Omega-3 polyunsaturated fatty acid supplementation and cognition: A systematic review and meta-analysis

Metabolic profiling reveals altered amino acid and fatty acid metabolism in children with Williams Syndrome

Williams Syndrome (WS) is a rare neurodevelopmental disorder with a prevalence of 1 in 7500 to 1 in 20,000 individuals, caused by a microdeletion in chromosome 7q11.23. Despite its distinctive clinical features, the underlying metabolic alterations remain largely unexplored. This study employs targeted metabolomics to investigate the metabolic characteristics of children with WS. Using liquid chromatography-tandem mass spectrometry (LC-MS/MS), we identified significant dysregulation of 15 metabolites, with 11 upregulated and 4 downregulated. Notably, amino acids such as alanine, proline, and arginine were significantly elevated. Fatty acid metabolism showed pronounced upregulation of long-chain saturated fatty acids (C18:0, C20:0, C22:0, C24:0, C26:0, and C28:0) and downregulation of long-chain unsaturated fatty acids (C18:2 LA, C22:6 DHA, C16:1 PLA, and t-C18:1 EA), except for upregulated nervonic acid (C24:1) and arachidonic acid (C20:4). Metabolic pathway analysis highlighted disruptions in arginine synthesis, arginine/proline metabolism, alanine, aspartate and glutamate metabolism, biosynthesis of unsaturated fatty acids, linoleic acid metabolism, and arachidonic acid metabolism. This study provides the first comprehensive analysis of amino acid and fatty acid metabolism in children with WS, offering insights into the disorder's complex metabolic landscape. Further validation in larger cohorts is essential to confirm these findings and their potential as biomarkers and therapeutic targets.

Interaction and association between multiple vitamins and social adaptability and severity of autism: A large-scale retrospective study from China

Since children with autism spectrum disorder (ASD) often exhibit selective eating behaviors, it is generally believed that they may have abnormal nutrient structure, leading to aberrant concentrations of some serum vitamins. However, previous studies on serum vitamins in individuals with ASD are mixed. Additionally, the interaction and association between multiple serum vitamin and ASD-related symptoms remain unclear. This study utilized a cross-sectional survey with a large sample size (n = 1235) from China to clarify previous mixed findings, and examine the interaction and association between multiple serum vitamins (including folic acid [FA], vitamin A [VA], vitamin E [VE], vitamin B12 [VB12], and vitamin D [VD]) and social adaptability and symptom severity in children with ASD. Findings found that symptom severity was negatively associated with concentrations of serum VA, VE, VB12, and VD; while, social adaptability was significantly associated with the natural log-transformed concentrations of FA and VB12. Finding also revealed the interaction of VA and VE on the association between both vitamins and severity of ASD symptoms, as well as the interaction of VB12 and FA on the association between both vitamins and social adaptability. In particular, the combination of low concentration of VA and high concentration of VE is associated with the lowest risk of being "severely autistic"; while, the combination of low concentration of FA and high concentration of VB12 is associated with the lowest risk of being "poor social adaptability". This study offers the evidence for the requirement of considering multiple vitamins comprehensively, as well as valuable references for revealing the association between vitamin disparities and food selectivity in children with ASD.

Implication of the endocannabidiome and metabolic pathways in fragile X syndrome pathophysiology

Fragile X Syndrome (FXS) results from the silencing of the FMR1 gene and is the most prevalent inherited cause of intellectual disability and the most frequent monogenic cause of autism spectrum disorder. It is well established that Fragile X individuals are subjected to a wide array of comorbidities, ranging from cognitive, behavioural, and medical origin. Furthermore, recent studies have also described metabolic impairments in FXS individuals. However, the molecular mechanisms linking FMRP deficiency to improper metabolism are still misunderstood. The endocannabinoidome (eCBome) is a lipid-based signalling system that regulates several functions across the body, ranging from cognition, behaviour and metabolism. Alterations in the eCBome have been described in FXS animal models and linked to neuronal hyperexcitability, a core deficit of the disease. However, the potential link between dysregulation of the eCBome and altered metabolism observed in FXS remains unexplored. As such, this review aims to overcome this issue by describing the most recent finding related to eCBome and metabolic dysfunctions in the context of FXS. A better comprehension of this association will help deepen our understanding of FXS pathophysiology and pave the way for future therapeutic interventions.

Combination Therapy for Sustainable Fish Oil Products: Improving Cognitive Function with n-3 PUFA and Natural Ingredients

Long-chain polyunsaturated omega-3 fatty acids (n-3 PUFAs), particularly docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), are recommended as beneficial dietary supplements for enhancing cognitive function. Although fish oil (FO) is renowned for its abundant n-3 PUFA content, combining FO with other natural products is considered as a viable option to support the sustainable development of FO products. This review aims to provide comprehensive insights into the advanced effects of combining FO or its components of DHA and EPA with natural products on protecting cognitive function. In two double-blind random control trials, no advanced effects were observed for adding curcumin to FO on cerebral function protection. However, 16 week's treatment of FO combined with vitamin E did not yield any advanced effects in cognitive factor scores. Several preclinical studies have demonstrated that combinations of FO with natural products can exhibit advanced effects in addressing pathological components in cognitive impairment, including neuroinflammation, oxidative stress, and neuronal survival. In conclusion, evidence from clinical trials for beneficial use of FO and natural ingredients combination is lacking. Greater cohesion is needed between preclinical and clinical data to substantiate the efficacy of FO and natural product combinations in preventing or slowing the progression of cognitive decline.

Nutraceuticals in Psychiatric Disorders: A Systematic Review

Correct nutrition and diet are directly correlated with mental health, functions of the immune system, and gut microbiota composition. Diets with a high content of some nutrients, such as fibers, phytochemicals, and short-chain fatty acids (omega-3 fatty acids), seem to have an anti-inflammatory and protective action on the nervous system. Among nutraceuticals, supplementation of probiotics and omega-3 fatty acids plays a role in improving symptoms of several mental disorders. In this review, we collect data on the efficacy of nutraceuticals in patients with schizophrenia, autism spectrum disorders, major depression, bipolar disorder, and personality disorders. This narrative review aims to provide an overview of recent evidence obtained on this topic, pointing out the direction for future research.

Omega-3 polyunsaturated fatty acids supplementation improves memory in first-diagnosed, drug-naïve patients with depression: Secondary analysis of data from a randomized controlled trial

INTRODUCTION

Cognitive impairments are found in most patients with major depressive disorder (MDD). It is believed that low Omega-3 polyunsaturated fatty acids (n-3 PUFAs) level raise the risk of anxiety, depressive symptoms and cognition dysfunction. Since our previous research has found n-3 PUFAs supplementation improves anxiety in MDD, this study was to further explore the effectiveness on cognitive impairment among depressed patients.

METHODS

A total of 72 venlafaxine treated outpatients with first-diagnosed, drug-naïve depression were enrolled. Daily n-3 PUFAs supplementation (2.4 g/d of fish oil, including 1440 mg eicosapentaenoic acid and 960 mg of docosahexaenoic acid) or placebo was used for 12 weeks. Cognitive function, measure by repeatable battery for the assessment of neuropsychological status ([RBANS]) scores, was compared over time.

RESULTS

Immediate memory, delayed memory and RBANS total scores were significant higher in both groups at week 4 and week 12 compared with baseline. Both groups exhibited improvement on attention scores at week 12. No significant differences were observed comparing n-3 PUFAs with placebo groups in the improvement of total RBANS scores and other subscales except in the change of immediate memory at both week 4 and week 12 (p < 0.05).

LIMITATIONS

Sample size was relatively low. Moreover, multiple ethnic populations and the income of patients should be considered. Lastly, we used raw scores instead of the standardized scores of RBANS.

CONCLUSION

N-3 PUFAs supplementation yielded a small but statistically significant improvement on immediate memory in first-diagnosed, drug-naïve depressed patients. While, antidepressant treatment resulted in significant improvement of cognitive function.

Integrative polygenic analysis of the protective effects of fatty acid metabolism on disease as modified by obesity

Dysregulation of fatty acid metabolites can play a crucial role in the progression of complex diseases, such as cardiovascular disease, digestive diseases, and metabolic diseases. Metabolites can have either protective or risk effects on a disease; however, the details of such associations remain contentious. In this study, we demonstrate an integrative PheWAS approach to establish high confidence, causally suggestive of metabolite-disease associations for three fatty acid metabolites, namely, omega-3 fatty acids, omega-6 fatty acids, and docosahexaenoic acid, for 1,254 disease endpoints. Metabolite-disease associations were established if there was a concordant direction of effect and significance for metabolite level and genetic risk score for the metabolite. There was enrichment for metabolite associations with diseases of the respiratory system for omega-3 fatty acids, diseases of the circulatory system and endocrine system for omega-6 fatty acids, and diseases of the digestive system for docosahexaenoic acid. Upon performing Mendelian randomization on a subset of the outcomes, we identified 3, 6, and 15 significant diseases associated with omega-3 fatty acids, omega-6 fatty acids, and docosahexaenoic acid, respectively. We then demonstrate a class of prevalence-risk relationships indicative of (de)canalization of disease under high and low fatty acid metabolite levels. Finally, we show that the interaction between the metabolites and obesity demonstrates that the degree of protection afforded by fatty acid metabolites is strongly modulated by underlying metabolic health. This study evaluated the disease architectures of three polyunsaturated fatty acids (PUFAs), which were validated by several PheWAS modes of support. Our results not only highlight specific diseases associated with each metabolite but also disease group enrichments. In addition, we demonstrate an integrative PheWAS methodology that can be applied to other components of the human metabolome or other traits of interest. The results of this study can be used as an atlas to cross-compare genetic with non-genetic disease associations for the three PUFAs investigated. The findings can be explored through our R shiny app at https://pufa.biosci.gatech.edu.

Plasma Phospholipid Polyunsaturated Fatty Acid Associations with Neurocognition

Neurocognitive deficits are implicated in major depressive disorder (MDD) and suicidal behavior, and cognitive function may be affected by blood levels of polyunsaturated fatty acids (PUFAs). Neuroprotective functions have been described for omega-3 (n-3) PUFAs, while omega-6 (n-6) PUFAs exhibit broadly opposing activities. Both classes of PUFAs are linked to MDD and suicidal behavior. However, few studies have investigated the relationships between PUFAs and neurocognitive function with respect to MDD or suicidal behavior. Among participants with MDD (n = 45) and healthy volunteers (HV, n = 30) we assessed performance on tasks of attentional capacity and executive function and its relationship to plasma phospholipid PUFA levels, expressed as a percentage of total plasma phospholipids, for eicosapentaenoic acid (EPA%), docosahexaenoic acid (DHA%), and arachidonic acid (AA%). Regression models tested the correlations between PUFA levels and task performance in three groups: MDD with a history of suicide attempt (SA, n = 20), MDD with no attempts (NA, n = 25), and HV. Interaction testing indicated a significant positive correlation of EPA% with continuous performance test scores in the NA group (F = 4.883, df = 2,72, p = 0.01), a measure of sustained attention. The AA% correlated negatively with performance on two executive function tasks, object alternation (beta = -3.97, z-score = -2.67, p = 0.008) and the Wisconsin card sort (beta = 0.80, t-score = -2.16, df = 69, p = 0.035), after adjustment for group and age, with no group effects. Our findings suggest a role for PUFA imbalance in attentional functioning and executive performance; however, no MDD-specific effect was observed.

Omega-3 Fatty Acids, Cognition, and Brain Volume in Older Adults

The elderly population is growing at increased rates and is expected to double in size by 2050 in the United States and worldwide. The consumption of healthy foods and enriched diets have been associated with improved cognition and brain health. The key nutrients common to many healthy foods and diets are the omega-3 polyunsaturated fatty acids (omega-3 FAs), such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). We explored whether omega-3 FA levels are associated with brain volume and cognition. Forty healthy, cognitively normal, Seventh-day Adventist older adults (mean age 76.3 years at MRI scan, 22 females) completed neurocognitive testing, a blood draw, and structural neuroimaging from 2016 to 2018. EPA and an overall omega-3 index were associated with individual measures of delayed recall (RAVLT-DR) and processing speed (Stroop Color) as well as entorhinal cortex thickness. EPA, DHA, and the omega-3 index were significantly correlated with the total white matter volume. The entorhinal cortex, frontal pole, and total white matter were associated with higher scores on delayed memory recall. This exploratory study found that among healthy, cognitively older adults, increased levels of omega-3 FAs are associated with better memory, processing speed, and structural brain measures.

Fat Intake and Fat Quality in Pregnant and Lactating Women, Infants, Children, and Adolescents and Related Health Outcomes: A Scoping Review of Systematic Reviews of Prospective Studies

INTRODUCTION

Dietary fat intake during pregnancy and childhood is important for health. However, several health aspects are inconclusive.

METHODS

We systematically searched Medline, Cochrane Library, and Epistemonikos for systematic reviews (SRs) of randomized controlled trials (RCTs) and/or prospective cohort studies published from January 01, 2015, to December 31, 2019, assessing the association of dietary fat intake (including dietary supplements) during pregnancy and across childhood with pregnancy, perinatal, and child health outcomes.

RESULTS

Thirty-one SRs, mainly of RCTs, were included. Omega-3 fatty acids supplementation during pregnancy reduced the risk of early preterm birth, and in some SRs also any preterm birth, increased gestation length and birth weight, but mostly was not associated with other pregnancy/perinatal outcomes. Pre- and postnatal polyunsaturated fatty acids (PUFAs) intake was not consistently associated with growth, neurological, visual and cognitive outcomes, allergic diseases, cardiovascular, and metabolic health in childhood. Reduced saturated fatty acids (SFAs) intake and its replacement with PUFA/monounsaturated fatty acids had favourable effects on blood pressure and blood lipids in children. No apparent effects of total or trans fat on health outcomes across target groups were observed.

CONCLUSION

Omega-3 PUFA supplementation during pregnancy and SFA intake reduction in childhood require further consideration in dietary recommendations targeting these populations.

Polyunsaturated fatty acids (PUFA) for attention deficit hyperactivity disorder (ADHD) in children and adolescents

BACKGROUND

Attention deficit hyperactivity disorder (ADHD) is a major problem in children and adolescents, characterised by age-inappropriate levels of inattention, hyperactivity, and impulsivity, and is associated with long-term social, academic, and mental health problems. The stimulant medications methylphenidate and amphetamine are the most frequently used treatments for ADHD, but these are not always effective and can be associated with side effects. Clinical and biochemical evidence suggests that deficiencies of polyunsaturated fatty acids (PUFA) could be related to ADHD. Research has shown that children and adolescents with ADHD have significantly lower plasma and blood concentrations of PUFA and, in particular, lower levels of omega-3 PUFA. These findings suggest that PUFA supplementation may reduce the attention and behaviour problems associated with ADHD. This review is an update of a previously published Cochrane Review. Overall, there was little evidence that PUFA supplementation improved symptoms of ADHD in children and adolescents.

OBJECTIVES

To compare the efficacy of PUFA to other forms of treatment or placebo in treating the symptoms of ADHD in children and adolescents.

SEARCH METHODS

We searched 13 databases and two trials registers up to October 2021. We also checked the reference lists of relevant studies and reviews for additional references.

SELECTION CRITERIA

We included randomised and quasi-randomised controlled trials that compared PUFA with placebo or PUFA plus alternative therapy (medication, behavioural therapy, or psychotherapy) with the same alternative therapy alone in children and adolescents (aged 18 years and under) diagnosed with ADHD.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methods. Our primary outcome was severity or improvement of ADHD symptoms. Our secondary outcomes were severity or incidence of behavioural problems; quality of life; severity or incidence of depressive symptoms; severity or incidence of anxiety symptoms; side effects; loss to follow-up; and cost. We used GRADE to assess the certainty of evidence for each outcome.

MAIN RESULTS

We included 37 trials with more than 2374 participants, of which 24 trials were new to this update. Five trials (seven reports) used a cross-over design, while the remaining 32 trials (52 reports) used a parallel design. Seven trials were conducted in Iran, four each in the USA and Israel, and two each in Australia, Canada, New Zealand, Sweden, and the UK. Single studies were conducted in Brazil, France, Germany, India, Italy, Japan, Mexico, the Netherlands, Singapore, Spain, Sri Lanka, and Taiwan. Of the 36 trials that compared a PUFA to placebo, 19 used an omega-3 PUFA, six used a combined omega-3/omega-6 supplement, and two used an omega-6 PUFA. The nine remaining trials were included in the comparison of PUFA to placebo, but also had the same co-intervention in the PUFA and placebo groups. Of these, four trials compared a combination of omega-3 PUFA plus methylphenidate to methylphenidate. One trial each compared omega-3 PUFA plus atomoxetine to atomoxetine; omega-3 PUFA plus physical training to physical training; and an omega-3 or omega-6 supplement plus methylphenidate to methylphenidate; and two trials compared omega-3 PUFA plus dietary supplement to dietary supplement. Supplements were given for a period of between two weeks and six months. Although we found low-certainty evidence that PUFA compared to placebo may improve ADHD symptoms in the medium term (risk ratio (RR) 1.95, 95% confidence interval (CI) 1.47 to 2.60; 3 studies, 191 participants), there was high-certainty evidence that PUFA had no effect on parent-rated total ADHD symptoms compared to placebo in the medium term (standardised mean difference (SMD) -0.08, 95% CI -0.24 to 0.07; 16 studies, 1166 participants). There was also high-certainty evidence that parent-rated inattention (medium-term: SMD -0.01, 95% CI -0.20 to 0.17; 12 studies, 960 participants) and hyperactivity/impulsivity (medium-term: SMD 0.09, 95% CI -0.04 to 0.23; 10 studies, 869 participants) scores were no different compared to placebo. There was moderate-certainty evidence that overall side effects likely did not differ between PUFA and placebo groups (RR 1.02, 95% CI 0.69 to 1.52; 8 studies, 591 participants). There was also moderate-certainty evidence that medium-term loss to follow-up was likely similar between groups (RR 1.03, 95% CI 0.77 to 1.37; 13 studies, 1121 participants).

AUTHORS' CONCLUSIONS

Although we found low-certainty evidence that children and adolescents receiving PUFA may be more likely to improve compared to those receiving placebo, there was high-certainty evidence that PUFA had no effect on total parent-rated ADHD symptoms. There was also high-certainty evidence that inattention and hyperactivity/impulsivity did not differ between PUFA and placebo groups. We found moderate-certainty evidence that overall side effects likely did not differ between PUFA and placebo groups. There was also moderate-certainty evidence that follow-up was similar between groups. It is important that future research addresses the current weaknesses in this area, which include small sample sizes, variability of selection criteria, variability of the type and dosage of supplementation, and short follow-up times.

New perspectives on randomized controlled trials with omega-3 fatty acid supplements and cognition: A scoping review

Long chain polyunsaturated omega-3 fatty acids (n-3 FA), such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), are known to be important components in a healthy diet and contribute to healthy functioning of the heart and the brain, among other organs. Although there are epidemiological studies on the strong relationship between fish or n-3 FA consumption and lower risk of cognitive decline, results from randomized controlled trials (RCTs) are less consistent. Here, we performed a scoping review on RCTs with n-3 FA supplementation where cognition was evaluated. Seventy-eight RCTs published before April 2022 were included in this review. Among these RCTs, 43.6% reported a positive cognitive outcome after the consumption of n-3 FA compared to the placebo. However, there was a large diversity of populations studied (age ranges and health status), wide range of doses of EPA + DHA supplemented (79 mg/day - 5200 mg/day) and a multitude of tests evaluating cognition, mainly diagnostic tests, that were used to assess cognitive scores and overall cognitive status. RCTs were thereafter categorized into non-cognitively impaired middle-aged adults (n = 24), non-cognitively impaired older adults (n = 24), adults with subjective memory complaints (n = 14), adults with mild cognitive impairments (MCI, n = 9) and people with diagnosed dementia or other cognitive changes (n = 7). Among these categories, 66.7% of RCTs conducted with MCI adults reported a positive cognitive outcome when supplemented with n-3 FA vs. the placebo. Therefore, this scoping review provides rationale and questions to a) strengthen the design of future RCTs with n-3 FA for cognitive outcomes, and b) generate more informative data to support clinicians in their practice in assessing cognition before and after a nutritional intervention.

Unsaturated Fatty Acids in Mental Disorders: An Umbrella Review of Meta-Analyses

Unsaturated fatty acids might be involved in the prevention of and improvement in mental disorders, but the evidence on these associations has not been comprehensively assessed. This umbrella review aimed to appraise the credibility of published evidence evaluating the associations between unsaturated fatty acids and mental disorders. In this umbrella review, systematic reviews and meta-analyses of studies comparing unsaturated fatty acids (including supplementation, dietary intake, and blood concentrations) in participants with mental disorders with healthy individuals were included. We reanalyzed summary estimates, between-study heterogeneity, predictive intervals, publication bias, small-study effects, and excess significance bias for each meta-analysis. Ninety-five meta-analyses from 29 systematic reviews were included, encompassing 43 studies on supplementation interventions, 32 studies on dietary factors, and 20 studies on blood biomarkers. Suggestive evidence was only observed for dietary intake, in which higher intake of fish was associated with reduced risk of depression (RR: 0.78; 95% CI: 0.69, 0.89) and Alzheimer disease (RR: 0.74; 95% CI: 0.63, 0.87), and higher intake of total PUFAs might be associated with a lower risk of mild cognitive impairment (RR: 0.71; 95% CI: 0.61, 0.84). Evidence showed that PUFA supplementation was favorable but had weak credibility in anxiety, depression, attention-deficit/hyperactivity disorder (ADHD), autism spectrum disorder (ASD), dementia, mild cognitive impairment, Huntington's disease, and schizophrenia (P-random effects <0.001-0.040). There was also weak evidence on the effect of decreased circulating n-3 (ɷ-3) PUFAs among patients on risk of ADHD, ASD, bipolar disorder, and schizophrenia (P-random effects <10-6-0.037). Our results suggest that higher levels of unsaturated fatty acids may relieve symptoms or reduce the risk of various mental disorders; however, the strength of the associations and credibility of the evidence were generally weak. Future high-quality research is needed to identify whether PUFA interventions should be prioritized to alleviate mental disorders.

Implication of saturated fats in the aetiology of childhood attention deficit/hyperactivity disorder - A narrative review

Attention Deficit/Hyperactivity Disorder (ADHD) is the most common mental health disorder in the paediatric population. ADHD is highly comorbid with obesity, and has also been associated with poor dietary patterns such as increased consumption of refined carbohydrates and saturated fats. Although ADHD in children was associated with high consumption of saturated fats, so far there has been no evidence-based attempt to integrate dietary strategies controlling for intake of saturated fats into the etiological framework of the disorder. Evidence from human studies and animal models has shown that diets high in saturated fats are detrimental for the development of dopaminergic neurocircuitries, synthesis of neurofactors (e.g. brain derived neurotrophic factor) and may promote brain inflammatory processes. Notably, animal models provide evidence that early life consumption of a high saturated fats diet may impair the development of central dopamine pathways. In the present paper, we review the impact of high saturated fats diets on neurobiological processes in human studies and animal models, and how these associations may be relevant to the neuropathophysiology of ADHD in children. The validation of this relationship and its underlying mechanisms through future investigative studies could have implications for the prevention or exacerbation of ADHD symptoms, improve the understanding of the pathogenesis of the disorder, and help design future dietary studies in patients with ADHD.

Effects of omega-3 polyunsaturated fatty acid supplementation on cognitive functioning in youth at ultra-high risk for psychosis: secondary analysis of the NEURAPRO randomised controlled trial

BACKGROUND

Cognitive impairments are well-established features of psychotic disorders and are present when individuals are at ultra-high risk for psychosis. However, few interventions target cognitive functioning in this population.

AIMS

To investigate whether omega-3 polyunsaturated fatty acid (n-3 PUFA) supplementation improves cognitive functioning among individuals at ultra-high risk for psychosis.

METHOD

Data (N = 225) from an international, multi-site, randomised controlled trial (NEURAPRO) were analysed. Participants were given omega-3 supplementation (eicosapentaenoic acid and docosahexaenoic acid) or placebo over 6 months. Cognitive functioning was assessed with the Brief Assessment of Cognition in Schizophrenia (BACS). Mixed two-way analyses of variance were computed to compare the change in cognitive performance between omega-3 supplementation and placebo over 6 months. An additional biomarker analysis explored whether change in erythrocyte n-3 PUFA levels predicted change in cognitive performance.

RESULTS

The placebo group showed a modest greater improvement over time than the omega-3 supplementation group for motor speed (η_p² = 0.09) and BACS composite score (η_p² = 0.21). After repeating the analyses without individuals who transitioned, motor speed was no longer significant (η_p² = 0.02), but the composite score remained significant (η_p² = 0.02). Change in erythrocyte n-3 PUFA levels did not predict change in cognitive performance over 6 months.

CONCLUSIONS

We found no evidence to support the use of omega-3 supplementation to improve cognitive functioning in ultra-high risk individuals. The biomarker analysis suggests that this finding is unlikely to be attributed to poor adherence or consumption of non-trial n-3 PUFAs.

Potential for non-starch polysaccharides in the prevention and remediation of cognitive impairment: A comprehensive review

Non-starch polysaccharides (NSPs) are food ingredients proven to be beneficial in a large number of health issues. However, there is no literature systematic review about the effects and corresponding mechanisms of NSPs on the prevention and remediation of cognitive impairment. In this review, studies on prevention and remediation of NSPs for cognitive deficit caused by diseases, menopause, ageing, chronic stress and environmental pollutants were summarized and the corresponding mechanisms were established. The anti-cognitive deficit effects of NSPs were associated with the modulation of amyloid β (Aβ) deposition, p-Tau aggregation, oxidative stress, inflammation, neuron apoptosis, neurogenesis, neurotransmitters, synaptic plasticity, autophagy and gut microbiota. Although the structure-function relationship has not been elucidated, several structural properties of NSPs such as molecular weight, sulfate content, hydroxyl group content, monosaccharide composition and molecular chain linkage might be crucial for the anti-cognitive deficit property. Notably, this review revealed that NSPs had a positive effect on cognitive impairment and proposed the future perspectives for further research on the anti-cognitive dysfunction effects of NSPs.

Long-chain Omega-3 fatty acids supplementation and cognitive performance throughout adulthood: A 6-month randomized controlled trial

OBJECTIVE

To investigate whether omega-3 polyunsaturated fatty acids (n-3 PUFA) supplementation improve cognitive performance and if apolipoprotein E (APOE) genotype or age were effect modifiers.

METHODS

Healthy adults of 20 to 80 years old (n = 193) were completed a 6-month double-blind randomized controlled trial with two groups: 2.5 g/day of n-3 PUFA or a placebo. Primary outcomes were visuospatial ability and working memory and secondary outcomes were episodic memory and executive function, measured at baseline and 6 months.

RESULTS

Cognitive performances did not significantly differ between groups on primary or secondary outcomes after 6 months of treatment. APOE carriers and age were not effect modifiers for any outcomes. Those with low episodic memory scores and taking the n-3 PUFA supplement, significantly improved their scores (p = 0.043).

CONCLUSIONS

A 6-month n-3 PUFA supplementation did not improve cognitive performance in cognitively healthy adults and APOE status or age were not effect modifiers.

Fatty Acids: An Insight into the Pathogenesis of Neurodegenerative Diseases and Therapeutic Potential

One of the most common lipids in the human body is palmitic acid (PA), a saturated fatty acid with essential functions in brain cells. PA is used by cells as an energy source, besides being a precursor of signaling molecules and protein tilting across the membrane. Although PA plays physiological functions in the brain, its excessive accumulation leads to detrimental effects on brain cells, causing lipotoxicity. This mechanism involves the activation of toll-like receptors (TLR) and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) pathways, with the consequent release of pro-inflammatory cytokines, increased production of reactive oxygen species (ROS), endoplasmic reticulum (ER) stress, and autophagy impairment. Importantly, some of the cellular changes induced by PA lead to an augmented susceptibility to the development of Alzheimer's and Parkinson´s diseases. Considering the complexity of the response to PA and the intrinsic differences of the brain, in this review, we provide an overview of the molecular and cellular effects of PA on different brain cells and their possible relationships with neurodegenerative diseases (NDs). Furthermore, we propose the use of other fatty acids, such as oleic acid or linoleic acid, as potential therapeutic approaches against NDs, as these fatty acids can counteract PA's negative effects on cells.

Fish oil supplementation may improve attention, working memory and attention-deficit/hyperactivity disorder symptoms in adults with autism spectrum disorder: a randomised crossover trial

Marine n-3 fatty acids (n-3LCPUFA) have shown neurocognitive benefits in children with attention-deficit/hyperactivity disorder (ADHD), but few trials have examined effects in adults with autism spectrum disorder (ASD). We explored, if n-3LCPUFA affect cognitive functions in adults with ASD, and if effects are modified by comorbid ADHD. In a 2 × 4 week crossover study, twenty-six participants were randomised to sequence of supplementation with fish oil (FO, 5·2 g/d n-3PUFA) and safflower oil (SO). At baseline and after each period, we measured primary outcomes: attention (d2-test) and spatial working memory (Corsi test) and secondary outcomes: flexibility (Stroop word-colour test), ADHD symptoms (Conners scales), executive functions (Behavioural Inventory of Executive Function) and social behaviour (Social Responsiveness Scale). The dropout rate was 15 %. Compliance was 94 % and correlated with whole-blood n-3LCPUFA. Corsi scores improved by ∼0·3 × sd (P = 0·032) after FO v. SO, and the odds for d2 errors were 30 % lower (P = 0·016), which was supported by improved Conners scores of attention (P = 0·023). Improvement in Conners ADHD symptom score was limited to participants with ADHD (-3·5(-6·0; -1·0), n 10 v. -0·2(-2·5;2·2), n 11 without ADHD, Pinteraction = 0·096), who also improved their behavioural regulation index by 0·3 × sd after FO (Pinteraction = 0·016). Participants without ADHD gained most in d2 test performance (OR = 0·4(0·2;0·7) v. 0·9(0·6;1·3) in those with ADHD, Pinteraction = 0·002), but their executive function score was exacerbated after FO (5·9(0·0,11·8), Pinteraction = 0·039). Our results did not show any effects on ASD symptoms, but suggest that FO may improve attention and working memory in adults with ASD and ameliorate ADHD symptoms in those with comorbid ADHD.

Efficacy of Omega-3 and Korean Red Ginseng in Children with Subthreshold ADHD: A Double-Blind, Randomized, Placebo-Controlled Trial

OBJECTIVE

The purpose of the present study was to investigate the efficacy of combined omega-3 and Korean red ginseng supplementation on ADHD symptoms and cognitive function in children with subthreshold ADHD.

METHOD

120 children from 6 to 12 years with subthreshold ADHD were enrolled in this 12-week, double-blind, randomized, placebocontrolled study. The primary outcome was measured by Attention-Deficit Hyperactivity Disorder Rating Scale (ADHD-RS). Children Behavior Check List (CBCL), and neuropsychological tests assessing attention, memory, and executive function were included as secondary primary outcome measures.

RESULTS

Significant effects on the scores of ADHDRS, as well as several subscales of CBCL including ADHD and attention problem subscales were revealed.

CONCLUSION

The combination of omega-3 and Korean red ginseng may have beneficial effects in children with subthreshold ADHD. Increased clinical awareness of ADHD symptoms even at a subthreshold level is needed.

Regulation of blood-brain barrier integrity by microbiome-associated methylamines and cognition by trimethylamine N-oxide

BACKGROUND

Communication between the gut microbiota and the brain is primarily mediated via soluble microbe-derived metabolites, but the details of this pathway remain poorly defined. Methylamines produced by microbial metabolism of dietary choline and L-carnitine have received attention due to their proposed association with vascular disease, but their effects upon the cerebrovascular circulation have hitherto not been studied.

RESULTS

Here, we use an integrated in vitro/in vivo approach to show that physiologically relevant concentrations of the dietary methylamine trimethylamine N-oxide (TMAO) enhanced blood-brain barrier (BBB) integrity and protected it from inflammatory insult, acting through the tight junction regulator annexin A1. In contrast, the TMAO precursor trimethylamine (TMA) impaired BBB function and disrupted tight junction integrity. Moreover, we show that long-term exposure to TMAO protects murine cognitive function from inflammatory challenge, acting to limit astrocyte and microglial reactivity in a brain region-specific manner.

CONCLUSION

Our findings demonstrate the mechanisms through which microbiome-associated methylamines directly interact with the mammalian BBB, with consequences for cerebrovascular and cognitive function. Video abstract.

Effect of Omega-3 Supplementation on Self-Regulation in Typically Developing Preschool-Aged Children: Results of the Omega Kid Pilot Study-A Randomised, Double-Blind, Placebo-Controlled Trial

Supplementation of omega-3 long chain polyunsaturated fatty acids (n-3 LCPUFA) may enhance self-regulation (SR) and executive functioning (EF) in children of preschool age. The aim of the Omega Kid Study was to investigate the effect of n-3 LCPUFA supplementation on SR and EF in typically developing preschool-aged children. A double-blind placebo-controlled pilot trial was undertaken, the intervention was 12 weeks and consisted of 1.6 g of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) per day compared to placebo. The HS-Omega-3 Index^® was assessed by capillary blood samples at baseline and post-intervention. Seventy-eight children were enrolled and randomised to either the n-3 LCPUFA treatment (n = 39) or placebo (n = 39) group. Post intervention, there was a significant three-fold increase in the HS-Omega-3 Index^® in the n-3 LCPUFA group (p < 0.001). There were no improvements in SR or EF outcome variables for the n-3 LCPUFA group post intervention compared to the placebo group determined by linear mixed models. At baseline, there were significant modest positive Spearman correlations found between the HS-Omega-3 index^® and both behavioural self-regulation and cognitive self-regulation (r = 0.287, p = 0.015 and r = 0.242, p = 0.015 respectively). Although no treatment effects were found in typically developing children, further research is required to target children with sub-optimal self-regulation who may benefit most from n-3 LCPUFA supplementation.

Personalised medicine in child and Adolescent Psychiatry: Focus on omega-3 polyunsaturated fatty acids and ADHD

Attention deficit hyperactivity disorder, or ADHD, is a common childhood disorder with a prevalence rate of 5–10%. There have been many theories proposed to explain ADHD, and one of them focuses on the deficiency of essential fatty acids (EFA), particularly omega-3 polyunsaturated fatty acids (n-3 PUFAs) including docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA). Studies have shown that there is a positive correlation between EFA deficiency severity and ADHD symptoms, and a negative association between blood PUFAs levels and ADHD symptoms. Moreover, clinical studies have shown a promising effect of n-3 PUFAs in the treatment of both clinical and cognitive symptoms in children with ADHD. In addition, with the more relatively safe and tolerable properties of n-3 PUFAs when comparing with the standard pharmacotherapy, n-3 PUFAs may be a potential treatment option for children with ADHD. Of note, the association between n-3 PUFAs deficiency and ADHD has been suggested to involve several biological systems, including inflammation, dysregulation of the hypothalamus-pituitary-adrenal (HPA) axis and the autonomic nervous system (ANS), and an imbalanced gut-microbiota axis (GBA). Thus, the biomarkers from these biological systems may serve as possible treatment response predictors of n-3 PUFAs in children with ADHD.

•

Children with ADHD have lower levels of DHA, EPA and total n-3 PUFAs

•N-3 PUFAs improved clinical and cognitive symptoms in children with ADHD

•Inflammatory status and endogenous n-3 PUFAs levels may serve as treatment response predictors

•N-3 PUFAs may be a treatment option for a subgroup of children with ADHD

Supplementation with oil rich in eicosapentaenoic acid, but not in docosahexaenoic acid, improves global cognitive function in healthy, young adults: results from randomized controlled trials

BACKGROUND

Evidence regarding the effects of the omega-3 (ɷ-3) PUFAs (n-3 PUFAs) DHA and EPA on cognition is lacking.

OBJECTIVES

We investigated whether supplementation with oils rich in EPA or DHA improves cognition, prefrontal cortex (PFC) hemoglobin (Hb) oxygenation, and memory consolidation.

METHODS

Healthy adults (n = 310; age range: 25-49 y) completed a 26-wk randomized controlled trial in which they consumed either 900 mg DHA/d and 270 mg EPA/d (DHA-rich oil), 360 mg DHA/d and 900 mg EPA/d (EPA-rich oil), or 3000 mg/d refined olive oil (placebo). Cognitive performance and memory consolidation were assessed via computerized cognitive test battery. PFC Hb oxygenation was measured using near infrared spectroscopy (NIRS).

RESULTS

Both global accuracy and speed improved with EPA-rich oil compared with placebo and DHA-rich oil [EPA vs. placebo accuracy: estimated marginal mean (EMM) = 0.17 (95% CI: 0.09, 0.24) vs. EMM = 0.03 (95% CI = -0.04, 0.11); P = 0.044; EPA vs. placebo speed: EMM = -0.15 (95% CI: -0.22, -0.07) vs. EMM = 0.03 (95% CI: -0.05, 0.10); P = 0.003]. Accuracy of memory was improved with EPA compared with DHA [EMM = 0.66 (95% CI: 0.26, 1.06) vs. EMM = -0.08 (95% CI: -0.49, 0.33); P = 0.034]. Both EPA- and DHA-rich oils showed trends towards reduced PFC oxygenated Hb (oxy-Hb) compared with placebo [placebo: EMM = 27.36 µM (95% CI: 25.73, 28.98); DHA: EMM = 24.62 µM (95% CI: 22.75, 26.48); P = 0.060; EPA: EMM = 24.97 µM (95% CI: 23.35, 26.59); P = 0.082].

CONCLUSIONS

EPA supplementation improved global cognitive function and was superior to the oil enriched with DHA. Interpreted within a neural efficiency framework, reduced PFC oxygenated Hb suggests that n-3 PUFAs may be associated with increased efficiency.These trials were registered in the clinical trials registry (https://clinicaltrials.gov/) as NCT03158545, NCT03592251, NCT02763514.

Impact of omega-3 fatty acid DHA and EPA supplementation in pregnant or breast-feeding women on cognitive performance of children: systematic review and meta-analysis

INTRODUCTION

The omega-3 long-chain polyunsaturated fatty acids docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) are important for brain development and cognitive performance. Because they are semi-essential fatty acids, they must be obtained from food. However, the dietary reference intakes of DHA and EPA have not yet been established. In women, a low DHA and/or EPA serum level during pregnancy or breastfeeding might negatively affect their children. For this study, we conducted a systematic review and meta-analysis of randomized control trials on the association between the consumption of fish oil supplements in pregnant and/or breastfeeding women and the cognitive performance of their children.

METHODS

The PubMed, Embase, and Central literature databases were systematically searched. We included and extracted relevant studies in duplicate and assessed study quality. Cognitive outcomes were grouped according to published criteria and according to time elapsed after the intervention. We performed fixed-effects meta-analyses for each cognitive outcome and for birth weight. We assessed potential confounding with meta-regressions and sensitivity analyses.

RESULTS

A total of 11 trials were included. No significant association was found between DHA/EPA supplementation and any of the assessed cognitive parameters or birth weight.

DISCUSSION

Our results confirm previous reviews on the studied topic. Reasons for inconclusive results may be small sample sizes for each assessed category, questionable quality of included studies, and the difficulty of reliably measuring cognitive performance in small children. Blood levels of omega-3 long-chain polyunsaturated fatty acids were mostly not comparable. Furthermore, the influence of genetic and environmental factors could not be assessed. Studies in this field should address such shortcomings.

Olive oil and oleic acid-based self nano-emulsifying formulation of omega-3-fatty acids with improved strength, stability, and therapeutics

AIM

To develop, characterise, and optimise SNEDDS formulation to enhance organoleptics, bioavailability, physical & oxidative-stability, and extend shelf-life of pure Ω-3-fatty acids oil for use in the food fortification industry as nutraceuticals.

METHODS

SNEDDS formulations were prepared using a simple stirring technique and optimised based on in-vitro characterisation.

RESULTS

The optimised SNEDDS formulation (F3) had a mean diameter of 52.9 ± 0.4 nm, PDI of 0.229 ± 0.02, zeta potential of -17.3 ± 0.1 mV, cloud temperature of 92 ± 0.2 °C, self-emulsification time of 50 ± 0.2 sec, and stable under accelerated stability conditions. Intestinal permeability study on rat ileum depicted absorption of 88.5 ± 0.2% DHA at 5 h for F3 formulation in comparison to 61.5 ± 0.2% for commercial counterpart. F3 formulation exhibited better therapeutics for melamine-induced cognitive dysfunction.

CONCLUSIONS

The developed Ω-3-loaded SNEDDS heralds the future for an efficacious, safer, and higher strength formulation intended as a better substitute for currently available formulations.

Diet, Physical Activity, and Disinhibition in Middle-Aged and Older Adults: A UK Biobank Study

Disinhibition is a prominent feature of multiple psychiatric disorders, and has been associated with poor long-term somatic outcomes. Modifiable lifestyle factors including diet and moderate-to-vigorous physical activity (MVPA) may be associated with disinhibition, but their contributions have not previously been quantified among middle-aged/older adults. Here, among N = 157,354 UK Biobank participants aged 40-69, we extracted a single disinhibition principal component and four dietary components (prudent diet, elimination of wheat/dairy/eggs, meat consumption, full-cream dairy consumption). In addition, latent profile analysis assigned participants to one of five empirical dietary groups: prudent-moderate, unhealthy, restricted, meat-avoiding, low-fat dairy. Disinhibition was regressed on the four dietary components, the dietary grouping variable, and self-reported MVPA. In men and women, disinhibition was negatively associated with prudent diet, and positively associated with wheat/dairy/eggs elimination. In men, disinhibition was also associated with consumption of meat and full-cream dairy products. Comparing groups, disinhibition was lower in the prudent-moderate diet (reference) group compared to all other groups. Absolute βs ranged from 0.02-0.13, indicating very weak effects. Disinhibition was not associated with MVPA. In conclusion, disinhibition is associated with multiple features of diet among middle-aged/older adults. Our findings foster specific hypotheses (e.g., early malnutrition, elevated immune-response) to be tested in alternative study designs.

Pharmacy Students' Perception of an Elective Course on Evidence-based Learning Strategies

Objective. To examine pharmacy students' perceptions of an elective course on evidence-based learning strategies.Methods. Pre- and post-course survey questionnaires were administered to students who enrolled in an elective course, to determine the learning strategies they used prior to course attendance, track their use of evidence-based learning strategies and observance of healthy lifestyle habits, and assess their perception of the course. A written assignment was given that required students to reflect on the learning outcomes that resulted from their application of evidence-based learning strategies. Mean scores on the pre- and post-course survey were analyzed using a general linear model repeated measures test.Results. The 59 students in this study predominantly used less-effective strategies (eg, re-reading and re-writing of notes) prior to taking the course. They reported increased use of evidence-based learning strategies, particularly retrieval practice and elaboration, and practice of healthy lifestyle habits (ie, enough sleep, exercise, good nutrition) after course completion. Students believed that using the above learning strategies improved their learning and memory and performance on graded assessments, among other benefits. Students had a positive perception of the course.Conclusion. The elective course was associated with increased use of effective learning strategies, adoption of healthy lifestyle practices that aid learning, and increased appreciation for evidence-based learning strategies by the students. Future studies are needed to examine actual learning outcomes and barriers to implementation of evidence-based learning techniques.

Nutritional Neuroscience as Mainstream of Psychiatry: The Evidence- Based Treatment Guidelines for Using Omega-3 Fatty Acids as a New Treatment for Psychiatric Disorders in Children and Adolescents

Omega-3 polyunsaturated fatty acids (or omega-3 PUFAs, n-3 PUFAs) are essential nutrients throughout the life span. Recent studies have shown the importance of n-3 PUFAs supplementation during prenatal and perinatal period as a potential protective factor of neurodevelopmental disorders. N-3 PUFAs have been reported to be lower in youth with attention deficit hyperactivity disorder (ADHD), autism spectrum disorder (ASD) and major depressive disorder (MDD). N-3 PUFAs supplementation has shown potential effects in the improvement of clinical symptoms in youth with ADHD, ASD, and MDD, especially those with high inflammation or a low baseline n-3 index. Moreover, it has been suggested that n-3 PUFAs had positive effects on lethargy and hyperactivity symptoms in ASD. For clinical application, the following dosage and duration are recommended in youth according to available randomized controlled trials and systemic literature review: (1) ADHD: a combination of eicosapentaenoic acid (EPA) + docosahexaenoic acid (DHA) ≥ 750 mg/d, and a higher dose of EPA (1,200 mg/d) for those with inflammation or allergic diseases for duration of 16−24 weeks; (2) MDD: a combination of a EPA + DHA of 1,000−2,000 mg/d, with EPA:DHA ratio of 2 to 1, for 12−16 weeks; (3) ASD: a combination of EPA + DHA of 1,300−1,500 mg/d for 16−24 weeks as add-on therapy to target lethargy and hyperactivity symptoms. The current review also suggested that n-3 index and inflammation may be potential treatment response markers for youth, especially in ADHD and MDD, receiving n-3 PUFA.

Verbal Memory Performance in Depressed Children and Adolescents: Associations with EPA but Not DHA and Depression Severity

Omega-3 polyunsaturated fatty acids (n-3 PUFAs) have been described as positively associated with cognitive functioning. Current meta-analyses have identified eicosapentaenoic acid (EPA) as potentially more effective than docosahexaenoic acid (DHA). An especially vulnerable subgroup that might benefit from these beneficial effects are depressed youths. In this study, we examined associations between red blood cell (RBC) DHA and EPA levels and depression severity and verbal memory performance in a sample of 107 moderately (n = 63) and severely (n = 44) depressed youths. The findings showed that youths with high RBC EPA levels had steeper learning curves compared to those with moderate or low RBC EPA levels (Pillai's Trace = 0.195, p = 0.027, η_p² = 0.097). No associations between RBC DHA levels or depression severity and verbal memory performance were observed. Our results further confirm previous findings indicating a more important role of EPA compared to DHA in relation to cognitive functioning. Future research should further investigate the differential role of EPA and DHA concerning cognitive functioning in depressed youths. Evidence supporting beneficial supplementation effects could potentially establish a recommendation for a natural and easily accessible intervention for cognitive improvement or remission.

Psychosocial interventions for people with schizophrenia or psychosis on minimal or no antipsychotic medication: A systematic review

Antipsychotics are the first-line treatment for people with schizophrenia or psychosis. There is evidence that they can reduce the symptoms of psychosis and risk of relapse. However many people do not respond to these drugs, or experience adverse effects and stop taking them. In the UK, clinical guidelines have stressed the need for research into psychosocial interventions without antipsychotics. This systematic review examines the effects of psychosocial interventions for people with schizophrenia or psychosis who are on no/minimal antipsychotics. Databases were searched for empirical studies investigating a psychosocial intervention in people with a schizophrenia spectrum disorder who were not taking antipsychotics or had received an antipsychotic minimisation strategy. We identified nine interventions tested in 17 studies (N = 2250), including eight randomised controlled trials. Outcomes were generally equal to or in a small number of cases better than the control group (antipsychotics/treatment as usual) for Cognitive Behavioural Therapy (CBT), Need Adapted Treatment and Soteria. The remaining interventions provided some encouraging, but overall inconsistent findings and were Psychosocial Outpatient Treatment, Open Dialogue, Psychosocial Inpatient Treatment, Psychoanalysis/Psychodynamic Psychotherapy, Major Role Therapy, and Milieu Treatment. Study quality was generally low with little recent research. In conclusion, nine psychosocial interventions have been studied for patients on no/minimal antipsychotics. The majority of studies reported outcomes for the intervention which were the same as the control group, however, study quality was problematic. Given the adverse effects of antipsychotics and that many people do not want to take them, high quality trials of psychosocial treatments for people on minimal/no antipsychotics are needed.

Effect of Omega-3 Long Chain Polyunsaturated Fatty Acids (n-3 LCPUFA) Supplementation on Cognition in Children and Adolescents: A Systematic Literature Review with a Focus on n-3 LCPUFA Blood Values and Dose of DHA and EPA

Omega-3 long chain polyunsaturated fatty acids (n-3 LCPUFA) supplementation in the cardiovascular field is effective if a certain Omega-3 index (O3I) is achieved or the daily n-3 LCPUFA dose is high enough. Whether this applies to studies on cognition in children and adolescents is unclear. The aims of the current review were to investigate whether: (1) a certain O3I level and (2) a minimum daily n-3 LCPUFA dose are required to improve cognition in 4-25 year olds. Web of Science and PubMed were searched. Inclusion criteria: placebo controlled randomized controlled trial; participants 4-25 years; supplementation with docosahexaenoic acid (DHA) and/or eicosapentaenoic acid (EPA); assessing cognition; in English and ≥10 participants per treatment arm. Thirty-three studies were included, 21 in typically developing participants, 12 in those with a disorder. A positive effect on cognitive measures was more likely in studies with an increase in O3I to >6%. Half of the studies in typically developing children with daily supplementation dose ≥450 mg DHA + EPA showed improved cognition. For children with a disorder no cut-off value was found. In conclusion, daily supplementation of ≥450 mg DHA + EPA per day and an increase in the O3I to >6% makes it more likely to show efficacy on cognition in children and adolescents.

Combined effects of caloric restriction and fish oil attenuated anti-depressant and anxiolytic-like effects of fish oil: association with hippocampal BDNF concentrations

Omega-3-enriched fish oil (FO) and caloric restriction (CR) are nutritional therapeutic approaches that exert an important impact on brain function, behavior, memory, and neuroprotection. Here, we investigate the synergic effects of both therapeutic approaches combined (CR + FO) on behavior (memory, anxiety-like behavior, antidepressant-like behavior), as well as its association with hippocampal brain-derived neurotrophic factor (BDNF) concentrations. Adult male Wistar rats were divided into four dietary groups: Control group (C) - chow ad libitum; CR group - 30 % CR, considering C group food intake; FO group - FO-enriched chow ad libitum; and CR + FO group - FO-enriched 30 % CR chow. After 12 weeks of dietary treatment, behavioural analysis set was conducted, and hippocampal BDNF concentrations were measured. FO group presented anxiolytic-like and antidepressant-like behaviors as well as improved memory in the Morris' water maze. These effects were attenuated by the combined CR + FO treatment. FO group also presented higher BDNF concentrations. There was a positive association between the number of entries in the platform quadrant in the MWM and hippocampal BDNF concentrations (β = 0.39; R² = 0.15; p = 0.042) and an inverse association between forced swim immobility time and BDNF concentrations (β = -0.39; R² = 0.15; p = 0.041). Taken together, our data showed that the 12-week FO dietary treatment promoted anxiolytic-like and antidepressant-like behaviors as well as memory improvement, and these effects were associated with BDNF concentrations. Synergic effects of interventions attenuated FO-related behavioral responses and BDNF concentrations and probably reduced hippocampal neuroplasticity.

Effects of oily fish intake on cognitive and socioemotional function in healthy 8-9-year-old children: the FiSK Junior randomized trial

BACKGROUND

Long-chain n-3 PUFAs (n-3 LCPUFAs) accrete in the brain during childhood and affect brain development. Randomized trials in children show inconsistent effects of n-3 LCPUFAs on cognitive and socioemotional function, and few have investigated effects of fish per se.

OBJECTIVES

We aimed to investigate the effects of oily fish consumption on overall and domain-specific cognitive and socioemotional scores and explore sex differences.

METHODS

Healthy 8-9-y-old children (n = 199) were randomly allocated to receive ∼300 g/wk oily fish or poultry (control) for 12 ± 2 wk. At baseline and endpoint, we assessed attention, processing speed, executive functions, memory, emotions, and behavior with a large battery of tests and questionnaires and analyzed erythrocyte fatty acid composition.

RESULTS

One hundred and ninety-seven (99%) children completed the trial. Children in the fish group consumed 375 (25th-75th percentile: 325-426) g/wk oily fish resulting in 2.3 (95% CI: 1.9, 2.6) fatty acid percentage points higher erythrocyte n-3 LCPUFA than in the poultry group. The overall cognitive performance score tended to improve by 0.17 (95% CI: -0.01, 0.35) points in children who received fish compared with poultry, supported by n-3 LCPUFA dose dependency. This was driven mainly by fewer errors [-1.9 (95% CI: -3.4, -0.3)] in an attention task and improved cognitive flexibility measured as faster reaction time [-51 ms (95% CI: -94, -7 ms)] in a complex relative to a simple task ("mixing cost"). The fish intervention furthermore reduced parent-rated Strength and Difficulties Questionnaire total difficulties by -0.89 (95% CI: -1.60, -0.18) points mainly due to a -0.63 (95% CI: -1.11, -0.16) points reduction in internalizing problems that was reflected in tendency to a decrease in the overall socioemotional problems score of -0.13 (95% CI: -0.26, 0.01) points. The overall effects were similar in boys and girls.

CONCLUSIONS

Oily fish dose-dependently improved cognitive function, especially attention and cognitive flexibility, and reduced socioemotional problems. The results support the importance of n-3 LCPUFAs for optimal brain function and fish intake recommendations in children.The trial was registered at www.clinicaltrials.gov as NCT02809508.

Diurnal rhythm of plasma EPA and DHA in healthy adults

Knowledge of the diurnal variation in circulating omega-3 polyunsaturated fatty acids (n-3 PUFAs) may be an important consideration for the development of dosing protocols designed to optimise tissue delivery of these fatty acids. The objective of the current study was to examine the variation in plasma concentrations of eicosapentaenoic acid (EPA; 20:5n-3) and docosahexaenoic acid (DHA; 22:6n-3) over a 24-h period in healthy adults under eating and sleeping conditions generally approximate to a free-living environment. Twenty-one healthy participants aged 25-44 years took part in a single laboratory visit encompassing an overnight stay. EPA and DHA were measured in plasma samples collected every two hours from 22:00 until 22:00 the following day, with all meals being provided at conventional times. Cosinor analysis was used to estimate the diurnal variation in each fatty acid from pooled data across all participants. A significant diurnal variation in the pooled plasma concentrations of both fatty acids was detected. However, evidence of distinct rhythmicity was strongest for DHA. The timing of the peak concentration of DHA was 17:43 with a corresponding nadir at 05:43. In comparison, the observed acrophase for EPA was delayed by three hours, occurring at 20:41, with a nadir at 08:41. This is the first time that the diurnal variation in these important bioactive fatty acids has been described in a sample of healthy adults following a normal pattern of eating and sleeping. In the absence of any dietary intake of EPA and DHA, circulating levels of these fatty acids fall during the overnight period and reach their lowest point in the morning. Consumption of n-3 PUFAs at night time, which counteracts this pattern, may have functional significance.

Favorable effects of omega-3 polyunsaturated fatty acids in attentional control and conversion rate to psychosis in 22q11.2 deletion syndrome

Omega-3-polyunsaturated-fatty-acids were suggested against cognitive dysfunctions and conversion to psychosis. However, a recent multicenter trial found no effect in reducing conversion rates in individuals at risk of developing schizophrenia. Patients' genetic heterogeneity and the timing of treatment might influence omega-3 efficacy. Here, we addressed the impact of omega-3 early treatment in both mice and human subjects with a 22q11.2 genetic hemi-deletion (22q11DS), characterized by cognitive dysfunctions and high penetrance of schizophrenia. We first tested the behavioural and cognitive consequences of adolescent exposure to normal or omega-3-enriched diets in wild-type and 22q11DS (LgDel/+) mice. We then contrasted mouse data with those gathered from sixty-two patients with 22q11DS exposed to a normal diet or supplemented with omega-3 during pre-adolescence/adolescence. Adolescent omega-3 exposure had no effects in wild-type mice. However, this treatment ameliorated distractibility deficits revealed in LgDel/+ mice by the Five Choice Serial Reaction Time Task (5CSRTT). The omega-3 improvement in LgDel/+ mice was selective, as no other generalized cognitive and non-cognitive effects were evident. Similarly, omega-3-exposed 22q11DS patients showed long-lasting improvements on distractibility as revealed by the continuous performance test (CPT). Moreover, omega-3-exposed 22q11DS patients showed less risk of developing an Ultra High Risk status and lower conversion rate to psychosis. Our convergent mouse-human findings represent a first analysis on the effects of omega-3 early treatment in 22q11DS. The beneficial effects in attentional control and transition to psychosis could support the early use of omega-3 supplementation in the 22q11DS population.

Effects of soy isoflavones on cognitive function: a systematic review and meta-analysis of randomized controlled trials

CONTEXT

The results of preclinical and observational studies support the beneficial effect of soy isoflavones on cognition.

OBJECTIVE

This review aimed to evaluate the effects of soy isoflavones on cognition in adults.

DATA SOURCES

The PUBMED, EMBASE, Ovid Medline, Cochrane Library, and clinicaltrials.gov databases were searched.

STUDY SELECTION

Two researchers independently screened 1955 records, using the PICOS criteria: participants were adults; intervention was dietary sources with soy isoflavones or isolated soy isoflavones; comparator was any comparator; outcome was cognitive function; study type was randomized controlled trials (RCTs). A third researcher was consulted to resolve any discrepancies. Sixteen RCTs were included and their quality assessed.

DATA EXTRACTION

Information on study design, characteristics of participants, and outcomes was extracted. PRISMA guidelines were followed.

DATA ANALYSIS

A random-effects meta-analysis was used to pool estimates across studies. In the 16 RCTs (1386 participants, mean age = 60 y), soy isoflavones were found to improve overall cognitive function (standardized mean difference [SMD], 0.19; 95% confidence interval [CI], 0.07-0.32) and memory (SMD, 0.15; 95%CI, 0.03-0.26).

CONCLUSION

The results showed that soy isoflavones may improve cognitive function in adults.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration no. CRD42018082070.

High-dose eicosapentaenoic acid (EPA) improves attention and vigilance in children and adolescents with attention deficit hyperactivity disorder (ADHD) and low endogenous EPA levels

No studies have examined the relationship between endogenous polyunsaturated fatty acids (PUFAs) levels and treatment response to PUFAs. We conducted a 12-week, double-blind, placebo-controlled trial comparing the effects of high-dose eicosapentaenoic acid (EPA, 1.2 g) and placebo on cognitive function (continuous performance test) in n = 92 youth (age 6-18-years-old) with Attention Deficit Hyperactivity Disorder (ADHD). Blood erythrocytes PUFAs were measured before and after treatment, to examine the effects of baseline endogenous EPA levels on treatment response and the effects of EPA treatment on PUFAs levels. Secondary measures included other ADHD symptoms, emotional symptoms, and levels of plasma high-sensitivity c-reactive protein (hs-CRP) and brain-derived neurotrophic factor (BDNF). Overall, EPA group improved more than placebo group on focused attention (variability, Effect size (ES) = 0.38, p = 0.041); moreover, within youth with the lowest baseline endogenous EPA levels, EPA group improved more than placebo group in another measure of focused attention (hit reaction time, HRT, ES = 0.89, p = 0.015) and in vigilance (HRT interstimulus interval changes, HRTISIC, ES = 0.83, p = 0.036). Interestingly, EPA group improved less than placebo group in impulsivity (commission errors), both overall and in youth with the highest baseline EPA levels, who also showed less improvement in other ADHD and emotional symptoms. EPA increased blood erythrocytes EPA by 1.6-fold but not DHA levels, and did not affect hs-CRP and BDNF plasma levels. In conclusion, EPA treatment improves cognitive symptoms in ADHD youth, especially if they have a low baseline endogenous EPA level, while youth with high EPA levels may be negatively affected by this treatment.

Omega-3 polyunsaturated fatty acids status and cognitive function in young women

Background

Research indicates that low omega-3 polyunsaturated fatty acid (n-3 PUFA) may be associated with decreased cognitive function. This study examined the association between n-3 PUFA status and cognitive function in young Australian women.

Methods

This was a secondary outcome analysis of a cross-sectional study that recruited 300 healthy women (18–35 y) of normal weight (NW: BMI 18.5–24.9 kg/m²) or obese weight (OB: BMI ≥30.0 kg/m²). Participants completed a computer-based cognition testing battery (IntegNeuro™) evaluating the domains of impulsivity, attention, information processing, memory and executive function. The Omega-3 Index (O3I) was used to determine n-3 PUFA status (percentage of EPA (20:5n-3) plus DHA (22:6n3) in the red cell membrane) and the participants were divided into O3I tertile groups: T1 < 5.47%, T2 = 5.47–6.75%, T3 > 6.75%. Potential confounding factors of BMI, inflammatory status (C-reactive Protein), physical activity (total MET-min/wk), alpha1-acid glycoprotein, serum ferritin and hemoglobin, were assessed. Data reported as z-scores (mean ± SD), analyses via ANOVA and ANCOVA.

Results

Two hundred ninety-nine women (26.9 ± 5.4 y) completed the study (O3I data, n = 288). The ANOVA showed no overall group differences but a significant group × cognition domain interaction (p < 0.01). Post hoc tests showed that participants in the low O3I tertile group scored significantly lower on attention than the middle group (p = 0.01; ES = 0.45 [0.15–0.74]), while the difference with the high group was borderline significant (p = 0.052; ES = 0.38 [0.09–0.68]). After confounder adjustments, the low group had lower attention scores than both the middle (p = 0.01) and high (p = 0.048) groups. These findings were supported by univariate analyses which found significant group differences for the attention domain only (p = 0.004).

Conclusions

Cognitive function in the attention domain was lower in women with lower O3I, but still within normal range. This reduced but normal level of cognition potentially provides a lower baseline from which cognition would decline with age. Further investigation of individuals with low n-3 PUFA status is warranted.

The efficacy and safety of nutrient supplements in the treatment of mental disorders: a meta-review of meta-analyses of randomized controlled trials

The role of nutrition in mental health is becoming increasingly acknowledged. Along with dietary intake, nutrition can also be obtained from "nutrient supplements", such as polyunsaturated fatty acids (PUFAs), vitamins, minerals, antioxidants, amino acids and pre/probiotic supplements. Recently, a large number of meta-analyses have emerged examining nutrient supplements in the treatment of mental disorders. To produce a meta-review of this top-tier evidence, we identified, synthesized and appraised all meta-analyses of randomized controlled trials (RCTs) reporting on the efficacy and safety of nutrient supplements in common and severe mental disorders. Our systematic search identified 33 meta-analyses of placebo-controlled RCTs, with primary analyses including outcome data from 10,951 individuals. The strongest evidence was found for PUFAs (particularly as eicosapentaenoic acid) as an adjunctive treatment for depression. More nascent evidence suggested that PUFAs may also be beneficial for attention-deficit/hyperactivity disorder, whereas there was no evidence for schizophrenia. Folate-based supplements were widely researched as adjunctive treatments for depression and schizophrenia, with positive effects from RCTs of high-dose methylfolate in major depressive disorder. There was emergent evidence for N-acetylcysteine as a useful adjunctive treatment in mood disorders and schizophrenia. All nutrient supplements had good safety profiles, with no evidence of serious adverse effects or contraindications with psychiatric medications. In conclusion, clinicians should be informed of the nutrient supplements with established efficacy for certain conditions (such as eicosapentaenoic acid in depression), but also made aware of those currently lacking evidentiary support. Future research should aim to determine which individuals may benefit most from evidence-based supplements, to further elucidate the underlying mechanisms.

Effect of omega-3 fatty acids on cognition: an updated systematic review of randomized clinical trials

Context

The increasing number of studies on the effects of n-3 long-chain polyunsaturated fatty acids (LC-PUFAs) on health, particularly cognition, in the last 5 years reflects the growing interest in this area of research.

Objective

The aim for this systematic review was to evaluate the scientific evidence published in the last 5 years (2012-2017) on the effects of n-3 LC-PUFA intake on cognition, cognitive development, and cognitive decline to determine whether n-3 LC-PUFAs support cognitive development and prevent cognitive decline.

Data Sources

The PubMed database was searched.

Study Selection

The 51 articles included in this systematic review reported on healthy individuals with mild or moderate cognitive impairment and patients with Alzheimer's disease. Risk of bias was assessed using Cochrane methodology.

Data Extraction

The number of study participants, the type of study, the type and dose of n-3 LC-PUFAs, and the key results are reported here.

Results

Current evidence indicates that n-3 LC-PUFAs administered during pregnancy or breastfeeding have no effect on the skills or cognitive development of children in later stages of development. Evidence regarding the improvement of cognitive function during childhood and youth or in attention deficit/hyperactivity disorder is inconclusive. Moreover, it is still unclear if n-3 LC-PUFAs can improve cognitive development or prevent cognitive decline in young or older adults.

Trim the fat: the role of omega-3 fatty acids in psychopharmacology

The American Psychiatric Association (APA) currently recommends the use of omega-3 fatty acid supplementation for depressive disorders, impulse-control disorders, and psychotic disorders in treatment guidelines. This review examines the evidence for efficacy of omega-3 fatty acids in depressive disorders, bipolar disorder, anxiety disorders, post-traumatic stress disorder (PTSD), and psychosis. Meta-analysis of randomized-controlled trials of omega-3 fatty acids for depression are inconclusive, with strong evidence of publication bias, sizable heterogeneity between included studies, and substantial methodological shortcomings in included trials. The large amount of heterogeneity in findings of RCTs of omega-3 fatty acids for unipolar depression is likely attributable to highly heterogeneous sample populations that are given different omega-3 supplements [which differ widely in eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) content, ratio, and dosage] as either adjunctive or monotherapy of other existing treatments, and then measure several different outcomes of depression symptomatology with likely incomplete blinding. Evidence of efficacy of omega-3 supplementation in treating psychosis, PTSD, anxiety, and bipolar mania is minimal. The current guidelines recommending the use of omega-3 fatty acids in adulthood psychiatric conditions should be revisited, especially given several recent negative studies examining the effects of omega-3 fatty acids for cardiovascular disease. Recommending likely ineffective treatment to patients, no matter how benign the side-effect profile, has opportunity cost (e.g. other more effective medications or therapies not being utilized) and likely affects patient compliance with other evidence-based treatments.

Associations and effects of omega-3 polyunsaturated fatty acids on cognitive function and mood in healthy adults: a protocol for a systematic review of observational and interventional studies

INTRODUCTION

The association between long-chain omega-3 polyunsaturated fatty acids (PUFAs), brain health, cognitive function and mood has been the subject of intensive research. Marine-derived omega-3 PUFAs, such as docosahexaenoic acid and eicosapentaenoic acid, are highly concentrated in neuronal membranes and affect brain function. Many studies have found that consumption of omega-3 PUFAs is associated with lower risk of cognitive or mood dysfunction. However, other studies have demonstrated no beneficial effects. There appears to be inconsistent findings from both epidemiological and randomised controlled trial (RCT) studies. The aim of this review is to compile the previous literature and establish the efficacy of omega-3 PUFAs in enhancing cognitive performance and mood in healthy adults.

METHODS AND ANALYSIS

Prospective cohort studies, RCTs, controlled clinical trials, controlled before and after studies, interrupted time series with a minimum of 3 months duration will be eligible for inclusion. Studies on healthy adults over the age of 18, where the intervention/exposure of interest is omega-3 PUFAs will be included. The outcomes of interest are cognition and mood. Studies will be eligible for inclusion if they measure changes in cognitive function or mood, or the risk of developing cognitive or mood disorders using validated tools and assessments. Relevant search terms and keywords will be used to generate a systematic search in Cochrane Library, MEDLINE, EMBASE, PsycINFO, Cumulative Index to Nursing and Allied Health Literature, Web of Science, Scopus and the grey literature. Two independent reviewers will screen studies for eligibility. Risk of bias in cohort and non-randomised studies will be assessed using the ROBINS-I tool. The Cochrane Collaboration's tool for assessing risk of bias in randomised trials will be used for RCTs. If there are sufficient data, a meta-analysis will be conducted.

ETHICS AND DISSEMINATION

This systematic review does not involve primary data collection and therefore formal ethical approval is not required. Results will be disseminated through peer reviewed publications, conference presentations and the popular press.

PROSPERO REGISTRATION NUMBER

CRD42018080800.

Dietary intake and cognitive function: evidence from the Bogalusa Heart Study

BACKGROUND

Dementia and late-life cognitive decline are leading causes of death and disability in the United States. Prevention of these diseases, by maintaining brain health throughout the life course, is essential. Diet and lifestyle changes are the chief strategies aimed at primary prevention for many of the risk factors of cognitive decline.

OBJECTIVE

The aim of this study was to examine the potential impact of dietary factors on cognitive function.

METHODS

This prospective cohort study followed 516 young adults through midlife. The Youth/Adolescent Questionnaire was used to collect habitual nutrition data (mean age: 32.03 ± 5.96 y) at baseline. Scores from a neurocognitive battery were used to assess cognitive function (mean age: 49.03 ± 4.86 y) at follow-up and were transformed to z scores. Separate multivariable-adjusted linear regression models were fitted. The trend across quintiles for each dietary variable was assessed.

RESULTS

Vitamin B-6, whole grains, processed meats, and foods fried at home all displayed significant linear trends in their relation with cognitive function. Dietary intake of vitamin B-6 and whole grains was directly associated with better cognitive function after adjustment for age, race, sex, and total calorie intake (β coefficient from linear regression and SE: 1.755 ± 0.621, P = 0.005, and 0.001 ± 0.000, P = 0.018, respectively). Processed meat and foods fried at home consistently displayed inverse associations with cognitive function across crude and adjusted models (linear trend P values were 0.05 and <0.0001, respectively).

CONCLUSIONS

Our findings suggest that dietary consumption in young adulthood may affect cognitive function in midlife. Strong associations between dietary intake and cognition were observed in our analysis, but as with all observational studies, the possibility of residual confounding cannot be excluded.

Omega-3 Long-Chain Polyunsaturated Fatty Acids Intake in Children with Attention Deficit and Hyperactivity Disorder

Omega-3 long-chain polyunsaturated fatty acids (LC-PUFA) play a central role in neuronal growth and in the development of the human brain, and a deficiency of these substances has been reported in children with attention deficit hyperactive disorder (ADHD). In this regard, supplementation with omega-3 polyunsaturated fatty acids is used as adjuvant therapy in ADHD. Seafood, particularly fish, and some types of nuts are the main dietary sources of such fatty acids in the Spanish diet. In order to assess the effect of the intake of common foods containing high amounts of omega-3 polyunsaturated fatty acids, a food frequency questionnaire was administered to parents of children with ADHD (N = 48) and to parents of normally developing children (control group) (N = 87), and the intake of dietary omega-3 LC-PUFA, such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), was estimated. Children with ADHD consumed fatty fish, lean fish, mollusks, crustaceans, and chicken eggs significantly less often (p < 0.05) than children in the control group. The estimated daily omega-3 LC-PUFA intake (EPA + DHA) was significantly below that recommended by the public health agencies in both groups, and was significantly lower in children with ADHD (p < 0.05, Cohen’s d = 0.45) compared to normally developing children. Dietary intervention to increase the consumption of fish and seafood is strongly advised and it is especially warranted in children with ADHD, since it could contribute to improve the symptoms of ADHD.

Exploring correlations between neuropsychological measures and domain-specific consistency in associations with n-3 LCPUFA status in 8-9 year-old boys and girls

Long-chain n-3 polyunsaturated fatty acids (n-3 LCPUFA) have in some studies been associated with cognitive and socioemotional outcomes in children, but results are inconsistent possibly due to the use of different tests and potential gender-specific effects. The objective of this cross-sectional study was to explore overall patterns in neuropsychological scores as well as correlations between scores within specific domains, and to examine potential gender differences and consistency in associations with n-3 LCPUFA status. In 199 Danish 8–9 year-old children, we performed a large battery of tests and questionnaires on attention, processing speed, executive functions, memory, and socioemotional traits, and measured erythrocyte fatty acid composition. Principal component analyses (PCA) showed that most of the variation in both cognitive performance and socioemotional traits was explained by overall performance, followed by speed-accuracy trade off and externalizing vs. internalizing problems, respectively. Boys had higher speed, lower attention and higher externalizing problem scores than girls. Measures of performance within both processing speed and attention domains correlated moderately, whereas no correlations were found for measures of executive functions apart from some weak correlations for impulsivity. Parent-rated scores for both externalizing and internalizing problems correlated strongly, whereas correlations with child-rated scores were weak. Scores within specific domains did not consistently associate with n-3 LCPUFA, except for processing speed measures which all pointed to faster processing with increased n-3 LCPUFA status. Gender differences in the associations were observed for attention and impulsivity. Child- but not parent-rated internalizing and social problems tended to associate directly with n-3 LCPUFA, supported by increased internalizing problems measured by the PCA component. In conclusion, measures of speed and attention seem to represent these domains in general, whereas single measures of more complex cognitive functions should be interpreted with caution. One approach could be to use multiple tests and create multivariate scores to guide interpretations. Furthermore, the results indicate a need to consider both parent- and child-rated socioemotional scores and gender differences in neuropsychological functions e.g. in investigations of n-3 LCPUFA effects.