Possibility of polyunsaturated fatty acids for the prevention and treatment of neuropsychiatric illnesses

Differential impact of intermittent versus continuous treatment with clozapine on fatty acid metabolism in the brain of an MK-801-induced mouse model of schizophrenia

Continuous antipsychotic treatment is often recommended to prevent relapse in schizophrenia. However, the efficacy of antipsychotic treatment appears to diminish in patients with relapsed schizophrenia and the underlying mechanisms are still unknown. Moreover, though the findings are inconclusive, several recent studies suggest that intermittent versus continuous treatment may not significantly differ in recurrence risk and therapeutic efficacy but potentially reduce the drug dose and side effects. Notably, disturbances in fatty acid (FA) metabolism are linked to the onset/relapse of schizophrenia, and patients with multi-episode schizophrenia have been reported to have reduced FA biosynthesis. We thus utilized an MK-801-induced animal model of schizophrenia to evaluate whether two treatment strategies of clozapine would affect drug response and FA metabolism differently in the brain. Schizophrenia-related behaviors were assessed through open field test (OFT) and prepulse inhibition (PPI) test, and FA profiles of prefrontal cortex (PFC) and hippocampus were analyzed by gas chromatography-mass spectrometry. Additionally, we measured gene expression levels of enzymes involved in FA synthesis. Both intermittent and continuous clozapine treatment reversed hypermotion and deficits in PPI in mice. Continuous treatment decreased total polyunsaturated fatty acids (PUFAs), saturated fatty acids (SFAs) and FAs in the PFC, whereas the intermittent administration increased n-6 PUFAs, SFAs and FAs compared to continuous administration. Meanwhile, continuous treatment reduced the expression of Fads1 and Elovl2, while intermittent treatment significantly upregulated them. This study discloses the novel findings that there was no significant difference in clozapine efficacy between continuous and intermittent administration, but intermittent treatment showed certain protective effects on phospholipid metabolism in the PFC.

The effects of omega-3, DHA, EPA, Souvenaid® in Alzheimer's disease: A systematic review and meta-analysis

BACKGROUND

Alzheimer's disease (AD) is the most common cause of dementia worldwide. Omega-3 fatty acids (n-3-PUFA) are essential to normal neural development and function. Souvenaid®, a medical supplement that contains n-3-PUFA's: eicosatetraenoic acid (EPA) and docosahexaenoic acid (DHA), has emerged as an alternative, slowing cognitive decline in AD patients. In this study, we investigated the effect of dietary supplementation with n-3-PUFA, EPA, DHA, and Souvenaid® in AD patients.

AIM

This systematic review and meta-analysis aim to establish the relationship between n-3-PUFA, EPA, DHA, and Souvenaid® with cognitive effects, ventricular volume and adverse events in AD patients.

METHODS

A systematic search of randomized control trials (RCT), cohorts, and case-control studies was done in PubMed, Scopus, Web of Science, Cochrane, and Embase for AD adult patients with dietary supplementation with n-3-PUFA, EPA, DHA, or Souvenaid® between 2003 and 2024.

RESULTS

We identified 14 studies with 2766 subjects aligned with our criteria. Most publications described positive cognitive outcomes from supplements (58%). The most common adverse events reported were gastrointestinal symptoms. CDR scale showed reduced progression of cognitive decline (SMD = -0.4127, 95% CI: [-0.5926; -0.2327]), without subgroup differences between different dietary supplement interventions. ADCS-ADL, MMSE, ADAS-cog, adverse events, and ventricular volume did not demonstrate significant differences. However, Souvenaid® showed a significant negative effect (SMD = -0.3593, 95% CI: -0.5834 to -0.1352) in ventricular volumes.

CONCLUSIONS

The CDR scale showed reduced progression of cognitive decline among patients with n-3-PUFA supplemental interventions, with no differences between different n-3-PUFA supplements.

Efficacy of Polyunsaturated Fatty Acids as a Treatment for Post-traumatic Stress Disorder: A Systematic Review

INTRODUCTION

Post-traumatic stress disorder (PTSD) is a prevalent health condition among members of the military. Although the efficacy of pharmacological and psychiatric interventions for PTSD has been well studied, there are limited data on the effects of omega-3 (n-3) polyunsaturated fatty acid (PUFA) interventions on PTSD. The use of PUFAs shows promise because of their neuroprotective effects. Thus, this systematic review will synthesize the current state of the evidence regarding the effectiveness of PUFA treatment for PTSD.

MATERIALS AND METHODS

Using the PubMed, PsychINFO, Embase, and CINAHL databases, a search of the literature was conducted using the search terms "posttraumatic-stress-disorder, combat disorders, trauma-related-stress-disorder, omega-3, fatty acid, and polyunsaturated fatty acids" to identify articles published from January 1, 2008, to January 1, 2024, that focused on PUFA interventions for PTSD. A total of 281 articles were identified. Following exclusions and quality assessments using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) criteria proposed by Cochrane, 6 randomized controlled trials (RCTs) and preclinical studies were chosen for inclusion, and data were then extracted into a data matrix for final synthesis and analysis.

RESULTS

The RCTs (n = 3) showed no significant effect of PUFAs in the prevention of PTSD symptom onset. Among preclinical studies (n = 3), PUFAs resulted in a significant decrease in anxiety-like behavior and fear memory and an increase in spatial learning and memory. The quality of evidence among the 6 RCTs and preclinical studies using the Cochrane GRADE criteria ranged from low to high.

CONCLUSIONS

The results from this systematic review suggest that more evidence is needed before making any recommendations for the clinical use of dietary PUFAs in the management of PTSD symptoms.

Challenges in Functional Food Products with the Incorporation of Some Microalgae

Much attention has been given to the use of microalgae to produce functional foods that have valuable bioactive chemicals, including essential amino acids, polyunsaturated fatty acids, vitamins, carotenoids, fiber, and minerals. Microalgal biomasses are increasingly being used to improve the nutritional values of foods because of their unique nutrient compositions that are beneficial to human health. Their protein content and amino acid composition are the most important components. The microalgal biomass used in the therapeutic supplement industry is dominated by bio-compounds like astaxanthin, β-carotene, polyunsaturated fatty acids like eicosapentaenoic acid and docosahexaenoic acid, and polysaccharides such as β-glucan. The popularity of microalgal supplements is growing because of the health benefits of their bioactive substances. Moreover, some microalgae, such as Dunaliella, Arthrospira (Spirulina), Chlorella, and Haematococcus, are commonly used microalgal species in functional food production. The incorporation of microalgal biomass leads not only to enhanced nutritional value but also to improved sensory quality of food products without altering their cooking or textural characteristics. Microalgae, because of their eco-friendly potential, have emerged as one of the most promising and novel sources of new functional foods. This study reviews some recent and relevant works, as well as the current challenges for future research, using different methods of chemical modification in foods with the addition of a few commercial algae to allow their use in nutritional and sensory areas. It can be concluded that the production of functional foods through the use of microalgae in foods has become an important issue.

Correlations between omega-3 fatty acids and inflammatory/glial abnormalities: the involvement of the membrane and neurotransmitter dysfunction in schizophrenia

Introduction

Macrophages or T-lymphocytes triggered inflammation and, consequently, activated glial cells may contribute to neuroinflammation and neurotransmitter dysfunction in schizophrenia (SZ), while omega(n)-3 polyunsaturated fatty acids (PUFAs) can attenuate some SZ symptoms through anti-inflammatory effects. However, the correlations between macrophage/T-lymphocyte-produced cytokines and glia phenotypes, between inflammatory status and PUFAs composition, between cytokines and neurotransmitter function, and between n-3 PUFAs and neurotransmitter abnormality in SZ are unclear.

Methods

Changes in T-helper (h) patterns, peripheral macrophage/glial markers, PUFAs profile, membrane fluidity, and neurotransmitter functions were evaluated in SZ patients (n = 50) and healthy controls (n = 30) using ELISA, gas chromatography, fluorescence anisotropy techniques, and HPLC, respectively.

Results

Compared to the control, blood lymphocyte proliferation, the concentration of macrophage/microglia phenotype M1 markers, including cytokines IL-1β, TNF-α (Th1) and IL-6 (Th2), and astrocyte phenotype A1 marker S100β was significantly increased, while IL-17 and n-3 PUFAs contents, n-3/n-6 ratio, and membrane fluidity (FLU) were significantly decreased in SZ. Moreover, increased DA and HVA, decreased 5-HT and NE, and their metabolites appeared in SZ. Moreover, negative correlations between IL-6 and A2 marker Brain-Derived Neurotrophic Factor (BDNF) or n-3 PUFAs EPA and between IL-1β and FLU or 5HIAA, while positive correlations between EPA and 5-HIAA and between FLU and DHA were found in SZ.

Discussion

These findings showed (1) no clear Th pattern, but pro-inflammatory-dominant immunity occurred; (2) the pro-inflammatory pattern may result in the activated microglia M1 and astrocyte A1 phenotype; and (3) increased pro-inflammatory cytokines were related to decreased n-3 PUFA and decreased membrane fluidity and dysfunctional neurotransmitter systems in SZ.

Causal relationship between human blood omega-3 fatty acids and the risk of epilepsy: A two-sample Mendelian randomization study

Background

Though omega-3 fatty acids reduce seizures in several animal models, considerable controversy exists regarding the association between omega-3 fatty acids and epilepsy in human.

Objective

To assess whether genetically determined human blood omega-3 fatty acids are causally associated with the risk of epilepsy outcomes.

Methods

We conducted a two-sample Mendelian randomization (MR) analysis by applying summary statistics of genome-wide association study datasets of both exposure and outcomes. Single nucleotide polymorphisms significantly associated with blood omega-3 fatty acids levels were selected as instrumental variables to estimate the causal effects on epilepsy. Five MR analysis methods were conducted to analyze the final results. The inverse-variance weighted (IVW) method was used as the primary outcome. The other MR analysis methods (MR-Egger, weighted median, simple mode, and weighted mode) were conducted as the complement to IVW. Sensitivity analyses were also conducted to evaluate heterogeneity and pleiotropy.

Results

Genetically predicted the increase of human blood omega-3 fatty acids levels was associated with a higher risk of epilepsy (OR = 1.160, 95%CI = 1.051–1.279, P = 0.003).

Conclusions

This study revealed a causal relationship between blood omega-3 fatty acids and the risk of epilepsy, thus providing novel insights into the development mechanism of epilepsy.

Esterification of Docosahexaenoic Acid Enhances Its Transport to the Brain and Its Potential Therapeutic Use in Brain Diseases

Docosahexaenoic acid-containing lysophosphatidylcholine (DHA-LysoPC) is presented as the main transporter of DHA from blood plasma to the brain. This is related to the major facilitator superfamily domain-containing protein 2A (Mfsd2a) symporter expression in the blood-brain barrier that recognizes the various lyso-phospholipids that have choline in their polar head. In order to stabilize the DHA moiety at the sn-2 position of LysoPC, the sn-1 position was esterified by the shortest acetyl chain, creating the structural phospholipid 1-acetyl,2-docosahexaenoyl-glycerophosphocholine (AceDoPC). This small structure modification allows the maintaining of the preferential brain uptake of DHA over non-esterified DHA. Additional properties were found for AceDoPC, such as antioxidant properties, especially due to the aspirin-like acetyl moiety, as well as the capacity to generate acetylcholine in response to the phospholipase D cleavage of the polar head. Esterification of DHA within DHA-LysoPC or AceDoPC could elicit more potent neuroprotective effects against neurological diseases.

Fatty Acid Content of Four Salmonid Fish Consumed by Indigenous Peoples from the Yamal-Nenets Autonomous Okrug (Northwestern Siberia, Russia)

We assayed fatty acids in the flesh of Arctic cisco Coregonus autumnalis (adult and juvenile), least cisco Coregonus sardinella, muksun Coregonus muksun, and Arctic charr Salvelinus alpinus inhabiting water bodies of the Gydan Peninsula, Siberia, Russia. The highest concentrations of total and polyunsaturated fatty acids (PUFAs) were found in Arctic charr (27.8 and 9.5 mg g−1) and adult Arctic cisco (20.2 and 7.6 mg g−1), while the lowest concentrations occurred in juvenile Arctic cisco (7.5 and 3.6 mg g−1). Multivariate analyses divided all studied fish into five distinct groups with the highest similarity between least cisco and muksun and the highest dissimilarity between juvenile Arctic cisco and Arctic charr. Coregonid fish from the study area had a higher content of docosahexaenoic and eicosapentaenoic acids than their conspecifics from subarctic and temperate habitats. The flesh of the studied fish is a source of a healthy diet for humans. Taking into account that all the studied fish are components of the traditional diet of indigenous peoples in northwestern Siberia, our data may be useful not only for local consumers and anglers but also for stakeholders focused on food policy and food security in the area.

Understanding the Role of the Gut Microbiome in Brain Development and Its Association With Neurodevelopmental Psychiatric Disorders

The gut microbiome has a tremendous influence on human physiology, including the nervous system. During fetal development, the initial colonization of the microbiome coincides with the development of the nervous system in a timely, coordinated manner. Emerging studies suggest an active involvement of the microbiome and its metabolic by-products in regulating early brain development. However, any disruption during this early developmental process can negatively impact brain functionality, leading to a range of neurodevelopment and neuropsychiatric disorders (NPD). In this review, we summarize recent evidence as to how the gut microbiome can influence the process of early human brain development and its association with major neurodevelopmental psychiatric disorders such as autism spectrum disorders, attention-deficit hyperactivity disorder, and schizophrenia. Further, we discuss how gut microbiome alterations can also play a role in inducing drug resistance in the affected individuals. We propose a model that establishes a direct link of microbiome dysbiosis with the exacerbated inflammatory state, leading to functional brain deficits associated with NPD. Based on the existing research, we discuss a framework whereby early diet intervention can boost mental wellness in the affected subjects and call for further research for a better understanding of mechanisms that govern the gut-brain axis may lead to novel approaches to the study of the pathophysiology and treatment of neuropsychiatric disorders.

Association between mothers' fish intake during pregnancy and infants' sleep duration: a nationwide longitudinal study-The Japan Environment and Children's Study (JECS)

Purpose

N-3 polyunsaturated fatty acids (n-3 PUFAs), which are an important nutrient for humans, are particularly essential to the growth and development of the central nervous system (CNS) in fetuses and infants. Consequently, sufficient n-3 PUFA intake by mothers during pregnancy is considered to contribute to CNS development in their infants. CNS development is known to be associated with sleep, but no large epidemiological studies have yet confirmed that n-3 PUFA intake during pregnancy is associated with infants’ sleep.

Methods

After exclusion and multiple imputation from a dataset comprising 104 065 records from the Japan Environment and Children’s Study (JECS), we examined 87 337 mother–child pairs for the association between mothers’ fish and n-3 PUFA intakes and risk of their infants sleeping less than 11 h at 1 year of age.

Results

Multiple logistic regression analysis with the lowest quintile used as a reference revealed odds ratios for the second through fifth quintiles of 0.81 (95% confidence interval [95% CI] 0.76–0.87), 0.81 (95% CI 0.76–0.87), 0.78 (95% CI 0.72–0.84), and 0.82 (95% CI 0.76–0.88) for fish intake (p for trend < 0.001) and 0.90 (95% CI 0.84–0.97), 0.88 (95% CI 0.81–0.94), 0.88 (95% CI 0.82–0.95), and 0.93 (95% CI 0.86–0.998) for n-3 PUFA intake (p for trend = 0.04).

Conclusions

Low fish intake during pregnancy may increase the risk of infants sleeping less than 11 h at 1 year of age. This relationship may have been mediated by maternal n-3 PUFA intake and infant neurodevelopment, but further evidence from interventional and other studies is needed to determine the appropriate level of fish intake during pregnancy.

Trial registration

The Japan Environment and Children’s Study, https://upload.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000035091 (Registration no. UMIN000030786).

Supplementary Information

The online version contains supplementary material available at 10.1007/s00394-021-02671-4.

Perilla Seed Oil Enhances Cognitive Function and Mental Health in Healthy Elderly Japanese Individuals by Enhancing the Biological Antioxidant Potential

Oxidative stress plays an important role in age-associated cognitive decline. We recently reported that dietary intake of perilla seed oil (PO), a rich source of α-linolenic acid (LNA, C18:3, ω-3), helps in maintaining good mental health in adults. This study aimed to investigate the impacts of dietary PO intake on cognitive functions and mental health in healthy, elderly Japanese individuals. Seventy-five healthy volunteers aged 64–84 years were randomly divided into two groups: a control group and a PO-administered group. At baseline and at 12 months of intervention, cognitive function, mental health condition, fatty acid profile of the red blood cell plasma membranes (RBC-PM), and serum biochemical parameters were evaluated. Results showed that serum biological antioxidant potential and LNA levels in the RBC-PM at 12 months after the trial were significantly higher in the PO group compared to the control group. Further, both the cognitive function measures, as evaluated by the Frontal Assessment Battery test and the apathy scores, tended to be improved after 12 months in the PO group. Our results demonstrate that dietary PO intake enhances the antioxidant potential and prevents the age-related cognitive and mental decline in healthy elderly individuals by enhancing the blood LNA levels.

ω-3 Ethyl ester results in better cognitive function at 12 and 30 months than control in cognitively healthy subjects with coronary artery disease: a secondary analysis of a randomized clinical trial

BACKGROUND

Omega-3 (n-3) fatty acids have shown benefit in cognitively impaired subjects, but the effect on cognitively healthy older subjects is unclear.

OBJECTIVES

Our aim was to determine if long-term, high-dose ω-3 ethyl esters, EPA (20:5n-3) and DHA (22:6n-3), prevent deterioration of cognitive function in cognitively healthy older adults.

METHODS

A total of 285 subjects with stable coronary artery disease (CAD) on statin treatment were randomly assigned to 3.36 g EPA and DHA or none (control) for 30 mo. Cognitive function was assessed in all 285 subjects at baseline and in 268 and 250 subjects who returned at 12- and 30-mo follow-up, respectively, with neuropsychological testing as a prespecified secondary outcome. A completer's analysis, along with a sensitivity analysis carrying forward the last observation, was performed.

RESULTS

Over the 30-mo period, subjects randomly assigned to EPA and DHA had significantly better scores than control for verbal fluency, language, and memory (mean: 1.08; 95% CI: 0.25, 1.91; P = 0.011) and 2 tests of visual-motor coordination (mean: -2.95; 95% CI: -5.33, -0.57; P = 0.015 and mean: -9.44; 95% CI: -18.60, -0.30; P = 0.043, respectively). The better scores for EPA and DHA were due to an improvement at 12 mo compared with baseline in verbal fluency, language, and memory (P = 0.047) and 2 tests of visual-motor coordination (P = 0.033 and P < 0.001, respectively), whereas control had no change. Post hoc analyses indicated no difference by age, sex, or diabetes status.

CONCLUSIONS

Cognitively healthy older adults with stable CAD randomly assigned to high-dose EPA and DHA had improved cognitive function over a 30-mo period compared with control. These findings may be especially important for CAD patients because CAD is a risk factor for cognitive decline.This trial was registered at clinicaltrials.gov as NCT01624727.

Docosahexaenoic Acid (DHA) Supplementation Alters Phospholipid Species and Lipid Peroxidation Products in Adult Mouse Brain, Heart, and Plasma

The abundance of docosahexaenoic acid (DHA) in phospholipids in the brain and retina has generated interest to search for its role in mediating neurological functions. Besides the source of many oxylipins with pro-resolving properties, DHA also undergoes peroxidation, producing 4-hydroxyhexenal (4-HHE), although its function remains elusive. Despite wide dietary consumption, whether supplementation of DHA may alter the peroxidation products and their relationship to phospholipid species in brain and other body organs have not been explored sufficiently. In this study, adult mice were administered a control or DHA-enriched diet for 3 weeks, and phospholipid species and peroxidation products were examined in brain, heart, and plasma. Results demonstrated that this dietary regimen increased (n-3) and decreased (n-6) species to different extent in all major phospholipid classes (PC, dPE, PE-pl, PI and PS) examined. Besides changes in phospholipid species, DHA-enriched diet also showed substantial increases in 4-HHE in brain, heart, and plasma. Among different brain regions, the hippocampus responded to the DHA-enriched diet showing significant increase in 4-HHE. Considering the pro- and anti-inflammatory pathways mediated by the (n-6) and (n-3) polyunsaturated fatty acids, unveiling the ability for DHA-enriched diet to alter phospholipid species and lipid peroxidation products in the brain and in different body organs may be an important step forward towards understanding the mechanism(s) for this (n-3) fatty acid on health and diseases.

Effect of Supplemental Enteral Fish Oil on the Development of Psychological Complications in Critically Ill Multiple-Trauma Patients: 6 Months' Follow-Up

BACKGROUND

Posttraumatic stress disorder (PTSD) is common in intensive care unit (ICU) patients. Defic it intake of ω-3 polyuns aturated fatty ac ids (PUFAs) may be as sociated with developm ent of PTSD.

METHODS

This study randomized mechanically ventilated patients suffering from multiple trauma (n = 150) into 2 groups: a study and a control group that received enteral feeding with or without fish oil. Fifty-one patients were interviewed 6 months after discharge from the ICU. Psychometric parameters of PTSD were assessed by questionnaires. The fatty acid composition of erythrocyte membranes was performed by homogenization of the cells in hexane-isopropanol.

RESULTS

No differences were found in baseline characteristics between the groups. Erythrocyte membrane composition showed significantly higher concentrations of ω-3 fatty acids in the study group. Anxiety and depression symptoms were correlated with an increase in eicosapentaenoic acid (EPA) on days 4 and 8 for depression and EPA on day 4 and docosahexaenoic acid (DHA) on day 8 for anxiety. Total ω-3 content was positively correlated with anxiety and depression as well. An inverse correlation was found between DHA and EPA in the treatment group and with the total ω-3 and DHA in the control group for the Brief Illness Perceptions Questionnaire.

CONCLUSION

Administration of an ω-3 PUFA-enriched diet during the ICU stay did not prevent development of PTSD in trauma patients 6 months after discharge from ICU.

Twelve-month Studies on Perilla Oil Intake in Japanese Adults-Possible Supplement for Mental Health

Perilla oil (PO), rich in α-linolenic acid (LNA, C18:3, ω-3), is increasingly alleged to have numerous health benefits in humans. However, the current reports detailing the effects of PO on human mental health are not adequate. Therefore, in the current investigation we compared the effects of PO or placebo treatment on the mental condition of healthy adult Japanese volunteers. At baseline and after 12 months of treatment, mental health condition was assessed using the Zung Self-Rating Depression Scale (SDS) and Apathy Scale, and serum biochemical parameters were determined. From baseline to 12 months of intervention, both SDS depression and apathy scores improved significantly in the PO-administered group. Compared to those of control group, serum norepinephrine and serotonin levels after 12 months decreased in the PO-administered group. The enhanced mental state observed in PO-subjects was accompanied by LNA level increases in erythrocyte plasma membranes. Our data demonstrate that PO intake enhances blood LNA levels and may maintain healthy mental conditions in adult subjects.

Cognitive impairments in type 2 diabetes, risk factors and preventive strategies

Mild cognitive impairment (MCI) is a modifiable risk factor in progression of several diseases including dementia and type 2 diabetes. If cognitive impairments are not reversed at an early stage of appearance of symptoms, then the prolonged pathogenesis can lead to dementia and Alzheimer's disease (AD). Therefore, it is necessary to detect the risk factors and mechanism of prevention of cognitive dysfunction at an early stage of disease. Poor lifestyle, age, hyperglycemia, hypercholesterolemia, and inflammation are some of the major risk factors that contribute to cognitive and memory impairments in diabetic patients. Mild cognitive impairment was seen in those individuals of type 2 diabetes, who are on an unhealthy diet. Physical inactivity, frequent alcohol consumptions, and use of packed food products that provides an excess of cheap calories are found associated with cognitive impairment and depression in diabetic patients. Omega fatty acids (FAs) and polyphenol-rich foods, especially flavonoids, can reduce the bad effects of an unhealthy lifestyle; therefore, the consumption of omega FAs and flavonoids may be beneficial in maintaining normal cognitive function. These functional foods may improve cognitive functions by targeting many enzymes and molecules in cells chiefly through their anti-inflammatory, antioxidant, or signaling actions. Here, we provide the current concepts on the risk factors of cognitive impairments in type 2 diabetes and the mechanism of prevention, using omega FAs and bioactive compounds obtained from fruits and vegetables. The knowledge derived from such studies may assist physicians in managing the health care of patients with cognitive difficulties.

Altered polyunsaturated fatty acid levels in relation to proinflammatory cytokines, fatty acid desaturase genotype, and diet in bipolar disorder

Inflammation and altered polyunsaturated fatty acid (PUFA) levels have been implicated in bipolar disorder (BD). A recent genome-wide association study identified a locus in the fatty acid desaturase (FADS) gene cluster conferring susceptibility to BD. In this study, we examined PUFA levels in patients with BD in relation to proinflammatory cytokines, FADS genotype, and dietary habits. We enrolled 83 patients with BD and 217 healthy controls who underwent plasma PUFA measurement. A subsample of 65 patients and 90 controls underwent plasma interleukin (IL)-6 and tumor necrosis factor alpha (TNFα) measurement, and three FADS single nucleotide polymorphisms (SNPs) were genotyped. Information on fish consumption was obtained by a self-reported diet history questionnaire. In comparing PUFA levels between patients and controls, significant differences were found for all 7 PUFAs tested. Specifically, n-3 eicosapentaenoic acid (EPA) level was decreased, and n-6 arachidonic acid level was increased in the patients (p < 0.0001 for both). Plasma IL-6 and TNFα levels were both significantly increased in the patients. Plasma EPA level was negatively correlated with IL-6 and TNFα levels. The FADS genotype, which was associated with increased n-6 PUFA levels, was also associated with marked elevation in TNFα levels. Less frequent fish intake was associated with low EPA and high IL-6 level. Taken together, our results provide strong evidence for altered plasma PUFA and proinflammatory cytokine levels in patients with BD. Furthermore, FADS genotype and fish consumption may contribute not only to altered PUFA levels but also to inflammation in BD.

Food Components with the Potential to be Used in the Therapeutic Approach of Mental Diseases

BACKGROUND

Neurological disorders represent a high influence in our society throughout the world. Although the symptoms arising from those diseases are well known, the causes and mechanisms are complex and depending on multiple factors. Some food components consumed as part of our diet have been studied regarding their incidence in different common neurological diseases such as Alzheimer disease, major depression, Parkinson disease, autism and schizophrenia among others.

OBJECTIVE

In this review, information has been gathered on the main evidences arising from studies on the most promising food components, related to their therapeutic potential, as part of dietary supplements or through the diet, as an alternative or a complement of the traditional drug treatments. Those food components include vitamins, minerals, fatty acids, carotenoids, polyphenols, bioactive peptides, probiotics, creatine and saponins.

RESULTS

Many in vitro and in vivo animal studies, randomized and placebo control trials, and systematic reviews on the scientific results published in the literature, have been discussed, highlighting the more recent advances, also with the aim to explore the main research needs. Particular attention has been paid to the mechanisms of action of the compounds regarding their anti-inflammatory, antioxidative properties and neuronal protection.

CONCLUSION

More research is needed to prove the therapeutic potential of the food components based on scientific evidence, also on intervention studies to demonstrate the improvement of neuronal and cognitive impairments.

Omega-3 polyunsaturated fatty acids and reduction of depressive symptoms in older adults: A systematic review and meta-analysis

OBJECTIVE

The aim of this study is to systematically review the efficacy of omega-3 polyunsaturated fatty acid (n-3 PUFA) supplements in reducing depressive symptoms among older adults aged 60 and above.

METHODS

Relevant electronic databases were searched from their inception to June 4, 2018, including Medline, Embase, Web of Science, Cochrane Library, PsycINFO, Global Health, CINAHL, ClinicalTrials.gov and Chinese Biomedical Medicine Database. Two reviewers independently screened for eligible studies, extracted data, and assessed risk of bias of the included studies. The effect size data were analyzed using robust variance estimation in meta-regression.

RESULTS

Nine studies were included. The overall treatment effects of n-3 PUFA supplements in reducing depressive symptoms for older adults was not statistically significant (d = -0.202, 95% CI = -0.463, 0.060). Meta-regression found interventions with dosage of n-3 PUFA greater than 1.5 g/d had an average effect size of -0.428, with a 95% confidence interval of [-0.822, -0.035], which is statistically significant. Meta-regression did not find significant moderating effects of comorbidity, baseline depression, intervention duration, and EPA-DHA ratio, potentially due to limited statistical power.

LIMITATIONS

The current review only included 9 studies based on literature search in major English and Chinese databases, which provided limited statistical power for moderator analysis and the results are suggestive only.

CONCLUSIONS

The meta-analysis of 9 RCTs found mixed findings of the efficacy of n-3 PUFA in the treatment of depressive symptoms among older adults aged 60 and above. More high-quality, large-scale RCTs are needed to confirm the current conclusions.

The role of the gut microbiota in schizophrenia: Current and future perspectives

OBJECTIVES

Schizophrenia is a poorly understood chronic disease. Its pathophysiology is complex, dynamic, and linked to epigenetic mechanisms and microbiota involvement. Nowadays, correlating schizophrenia with the environment makes sense owing to its multidimensional implications: temporal and spatial variability. Microbiota involvement and epigenetic mechanisms are factors that are currently being considered to better understand another dimension of schizophrenia.

METHODS

This review summarises and discusses currently available information, focussing on the microbiota, epigenetic mechanisms, technological approaches aimed at performing exhaustive analyses of the microbiota, and psychotherapies, to establish future perspectives.

RESULTS

The connection between the microbiota, epigenetic mechanisms and technological developments allows for formulating new approaches objectively oriented towards the development of alternative psychotherapies that may help treat schizophrenia.

CONCLUSIONS

In this review, the gut microbiota and epigenetic mechanisms were considered as key regulators, revealing a potential new aetiology of schizophrenia. Likewise, continuous technological advances (e.g. culturomics), aimed at the microbiota-gut-brain axis generate new evidence on this concept.

Association of Use of Omega-3 Polyunsaturated Fatty Acids With Changes in Severity of Anxiety Symptoms: A Systematic Review and Meta-analysis

IMPORTANCE

No systematic review or meta-analysis has assessed the efficacy of omega-3 polyunsaturated fatty acids (PUFAs) for anxiety.

OBJECTIVE

To evaluate the association of anxiety symptoms with omega-3 PUFA treatment compared with controls in varied populations.

DATA SOURCES

PubMed, Embase, ProQuest, ScienceDirect, Cochrane Library, ClinicalKey, Web of Science, and ClinicalTrials.gov databases were searched up to March 4, 2018.

STUDY SELECTION

A search was performed of clinical trials assessing the anxiolytic effect of omega-3 PUFAs in humans, in either placebo-controlled or non-placebo-controlled designs. Of 104 selected articles, 19 entered the final data extraction stage.

DATA EXTRACTION AND MEASURES

Two authors independently extracted the data according to a predetermined list of interests. A random-effects model meta-analysis was performed and this study was conducted based on Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines.

MAIN OUTCOMES AND MEASURES

Changes in the severity of anxiety symptoms after omega-3 PUFA treatment.

RESULTS

In total, 1203 participants with omega-3 PUFA treatment (mean age, 43.7 years; mean female proportion, 55.0%; mean omega-3 PUFA dosage, 1605.7 mg/d) and 1037 participants without omega-3 PUFA treatment (mean age, 40.6 years; mean female proportion, 55.0%) showed an association between clinical anxiety symptoms among participants with omega-3 PUFA treatment compared with control arms (Hedges g, 0.374; 95% CI, 0.081-0.666; P = .01). Subgroup analysis showed that the association of treatment with reduced anxiety symptoms was significantly greater in subgroups with specific clinical diagnoses than in subgroups without clinical conditions. The anxiolytic effect of omega-3 PUFAs was significantly better than that of controls only in subgroups with a higher dosage (at least 2000 mg/d) and not in subgroups with a lower dosage (<2000 mg/d).

CONCLUSIONS AND RELEVANCE

This review indicates that omega-3 PUFAs might help to reduce the symptoms of clinical anxiety. Further well-designed studies are needed in populations in whom anxiety is the main symptom.

Dietary fatty acids augment tissue levels of n-acylethanolamines in n-acylphosphatidylethanolamine phospholipase D (NAPE-PLD) knockout mice

N-acylethanolamines (NAEs) are lipid signaling mediators, which can be synthesized from dietary fatty acids via n-acylphosphatidylethanolamine-phospholipase D (NAPE-PLD) and in turn influence physiological outcomes; however, the roles of NAPE-PLD upon dietary fatty acid modulation are not fully understood. Presently, we examine if NAPE-PLD is necessary to increase NAEs in response to dietary fatty acid manipulation. Post-weaning male wild-type (C57Bl/6), NAPE-PLD (-/+) and NAPE-PLD (-/-) mice received isocaloric fat diets containing either beef tallow, corn oil, canola oil or fish oil (10% wt/wt from fat) for 9 weeks. Brain docosahexaenoic acid (DHA) levels were higher (P<.01) in NAPE-PLD (-/+) (10.01±0.31 μmol/g) and NAPE-PLD (-/-) (10.89±0.61 μmol/g) than wild-type (7.72±0.61 μmol/g) consuming fish oil. In NAPE-PLD (-/-) mice, brain docosahexaenoylethanolamide (DHEA) levels were higher (P<.01) after fish oil feeding suggesting that NAPE-PLD was not necessary for DHEA synthesis. Liver and jejunum arachidonoylethanolamide, 1,2-arachidonoylglycerol and DHEA levels reflected their corresponding fatty acid precursors suggesting that alternate pathways are involved in NAE synthesis. NAPE-PLD (-/-) mice had lower oleoylethanolamide levels in the jejunum and a leaner phenotype compared to wild-type mice. Overall, these results demonstrate that dietary fatty acid can augment tissue NAEs in the absence of NAPE-PLD.

Association between the ratio of serum arachidonic acid to eicosapentaenoic acid and the presence of depressive symptoms in a general Japanese population: the Hisayama Study

BACKGROUND

Epidemiological evidence suggests that fish consumption and intake of n-3 polyunsaturated fatty acids (PUFA)-namely, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA)-confer protection against depression. However, few studies have addressed the influence of the balance between n-3 PUFA and n-6 PUFA in the human body on depression.

METHODS

A total of 2,529 community-dwelling Japanese residents aged ≥ 40 years were assessed for depressive symptoms (defined as a score of 16 points or more on the Center for Epidemiologic Studies Depression Scale [CES-D]) in 2007. The serum arachidonic acid (AA) /EPA ratio and AA/DHA ratio were measured in frozen samples collected in 2002 and categorized into quartiles. The odds ratios (ORs) for the presence of depressive symptoms were calculated using a logistic regression model.

RESULTS

The prevalence of depressive symptoms was 4.3%. There was no significant association between either the serum AA/EPA ratio or AA/DHA ratio and the presence of depressive symptoms. However, subjects with the highest serum AA/EPA ratios (range: 3.28-13.3) had a 4.10 times (95%CI: 1.13-19.80) greater OR for the presence of depressive symptoms than those with the lowest ratios (0.30-1.65) after adjusting for confounding factors in the subgroup with high-sensitivity C-reactive protein (hs-CRP) ≥ 1.0 mg/L, while no clear association was observed in the subgroup with hs-CRP < 1.0 mg/L.

LIMITATIONS

Reverse causality is possible due to the cross-sectional study design.

CONCLUSIONS

Our findings suggest that a higher serum AA/EPA ratio is associated with a greater likelihood of depressive symptoms in subjects with systemic inflammation in the general Japanese population.

Increased brain docosahexaenoic acid has no effect on the resolution of neuroinflammation following intracerebroventricular lipopolysaccharide injection

Resolution of inflammation in the periphery was once thought to be a passive process, but new research now suggests it is an active process mediated by specialized pro-resolving lipid mediators (SPM) derived from omega-3 polyunsaturated fatty acids (n-3 PUFA). However, this has yet to be illustrated in neuroinflammation. The purpose of this study was to measure resolution of neuroinflammation and to test whether increasing brain docosahexaenoic acid (DHA) affects the resolution of neuroinflammation. C57Bl/6 mice, fat-1 mice and their wildtype littermates, fed either fish oil or safflower oil, received lipopolysaccharide (LPS) in the left lateral ventricle. Animals were then euthanized at various time points for immunohistochemistry, gene expression, and lipidomic analyses. Peak microglial activation was observed at 5 days post-surgery and the resolution index was 10 days. Of the approximately 350 genes significantly changed over the 28 days post LPS injection, 130 were uniquely changed at 3 days post injection. No changes were observed in the bioactive mediator pools. However, a few lysophospholipid species were decreased at 24hr post surgery. When brain DHA is increased, microglial cell density did not resolve faster and did not alter gene expression. In conclusion, resolution of neuroinflammation appears to be independent of SPM. Increasing brain DHA had no effect in this model.

The role of n-3 polyunsaturated fatty acids (n-3PUFAs) in affective disorders

BACKGROUND

Among emerging treatments for depressive disorders several studies suggested that n-3 polyunsaturated fatty acids (n-3PUFAs) supplementation can be used. However, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) differ in terms of biochemistry, metabolism and therapeutic effects. Therefore, a clear picture of their specific and different role on affective disorders has not yet emerged.

OBJECTIVES

To investigate the effects of n-3PUFAs on affective disorders including major depression, bipolar disorder and perinatal depression.

METHODS

a comprehensive search on PUBMED, Medline and PsychINFO of all RCTs using n-3PUFAs patients with depressive symptoms published up to April 2016 was performed. We included trials that examined unipolar or bipolar disorder and trials that investigated depressive symptoms in relation to pregnancy. Trials were excluded if the depressive symptomatology was related to other primary organic diseases.

RESULTS

264 RCT studies were identified but only 36 met the inclusion criteria. First, it has been reported that n-3PUFAs supplementation might have clinical benefits on depressive symptoms. Second, EPA supplement, rather than DHA, seems to be more effective in treating major depression. Third, n-3PUFAs can have beneficial effects in bipolar depression but not in perinatal depression.

CONCLUSIONS

there are only some evidence on the efficacy of n-3PUFAs in affective disorders especially to unipolar and bipolar depression not powered enough to confirm a therapeutic effect for affective disorder. Therefore, further studies with larger and more homogeneous samples, are required to confirm these effects.

Preoperative Serum Metabolites Are Associated With Postoperative Delirium in Elderly Hip-Fracture Patients

Background

Hypotheses on the development of postoperative delirium (PD) include "neuroinflammatory," "neuronal aging," "oxidative stress," "neurotransmitter deficiency," and "neuroendocrine." Here, we employed metabolomics to determine the serum metabolites in the baseline associated with an increased risk of PD.

Methods

Two hundred and nine elderly hip-fracture patients who had undergone hemiarthroplasty and had completed our assessments were selected. Fasting venous blood was collected at 7:00 on the morning of surgery and a serum sample bank was created for analysis. On the first 3 postoperative days, the patients were assessed twice daily using the Confusion Assessment Method - Chinese Revision. Ultimately, 43 patients were diagnosed with PD, who comprised the PD group. Meanwhile, 43 matched non-PD patients were selected based on age, sex, and body mass index. Serum samples from the two groups were analyzed by gas chromatography-time-of-flight mass spectrometry and Acquity ultra-performance liquid chromatography-quadrupole time-of-flight mass spectrometry.

Results

The demographic characteristics of the groups were matched. Four metabolites associated with an increased risk of PD were identified, including S-methylcysteine, linolenic acid, eicosapentaenoic acid, and linoleic acid.

Conclusions

Multiple metabolic pathways in the PD group altered before surgery, including deficiency of ω3 and ω6 fatty acids, energy metabolism and oxidative stress with interactions between hypoxia and mitochondrial dysfunction, in addition to glutamate-glutamine cycle dysfunction. These metabolic abnormalities could possibly increase the fragility of the brain and then contribute to PD.

Regulation of inflammation by lipid mediators in oral diseases

Lipid mediators (LM) of inflammation are a class of compounds derived from ω-3 and ω-6 fatty acids that play a wide role in modulating inflammatory responses. Some LM possess pro-inflammatory properties, while others possess proresolving characteristics, and the class switch from pro-inflammatory to proresolving is crucial for tissue homeostasis. In this article, we review the major classes of LM, focusing on their biosynthesis and signaling pathways, and their role in systemic and, especially, oral health and disease. We discuss the detection of these LM in various body fluids, focusing on diagnostic and therapeutic applications. We also present data showing gender-related differences in salivary LM levels in healthy controls, leading to a hypothesis on the etiology of inflammatory diseases, particularly Sjögren's syndrome. We conclude by enumerating open areas of research where further investigation of LM is likely to result in therapeutic and diagnostic advances.

Omega-3 fatty acids related to cognitive impairment in patients with schizophrenia

Cognitive impairment is strongly associated with functional outcome in patients with schizophrenia but its pathophysiology remains largely unclear. Involvement of omega-3 fatty acids in the cognitive function of healthy individuals and patients with neuropsychiatric disease has received increasing attention. The aim of this study was to examine the relationship between omega-3 fatty acids with cognitive function, social function, and psychiatric symptoms in patients with schizophrenia. The subjects included 30 patients with schizophrenia or schizoaffective disorder. Psychiatric symptoms, cognitive function, and social function were assessed using the Positive and Negative Syndrome Scale, the Brief Assessment of Cognition in Schizophrenia (BACS), and the Social Functioning Scale (SFS), respectively. Blood serum omega-3 fatty acids were assessed using gas chromatography. The BACS composite score was significantly correlated with blood eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) levels. In addition, a daily dose of antipsychotic medication was negatively and significantly correlated with the blood DHA level and with the BACS composite score. Step-wise multiple regression analyses demonstrated that the SFS score was significantly associated with the BACS composite score. Our results indicate that reduced blood omega-3 fatty acids are associated with cognitive impairment, which then impacts social functioning outcomes in schizophrenia.

Cannabimimetic phytochemicals in the diet - an evolutionary link to food selection and metabolic stress adaptation?

The endocannabinoid system (ECS) is a major lipid signalling network that plays important pro-homeostatic (allostatic) roles not only in the nervous system but also in peripheral organs. There is increasing evidence that there is a dietary component in the modulation of the ECS. Cannabinoid receptors in hominids co-evolved with diet, and the ECS constitutes a feedback loop for food selection and energy metabolism. Here, it is postulated that the mismatch of ancient lipid genes of hunter-gatherers and pastoralists with the high-carbohydrate diet introduced by agriculture could be compensated for via dietary modulation of the ECS. In addition to the fatty acid precursors of endocannabinoids, the potential role of dietary cannabimimetic phytochemicals in agriculturist nutrition is discussed. Dietary secondary metabolites from vegetables and spices able to enhance the activity of cannabinoid-type 2 (CB₂ ) receptors may provide adaptive metabolic advantages and counteract inflammation. In contrast, chronic CB₁ receptor activation in hedonic obese individuals may enhance pathophysiological processes related to hyperlipidaemia, diabetes, hepatorenal inflammation and cardiometabolic risk. Food able to modulate the CB₁ /CB₂ receptor activation ratio may thus play a role in the nutrition transition of Western high-calorie diets. In this review, the interplay between diet and the ECS is highlighted from an evolutionary perspective. The emerging potential of cannabimimetic food as a nutraceutical strategy is critically discussed.

LINKED ARTICLES

This article is part of a themed section on Principles of Pharmacological Research of Nutraceuticals. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v174.11/issuetoc.

GPR40/FFAR1 deficient mice increase noradrenaline levels in the brain and exhibit abnormal behavior

The free fatty acid receptor 1 (GPR40/FFAR1) is a G protein-coupled receptor, which is activated by long chain fatty acids. We have previously demonstrated that activation of brain GPR40/FFAR1 exerts an antinociceptive effect that is mediated by the modulation of the descending pain control system. However, it is unclear whether brain GPR40/FFAR1 contributes to emotional function. In this study, we investigated the involvement of GPR40/FFAR1 in emotional behavior using GPR40/FFAR1 deficient (knockout, KO) mice. The emotional behavior in wild and KO male mice was evaluated at 9-10 weeks of age by the elevated plus-maze test, open field test, social interaction test, and sucrose preference test. Brain monoamines levels were measured using LC-MS/MS. The elevated plus-maze test and open field tests revealed that the KO mice reduced anxiety-like behavior. There were no differences in locomotor activity or social behavior between the wild and KO mice. In the sucrose preference test, the KO mice showed reduction in sucrose preference and intake. The level of noradrenaline was higher in the hippocampus, medulla oblongata, hypothalamus and midbrain of KO mice. Therefore, these results suggest that brain GPR40/FFAR1 is associated with anxiety- and depression-related behavior regulated by the increment of noradrenaline in the brain.

From Molecules to the Clinic: Linking Schizophrenia and Metabolic Syndrome through Sphingolipids Metabolism

Metabolic syndrome (MS) is a prevalent and severe comorbidity observed in schizophrenia (SZ). The exact nature of this association is controversial and very often accredited to the effects of psychotropic medications and disease-induced life-style modifications, such as inactive lifestyle, poor dietary choices, and smoking. However, drug therapy and disease-induced lifestyle factors are likely not the only factors contributing to the observed converging nature of these conditions, since an increased prevalence of MS is also observed in first episode and drug-naïve psychosis populations. MS and SZ share common intrinsic susceptibility factors and etiopathogenic mechanisms, which may change the way we approach clinical management of SZ patients. Among the most relevant common pathogenic pathways of SZ and MS are alterations in the sphingolipids (SLs) metabolism and SLs homeostasis. SLs have important structural functions as they participate in the formation of membrane “lipid rafts.” SLs also play physiological roles in cell differentiation, proliferation, and inflammatory processes, which might be part of MS/SZ common pathophysiological processes. In this article we review a plausible mechanism to explain the link between MS and SZ through a disruption in SL homeostasis. Additionally, we provide insights on how this hypothesis can lead to the developing of new diagnostic/therapeutic technologies for SZ patients.

Clinical studies of neuroinflammatory mechanisms in schizophrenia

Schizophrenia is a pervasive neurodevelopmental disorder that appears to result from genetic and environmental factors. Although the dopamine hypothesis is the driving theory behind the majority of translation research in schizophrenia, emerging evidence suggests that aberrant immune mechanisms in the peripheral and central nervous system influence the etiology of schizophrenia and the pathophysiology of psychotic symptoms that define the illness. The initial interest in inflammatory processes comes from epidemiological data and historical observations, dating back several decades. A growing body of research on developmental exposure to infection, stress-induced inflammatory response, glial cell signaling, structural and functional brain changes and therapeutic trials demonstrates the impact that inflammation has on the onset and progression of schizophrenia. Research in animal models of psychosis has helped to advance clinical and basic science investigations of the immune mechanisms disrupted in schizophrenia. However, they are limited by the inability to recapitulate the human experience of hallucinations, delusions and thought disorder that define psychosis. To date, translational studies of inflammatory mechanisms in human subjects have not been reviewed in great detail. Here, we critically review clinical studies that focus on inflammatory mechanisms in schizophrenia. Understanding the neuroinflammatory mechanisms involved in schizophrenia may be essential in identifying potential therapeutic targets to minimize the morbidity and mortality of schizophrenia by interrupting disease development.

Mechanisms of DHA transport to the brain and potential therapy to neurodegenerative diseases

Docosahexaenoic acid (DHA; 22:6 ω-3) is highly enriched in the brain and is required for proper brain development and function. Its deficiency has been shown to be linked with the emergence of neurological diseases. Dietary ω-3 fatty acid supplements including DHA have been suggested to improve neuronal development and enhance cognitive functions. However, mechanisms of DHA incorporation in the brain remain to be fully understood. Findings suggested that DHA is better incorporated when esterified within lysophospholipid rather than under its non-esterified form. Furthermore, DHA has the potential to be converted into diverse oxylipins with potential neuroprotective effects. Since DHA is poorly synthesized de novo, targeting the brain with specific carriers of DHA might provide novel therapeutic approaches to neurodegenerative diseases.

Altering the course of schizophrenia: progress and perspectives

Despite a lack of recent progress in the treatment of schizophrenia, our understanding of its genetic and environmental causes has considerably improved, and their relationship to aberrant patterns of neurodevelopment has become clearer. This raises the possibility that 'disease-modifying' strategies could alter the course to - and of - this debilitating disorder, rather than simply alleviating symptoms. A promising window for course-altering intervention is around the time of the first episode of psychosis, especially in young people at risk of transition to schizophrenia. Indeed, studies performed in both individuals at risk of developing schizophrenia and rodent models for schizophrenia suggest that pre-diagnostic pharmacotherapy and psychosocial or cognitive-behavioural interventions can delay or moderate the emergence of psychosis. Of particular interest are 'hybrid' strategies that both relieve presenting symptoms and reduce the risk of transition to schizophrenia or another psychiatric disorder. This Review aims to provide a broad-based consideration of the challenges and opportunities inherent in efforts to alter the course of schizophrenia.

Levels of Red Blood Cell Fatty Acids in Patients With Psychosis, Their Unaffected Siblings, and Healthy Controls

BACKGROUND

Two recent meta-analyses showed decreased red blood cell (RBC) polyunsaturated fatty acids (FA) in schizophrenia and related disorders. However, both these meta-analyses report considerable heterogeneity, probably related to differences in patient samples between studies. Here, we investigated whether variations in RBC FA are associated with psychosis, and thus may be an intermediate phenotype of the disorder.

METHODS

For the present study, a total of 215 patients (87% outpatients), 187 siblings, and 98 controls were investigated for multiple FA analyses. Based on previous studies, we investigated docosahexaenoic acid (DHA), docosapentaenoic acid (DPA), arachidonic acid (AA), linoleic acid (LA), nervonic acid (NA), and eicasopentaenoic acid (EPA). On an exploratory basis, a large number of additional FA were investigated. Multilevel mixed models were used to compare the FA between the 3 groups.

RESULTS

Compared to controls, both patients and siblings showed significantly increased DHA, DPA, AA, and NA. LA was significantly higher in siblings compared to controls. EPA was not significantly different between the 3 groups. Also the exploratory FA were increased in patients and siblings.

CONCLUSIONS

We found increased RBC FA DHA, DPA, AA, and NA in patients and siblings compared to controls. The direction of change is similar in both patients and siblings, which may suggest a shared environment and/or an intermediate phenotype. Differences between patient samples reflecting stage of disorder, dietary patterns, medication use, and drug abuse are possible modifiers of FA, contributing to the heterogeneity in findings concerning FA in schizophrenia patients.

Beneficial effects of dietary docosahexaenoic acid intervention on cognitive function and mental health of the oldest elderly in Japanese care facilities and nursing homes

AIM

We examined the effects of the administration of docosahexaenoic acid (DHA)-enriched meals on cognitive function in the oldest elderly with cognitive impairment, such as dementia, living in nursing homes, and on the improvement in caregiver burden at aging agencies.

METHODS

Participants in elderly care facilities and nursing homes (n = 75; 88.5 ± 0.6 years) were randomized in active and placebo groups. The active group had family-style meals containing an additional 1720 mg of docosahexaenoic acid per day for 12 months. At baseline, and after 6 and 12 months of intervention, cognitive function was assessed using Hasegawa's Dementia Scale-Revised and the Mini-Mental State Examination; mental health condition was assessed with the Apathy scale and the Zung Self-Rating Depression Scale; caregiver burden was evaluated using Zarit Burden Interview scores; and participants' serum biochemical factors were measured.

RESULTS

The participants were suggested to have dementia. After 12 months, the mean change in Mini-Mental State Examination subitem "Registration" score from baseline to month 12 showed a tendency to be greater in the active group than that in the placebo group. Mean changes in the Apathy scale from baseline to month 12 were less, and the changes in the Zung Self-Rating Depression Scale and the total Zarit Burden Interview scores showed a tendency to be lower in the active group than in the placebo group, respectively.

CONCLUSION

These results suggest that docosahexaenoic acid-enriched meals protect against age-related cognitive decline, and also improve apathy and caregiver burden for the oldest-elderly Japanese with cognitive impairment, such as dementia. Geriatr Gerontol Int 2017; 17: 330-337.

DHA Effects in Brain Development and Function

Docosahexaenoic acid (DHA) is a structural constituent of membranes specifically in the central nervous system. Its accumulation in the fetal brain takes place mainly during the last trimester of pregnancy and continues at very high rates up to the end of the second year of life. Since the endogenous formation of DHA seems to be relatively low, DHA intake may contribute to optimal conditions for brain development. We performed a narrative review on research on the associations between DHA levels and brain development and function throughout the lifespan. Data from cell and animal studies justify the indication of DHA in relation to brain function for neuronal cell growth and differentiation as well as in relation to neuronal signaling. Most data from human studies concern the contribution of DHA to optimal visual acuity development. Accumulating data indicate that DHA may have effects on the brain in infancy, and recent studies indicate that the effect of DHA may depend on gender and genotype of genes involved in the endogenous synthesis of DHA. While DHA levels may affect early development, potential effects are also increasingly recognized during childhood and adult life, suggesting a role of DHA in cognitive decline and in relation to major psychiatric disorders.

N-3 polyunsaturated fatty acids in animal models with neuroinflammation: An update

Neuroinflammation is a characteristic of a multitude of neurological and psychiatric disorders. Modulating inflammatory pathways offers a potential therapeutic target in these disorders. Omega-3 polyunsaturated fatty acids have anti-inflammatory and pro-resolving properties in the periphery, however, their effect on neuroinflammation is less studied. This review summarizes 61 animal studies that tested the effect of omega-3 polyunsaturated fatty acids on neuroinflammatory outcomes in vivo in various models including stroke, spinal cord injury, aging, Alzheimer's disease, Parkinson's disease, lipopolysaccharide and IL-1β injections, diabetes, neuropathic pain, traumatic brain injury, depression, surgically induced cognitive decline, whole body irradiation, amyotrophic lateral sclerosis, N-methyl-D-aspartate-induced excitotoxicity and lupus. The evidence presented in this review suggests anti-neuroinflammatory properties of omega-3 polyunsaturated fatty acids, however, it is not clear by which mechanism omega-3 polyunsaturated fatty acids exert their effect. Future research should aim to isolate the effect of omega-3 polyunsaturated fatty acids on neuroinflammatory signaling in vivo and elucidate the mechanisms underlying these effects.

Low-level mercury, omega-3 index and neurobehavioral outcomes in an adult US coastal population

BACKGROUND

Neurodevelopmental effects of omega-3 fatty acids and mercury from fish consumption have been characterized in children. In contrast, neurobehavioral outcomes associated with fish are not well studied in adults.

OBJECTIVE

This study of avid seafood consumers on Long Island (NY, USA) sought to define associations between mercury, seafood consumption, omega-3 fatty acids and neurobehavioral outcomes.

METHODS

A computer-based test system was used to assess neurobehavioral function. Blood total Hg (Hg) and omega-3 index were measured in 199 adult avid seafood eaters, who also completed the neurobehavioral assessment and an extensive food and fish frequency and demographic questionnaire.

RESULTS

For most of the outcomes considered, neither Hg nor omega-3 index was associated with neurobehavioral outcomes after adjustment for key confounding variables. Fish consumption, however, was associated with decreased odds of both self-reported fatigue (OR 0.85; 95 % CI 0.72, 1.01) and a constellation of neurologic symptoms (OR 0.79; 95 % CI 0.66, 0.96).

CONCLUSIONS

Results from our study provide little evidence that omega-3 fatty acids or Hg is associated with cognitive function in adult avid seafood consumers. Larger studies are needed to confirm our finding of associations between fish consumption and decreased self-reported fatigue and neurologic impairment.