutrition interventions can be optimally funded by the health care system, given the clinical value they bring to patients in their recovery process.

What have novel imaging techniques revealed about metabolism in the aging brain?

Brain metabolism declines with age and do so in an accelerated manner in neurodegenerative disorders. Noninvasive neuroimaging techniques have played an important role to identify the metabolic biomarkers in aging brain. Particularly, PET with fluorine-18 (¹⁸F)-labeled 2-fluoro-2-deoxy-d-glucose tracer and proton magnetic resonance spectroscopy (MRS) have been widely used to monitor changes in brain metabolism over time, identify the risk for Alzheimer's disease (AD) and predict the conversion from mild cognitive impairment to AD. Novel techniques, including PET carbon-11 Pittsburgh compound B, carbon-13 and phosphorus-31 MRS, have also been introduced to determine Aβ plaques deposition, mitochondrial functions and brain bioenergetics in aging brain and neurodegenerative disorders. Here, we introduce the basic principle of the imaging techniques, review the findings from 2-fluoro-2-deoxy-d-glucose-PET, Pittsburgh compound B PET, proton, carbon-13 and phosphorus-31 MRS on changes in metabolism in normal aging brain, mild cognitive impairment and AD, and discuss the potential of neuroimaging to identify effective interventions and treatment efficacy for neurodegenerative disorders.

Ketone bodies as signaling metabolites

Traditionally, the ketone body β-hydroxybutyrate (βOHB) has been looked upon as a carrier of energy from liver to peripheral tissues during fasting or exercise. However, βOHB also signals via extracellular receptors and acts as an endogenous inhibitor of histone deacetylases (HDACs). These recent findings support a model in which βOHB functions to link the environment, in this case the diet, and gene expression via chromatin modifications. We review the regulation and functions of ketone bodies, the relationship between ketone bodies and calorie restriction, and the implications of HDAC inhibition by the ketone body βOHB in the modulation of metabolism and in diseases of aging.

Cognition and nutrition

PURPOSE OF REVIEW

Aging is associated with a decline in cognition. This review examines the available data on the effects of nutrition on cognitive impairment. It also explores the mechanism(s) by which food may enhance memory.

RECENT FINDINGS

An increasing body of evidence has supported the role of the Mediterranean diet and extra-virgin olive oil in protecting cognition. A number of nutritional formulations to improve deteriorating memory are being studied. Undernutrition is associated with cognitive decline. Hyperglycemia and hypertriglyceridemia cause cognitive impairment.

SUMMARY

There are increasing data to support the role of nutrition in maintaining cognition.

Alterations of hippocampal glucose metabolism by even versus uneven medium chain triglycerides

Medium chain triglycerides (MCTs) are used to treat neurologic disorders with metabolic impairments, including childhood epilepsy and early Alzheimer's disease. However, the metabolic effects of MCTs in the brain are still unclear. Here, we studied the effects of feeding even and uneven MCTs on brain glucose metabolism in the mouse. Adult mice were fed 35% (calories) of trioctanoin or triheptanoin (the triglycerides of octanoate or heptanoate, respectively) or a matching control diet for 3 weeks. Enzymatic assays and targeted metabolomics by liquid chromatography tandem mass spectrometry were used to quantify metabolites in extracts from the hippocampal formations (HFs). Both oils increased the levels of β-hydroxybutyrate, but no other significant metabolic alterations were observed after triheptanoin feeding. The levels of glucose 6-phosphate and fructose 6-phosphate were increased in the HF of mice fed trioctanoin, whereas levels of metabolites further downstream in the glycolytic pathway and the pentose phosphate pathway were reduced. This indicates that trioctanoin reduces glucose utilization because of a decrease in phosphofructokinase activity. Trioctanoin and triheptanoin showed similar anticonvulsant effects in the 6 Hz seizure model, but it remains unknown to what extent the anticonvulsant mechanism(s) are shared. In conclusion, triheptanoin unlike trioctanoin appears to not alter glucose metabolism in the healthy brain.

Retrospective cohort study of the efficacy of caprylic triglyceride in patients with mild-to-moderate alzheimer's disease

BACKGROUND

The purpose of this study was to evaluate the effects of caprylic triglyceride (CT) in patients with mild-to-moderate Alzheimer's disease (AD) in routine clinical practice via review of medical records and caregiver questionnaires.

METHODS

Participants were outpatients aged ≥50 years with a diagnosis of probable mild-to-moderate AD who had received CT for ≥6 months. The primary outcome was change from baseline in the patient's condition as rated by the treating physician using a physician's overall assessment.

RESULTS

A total of 55 patients were included. The physician's overall assessment indicated that ~80% of patients who had CT added to ongoing pharmacotherapy were stable or improved. Mini-Mental State Examination scores also remained stable over 15 months of therapy (20.6 ± 3.0 at baseline and 20.1 ± 5.6 at follow-up, P = 0.5233, n = 27). Caregiver assessments indicated that most patients were stable or improved with respect to memory and ability to carry out activities of daily living. The most frequent adverse events with CT involved the gastrointestinal system.

CONCLUSION

Results from this chart review indicate that addition of CT to pharmacotherapy was associated with stable disease or improvement over a follow-up period of 18.8 months.

Retrospective case studies of the efficacy of caprylic triglyceride in mild-to-moderate Alzheimer's disease

Under normal conditions, the adult human brain is fueled primarily by glucose. A prominent feature of Alzheimer's disease (AD) is region-specific decreases in cerebral glucose metabolism. Ketone bodies are a group of compounds produced from fat stores during periods of low glucose availability that can provide an alternative to glucose for brain metabolism. Consumption of sufficient quantities of caprylic triglyceride (CT) increases plasma concentrations of ketone bodies and may be beneficial in conditions of compromised glucose metabolism, such as AD. The present study describes the use of CT in mild-to-moderate AD in routine clinical practice. Case records from eight patients with extensive monitoring of cognitive function using the Mini-Mental State Examination (MMSE) and who had received CT for ≥6 months were reviewed. All were outpatients aged ≥50 years, cared for in standard practice, had a diagnosis of probable AD of mild-to-moderate severity (MMSE 14-24), and had received CT for at least 6 months in addition to other approved pharmacotherapy for AD. Response to CT administration as measured by MMSE scores varied by patient. However, the rate of decline in MMSE scores appeared slower than previously published reports for patients treated with pharmacotherapy alone. Profiling of individual patients may provide insight regarding those most likely to benefit from addition of CT to currently approved AD pharmacotherapy.

Treatment of Alzheimer's Disease: Current Management and Experimental Therapeutics

Alzheimer's disease (AD) is a major cause of morbidity in the elderly. AD affects aver 5 million persons in the United States, but because it increases in incidence in the elderly, and the "graying" population, AD is projected to increase in prevalence by many-fold over the coming decades. AD causes progressive mental impairment, resulting in the inability of persons to care for themselves. As a consequence, AD results in enormous costs to society due to both lost productivity, and required care. Thus, improved management and treatment is essential. In this review we will briefly review current understanding of the disease, including roles of beta-amyloid and tau proteins. We will then discuss current therapies in use, including the evidence for treatments with supplements, established drugs, and investigational therapeutic strategies, recently completed and ongoing.

Decoding Alzheimer's disease from perturbed cerebral glucose metabolism: implications for diagnostic and therapeutic strategies

Alzheimer's disease (AD) is an age-related devastating neurodegenerative disorder, which severely impacts on the global economic development and healthcare system. Though AD has been studied for more than 100 years since 1906, the exact cause(s) and pathogenic mechanism(s) remain to be clarified. Also, the efficient disease-modifying treatment and ideal diagnostic method for AD are unavailable. Perturbed cerebral glucose metabolism, an invariant pathophysiological feature of AD, may be a critical contributor to the pathogenesis of this disease. In this review, we firstly discussed the features of cerebral glucose metabolism in physiological and pathological conditions. Then, we further reviewed the contribution of glucose transportation abnormality and intracellular glucose catabolism dysfunction in AD pathophysiology, and proposed a hypothesis that multiple pathogenic cascades induced by impaired cerebral glucose metabolism could result in neuronal degeneration and consequently cognitive deficits in AD patients. Among these pathogenic processes, altered functional status of thiamine metabolism and brain insulin resistance are highly emphasized and characterized as major pathogenic mechanisms. Finally, considering the fact that AD patients exhibit cerebral glucose hypometabolism possibly due to impairments of insulin signaling and altered thiamine metabolism, we also discuss some potential possibilities to uncover diagnostic biomarkers for AD from abnormal glucose metabolism and to develop drugs targeting at repairing insulin signaling impairment and correcting thiamine metabolism abnormality. We conclude that glucose metabolism abnormality plays a critical role in AD pathophysiological alterations through the induction of multiple pathogenic factors such as oxidative stress, mitochondrial dysfunction, and so forth. To clarify the causes, pathogeneses and consequences of cerebral hypometabolism in AD will help break the bottleneck of current AD study in finding ideal diagnostic biomarker and disease-modifying therapy.

3-Hydroxybutyrate methyl ester as a potential drug against Alzheimer's disease via mitochondria protection mechanism

Alzheimer's disease (AD) is induced by many reasons, including decreased cellular utilization of glucose and brain cell mitochondrial damages. Degradation product of microbially synthesized polyhydroxybutyrate (PHB), namely, 3-hydroxybutyrate (3HB), can be an alternative to glucose during sustained hypoglycemia. In this study, the derivative of 3HB, 3-hydroxybutyrate methyl ester (HBME), was used by cells as an alternative to glucose. HBME inhibited cell apoptosis under glucose deprivation, rescued activities of mitochondrial respiratory chain complexes that were impaired in AD patients and decreased the generation of ROS. Meanwhile, HBME stabilized the mitochondrial membrane potential. In vivo studies showed that HBME crossed the blood brain barrier easier compared with charged 3HB, resulting in a better bioavailability. AD mice treated with HBME performed significantly better (p < 0.05) in the Morris water maze compared with other groups, demonstrating that HBME has a positive in vivo pharmaceutical effect to improve the spatial learning and working memory of mice. A reduced amyloid-β deposition in mouse brains after intragastric administration of HBME was also observed. Combined with the in vitro and in vivo results, HBME was proposed to be a drug candidate against AD, its working mechanism appeared to be mediated by various effects of protecting mitochondrial damages.

How to design nutritional intervention trials to slow cognitive decline in apparently healthy populations and apply for efficacy claims: a statement from the International Academy on Nutrition and Aging Task Force

Interventions are crucial as they offer simple and inexpensive public health solutions that will be useful over the long term use. A Task Force on designing trials of nutritional interventions to slow cognitive decline in older adults was held in Toulouse in September 2012. The aim of the Task Force was to bring together leading experts from academia, the food industry and regulatory agencies to determine the best trial designs that would enable us to reach our goal of maintaining or improving cognitive function in apparently healthy aging people. An associated challenge for this Task Force was to determine the type of trials required by the Public Food Agencies for assessing the impact of nutritional compounds in comparison to well established requirements for drug trials. Although the required quality of the study design, rationale and statistical analysis remains the same, the studies designed to show reduction of cognitive decline require a long duration and the objectives of this task force was to determine best design for these trials. Two specific needs were identified to support trials of nutritional interventions: 1- Risk- reduction strategies are needed to tackle the growing burden of cognitive decline that may lead to dementia, 2- Innovative study designs are needed to improve the quality of these studies.

Beyond weight loss: a review of the therapeutic uses of very-low-carbohydrate (ketogenic) diets

Very-low-carbohydrate diets or ketogenic diets have been in use since the 1920s as a therapy for epilepsy and can, in some cases, completely remove the need for medication. From the 1960s onwards they have become widely known as one of the most common methods for obesity treatment. Recent work over the last decade or so has provided evidence of the therapeutic potential of ketogenic diets in many pathological conditions, such as diabetes, polycystic ovary syndrome, acne, neurological diseases, cancer and the amelioration of respiratory and cardiovascular disease risk factors. The possibility that modifying food intake can be useful for reducing or eliminating pharmaceutical methods of treatment, which are often lifelong with significant side effects, calls for serious investigation. This review revisits the meaning of physiological ketosis in the light of this evidence and considers possible mechanisms for the therapeutic actions of the ketogenic diet on different diseases. The present review also questions whether there are still some preconceived ideas about ketogenic diets, which may be presenting unnecessary barriers to their use as therapeutic tools in the physician's hand.

Dietary energy substrates reverse early neuronal hyperactivity in a mouse model of Alzheimer's disease

Deficient energy metabolism and network hyperactivity are the early symptoms of Alzheimer's disease (AD). In this study, we show that administration of exogenous oxidative energy substrates (OES) corrects neuronal energy supply deficiency that reduces the amyloid-beta-induced abnormal neuronal activity in vitro and the epileptic phenotype in AD model in vivo. In vitro, acute application of protofibrillar amyloid-β1-42 (Aβ1-42) induced aberrant network activity in wild-type hippocampal slices that was underlain by depolarization of both the neuronal resting membrane potential and GABA-mediated current reversal potential. Aβ1-42 also impaired synaptic function and long-term potentiation. These changes were paralleled by clear indications of impaired energy metabolism, as indicated by abnormal NAD(P)H signaling induced by network activity. However, when glucose was supplemented with OES pyruvate and 3-beta-hydroxybutyrate, Aβ1-42 failed to induce detrimental changes in any of the above parameters. We administered the same OES as chronic supplementation to a standard diet to APPswe/PS1dE9 transgenic mice displaying AD-related epilepsy phenotype. In the ex-vivo slices, we found neuronal subpopulations with significantly depolarized resting and GABA-mediated current reversal potentials, mirroring abnormalities we observed under acute Aβ1-42 application. Ex-vivo cortex of transgenic mice fed with standard diet displayed signs of impaired energy metabolism, such as abnormal NAD(P)H signaling and strongly reduced tolerance to hypoglycemia. Transgenic mice also possessed brain glycogen levels twofold lower than those of wild-type mice. However, none of the above neuronal and metabolic dysfunctions were observed in transgenic mice fed with the OES-enriched diet. In vivo, dietary OES supplementation abated neuronal hyperexcitability, as the frequency of both epileptiform discharges and spikes was strongly decreased in the APPswe/PS1dE9 mice placed on the diet. Altogether, our results suggest that early AD-related neuronal malfunctions underlying hyperexcitability and energy metabolism deficiency can be prevented by dietary supplementation with native energy substrates.

APOE and neuroenergetics: an emerging paradigm in Alzheimer's disease

APOE is the major known genetic risk factor for late-onset Alzheimer's disease. Though relationships between APOE-encoded apolipoprotein E and β-amyloid are increasingly well described, mounting evidence supports wide-ranging effects of APOE on the brain. Specifically, APOE appears to affect brain network activity and closely related neuroenergetic functions that might be involved in vulnerability to neurodegenerative pathophysiology. These effects highlight the salience of further investigation into the diverse influences of APOE. Therefore, this article reviews the interplay between APOE and neuroenergetics and proposes areas for further investigation. This research might lead to the identification of novel therapeutic targets for the treatment and/or prevention of Alzheimer's disease.

Caprylic triglyceride as a novel therapeutic approach to effectively improve the performance and attenuate the symptoms due to the motor neuron loss in ALS disease

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disorder of motor neurons causing progressive muscle weakness, paralysis, and finally death. ALS patients suffer from asthenia and their progressive weakness negatively impacts quality of life, limiting their daily activities. They have impaired energy balance linked to lower activity of mitochondrial electron transport chain enzymes in ALS spinal cord, suggesting that improving mitochondrial function may present a therapeutic approach for ALS. When fed a ketogenic diet, the G93A ALS mouse shows a significant increase in serum ketones as well as a significantly slower progression of weakness and lower mortality rate. In this study, we treated SOD1-G93A mice with caprylic triglyceride, a medium chain triglyceride that is metabolized into ketone bodies and can serve as an alternate energy substrate for neuronal metabolism. Treatment with caprylic triglyceride attenuated progression of weakness and protected spinal cord motor neuron loss in SOD1-G93A transgenic animals, significantly improving their performance even though there was no significant benefit regarding the survival of the ALS transgenic animals. We found that caprylic triglyceride significantly promoted the mitochondrial oxygen consumption rate in vivo. Our results demonstrated that caprylic triglyceride alleviates ALS-type motor impairment through restoration of energy metabolism in SOD1-G93A ALS mice, especially during the overt stage of the disease. These data indicate the feasibility of using caprylic acid as an easily administered treatment with a high impact on the quality of life of ALS patients.

Association between vitamin A, vitamin E and apolipoprotein E status with mild cognitive impairment among elderly people in low-cost residential areas

RATIONALE

The influence of nutritional parameters and genetic susceptibility on poor cognitive impairment has been documented; however, the association between lipid-soluble vitamins with genetic susceptibility on mild cognitive impairment (MCI) has not yet been studied extensively.

OBJECTIVES

The aim of the present study was (i) to determine the prevalence of MCI and its associated risk factors and (2) to investigate the influence of the apolipoprotein E (APOE) ε4 allele on peripheral vitamin A and E concentration in MCI and non-MCI groups.

METHODS

A total of 333 subjects aged 60 years and above, residing in public housing areas in Kuala Lumpur, Malaysia were interviewed to obtain information on their neuropsychological status. Fasting venous blood was taken for determination of vitamin A and vitamin E concentration using high-performance liquid chromatography. Restriction fragment length polymorphism analysis was performed to determine the APOE genotypes.

RESULTS

The prevalence of MCI was 21.1%. Binary logistic regression indicated that the predictors of MCI were being married, overweight or obesity, and had vitamin A deficiency. In non-MCI subjects, vitamin E levels were lower among APOEε4 allele carriers as compared to the non-carriers (P < 0.05).

CONCLUSION

The study highlighted the importance of maintaining good nutritional status and vitamin A status for optimal cognitive function. The presence of APOEε4 allele has a prominent role in affecting vitamin E levels, particularly among cognitively healthy elderly in our unique population.

The ketogenic diet increases brain glucose and ketone uptake in aged rats: a dual tracer PET and volumetric MRI study

Despite decades of study, it is still unclear whether regional brain glucose uptake is lower in the cognitively healthy elderly. Whether regional brain uptake of ketones (β-hydroxybutyrate and acetoacetate [AcAc]), the main alternative brain fuel to glucose, changes with age is unknown. We used a sequential, dual tracer positron emission tomography (PET) protocol to quantify brain (18)F-fluorodeoxyglucose ((18)F-FDG) and (11)C-AcAc uptake in two studies with healthy, male Sprague-Dawley rats: (i) Aged (21 months; 21M) versus young (4 months; 4M) rats, and (ii) The effect of a 14 day high-fat ketogenic diet (KD) on brain (18)F-FDG and (11)C-AcAc uptake in 24 month old rats (24M). Similar whole brain volumes assessed by magnetic resonance imaging, were observed in aged 21M versus 4M rats, but the lateral ventricles were 30% larger in the 21M rats (p=0.001). Whole brain cerebral metabolic rates of AcAc (CMR(AcAc)) and glucose (CMR(glc)) did not differ between 21M and 4M rats, but were 28% and 44% higher, respectively, in 24M-KD compared to 24M rats. The region-to-whole brain ratio of CMR(glc) was 37-41% lower in the cortex and 40-45% lower in the cerebellum compared to CMR(AcAc) in 4M and 21M rats. We conclude that a quantitative measure of uptake of the brain's two principal exogenous fuels was generally similar in healthy aged and young rats, that the % of distribution across brain regions differed between ketones and glucose, and that brain uptake of both fuels was stimulated by mild, experimental ketonemia.

Genetics of dementia

Neurodegenerative adult-onset dementias are complex and multifactorial diseases that are most commonly caused by environmental, genetic, or mixed environmental and genetic factors. Regarding the genetic causes, a variety of phenotypes may present. This article reviews several of the genetic risk factors for the most common dementias encountered in neurology. Practical implications of genetic testing and pharmacogenomic considerations for clinical practice are also discussed.

The use of ketogenic diet in special situations: expanding use in intractable epilepsy and other neurologic disorders

The ketogenic diet has been widely used and proved to be effective for intractable epilepsy. Although the mechanisms underlying its anti-epileptic effects remain to be proven, there are increasing experimental evidences for its neuroprotective effects along with many researches about expanding use of the diet in other neurologic disorders. The first success was reported in glucose transporter type 1 deficiency syndrome, in which the diet served as an alternative metabolic source. Many neurologic disorders share some of the common pathologic mechanisms such as mitochondrial dysfunction, altered neurotransmitter function and synaptic transmission, or abnormal regulation of reactive oxygen species, and the role of the ketogenic diet has been postulated in these mechanisms. In this article, we introduce an overview about the expanding use and emerging trials of the ketogenic diet in various neurologic disorders excluding intractable epilepsy and provide explanations of the mechanisms in that usage.

OPTIMIZING DIAGNOSIS AND MANANGEMENT IN MILD-TO-MODERATE ALZHEIMER'S DISEASE

Alzheimer's disease (AD) is characterized by progressive declines in cognitive function and ability to carry out activities of daily living; and the emergence and worsening of behavioral/neuropsychiatric symptoms. While there is no cure for AD, non-pharmacologic interventions and medications that modulate neurotransmission can slow symptomatic progression. Medical foods may also be useful as adjuncts to pharmacologic agents in AD. Medium chain triglycerides aimed at improving cerebral metabolism significantly improve Alzheimer's Disease Assessment Scale-Cognitive scores when added to ongoing pharmacotherapy in patients with mild-to-moderate AD. Combination of interventions, such as non-pharmacologic treatments, pharmacotherapy, and medical foods, with complementary mechanisms of action may provide a rational approach that may result in maximum preservation of cognitive function in patients with AD.

The ketogenic diet as a treatment paradigm for diverse neurological disorders

Dietary and metabolic therapies have been attempted in a wide variety of neurological diseases, including epilepsy, headache, neurotrauma, Alzheimer disease, Parkinson disease, sleep disorders, brain cancer, autism, pain, and multiple sclerosis. The impetus for using various diets to treat - or at least ameliorate symptoms of - these disorders stems from both a lack of effectiveness of pharmacological therapies, and also the intrinsic appeal of implementing a more "natural" treatment. The enormous spectrum of pathophysiological mechanisms underlying the aforementioned diseases would suggest a degree of complexity that cannot be impacted universally by any single dietary treatment. Yet, it is conceivable that alterations in certain dietary constituents could affect the course and impact the outcome of these brain disorders. Further, it is possible that a final common neurometabolic pathway might be influenced by a variety of dietary interventions. The most notable example of a dietary treatment with proven efficacy against a neurological condition is the high-fat, low-carbohydrate ketogenic diet (KD) used in patients with medically intractable epilepsy. While the mechanisms through which the KD works remain unclear, there is now compelling evidence that its efficacy is likely related to the normalization of aberrant energy metabolism. The concept that many neurological conditions are linked pathophysiologically to energy dysregulation could well provide a common research and experimental therapeutics platform, from which the course of several neurological diseases could be favorably influenced by dietary means. Here we provide an overview of studies using the KD in a wide panoply of neurologic disorders in which neuroprotection is an essential component.

Butyrylcholinesterase genotype and gender influence Alzheimer's disease phenotype

Retrospective data are presented to support a spectrum of early Alzheimer's disease (AD) along a continuum defined by gender and genotype. The putative neurodegenerative mechanisms driving distinct phenotypes at each end of the spectrum are glial hypoactivity associated with early failure of synaptic cholinergic neurotransmission and glial overactivation associated with loss of neural network connectivity due to accelerated age-related breakdown of myelin. In early AD, male butyrylcholinesterase K-variant carriers with one or two apolipoprotein ɛ4 alleles have prominent medial temporal atrophy, synaptic failure, cognitive decline, and accumulation of aggregated beta-amyloid peptide. Increasing synaptic acetylcholine in damaged but still functional cholinergic synapses improves cognitive symptoms, whereas increasing the ability of glia to support synapses and to clear beta-amyloid peptide might be disease-modifying. Conversely, chronic glial overactivation can also drive degenerative processes and in butyrylcholinesterase K-variant negative females generalized glial overactivation may be the main driver from mild cognitive impairment to AD. Females are more likely than males to have accelerated age-related myelin breakdown, more widespread white matter loss, loss of neural network connectivity, whole brain atrophy, and functional decline. Increasing extracellular acetylcholine levels blocks glial activation, reduces myelin loss and damage to neural network connectivity, and is disease-modifying. Between extremes characterized by gender, genotype, and age, pathophysiology may be mixed and this spectrum may explain much of the heterogeneity of amnestic mild cognitive impairment. Preservation of the functional integrity of the neural network may be an important component of strengthening cognitive reserve and significantly delaying the onset and progression of dementia, particularly in females. Prospective confirmation of these hypotheses is required. Implications for future research and therapeutic opportunities are discussed.