Fatty acid composition and fatty acid binding protein expression in the postmortem frontal cortex of patients with schizophrenia: A case-control study

What Is the Evidence for Dietary-Induced DHA Deficiency in Human Brains?

Docosahexaenoic acid (DHA) is a major constituent of neural and visual membranes and is required for optimal neural and visual function. DHA is derived from food or by endogenous synthesis from α-linolenic acid (ALA), an essential fatty acid. Low blood levels of DHA in some westernised populations have led to speculations that child development disorders and various neurological conditions are associated with sub-optimal neural DHA levels, a proposition which has been supported by the supplement industry. This review searched for evidence of deficiency of DHA in human populations, based on elevated levels of the biochemical marker of n-3 deficiency, docosapentaenoic acid (22:5n-6). Three scenarios/situations were identified for the insufficient supply of DHA, namely in the brain of new-born infants fed with high-linoleic acid (LA), low-ALA formulas, in cord blood of women at birth who were vegetarians and in the milk of women from North Sudan. Twenty post-mortem brain studies from the developed world from adults with various neurological disorders revealed no evidence of raised levels of 22:5n-6, even in the samples with reduced DHA levels compared with control subjects. Human populations most likely at risk of n-3 deficiency are new-born and weanling infants, children and adolescents in areas of dryland agriculture, in famines, or are refugees, however, these populations have rarely been studied. This is an important topic for future research.

Oxidative Stress-Related Mechanisms in Schizophrenia Pathogenesis and New Treatment Perspectives

Schizophrenia is recognized to be a highly heterogeneous disease at various levels, from genetics to clinical manifestations and treatment sensitivity. This heterogeneity is also reflected in the variety of oxidative stress-related mechanisms contributing to the phenotypic realization and manifestation of schizophrenia. At the molecular level, these mechanisms are supposed to include genetic causes that increase the susceptibility of individuals to oxidative stress and lead to gene expression dysregulation caused by abnormal regulation of redox-sensitive transcriptional factors, noncoding RNAs, and epigenetic mechanisms favored by environmental insults. These changes form the basis of the prooxidant state and lead to altered redox signaling related to glutathione deficiency and impaired expression and function of redox-sensitive transcriptional factors (Nrf2, NF-κB, FoxO, etc.). At the cellular level, these changes lead to mitochondrial dysfunction and metabolic abnormalities that contribute to aberrant neuronal development, abnormal myelination, neurotransmitter anomalies, and dysfunction of parvalbumin-positive interneurons. Immune dysfunction also contributes to redox imbalance. At the whole-organism level, all these mechanisms ultimately contribute to the manifestation and development of schizophrenia. In this review, we consider oxidative stress-related mechanisms and new treatment perspectives associated with the correction of redox imbalance in schizophrenia. We suggest that not only antioxidants but also redox-regulated transcription factor-targeting drugs (including Nrf2 and FoxO activators or NF-κB inhibitors) have great promise in schizophrenia. But it is necessary to develop the stratification criteria of schizophrenia patients based on oxidative stress-related markers for the administration of redox-correcting treatment.

Dietary intake of fish and n-3 polyunsaturated fatty acids and risk of postpartum depression: a nationwide longitudinal study - the Japan Environment and Children's Study (JECS)

BACKGROUND

Pregnant women require increased levels of n-3 polyunsaturated fatty acids (PUFAs) due to the demands of the growing fetus. Although some evidence indicates that maternal intake of fish and n-3 PUFAs is associated with reduced risk of postpartum depression, the results are inconsistent.

METHODS

We investigated whether dietary consumption of fish and/or n-3 PUFAs during pregnancy is associated with a reduced risk of maternal postpartum depression at 6 months after delivery and of serious mental illness at 1 year in a Japanese population. After exclusion and multiple imputation from a dataset comprising 103 062 pregnancies obtained in the Japan Environment and Children's Study, we evaluated 84 181 and 81 924 women at 6 months and 1 year after delivery, respectively.

RESULTS

Multivariable logistic regression showed a reduced risk of postpartum depression at 6 months in the second to fifth quintiles v. the lowest quintile for fish and n-3 PUFA intake, with trend tests also revealing a significant linear association. At 1 year after delivery, fish intake was associated with a reduced risk of serious mental illness in the second to fifth quintiles v. the lowest quintile for fish and in the third to fifth quintiles v. the lowest quintile for n-3 PUFA intake, with trend tests also revealing a significant linear association.

CONCLUSIONS

Women with higher fish and/or n-3 PUFA intake showed reduced risk of postpartum depression at 6 months after delivery and of serious mental illness at 1 year after delivery.

Evidence for Altered Metabolism of Sphingosine-1-Phosphate in the Corpus Callosum of Patients with Schizophrenia

The disturbed integrity of myelin and white matter, along with dysregulation of the lipid metabolism, may be involved in schizophrenia pathophysiology. Considering the crucial role of sphingolipids in neurodevelopment, particularly in oligodendrocyte differentiation and myelination, we examined the role of sphingolipid dynamics in the pathophysiology of schizophrenia. We performed targeted mass spectrometry-based analysis of sphingolipids from the cortical area and corpus callosum of postmortem brain samples from patients with schizophrenia and controls. We observed lower sphingosine-1-phosphate (S1P) levels, specifically in the corpus callosum of patients with schizophrenia, but not in major depressive disorder or bipolar disorder, when compared with the controls. Patient data and animal studies showed that antipsychotic intake did not contribute to the lowered S1P levels. We also found that lowered S1P levels in the corpus callosum of patients with schizophrenia may stem from the upregulation of genes for S1P-degrading enzymes; higher expression of genes for S1P receptors suggested a potential compensatory mechanism for the lowered S1P levels. A higher ratio of the sum of sphingosine and ceramide to S1P, which can induce apoptosis and cell-cycle arrest, was also observed in the samples of patients with schizophrenia than in controls. These results suggest that an altered S1P metabolism may underlie the deficits in oligodendrocyte differentiation and myelin formation, leading to the structural and molecular abnormalities of white matter reported in schizophrenia. Our findings may pave the way toward a novel therapeutic strategy.

Maternal dietary intake of fish and PUFAs and child neurodevelopment at 6 months and 1 year of age: a nationwide birth cohort-the Japan Environment and Children's Study (JECS)

BACKGROUND

Although emerging evidence indicates a relation between maternal intake of fish and improved child neurodevelopment, the results are inconsistent.

OBJECTIVES

This study investigated whether dietary consumption of fish during pregnancy is associated with offspring neurodevelopment at age 6 mo and 1 y. As exploratory research, we also examined the association between consumption of PUFAs and neurodevelopment at the same time points.

METHODS

After exclusion and multiple imputation from a dataset comprising 104,065 records from the Japan Environment and Children's Study, we evaluated 81,697 and 77,751 mother-child pairs at age 6 mo and 1 y, respectively.

RESULTS

Maternal fish intake during pregnancy was independently associated with reduced risk of delay in problem-solving at age 6 mo (lowest compared with highest quintile OR = 0.88; 95% CI: 0.79, 0.99; P-trend = 0.01) and in fine motor skills (highest quintile OR = 0.90; 95% CI: 0.81, 0.99; P-trend = 0.02) and problem-solving (fourth quintile OR = 0.89; 95% CI: 0.81, 0.98; and highest quintile OR = 0.90; 95% CI: 0.81, 0.99; P-trend = 0.005) at age 1 y. Dietary intake of total n-3 PUFAs was associated with reduced risk of delay in fine motor skills at 6 mo, and in fine motor skills and problem-solving at 1 y. Dietary intake of total n-6 PUFAs was associated with reduced risk of delay in communication and fine motor skills at 6 mo, and in gross motor skills, fine motor skills, and problem-solving at 1 y. In contrast, the dietary n-6/n-3 ratio was positively associated with increased risk of delay in problem-solving at 1 y.

CONCLUSIONS

The results of this study suggest there might be beneficial effects of fish intake during pregnancy on some domains of child psychomotor development and this effect might be partially explained by PUFA intake from fish. Trial registration: UMIN000030786.

Causal Link between n-3 Polyunsaturated Fatty Acid Deficiency and Motivation Deficits

Reward-processing impairment is a common symptomatic dimension of several psychiatric disorders. However, whether the underlying pathological mechanisms are common is unknown. Herein, we asked if the decrease in the n-3 polyunsaturated fatty acid (PUFA) lipid species, consistently described in these pathologies, could underlie reward-processing deficits. We show that reduced n-3 PUFA biostatus in mice leads to selective motivational impairments. Electrophysiological recordings revealed increased collateral inhibition of dopamine D2 receptor-expressing medium spiny neurons (D2-MSNs) onto dopamine D1 receptor-expressing MSNs in the nucleus accumbens, a main brain region for the modulation of motivation. Strikingly, transgenically preventing n-3 PUFA deficiency selectively in D2-expressing neurons normalizes MSN collateral inhibition and enhances motivation. These results constitute the first demonstration of a causal link between a behavioral deficit and n-3 PUFA decrease in a discrete neuronal population and suggest that lower n-3 PUFA biostatus in psychopathologies could participate in the etiology of reward-related symptoms.

Prefrontal fatty acid composition in schizophrenia and bipolar disorder: Association with reelin expression

OBJECTIVE

The extracellular matrix protein reelin regulates early brain development and synaptic plasticity in adulthood. Reelin is decreased in the postmortem brain in schizophrenia patients. Reelin's two receptors, ApoER2 and VLDLR, are also substrates for ApoE - a key lipoprotein that regulates phospholipid homeostasis in the brain. The goal of the present study was therefore to examine phospholipids and their constituent fatty acids, and determine whether there is an association between reelin, its receptors and phospholipids in the brain.

METHODS

Dorsolateral prefrontal cortex (BA9) grey matter was obtained from the Stanley Foundation Neuropathology Consortium. Samples included tissue from 35 controls, 35 schizophrenia and 34 bipolar disorder patients. Phospholipids were measured using gas liquid chromatography.

RESULTS

We quantified 15 individual fatty acid or plasmalogen species for phosphatidylethanolamine and phosphatidylcholine fractions, each comprising >0.5% of the total fatty acid pool. There were no group differences in phospholipids or individual fatty acid species after correcting for multiple comparisons. However, for the entire cohort, both the polyunsaturated subclass of fatty acids, and ApoE, correlated significantly with reelin expression, with a number of individual ω-6 fatty acid species also demonstrating a significant positive correlation. There was a non-significant trend for similar effects with VLDLR expression as for reelin.

CONCLUSION

Phospholipids and fatty acids in the dorsolateral cortex do not differ in patients with schizophrenia, bipolar disorder and controls. Reelin expression in this brain region is associated with polyunsaturated fatty acids and ApoE, suggesting further study of potential physiological interactions between these substrates is warranted.

The regulation of glutamic acid decarboxylases in GABA neurotransmission in the brain

Gamma-aminobutyric acid (GABA) is the main inhibitory neurotransmitter that is required for the control of synaptic excitation/inhibition and neural oscillation. GABA is synthesized by glutamic acid decarboxylases (GADs) that are widely distributed and localized to axon terminals of inhibitory neurons as well as to the soma and, to a lesser extent, dendrites. The expression and activity of GADs is highly correlated with GABA levels and subsequent GABAergic neurotransmission at the inhibitory synapse. Dysregulation of GADs has been implicated in various neurological disorders including epilepsy and schizophrenia. Two isoforms of GADs, GAD67 and GAD65, are expressed from separate genes and have different regulatory processes and molecular properties. This review focuses on the recent advances in understanding the structure of GAD, its transcriptional regulation and post-transcriptional modifications in the central nervous system. This may provide insights into the pathological mechanisms underlying neurological diseases that are associated with GAD dysfunction.

Redox lipidomics to better understand brain aging and function

Human prefrontal cortex (PFC) is a recently evolutionary emerged brain region involved in cognitive functions. Human cognitive abilities decline during aging. Yet the molecular mechanisms that sustain the preservation or deterioration of neurons and PFC functions are unknown. In this review, we focus on the role of lipids in human PFC aging. As the evolution of brain lipid concentrations is particularly accelerated in the human PFC, conferring a specific lipid profile, a brief approach to the lipidome of PFC was consider along with the relationship between lipids and lipoxidative damage, and the role of lipids in human PFC aging. In addition, the specific targets of lipoxidative damage in human PFC, the affected biological processes, and their potential role in the cognitive decline associated with aging are discussed. Finally, interventions designed to modify this process are considered. We propose that the dysfunction of key biological processes due to selective protein lipoxidation damage may have a role the cognitive decline of PFC during aging.

[Neurological mechanism and therapeutic strategy for posttraumatic stress disorders]

Posttraumatic stress disorder (PTSD) is most often induced by traumatic events and serious public health problems. PTSD is characterized by excessive response to contextual memory and impaired fear extinction and also associated with mild cognitive impairment, attention and learning deficits. Clinical and animal studies suggest that increased susceptibility of emotion- and fear-related neuronal circuits, including those in the amygdala, prefrontal cortex and hippocampus, contributes to development and retention of PTSD symptoms. However, mechanisms underlying this susceptibility to fear are not known and the useful therapeutic approaches are limited. Recently, there have been reports that ω3 LCPUFA supplementation can prevent development of PTSD and significantly ameliorate symptoms in patients with PTSD after accidental injury such as motor vehicle accidents and natural calamities. Importantly, Fabp7 null mice exhibit enhancement of fear memory consolidation and anxiety-related behaviors that resemble PTSD-like behaviors in humans. In this review, we focused behavioral phenotype of PTSD in Fabp3 null mice. The Fabp3 null mice exhibit cognitive deficits, hyperlocomotion and impaired fear extinction, and thus show PTSD-like behaviors. Chronic administration of ramelteon, a melatonin receptor agonist, improved all PTSD-like behaviors tested in Fabp3^－/－ mice. Relevant to mechanisms underlying impaired fear extinction, we observed that Ca^2＋/calmodulin-dependent protein kinase II (CaMKII) autophosphorylation increases in the basolateral amygdala (BLA) but remained unchanges in the hippocampus of Fabp3^－/－ mice. Likewise, the number of c-Fos positive neurons in BLA significantly increased after exposure to contextual fear conditions. Finally, chronic ramelteon administration restored abnormal c-Fos expression and CaMKII autophosphorylation in the BLA of Fabp3^－/－ mice. Taken together, Fabp3^－/－ mice show PTSD-like behaviors, and ramelteon is an attractive candidate for PTSD therapeutics in human.

Relationship Between Polyunsaturated Fatty Acids and Psychopathology in the NEURAPRO Clinical Trial

Background: Deficiencies in membrane polyunsaturated fatty acids (PUFA) such as omega-3 (n-3) fatty acids are thought to contribute to the pathophysiological processes underlying psychotic disorders. Emerging evidence suggests that the levels of PUFA are related to clinical symptoms but significant heterogeneity exists between studies. Here, we investigated associations of membrane PUFA with clinical symptoms and functioning in a large sample of individuals at ultra-high risk (UHR) for psychosis. Methods: A total of 285 participants of the NEURAPRO clinical trial were investigated for erythrocyte PUFA levels, including the n-3 index, n-6/n-3 PUFA ratio, docosahexaenoic acid (DHA), and eicosapentaenoic acid (EPA). Severity of general psychopathology [Brief Psychiatric Rating Scale (BPRS)], psychotic symptoms (BPRS psychosis subscale), negative symptoms [Scale for the Assessment of Negative Symptoms (SANS)], manic symptoms [Young Mania Rating Scale (YMRS)], depressive symptoms [Montgomery Asberg Depression Rating Scale (MADRS)], and functioning [Social and Occupational Functioning Scale (SOFAS), Global Functioning Social (GF-S) and Role (GF-R) scales] were assessed concurrently. Partial correlation taking into account the effects of gender, age, and smoking was used to examine the relationship between PUFAs and symptoms severity. Results: The n-3 index negatively correlated with the severity of general psychopathology, psychotic symptoms, depressive symptoms, and manic symptoms. The n-6/n-3 PUFA ratio positively correlated with severity of psychotic and depressive symptoms. The n-3 PUFA DHA negatively correlated with the severity of general psychopathology, positive, manic, and depressive symptoms. EPA negatively correlated with manic symptoms. Nervonic acid, an n-9 monounsaturated fatty acid, positively correlated with general psychopathology, positive and negative symptoms, depressive symptoms, and manic symptoms. The long-chain saturated fatty acid tetracosanoic acid positively correlated with general psychopathology, positive, manic, and depressive symptoms. Conclusions: Partially consistent with a previous study, psychotic symptoms, depressive symptoms, and symptoms of mania were associated with several classes of FAs in the present study. These findings support the relevance of membrane fatty acids for the onset of psychotic symptoms and indicate that FAs should be further evaluated as biomarkers in the UHR for psychosis group. Clinical Trial Registration: ANZCTR, identifier: 12608000475347.

Inverse Phosphatidylcholine/Phosphatidylinositol Levels as Peripheral Biomarkers and Phosphatidylcholine/Lysophosphatidylethanolamine-Phosphatidylserine as Hippocampal Indicator of Postischemic Cognitive Impairment in Rats

Vascular dementia is a transversal phenomenon in different kinds of neurodegenerative diseases involving acute and chronic brain alterations. Specifically, the role of phospholipids in the pathogenesis of dementia remains unknown. In the present study, we explored phospholipid profiles a month postischemia in cognitively impaired rats. The two-vessel occlusion (2-VO) model was used to generate brain parenchyma ischemia in adult male rats confirmed by alterations in myelin, endothelium, astrocytes and inflammation mediator. A lipidomic analysis was performed via mass spectrometry in the hippocampus and serum a month postischemia. We found decreases in phospholipids (PLs) associated with neurotransmission, such as phosphatidylcholine (PC 32:0, PC 34:2, PC 36:3, PC 36:4, and PC 42:1), and increases in PLs implied in membrane structure and signaling, such as lysophosphatidylethanolamine (LPE 18:1, 20:3, and 22:6) and phosphatidylserine (PS 38:4, 36:2, and 40:4), in the hippocampus. Complementarily, PC (PC 34:2, PC 34:3, PC 38:5, and PC 36:5) and ether-PC (ePC 34:1, 34:2, 36:2, 38:2, and 38:3) decreased, while Lyso-PC (LPC 18:0, 18:1, 20:4, 20:5, and LPC 22:6) and phosphatidylinositol (PI 36:2, 38:4, 38:5, and 40:5), as neurovascular state sensors, increased in the serum. Taken together, these data suggest inverse PC/LPC-PI levels as peripheral biomarkers and inverse PC/LPE-PS as a central indicator of postischemic cognitive impairment in rats.

Non-beta-amyloid/tau cerebrospinal fluid markers inform staging and progression in Alzheimer's disease

Background

Alzheimer’s disease (AD) is a complex neurodegenerative disorder characterized by neuropathologic changes involving beta-amyloid (Aβ), tau, neuronal loss, and other associated biological events. While levels of cerebrospinal fluid (CSF) Aβ and tau peptides have enhanced the antemortem detection of AD-specific changes, these two markers poorly reflect the severity of cognitive and functional deficits in people with altered Aβ and tau levels. While multiple previous studies identified non-Aβ, non-tau proteins as candidate neurodegenerative markers to inform the A/T/N biomarker scheme of AD, few have advanced beyond association with clinical AD diagnosis. Here we analyzed nine promising neurodegenerative markers in a three-centered cohort using independent assays to identify candidates most likely to complement Aβ and tau in the A/T/N framework.

Methods

CSF samples from 125 subjects recruited at the three centers were exchanged such that each of the nine previously identified biomarkers can be measured at one of the three centers. Subjects were classified according to cognitive status and CSF AD biomarker profiles as having normal cognition and normal CSF (n = 31), normal cognition and CSF consistent with AD (n = 13), mild cognitive impairment and normal CSF (n = 13), mild cognitive impairment with CSF consistent with AD (n = 23), AD dementia (n = 32; CSF consistent with AD), and other non-AD dementia (n = 13; CSF not consistent with AD).

Results

Three biomarkers were identified to differ among the AD stages, including neurofilament light chain (NfL; p < 0.001), fatty acid binding protein 3 (Fabp3; p < 0.001), and interleukin (IL)-10 (p = 0.033). Increased NfL levels were most strongly associated with the dementia stage of AD, but increased Fabp3 levels were more sensitive to milder AD stages and correlated with both CSF tau markers. IL-10 levels did not correlate with tau biomarkers, but were associated with rates of longitudinal cognitive decline in mild cognitive impairment due to AD (p = 0.006). Prefreezing centrifugation did not influence measured CSF biomarker levels.

Conclusion

CSF proteins associated with AD clinical stages and progression can complement Aβ and tau markers to inform neurodegeneration. A validated panel inclusive of multiple biomarker features (etiology, stage, progression) can improve AD phenotyping along the A/T/N framework.

Oxidative stress in drug-naïve first episode patients with schizophrenia and major depression: effects of disease acuity and potential confounders

Oxidative stress and immune dysregulation have been linked to schizophrenia and depression. However, it is unknown whether these factors are related to the pathophysiology or whether they are an epiphenomenon. Inconsistent oxidative stress-related findings in previous studies may have resulted from the use of different biomarkers which show disparate aspects of oxidative stress. Additionally, disease severity, medication, smoking, endocrine stress axis activation and obesity are potential confounders. In order to address some of these shortcomings, we have analyzed a broader set of oxidative stress biomarkers in our exploratory study, including urinary 8-iso-prostaglandin F2α (8-iso-PGF2α), 8-OH-2-deoyxguanosine (8-OH-2-dG), and blood levels of malondialdehyde (MDA), superoxide dismutase (SOD) and glutathione S-transferase (GST) in acutely ill drug-naïve first episode patients with schizophrenia (n = 22), major depression (n = 18), and controls (n = 43). Possible confounding factors were considered, and patients were followed-up after 6 weeks of treatment. No differences were observed regarding 8-OH-2-dG, MDA and GST. At baseline, 8-iso-PGF2α levels were higher in patients with schizophrenia (p = 0.004) and major depression (p = 0.037), with a trend toward higher SOD concentrations in schizophrenia (p = 0.053). After treatment, schizophrenia patients showed a further increase in 8-iso-PGF2α (p = 0.016). These results were not related to age, sex, disease severity, medication or adipose tissue mass. However, 8-iso-PGF2α was associated with smoking, endocrine stress axis activation, C-reactive protein levels and low plasma concentrations of brain-derived neurotrophic factor. This study suggests a role of lipid peroxidation particularly in drug-naïve acutely ill schizophrenia patients and highlights the importance of taking into account other confounding factors in biomarker studies.

Anti-Inflammatory Effects of Omega-3 Fatty Acids in the Brain: Physiological Mechanisms and Relevance to Pharmacology

Classically, polyunsaturated fatty acids (PUFA) were largely thought to be relatively inert structural components of brain, largely important for the formation of cellular membranes. Over the past 10 years, a host of bioactive lipid mediators that are enzymatically derived from arachidonic acid, the main n-6 PUFA, and docosahexaenoic acid, the main n-3 PUFA in the brain, known to regulate peripheral immune function, have been detected in the brain and shown to regulate microglia activation. Recent advances have focused on how PUFA regulate the molecular signaling of microglia, especially in the context of neuroinflammation and behavior. Several active drugs regulate brain lipid signaling and provide proof of concept for targeting the brain. Because brain lipid metabolism relies on a complex integration of diet, peripheral metabolism, including the liver and blood, which supply the brain with PUFAs that can be altered by genetics, sex, and aging, there are many pathways that can be disrupted, leading to altered brain lipid homeostasis. Brain lipid signaling pathways are altered in neurologic disorders and may be viable targets for the development of novel therapeutics. In this study, we discuss in particular how n-3 PUFAs and their metabolites regulate microglia phenotype and function to exert their anti-inflammatory and proresolving activities in the brain.

Evidence for altered cell membrane lipid composition in postmortem prefrontal white matter in bipolar disorder and schizophrenia

Brain imaging suggests that white matter abnormalities, including compromised white matter integrity in the frontal lobe, are shared across bipolar disorder (BD) and schizophrenia (SCZ). However, the precise molecular and cellular correlates remain to be elucidated. Given evidence for widespread alterations in cell membrane lipid composition in both disorders, we sought to investigate whether lipid composition is disturbed in frontal white matter in SCZ and BD. The phospholipids phosphatidylethanolamine (PE) and phosphatidylcholine (PC) were quantified in white matter adjacent to the dorsolateral prefrontal cortex in subjects with BD (n = 34), SCZ (n = 35), and non-psychiatric controls (n = 35) using high-pressure liquid chromatography. Individual fatty acid species and plasmalogens were then quantified separately in PE and PC fractions by gas liquid chromatography. PC was significantly lower in the BD group, compared to controls. The fatty acids PE22:0, PE24:1 and PE20:2n6 were higher, and PC20:4n6, PE22:5n6 and PC22:5n6 lower in the BD group, relative to the control group. PE22:1 was higher and PC20:3n6, PE22:5n6 and PC22:5n6 lower in the SCZ group, compared to the control group. These data provide evidence for altered lipid composition in white matter in both BD and SCZ. Changes in white matter lipid composition could ultimately contribute to dysfunction of frontal white matter circuits in SCZ and BD.

Low dietary intake of n-3 fatty acids, niacin, folate, and vitamin C in Korean patients with schizophrenia and the development of dietary guidelines for schizophrenia

Inappropriate dietary intake and poor nutritional status are reported to be associated with metabolic syndrome and psychopathology in patients with schizophrenia. We hypothesized that inappropriate dietary habits and insufficient dietary intake of specific nutrients are associated with schizophrenia. To test the hypothesis, we assessed the dietary habits and nutritional intake of patients with schizophrenia and then developed suitable dietary guidelines. In total, 140 subjects (73 controls and 67 patients with schizophrenia from community mental health centers) were included, and dietary intakes were analyzed using a semi-quantitative food frequency questionnaire. As a result, the proportion of overweight or obese patients was significantly higher in schizophrenia subjects (64.2%) compared with control subjects (39.7%) (P=.004). The male schizophrenia patients had significantly lower dietary intakes of protein, polyunsaturated fatty acids (PUFAs), vitamin K, niacin, folate, and vitamin C than the male control subjects. In all multiple logistic regression models, subjects with the "low" dietary intake of protein, n-3 PUFAs, niacin, folate, and vitamin C had a significantly higher odds ratios for schizophrenia compared with those with the "high" dietary intake category of each nutrient. Therefore, maintenance of a healthy body weight and sufficient dietary intake of protein, PUFAs, niacin, folate, and vitamin C are recommended for Korean patients with schizophrenia.

Omega – 3 fatty acids in schizophrenia – part I: importance in the pathophysiology of schizophrenia

Despite the increasing offer of antipsychotic drugs, the effectiveness of pharmacotherapy in schizophrenia is still unsatisfactory. Drug resistance, lack of complete remission and the increasing risk of metabolic complications are the reasons why the new forms of therapy in schizophrenia among which unsaturated essential fatty acids omega 3 (EFAs ω-3) affecting the proper functioning of nervous system, are mentioned, are being looked for.

Fatty acids represent 50-60% of the dry weight of the brain and diet is one of the factors that influence the value of each of the fat fractions in the neuron membranes. Patients with schizophrenia tend to have irregular nutritional status concerning essential fatty acids ω-3, which might result from metabolic disorders or irregular consumption of fatty acids.

Apart from being a review of the literature on this subject, this very paper characterizes essential fatty acids ω-3, their metabolism, the most important sources in the diet and the opinions of experts in the field about the recommended intake. It pays attention to the role of essential fatty acids in both the structure and functioning of the central nervous system is, as well as their role in the pathophysiology of schizophrenia, with particular emphasis on the membrane concept by David Horrobin. The assessment of the errors in consumption and metabolism of essential fatty acids are described as well.

The evidence was found both in epidemiological and modeling studies. It supports the participation of EFAs in etiopathogenesis and pathophysiology of schizophrenia. Further research is needed, both observational and interventional, as to the role of essential fatty acids ω-3 in the functioning of the CNS as well as the development and course of schizophrenia.

Fatty acid composition of the postmortem corpus callosum of patients with schizophrenia, bipolar disorder, or major depressive disorder

BACKGROUND

Studies investigating the relationship between n-3 polyunsaturated fatty acid (PUFA) levels and psychiatric disorders have thus far focused mainly on analyzing gray matter, rather than white matter, in the postmortem brain. In this study, we investigated whether PUFA levels showed abnormalities in the corpus callosum, the largest area of white matter, in the postmortem brain tissue of patients with schizophrenia, bipolar disorder, or major depressive disorder.

METHODS

Fatty acids in the phospholipids of the postmortem corpus callosum were evaluated by thin-layer chromatography and gas chromatography. Specimens were evaluated for patients with schizophrenia (n=15), bipolar disorder (n=15), or major depressive disorder (n=15) and compared with unaffected controls (n=15).

RESULTS

In contrast to some previous studies, no significant differences were found in the levels of PUFAs or other fatty acids in the corpus callosum between patients and controls. A subanalysis by sex gave the same results. No significant differences were found in any PUFAs between suicide completers and non-suicide cases regardless of psychiatric disorder diagnosis.

CONCLUSIONS

Patients with psychiatric disorders did not exhibit n-3 PUFAs deficits in the postmortem corpus callosum relative to the unaffected controls, and the corpus callosum might not be involved in abnormalities of PUFA metabolism. This area of research is still at an early stage and requires further investigation.