Omega-3 and polyunsaturated fat for prevention of depression and anxiety symptoms: systematic review and meta-analysis of randomised trials

Nutritional Psychology: Review the Interplay Between Nutrition and Mental Health

Nutritional psychology is a burgeoning field that examines the intricate relationship between nutrition and mental health. This concept, its historical development, and its current significance in understanding the complex interplay between diet and psychological well-being are explored in this article. The influence of various nutrients on mental health, the role of dietary patterns, and the impact of nutrition on specific mental disorders are examined. Highlighted are the potential mechanisms underlying the nutrition-mental health connection, and the implications for clinical practice and public health interventions are discussed. The discussion in this article underscores the importance of considering nutrition as essential in mental health promotion and treatment.

The association of the Prime Diet Quality Score (PDQS) with depression and anxiety symptoms: the Isfahan functional disorders (ISFUN) cohort study

BACKGROUND

Due to scarce epidemiologic data regarding the Prime Diet Quality Score (PDQS) and mental health disorders, this study aimed to investigate the association of PDQS with depression and anxiety symptoms in Iranian adults.

METHODS

This cross-sectional analysis was performed using the baseline data collected for the Isfahan functional disorders (ISFUN) cohort study. ISFUN was established in 2017 and enrolled apparently healthy adults, aged 18-65 years in Isfahan, Iran. Information on usual dietary intakes was collected using a validated Dish-based, 106-item food frequency questionnaire. The severity of depression and anxiety was assessed using a validated Iranian version of the Hospital Anxiety and Depression Scale.

RESULTS

A total number of1892 participants were enrolled in the present study. In total, 54.50% of subjects were female. In the fully adjusted model, participants with PDQS lower than median compared with those with PDQS higher than median had higher risk of depression (OR =   1.62; 95% CI: 1.11, 2.37) and anxiety (OR: 1.57; 95% CI: 1.08, 2.27). In stratified analysis by sex, males with PDQS lower than median compared with those with PDQS higher than median had greater risk for depressive (OR: 1.57) and anxiety symptoms (OR =   1.52). However, in females, no significant association was found between PDQS and odds of depression, and anxiety in the fully adjusted model.

CONCLUSION

We found evidence indicating a significant inverse association between PDQS and depression and anxiety symptoms among Iranian adults. Further studies, in particular with prospective design, are required to confirm these findings.

The N-3 polyunsaturated fatty acids supplementation to prevent depression recurrence in patients with late-life depression: A 52-week double-blind, placebo-controlled trial

BACKGROUND

Reports on the efficacy of omega-3 fatty acids (n-3 PUFAs) for the treatment of late-life depression (LLD) are mixed, and most studies focus on the modification of depressive symptoms rather than depression prevention. The aim of the present study was to investigate the efficacy of n-3 PUFAs in preventing depressive recurrence in patients with late-life depression. In addition, we investigated the effects of n-3 PUFAs on changes in depressive and anxiety symptoms and inflammatory markers in LLD.

METHODS

A 52-week, double-blind, randomized, controlled trial was conducted. We enrolled a total of 39 euthymic patients with LLD. They were randomized to receive either n-3 PUFAs (1.2 g per day of eicosapentaenoic acid and 1 g of docosahexaenoic acid) or placebo for 52 weeks. Recurrence of depression and severity of depression symptoms were assessed at baseline and weeks 4, 8, 16, 24, 32, 40, and 52.

RESULTS

A total of 39 patients completed the trial with 19 in the n-3 PUFAs group and 20 in the placebo group. Cox proportional hazard regression indicated that n-3 PUFAs had significant protective effect on depression recurrence (Hazard Ratio: 0.295, 95 % Confidence Interval: 0.093-0.931, p value =0.037). But n-3 PUFAs intervention had no significant effect in reducing depressive or anxiety symptoms, inflammatory markers over the placebo group.

LIMITATION

The results should be interpreted with consideration of the modest sample size.

CONCLUSION

These findings suggest that n-3 PUFAs may have a prophylactic effect in currently euthymic patients with LLD.

Plasma Polyunsaturated Fatty Acid Levels and Mental Health in Middle-Aged and Elderly Adults

Background: Polyunsaturated fatty acids (PUFAs) are promising nutrients for the prevention and management of psychiatric disorders. Both animal experiments and cohort studies have demonstrated the antidepressant effects of PUFAs, especially omega-3 PUFAs. However, inconsistent reports about specific types of PUFAs, such as the omega-3 and omega-6 PUFAs, still exist. Objectives: To assess the effects of specific PUFAs on mental disorders and related symptoms and explore the potential mechanisms involving white matter microstructure. Methods: Leveraging 102,252 residents from the UK Biobank, the effects of five PUFA measures on depressive disorder and anxiety disorder were explored through Cox regression models with full adjustment for possible confounders. Furthermore, the effects on related psychiatric symptoms and brain white matter microstructures were also estimated using logistic regression models and multiple linear regression models, respectively. Results: In this study, plasma levels of five PUFAs measured in quartile 4 were associated with lower risks of incident depressive disorder compared with the lowest quartile, with hazard ratios of 0.80 [95% confidence interval] = [0.71, 0.90] for total PUFAs, 0.86 [0.76, 0.97] for omega-3 PUFAs, 0.80 [0.71, 0.91] for docosahexaenoic acid, 0.79 [0.70, 0.89] for omega-6 PUFAs, and 0.77 [0.69, 0.87] for linoleic acid. Similar associations were observed between PUFAs and the incident risk of anxiety disorder. In addition, high plasma PUFA levels were also related to lower risks of occurrence of several adverse psychological symptoms, especially omega-3 PUFAs and DHA. Among the included participants, 8780 individuals with brain imaging information were included in further neuroimaging analyses, and significant associations with white matter microstructures were observed. Conclusions: Thus, this study provides population-based evidence to support the value of interventions to target PUFAs (specifically omega-3 PUFAs) for the prevention and improvement of mental health.

Associations of the intake of individual and multiple fatty acids with depressive symptoms among adults in NHANES 2007-2018

BACKGROUND

Previous studies have mainly focused on the effects of individual fatty acids on depressive symptoms, while the combined effect of fatty acids on the risk of depressive symptoms has not yet been extensively reported. This study evaluate the associations between individual and multiple fatty acids with depressive symptoms in U.S. adults.

METHODS

Data sets were obtained from the National Health and Nutrition Examination Survey (NHANES) 2007-2018 cycles. Both males and females aged above 18 years with complete information about dietary fatty acids intake, depression symptoms, and covariates were included. Weighted linear regression models were conducted to evaluate the relationships between individual fatty acid intake and depressive symptoms, and restricted cubic spline (RCS) models were utilized to explore the corresponding dose-response relationships. Additionally, we implemented the weighted quantile sum (WQS) regression and quantile g-computation (QGC) models to estimate the mixed effects of 19 fatty acids and identify the predominant types.

RESULTS

After multivariable adjustments, an increase of one unit in Linoleic acid (LA), Alpha-Linolenic Acid (ALA), Arachidonic acid (AA), Docosapentaenoic acid(DPA), Docosahexaenoic acid(DHA), was associated with a decrease in depressive scores by -0.021 (95 % CI: -0.039,-0.003, p = 0.021),-0.028 (95 % CI: -0.045,-0.011, p = 0.002),-0.026 (95 % CI: -0.044,-0.008, p = 0.005), -0.026 (95 % CI: -0.042,-0.009, p = 0.003), and - 0.022 (95 % CI: -0.041,-0.003, p = 0.022), respectively. However, a per unit increase in Hexanoic acid and Octanoic acid was associated with an increase in depressive scores of 0.020 (95 % CI: 0.002,0.038, p = 0.029) and 0.026 (95 % CI: 0.004,0.048, p = 0.020), respectively. Meanwhile, significant dose-response relationships were supported by the RCS models. As for the mixed effects, both WQS and QGC models demonstrated that the mixture of polyunsaturated fatty acids (PUFAs) was inversely related to depressive symptoms, and ALA and DPA were the most critical contributors. DHA was negatively correlated with depressive symptoms in WQS analysis, but positively correlated with depressive symptoms in QGC analysis.

LIMITATIONS

The cross-sectional design limits our ability to establish causality, and 24-hour dietary recall can lead to potential inaccuracies reflecting participants' true eating habits.

CONCLUSION

Our study suggests that the single effects of each PUFA were inversely associated with depressive symptoms, except for octadecatetraenoic acid. Moreover, higher combined intake of dietary PUFAs is inversely associated with depressive symptoms in U.S. adults. Among the mixed effects of PUFAs, ALA and DPA may play predominant roles. However, DHA mixed with other fatty acids may have different effects on depressive symptoms, and further study is needed.

Acute treatment of bilateral rTMS combined with antidepressants on the plasma fatty acids for major depressive episodes

Bilateral repetitive transcranial magnetic stimulation (B-rTMS) has been largely used in the treatment of major depressive disorder (MDD). Nonetheless, information on the acute treatment by B-rTMS combined with antidepressants (ADs) on the plasma fatty acids in MDD is limited. The present study focused on depressive symptoms; Plasma was obtained from 27 adult patients with MDD at baselinephase (MDD), after 2 weeks of treatment (MDD-2w), and 27 healthy controls (HC). Meanwhile, we evaluated the composition of short-chain fatty acids (SCFAs) and medium-and long-chain fatty acids (MLCFAs) in the plasma. Consequently, the levels of Isobutyric acid, Caproic acid, and Propionic acid were low both in the MDD and MDD-2w groups and negatively correlated with the scores of HAMD and HAMA. Besides, minimal changes were observed between the MDD and HC groups, whereas significant MLCFA levels were high in the MDD-2w group. Moreover, we developed combined panels that could effectively differentiate MDD from HCs (AUC=0.99), MDD-2w from HC (AUC=0.983), and MDD from MDD-2w (AUC=0.852). These findings may provide a reference for the use of B-rTMS combined with ADs against the acute phase of depressive episodes and shed light on the relationship between plasma FAs and MDD.

Is there any association between type of dietary fat and quality of life in hemodialysis patients? A cross-sectional study

Background

Hemodialysis (HD) patients have a low quality of life (QOL), and dietary intakes may impact both somatic and psychosocial aspects of QOL. Nevertheless, the relationship between QOL and different dietary fats has not yet been evaluated.

Objective

The purpose of this study was to assess the association between QOL and the types/quantities of dietary fats intake in HD patients.

Methods

In this multi-center cross-sectional study, 251 adult patients under dialysis for at least 3 months were included. Participants' dietary intakes were collected using a validated 168-item semi-quantitative FFQ during the past year. Moreover, to assess QOL, Kidney Disease Quality of Life Short Form (KDQOL-SF 1/3) was used. The linear regression between QOL and different types of dietary fats was conducted. p < 0.05 was statistically significant.

Results

Overall, 66 women and 185 men participated in our study. Regression analysis adjusted for total calorie intake showed that there was a negative association between QOL and total fat (95% CI: -0.187, -0.043), SFA (95% CI: -0.688, -0.143), MUFA (95% CI: -0.389, -0.065) and PUFA (95% CI: -0.401, -0.056) when types of dietary fats were individually included to the regression analysis. When all types of dietary fats were simultaneously entered into the analysis, the association between QOL and MUFA (95% CI: -0.243, 1.031) and PUFA (95% CI: -1.159, 0.084) were attenuated. The regression coefficient for SFA remained significant (95% CI: -0.968, -0.138). Also, there was a marginally significant association between SFA and the risk of low QOL was observed when all types of dietary fats were simultaneously entered into the analysis (OR = 1.051, 95% CI: 0.998-1.104).

Conclusion

Our investigation found a negative association between SFA consumption and QOL among different types of dietary fats. Furthermore, SFA mediated the relationship between QOL, MUFA, PUFA, and total fat. So, modification of dietary fat intake could enhance QOL in HD patients.

Omega-3 Polyunsaturated Fatty Acids in Depression

Omega-3 polyunsaturated fatty acids have received considerable attention in the field of mental health, in particular regarding the treatment of depression. This review presents an overview of current research on the role of omega-3 fatty acids in the prevention and treatment of depressive disorders. The existing body of evidence demonstrates that omega-3 fatty acids, in particular eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), have antidepressant effects that can be attributed to their modulation of neuroinflammation, neurotransmitter function, and neuroplasticity. Nevertheless, clinical trials of omega-3 supplementation have yielded inconsistent results. Some studies have demonstrated significant reductions in depressive symptoms following omega-3 treatment, whereas others have shown minimal to no beneficial impact. A range of factors, encompassing dosage, the ratio of EPA to DHA, and baseline nutritional status, have been identified as having a potential impact on the noted results. Furthermore, it has been suggested that omega-3 fatty acids may act as an adjunctive treatment for those undergoing antidepressant treatment. Notwithstanding these encouraging findings, discrepancies in study designs and variability in individual responses underscore the necessity of further research in order to establish uniform, standardized guidelines for the use of omega-3 fatty acids in the management of depressive disorders.

A systematic review of the effect of dietary and nutritional interventions on the behaviours and mental health of prisoners

Prisoners experience a higher burden of poor health, aggressive behaviours and worsening mental health than the general population. This systematic review aimed to identify research that used nutrition-based interventions in prisons, focusing on outcomes of mental health and behaviours. The systematic review was registered with Prospective Register of Systematic Reviews on 26 January 2022: CRD42022293370. Inclusion criteria comprised of current prisoners with no limit on time, location, age, sex or ethnicity. Only quantitative research in the English language was included. PubMed/Medline, Web of Science, EMBASE, PsycINFO and CINAHL were searched, retrieving 933 results, with 11 included for qualitative synthesis. Studies were checked for quality using the revised tool to assess risk of bias in randomised trials or risk of bias in non-randomised studies of interventions tool. Of the included studies, seven used nutritional supplements, three included diet changes, and one used education. Of the seven supplement-based studies, six included rule violations as an outcome, and only three demonstrated significant improvements. One study included mental health as an outcome; however, results did not reach significance. Of the three diet change studies, two investigated cognitive function as an outcome, with both reaching significance. Anxiety was included in one diet change study, which found a significant improvement through consuming oily fish. One study using diet education did not find a significant improvement in overall mental resilience. Overall, results are mixed, with the included studies presenting several limitations and heterogeneity. Future research should aim to consider increased homogeneity in research design, allowing for a higher quality of evidence to assess the role nutrition can play in improving the health of prisoners.

Efficacy and safety of omega-3 fatty acids supplementation for anxiety symptoms: a systematic review and dose-response meta-analysis of randomized controlled trials

BACKGROUND/OBJECTIVES

There is uncertainty about the optimum dose of omega-3 fatty acids for anxiety symptoms. We aimed to find the dose-dependent effect of omega-3 supplementation on anxiety symptoms.

METHODS

We systematically reviewed PubMed, Scopus, and Web of Science until December 2022 to find randomized trials that assessed the effects of omega-3 fatty acids supplementation on anxiety symptoms in adults. Investigators performed the literature search and screened the titles/abstracts and full-texts and between-reviewer agreement was assessed as Cohen's kappa coefficient. We conducted a random-effects dose-response meta-analysis to estimate standardized mean differences (SMD) and 95% confidence intervals (CIs) and assessed the certainty of evidence using the GRADE framework.

RESULTS

A total of 23 trials with 2189 participants were included. Each 1 gram per day supplementation with omega-3 fatty acids resulted in a moderate decrease in anxiety symptoms (SMD: -0.70, 95%CI: -1.17, -0.22; GRADE = low). The non-linear dose-response analysis indicated the greatest improvement at 2 g/d (SMD: -0.93, 95%CI: -1.85, -0.01), and that supplementation in a dose lower than 2 g/d did not affect anxiety symptoms. Omega-3 fatty acids did not increase adverse events (odds ratio: 1.20, 95%CI: 0.89, 1.61; GRADE = moderate).

CONCLUSIONS

The present dose-response meta-analysis suggested evidence of very low certainty that supplementation with omega-3 fatty acids may significantly improve anxiety symptoms, with the greatest improvements at 2 g/d. More trials with better methodological quality are needed to reach more robust evidence.

PROTOCOL REGISTRATION

PROSPERO (CRD42022309636).

Association of serum fatty acid pattern with depression in U.S. adults: analysis of NHANES 2011-2012

BACKGROUND

Exposure to different concentration levels of fatty acids (FAs) may have an impact on depression. However, previous studies using individual FAs may not reflect the performance of mixtures of various FAs, and the associations of FA patterns with depression remain unclear.

METHODS

We conducted the cross-sectional analysis in 792 adults aged 18 and older with available serum FAs and depression screening data in the National Health and Nutrition Examination Survey (NHANES) 2011-2012. The serum concentrations of thirty FAs were measured using gas chromatography-mass spectrometry and their percentage compositions were subsequently calculated. Depression was defined as the Patient Health Questionnaire-9 score ≥ 10. We employed principal component analysis to derive serum FA patterns. We examined the association between these patterns and depression in the overall population and various subgroups through survey-weighted logistic regression.

RESULTS

Four distinct patterns of serum FAs were identified: 'high eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA); low docosatetraenoic acid (DTA) and docosapentaenoic acid (DPA) n-6', 'high long-chain saturated FA and long chain FA', 'low median-chain saturated FA and myristoleic acid' and 'low capric acid and lauric acid; high gamma-linolenic acid (GLA) and stearidonic acid (SDA)' pattern. Individuals in the high tertile of 'high EPA and DHA; low DTA and DPA n-6' pattern score had 0.46 (95% CI: 0.22, 0.93) lower odds of developing depression compared to individuals in the lowest tertile after adjusting for confounders such as age, sex, physical activity and total energy intake, etc. The odds ratio (OR) of depression was increased in the population with the highest tertile of 'low capric acid and lauric acid; high GLA and SDA' pattern (OR: 2.45, 95% CI: 1.24, 4.83). In subgroup analyses, we observed that the association between 'high EPA and DHA; low DTA and DPA n-6' and depression persisted among specific demographic and lifestyle subgroups, including females, non-Mexican Americans, non-obese, those aged over 60 years, smokers and drinkers. Similarly, 'low capric acid and lauric acid; high GLA and SDA' showed stable associations in female, non-Mexican Americans and smokers.

CONCLUSIONS

Serum FA patterns are associated with depression, and their relationships vary across sex, race, BMI, age, smoking and drinking subgroups, highlighting the importance of considering specific FA patterns within these demographic and lifestyle categories. Utilization of combined FA administration may serve as a mitigation measure against depression in these specific populations.

Omega-3 fatty acids and major depression: a Mendelian randomization study

Omega-3 fatty acids have been implicated in the aetiology of depressive disorders, though trials supplementing omega-3 to prevent major depressive disorder (MDD) have so far been unsuccessful. Whether this association is causal remains unclear. We used two sample Mendelian randomization (MR) to investigate causality. Genetic variants associated with circulating omega-3 and omega-6 fatty acids in UK Biobank (UKBB, n = 115,078) were selected as exposures. The Psychiatric Genomics Consortium (PGC) genome-wide association studies (GWAS) of MDD (n = 430,775; cases = 116,209; controls = 314,566) and recurrent depression (rMDD, n = 80,933; cases = 17,451; controls = 62,482), were used as outcomes. Multivariable MR (MVMR) models were used to account for biologically correlated lipids, such as high- and low-density cholesterol and triglycerides, and to explore the relative importance of longer-chain omega-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) using data from the Cohorts for Heart and Aging Research in Genomic Epidemiology (CHARGE, n = 8866). Genetic colocalization analyses were used to explore the presence of a shared underlying causal variant between traits. Genetically predicted total omega-3 fatty acids reduced the odds of MDD (ORIVW 0.96 per standard deviation (SD, i.e. 0.22 mmol/l) (95% CIs 0.93-0.98, p = 0.003)). The largest point estimates were observed for eicosapentaenoic acid (EPA), a long-chain omega-3 fatty acid (OREPA 0.92; 95% CI 0.88-0.96; p = 0.0002). The effect of omega-3 fatty acids was robust to MVMR models accounting for biologically correlated lipids. 'Leave-one-out' analyses highlighted the FADS gene cluster as a key driver of the effect. Colocalization analyses suggested a shared causal variant using the primary outcome sample, but genomic confounding could not be fully excluded. This study supports a role for omega-3 fatty acids, particularly EPA, in the aetiology of depression, although pleiotropic mechanisms cannot be ruled out. The findings support guidelines highlighting the importance of EPA dose and ratio for MDD and question whether targeted interventions may be superior to universal prevention trials, as modest effect sizes will limit statistical power.

Clinical impacts of n-3 fatty acids supplementation on depression symptoms: an umbrella review of meta-analyses

Several meta-analyses investigating the efficacy of n-3 PUFA in alleviating depression symptoms have reported conflicting findings. In the present study, we aimed to perform an umbrella meta-analysis to provide a definite conclusion. A comprehensive systematic search of PubMed, Scopus, Embase, Web of Science and Cochrane Central Library was performed up to June 2021. Meta-analysis studies evaluating the effects of n-3 PUFA on depression symptoms were included. The quality of the included meta-analyses was assessed using AMSTAR questionnaire. Out of 101 studies, twenty-two studies with twenty-six effect sizes (ES) were eligible for inclusion. Sixteen ES showed significant improving effect of n-3 supplementation on depression symptoms among which eleven ES had small ES. The other studies observed no significant effect. Available evidence suggests that n-3 PUFA (EPA, DHA) supplementation could be considered as an effective add-on therapeutic approach in relieving depression symptoms.

The Addition of Fish Oil to Cognitive Behavioral Case Management for Youth Depression: A Randomized, Double-Blind, Placebo-Controlled, Multicenter Clinical Trial

BACKGROUND

Clinical trials suggest that long-chain omega-3 polyunsaturated fatty acids (n-3 PUFAs) (fish oil) may reduce depressive symptoms in adults with major depressive disorder. Therefore, n-3 PUFAs may be a potential treatment for depression in youth.

METHODS

Participants were 15- to-25 year-old individuals with major depressive disorder who sought care in one of three government-funded mental health services for young people in metropolitan Melbourne, Perth, or Sydney, Australia. Participants were randomly assigned in a double-blind, parallel-arm design to receive either fish oil (840 mg of eicosapentaenoic acid and 560 mg of docosahexaenoic acid) or placebo capsules as adjunct to cognitive behavioral case management. All participants were offered 50-minute cognitive behavioral case management sessions every 2 weeks delivered by qualified therapists (treatment as usual) at the study sites during the intervention period. The primary outcome was change in the interviewer-rated Quick Inventory of Depressive Symptomatology, Adolescent Version, score at 12 weeks. Erythrocyte n-3 PUFA levels were assessed pre-post intervention.

RESULTS

A total of 233 young people were randomized to the treatment arms: 115 participants to the n-3 PUFA group and 118 to the placebo group. Mean change from baseline in the Quick Inventory of Depressive Symptomatology score was -5.8 in the n-3 PUFA group and -5.6 in the placebo group (mean difference, 0.2; 95% CI, -1.1 to 1.5; p = .75). Erythrocyte PUFA levels were not associated with depression severity at any time point. The incidence and severity of adverse events were similar in the two groups.

CONCLUSIONS

This placebo-controlled trial and biomarker analysis found no evidence to support the use of fish oil for treatment in young people with major depressive disorder.

Efficacy and safety of n-3 fatty acids supplementation on depression: a systematic review and dose-response meta-analysis of randomised controlled trials

We aimed to investigate the effectiveness of n-3 fatty acids supplementation on the risk of developing depression, depressive symptoms and remission of depression. We searched PubMed, Scopus and Web of Science from inception to December 2022 to find randomised trials of n-3 fatty acids supplementation in adults. We conducted random-effects meta-analyses to estimate standardised mean differences (SMD) and 95 % CI for continuous outcomes and risk difference and 95 % CI for binary outcomes. A total of sixty-seven trials were included. Each 1 g/d n-3 fatty acids supplementation significantly improved depressive symptoms in adults with and without depression (moderate-certainty evidence), with a larger improvement in patients with existing depression. Dose-response analyses indicated a U-shaped effect in patients with existing depression, with the greatest improvement at 1·5 g/d. The analysis showed that n-3 fatty acid supplementation significantly increased depression remission by 19 more per 100 in patients with depression (low-certainty evidence). Supplementation with n-3 fatty acids did not reduce the risk of developing depression among the general population, but it did improve the severity of depression among patients with existing depression.

Determining the emotional regulation function of Bifidobacterium breve: the role of gut metabolite regulation over colonization capability

Psychobiotics that modulate the gut-brain axis have emerged as promising interventions for clinical mental disorders. Bifidobacterium breve CCFM1025 has demonstrated antidepressant effects in both mice and patients with major depression. Nevertheless, the precise mechanism of action of CCFM1025 in emotional regulation remains ambiguous. This study aimed to explore the colonization capacity of CCFM1025 and its dose-dependent effect on emotional regulation in mice exposed to chronic unpredictable mild stress (CUMS). Additionally, we examined its regulatory effects on intestinal and serum metabolites in mice. The results revealed that CCFM1025 did not exhibit a heightened gut retention capability compared to the conspecific control strain. Nevertheless, CCFM1025 exhibited dose-dependent mitigation of anxiety-like behavior and memory impairment induced by CUMS, while also restoring gut microbiota homeostasis. Notably, CCFM1025 demonstrated a robust ability to exert potent gut metabolite regulation, resulting in significant elevation of bile acid and tryptophan metabolites in the gut contents and serum of mice. These findings indicate that the impact of CCFM1025 on emotional regulation may be attributed to its regulation of gut metabolites rather than its gut retention capability. The potential of Bifidobacterium to modulate bile acid metabolism may serve as a valuable avenue for regulating the gut microbiota and successfully exert emotion regulation.

Effects of omega-3 supplementation on anxiety-like behaviors and neuroinflammation in Wistar rats following cafeteria diet-induced obesity

ABSTRACTObjetives: Omega-3 (n3) fatty acids have been studied as an option to alleviate the harmful effects of obesity. However, its role in obesity-related behavioral changes is still controversial. This study aimed to evaluate the effects of n3 on behavior and neuroinflammation in obese animals. Methods: Male Wistar rats were divided into four groups: control diet (CT), CT+n3, cafeteria diet (CAF), and CAF+n3. Diet was administered for 13 weeks, and n3 was supplemented during the last 5 weeks. Metabolic and biochemical parameters were evaluated, as well as anxiety-like behaviors. Immunoblots were conducted in the animals' cerebral cortex and hippocampus to assess changes in neuroinflammatory markers.Results: CAF-fed animals showed higher weight gain, visceral adiposity, fasting glucose, total cholesterol, triglycerides, and insulin levels, and n3 improved the lipid profile and restored insulin sensitivity. CAF-fed rats showed anxiety-like behaviors in the open field and light-dark box tasks but not in the contextual aversive conditioning. Omega-3 did not exert any effect on these behaviors. Regarding neuroinflammation, diet and supplementation acted in a region-specific manner. In the hippocampus, CAF reduced claudin-5 expression with no effect of n3, indicating a brain-blood barrier disruption following CAF. Furthermore, in the hippocampus, the glial fibrillary acidic protein (GFAP) and toll-like receptor 4 (TLR-4) were reduced in treated obese animals. However, n3 could not reverse the TLR-4 expression increase in the cerebral cortex.Discussion: Although n3 may protect against some neuroinflammatory manifestations in the hippocampus, it does not seem sufficient to reverse the increase in anxiolytic manifestations caused by CAF.

The role of polyunsaturated fatty acids in the neurobiology of major depressive disorder and suicide risk

Long-chain polyunsaturated fatty acids (LC-PUFAs) are obtained from diet or derived from essential shorter-chain fatty acids, and are crucial for brain development and functioning. Fundamentally, LC-PUFAs' neurobiological effects derive from their physicochemical characteristics, including length and double bond configuration, which differentiate LC-PUFA species and give rise to functional differences between n(omega)-3 and n-6 LC-PUFAs. LC-PUFA imbalances are implicated in psychiatric disorders, including major depression and suicide risk. Dietary intake and genetic variants in enzymes involved in biosynthesis of LC-PUFAs from shorter chain fatty acids influence LC-PUFA status. Domains impacted by LC-PUFAs include 1) cell signaling, 2) inflammation, and 3) bioenergetics. 1) As major constituents of lipid bilayers, LC-PUFAs are determinants of cell membrane properties of viscosity and order, affecting lipid rafts, which play a role in regulation of membrane-bound proteins involved in cell-cell signaling, including monoaminergic receptors and transporters. 2) The n-3:n-6 LC-PUFA balance profoundly influences inflammation. Generally, metabolic products of n-6 LC-PUFAs (eicosanoids) are pro-inflammatory, while those of n-3 LC-PUFAs (docosanoids) participate in the resolution of inflammation. Additionally, n-3 LC-PUFAs suppress microglial activation and the ensuing proinflammatory cascade. 3) N-3 LC-PUFAs in the inner mitochondrial membrane affect oxidative stress, suppressing production of and scavenging reactive oxygen species (ROS), with neuroprotective benefits. Until now, this wealth of knowledge about LC-PUFA biomechanisms has not been adequately tapped to develop translational studies of LC-PUFA clinical effects in humans. Future studies integrating neurobiological mechanisms with clinical outcomes may suggest ways to identify depressed individuals most likely to respond to n-3 LC-PUFA supplementation, and mechanistic research may generate new treatment strategies.

Fat and fatty acids - a scoping review for Nordic Nutrition Recommendations 2023

Two de novo NNR2022 systematic reviews (SRs) as well as 21 qualified SRs (qSRs) were available. A literature search yielded an additional ~70 SRs, meta-analyses and biomarker papers. Diets lower in total fat are associated with reductions in body weight and blood pressure compared with diets higher in total fat in adults. Partial replacement of saturated fatty acid (SFA) with n-6 polyunsaturated fatty acid (PUFA) improves blood lipid profile, decreases the risk of cardiovascular disease (CVD), improves glucose-insulin homeostasis and may decrease the risk of total mortality. Long-chain n-3 PUFAs (eicosapentaenoic acid [EPA] and docosahexaenoic acid [DHA]) decrease triglycerides and are associated with lower risk of CVD. Dietary PUFAs, both n-3 and n-6, may be associated with reduced risk of type 2 diabetes (T2D). There is inconclusive evidence to suggest that the type of dietary fat is associated with blood pressure, risk of hypertension or musculoskeletal health. Higher intake of total PUFA is associated with lower mortality from any cancer. Long-chain n-3 PUFA is associated with reduced risk of breast cancer, whereas biomarker levels of n-6 PUFA are associated with lower risk of any cancer. Intake of long-chain n-3 PUFA during pregnancy increases length of gestation and child birth weight and reduces the risk of preterm delivery, but there is inconclusive evidence to suggest that it may influence child neurodevelopment, growth or development of allergic disease. In studies with higher versus lower dietary cholesterol intake levels, total blood cholesterol increased or were unaffected by the dietary cholesterol, resulting in inconclusive results. Trans fatty acid (TFA), regardless of source, impairs blood lipid profile compared to unsaturated fat. In observational studies, TFA is positively associated with CVD and total mortality but whether associations differ by source is inconclusive. Ruminant TFA, as well as biomarker levels of odd-chain fatty acids, might be associated with lower risk of T2D.

[Dietary patterns and factors and their association with the anxiety in adult population: proposed recommendations based on a scoping review of systematic reviews and meta-analyses]

Introduction

A high percentage of the population suffers from anxiety, a disorder that can be influenced by dietary habits. The aim of this review was to compile the existing evidence on dietary patterns and factors, and their association with anxiety to propose clinically applicable recommendations. A scoping review of systematic reviews and meta-analyses was conducted in the MEDLINE database (PubMed) until January 2021, reporting the main findings based on PRISMA (2020). To construct the search strategy, MeSH language, keywords ("diet", "nutrients", "healthy lifestyle", "anxiety") and filters were used, combined using Boolean operators. Twelve articles, seven systematic reviews with meta-analysis and five systematic reviews were selected. Several results were obtained evaluating the relationship between anxiety and different aspects of diet. The main associations found were between increased consumption of raw vegetables and fruits, substitution of refined cereals by whole grains, intake of omega-3 and omega-6 fats, and increased intake of minerals and vitamins, tryptophan and antioxidants. Based on the systematic reviews and meta-analyses included as findings, ten recommendations on food consumption that should be considered as a priority for these patients were proposed. Based on the literature reviewed, it is concluded that there are dietary patterns and factors that could have a stronger positive influence on anxiety. This proposal of evidence-based dietary recommendations may allow healthcare professionals to have updated recommendations to provide a first orientation.

Nutrient intake, alcohol consumption, emotional eating and anxiety in women nursing students

Objective

The aim of the study was to analyze dietary habits, alcohol habits, emotional eating and anxiety in a sample of Spanish nursing students. These students appear to be essential to the field of public health and to teaching their future patients about their own good practices.

Methods

A cross-sectional investigation was conducted. Participants completed the Emotional Eater Questionnaire, the Alcohol Use Disorder Identification Test (AUDIT) test to evaluate alcohol intake, the State-Trait anxiety Inventory (STAI) test to measure levels of anxiety as a state and anxiety as a trait, and self-reported sociodemographic data. Following classroom instruction, three-day food records were used to gauge food intake.

Results

The calorie intake for the macronutrients Ca, Mg, K, and Fe were below the Recommended Dietary Intakes (DRI) and imbalanced. The percentage E of proteins was 132.7 % more than recommended, while the percentage of carbohydrates is below the recommended level. Dietary energy consumption barely equaled 78 % of the total energy consumed by this sex and age group. With respect to emotional eating, nursing women students were low emotional eater (44 %) > emotional eater (30 %) > non-emotional eater (22.7 %). The students' emotional eating is substantially connected with fast food and sweets, or less healthy food intake behaviors. According to the Alcohol Use Disorder Identification Test (AUDIT), 82.7 % of female students used alcohol on a regular basis in a low-risk manner.

Conclusion

The findings demonstrated a link between anxiety and dietary fat intake. Trait anxiety was negatively connected with emotional eating (EE), whereas state anxiety was positively correlated with meat consumption. It is crucial to consider these findings when creating prevention/intervention plans and profiles of harmful eating behaviors.

rTMS ameliorates depressive-like behaviors and regulates the gut microbiome and medium- and long-chain fatty acids in mice exposed to chronic unpredictable mild stress

INTRODUCTION

Repetitive transcranial magnetic stimulation (rTMS) is a clinically useful therapy for depression. However, the effects of rTMS on the metabolism of fatty acids (FAs) and the composition of gut microbiota in depression are not well established.

METHODS

Mice received rTMS (15 Hz, 1.26 T) for seven consecutive days after exposure to chronic unpredictable mild stress (CUMS). The subsequent depressive-like behaviors, the composition of gut microbiota of stool samples, as well as medium- and long-chain fatty acids (MLCFAs) in the plasma, prefrontal cortex (PFC), and hippocampus (HPC) were evaluated.

RESULTS

CUMS induced remarkable changes in gut microbiotas and fatty acids, specifically in community diversity of gut microbiotas and PUFAs in the brain. 15 Hz rTMS treatment alleviates depressive-like behaviors and partially normalized CUMS induced alterations of microbiotas and MLCFAs, especially the abundance of Cyanobacteria, Actinobacteriota, and levels of polyunsaturated fatty acids (PUFAs) in the hippocampus and PFC.

CONCLUSION

These findings revealed that the modulation of gut microbiotas and PUFAs metabolism might partly contribute to the antidepressant effect of rTMS.

Dietary fatty acids improve perceived sleep quality, stress, and health in migraine: a secondary analysis of a randomized controlled trial

Background

Migraine is a prevalent disabling condition often associated with comorbid physical and psychological symptoms that contribute to impaired quality of life and disability. Studies suggest that increasing dietary omega-3 fatty acid is associated with headache reduction, but less is known about the effects on quality of life in migraine.

Methods

After a 4-week run-in, 182 adults with 5-20 migraine days per month were randomized to one of the 3 arms for sixteen weeks. Dietary arms included: H3L6 (a high omega-3, low omega-6 diet), H3 (a high omega-3, an average omega-6 diet), or a control diet (average intakes of omega-3 and omega-6 fatty acids). Prespecified secondary endpoints included daily diary measures (stress perception, sleep quality, and perceived health), Patient-Reported Outcome Measurement Information System Version 1.0 ([PROMIS©) measures and the Migraine Disability Assessment (MIDAS). Analyses used linear mixed effects models to control for repeated measures.

Results

The H3L6 diet was associated with significant improvements in stress perception [adjusted mean difference (aMD): -1.5 (95% confidence interval: -1.7 to -1.2)], sleep quality [aMD: 0.2 (95% CI:0.1-0.2)], and perceived health [aMD: 0.2 (0.2-0.3)] compared to the control. Similarly, the H3 diet was associated with significant improvements in stress perception [aMD: -0.8 (-1.1 to -0.5)], sleep quality [aMD: 0.2 (0.1, 0.3)], and perceived health [aMD: 0.3 (0.2, 0.3)] compared to the control. MIDAS scores improved substantially in the intervention groups compared with the control (H3L6 aMD: -11.8 [-25.1, 1.5] and H3 aMD: -10.7 [-24.0, 2.7]). Among the PROMIS-29 assessments, the biggest impact was on pain interference [H3L6 MD: -1.8 (-4.4, 0.7) and H3 aMD: -3.2 (-5.9, -0.5)] and pain intensity [H3L6 MD: -0.6 (-1.3, 0.1) and H3 aMD: -0.6 (-1.4, 0.1)].

Discussion

The diary measures, with their increased power, supported our hypothesis that symptoms associated with migraine attacks could be responsive to specific dietary fatty acid manipulations. Changes in the PROMIS© measures reflected improvements in non-headache pain as well as physical and psychological function, largely in the expected directions. These findings suggest that increasing omega-3 with or without decreasing omega-6 in the diet may represent a reasonable adjunctive approach to reducing symptoms associated with migraine attacks. Trial Registration: ClinicalTrials.gov NCT02012790.

Shared genetic basis informs the roles of polyunsaturated fatty acids in brain disorders

The neural tissue is rich in polyunsaturated fatty acids (PUFAs), components that are indispensable for the proper functioning of neurons, such as neurotransmission. PUFA nutritional deficiency and imbalance have been linked to a variety of chronic brain disorders, including major depressive disorder (MDD), anxiety, and anorexia. However, the effects of PUFAs on brain disorders remain inconclusive, and the extent of their shared genetic determinants is largely unknown. Here, we used genome-wide association summary statistics to systematically examine the shared genetic basis between six phenotypes of circulating PUFAs (N = 114,999) and 20 brain disorders (N = 9,725-762,917), infer their potential causal relationships, identify colocalized regions, and pinpoint shared genetic variants. Genetic correlation and polygenic overlap analyses revealed a widespread shared genetic basis for 77 trait pairs between six PUFA phenotypes and 16 brain disorders. Two-sample Mendelian randomization analysis indicated potential causal relationships for 16 pairs of PUFAs and brain disorders, including alcohol consumption, bipolar disorder (BIP), and MDD. Colocalization analysis identified 40 shared loci (13 unique) among six PUFAs and ten brain disorders. Twenty-two unique variants were statistically inferred as candidate shared causal variants, including rs1260326 (GCKR), rs174564 (FADS2) and rs4818766 (ADARB1). These findings reveal a widespread shared genetic basis between PUFAs and brain disorders, pinpoint specific shared variants, and provide support for the potential effects of PUFAs on certain brain disorders, especially MDD, BIP, and alcohol consumption.

The relationship between dietary lipophilic index and load with depression, anxiety, and stress symptoms

BACKGROUND

Dietary fatty acids can affect brain health by modifying neuronal membrane fluidity. Dietary lipophilic index (LI) and load (LL) may be related to cell membrane fluidity. This study aimed to determine the relationship between dietary LI and LL with symptoms of depression, anxiety and stress.

METHODS

In this cross-sectional study, taken from the YaHS (Yazd Health Study) population-based cohort, the data of 2,982 individuals was extracted. Several questionnaires- a 178-item Food Frequency Questionnaire (FFQ), Depression, Anxiety and Stress Scale 21 (DASS 21), and International Physical Activity Questionnaire (IPAQ)- were used to obtain information on dietary intake, mental status, and physical activity, respectively. LI and LL were calculated using dietary intake and the melting point of each fatty acid.

RESULTS

The analysis was performed on 2982 individuals. The odds ratio of depression in the second tertile of dietary LI compared to the first tertile was 0.815 (95% CI 0.66-1.00, P = 0.051, Ptrend = 0.017) and after adjusting confounders was 0.793 (95% CI 0.63-0.99, P = 0.043, Ptrend = 0.011). Also, LL was related inversely with anxiety (0.771, 95% CI 0.63-0.93, P = 0.003) that after multiple regression, OR of anxiety was 0.762 (95% CI 0.53-1.07, P = 0.045). The odds of stress in the third tertile of LL was 1.064 but not statistically significant (95% CI 0.88-1.28, P = 0.729).

CONCLUSION

This study showed an inverse association between dietary LI and depression symptoms. Anxiety and stress did not show a significant relationship with LI or LL.

Gathering the Evidence on Diet and Depression: A Protocol for an Umbrella Review and Updated Meta-Analyses

Our objectives are to perform (1) an umbrella review on diet and depression, (2) a systematic review update on dietary patterns and depression, and (3) updated meta-analyses using studies from the previous two objectives. Systematic reviews examining the relationships between diet and depression and primary studies on the relationship between dietary patterns and depression will be systematically retrieved via several databases. All articles identified through the database searches will be imported into Covidence. Following duplicates removal, two authors will independently perform title and abstract screening and full-text assessment against eligibility criteria. Data will be extracted using tables developed for both systematic reviews and primary studies. The methodological quality of systematic reviews will be assessed using the AMSTAR-2 tool. The risk of bias in randomized trials, cohort and cross-sectional studies, as well as case-control studies, will be assessed with the Cochrane risk-of-bias (RoB-2) tool, the NHLBI Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies, and the NHLBI Quality Assessment Tool for Case-Control studies, respectively. For each dietary variable, data extracted will be used to produce: (1) a summary of systematic reviews' characteristics and results table, (2) a summary of the primary studies characteristics table, (3) a qualitative summary of results from the primary studies table, and (4) a quantitative summary of results in the form of forest plots. The certainty of evidence will be assessed using the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) approach. Upon completion, this systematic review will be the most comprehensive and up-to-date synthesis of currently available evidence on the relationships between diet and depression. It will serve as a key reference to guide future research and as a resource for health professionals in the fields of nutrition and psychiatry. PROSPERO CRD42022343253.

Influence of Weight-Control Attempts as Based on Self-Perception of Macronutrient Intake Among Young Females and Its Association with Mood Disorder

Background

There are a few studies on the association between macronutrients and mood, but none on weight control based on self-perception of specific macronutrients and mood.

Objective

To assess the association between anxiety and depression levels and weight-control attempts among young females based on self-perception of diet that impacts weight by limiting or boosting a certain macronutrient.

Methods

A cross-sectional survey conducted on young females (n=302) with an age range of 19 to 29. Dietary intake was measured using the Food frequency questionnaire (FFQ) and 24h-dietary recall. Anxiety and depression were measured using the Hospital Anxiety and Depression Scale (HADS) questionnaire.

Results

Analysis of the data showed a significant and inverse association of macronutrients - carbohydrates (OR 0.86; 95% CI 0.77-0.95; p < 0.01), protein (OR 0.87; 95% CI 0.78-0.97; p < 0.05), and fat (OR 0.79; 95% CI 0.63-0.99; p < 0.05) - with the odds of abnormal anxiety was noted. In addition, lower omega-3 intake was significantly associated with abnormal anxiety score (OR 0.85; 95% CI 0.76-0.97; p < 0.05) and abnormal depression score (OR 0.31; 95% CI 0.14-0.68; p < 0.01). Increased calorie intake is associated with an increased risk of anxiety scores.

Conclusion

This preliminary study found the importance of monitoring dietary intake, especially macronutrients, among the young population to screen for any onset of mood symptoms, especially for those who are following a specific diet without any supervision. Young people should be aware of the importance of following a balanced diet and seek dietitians' consultation.

Investigation of the interaction between Genetic Risk Score (GRS) and fatty acid quality indices on mental health among overweight and obese women

BACKGROUND & AIMS

Mental disorders are associated with dietary fatty acids and genome-wide association studies have found multiple risk loci robustly related to depression, anxiety, and stress. The aim of this study is to investigate the interaction of genetic risk score (GRS) and dietary fat quality indices on mental health.

METHODS

This cross-sectional study included 279 overweight and obese women for N6/N3 ratio and 378 overweight and obese women for CSI aged 18-68 years. Using reliable and verified standard protocols, body composition, anthropometric indices, blood pressure, physical activity, and dietary fat quality were measured. Serum samples were used to determine biochemical tests. A genetic risk score (GRS) was calculated using the risk alleles of the three SNPs. A generalized linear model (GLM) was applied to assess the interactions between GRS and fat quality indices. Mental health was evaluated using Depression Anxiety Stress Scales (DASS-21).

RESULTS

The mean (± SD) age and BMI of our participants were 36.48 (8.45) and 30.73 (3.72) kg/m2 respectively. There was a marginally significant mean difference among tertiles of the CSI in terms of stress (P = 0.051), DASS-21 (P = 0.078) in the crude model. After adjusting for age, energy intake, physical activity and BMI in model 1, there was a positive interaction between GRS and T3 of N6/N3 ratio on anxiety (β = 0.91, CI = 0.08,1.75, P = 0.031), depression (β = 1.05, CI = 0.06,2.04, P = 0.037), DASS-21 (β = 2.22, CI= -0.31,4.75, P = 0.086).

CONCLUSION

Our findings indicate that higher ratio of N-6 to N-3 considering genetics were predictive of mental disorder in our population.

REPEATED DONKEY MILK CONSUMPTION REDUCES ANXIETY-LIKE BEHAVIORS AND BRAIN OXIDATIVE DAMAGE TO LIPIDS IN MICE

Donkey milk (DM) is a source of bioactive compounds that can benefit neural functioning. In the present study, we investigated the effects of DM consumption on anxiolytic-related, despair-like, locomotion and coordination behaviors, as well as the provision of protection from oxidative damage to lipids and proteins in brain tissues and melatonin plasma levels. To achieve this, male mice orally received DM (4g.kg^-1) or vehicle for 18 days. Their behavior was assessed in the following tests: elevated plus maze (EPM), open field and rotarod tests (OF, RR) and forced swimming test (FST). Acute treatments with diazepam (DZP, 1.5mg.kg^-1, v.o.), fluoxetine (FLX, 20mg.kg^-1, i.p.) and nortriptyline (NTP, 20mg.kg^-1, i.p.) were used as positive controls. On the eighteenth day, the animals were euthanized and brain tissue and blood were collected to measure oxidative damage, and melatonin plasma levels. Similar to DZP, repeated DM consumption reduced exploration to open areas in the EPM test. Under our experimental conditions, conventional antidepressants reduced immobility time in the FST, and the benzodiazepine treatment impaired motor coordination in mice. No significant differences in locomotion, motor coordination and despair-related behaviors were observed in the mice treated with DM when assessed in the EPM, OF, RR and FST, respectively. Biochemical assays showed that repeated DM exposition protected against oxidative damage to lipids and increased plasma levels of melatonin. These findings suggest consumption of DM may be a promising food for the treatment of anxiety-related disorders, without depressant effects on the central nervous system.

Effects of long-chain omega-3 polyunsaturated fatty acids on reducing anxiety and/or depression in adults; A systematic review and meta-analysis of randomised controlled trials

The omega-3 polyunsaturated fatty acids (PUFAs) eicosapentaenoic- (EPA), docosahexaenoic- (DHA) and docosapentaenoic acid (DPAn-3) are promising therapeutic options in reducing the severity of anxious and depressive symptoms. However, meta-analyses of randomised controlled trials (RCTs) yield mixed findings. This systematic review and meta-analysis reviewed the evidence and assessed the efficacy of EPA, DHA and DPAn-3 in reducing the severity of anxiety and depression with specific consideration to methodological complications unique to the field e.g., dose and ratio of omega-3 PUFAs and placebo composition. Random-effects meta-analysis of ten RCTs comprising 1426 participants revealed statistically significant reduction in depression severity with EPA-enriched interventions at proportions ≥ 60% of total EPA + DHA (SMD: -0.36; 95% CI: -0.68, -0.05; p = 0.02) (I² = 86%) and EPA doses between ≥ 1 g/day and < 2 g/day (SMD: -0.43; 95% CI: -0.79, -0.07; p = 0.02) (I² = 88%); however, EPA doses ≥ 2 g/day were not associated with significant therapeutic effects (SMD: -0.20; 95% CI: -0.48, 0.07; p = 0.14). Only one study reported significant reduction in anxiety severity with 2.1 g/day EPA (85.6% of total EPA + DHA), therefore meta-analysis was not possible. No trials administering DPAn-3 were identified. Visual examination of the funnel plot revealed asymmetry, suggesting publication bias and heterogeneity amongst the trials. These results support the therapeutic potential of EPA in depression at proportions ≥ 60% of total EPA + DHA and doses ≥ 1 g/day and < 2 g/day. The observed publication bias and heterogeneity amongst the trials reflect the need for more high-quality trials in this area with consideration to the unique nature of omega-3 PUFAs research, to more fully elucidate the therapeutic potential of EPA, DHA and DPAn-3.

Omega-3 supplements in the prevention and treatment of youth depression and anxiety symptoms: A scoping review

INTRODUCTION

Omega-3 supplements may be efficacious in reducing symptoms of depression and anxiety in adults, particularly as an adjunct to antidepressant medication. However, research in young people is limited. Thus, this scoping review aimed to summarise existing evidence on the efficacy of omega-3 supplementation in treating depression and anxiety symptoms in young people aged 14-24. A secondary aim was to determine whether grey literature intended for the general public accurately reflects the evidence.

METHOD

Four databases (Cochrane CENTRAL, EmBASE, PsycINFO, PubMed) were searched from inception to 4th August 2021. Eligible peer-reviewed studies were empirical studies which examined the efficacy of omega-3 supplements in preventing/treating anxiety and/or depression symptoms in young people aged 14-24. Risk of bias was assessed for randomised studies using the Cochrane Risk of Bias Tool. Selected grey literature databases were also searched, with eligible sources assessed for quality. A stakeholder group including young people with lived experience of anxiety/depression, parents/carers and mental health professionals informed the research questions and data interpretation. Findings were summarised using narrative synthesis.

RESULTS

17 empirical studies (N = 1240 participants) meeting inclusion criteria were identified. Studies varied in treatment and participant characteristics. In general, the data did not support the view that omega-3 supplements were efficacious in improving symptoms of anxiety or depression in young people aged 14-24. In contrast, most grey literature sources recommended the use of omega-3 supplements in young people.

DISCUSSION

Evidence for efficacy of omega-3 supplementation in reducing symptoms of depression and anxiety in young people was inconclusive. More research is needed to identify potential mechanisms and moderators of the effect of omega-3 supplements on depression and anxiety symptoms in young people.

The role of diet in managing menopausal symptoms: A narrative review

Menopause is a natural stage that occurs when women stop menstruating, during which many women experience physical and psychological symptoms that can affect their quality of life and ability to work. Dietary modifications and food supplements may be explored by some women as alternatives to hormone replacement therapy, although existing reviews and expert position statements have given this limited consideration. This narrative review summarises the current evidence for dietary patterns, and botanical and food supplements, in the management of common menopausal symptoms, including vasomotor symptoms (VMS; hot flushes; night sweats), changes in bodyweight and composition, psychological symptoms (depression; anxiety; cognitive changes), sleep disturbances, joint pain, skin changes and urogenital symptoms. Soy isoflavones may reduce the frequency and/or severity of VMS, although results are inconsistent, and it is unclear whether dietary and supplemental sources have comparable effects. Adopting a healthier dietary pattern may support a healthy bodyweight and benefit VMS. However, evidence suggesting dietary patterns may benefit depression, anxiety, and cognition remains largely observational. While some botanicals, such as black cohosh and St John's Wort, have been reported in some studies to alleviate symptoms (such as VMS and depression), these are not currently recommended due to uncertainty about the appropriate dose and preparation, and potential safety concerns. Evidence for other symptoms is currently too limited to draw conclusions. While further trials at different menopausal stages are needed, adopting a healthier dietary pattern in accordance with dietary guidelines is likely to help support women's health before, during and after the menopausal transition.

A Preliminary Comparison of Plasma Tryptophan Metabolites and Medium- and Long-Chain Fatty Acids in Adult Patients with Major Depressive Disorder and Schizophrenia

Background and Objectives: Disturbance of tryptophan (Trp) and fatty acid (FA) metabolism plays a role in the pathogenesis of psychiatric disorders. However, quantitative analysis and comparison of plasma Trp metabolites and medium- and long-chain fatty acids (MCFAs and LCFAs) in adult patients with major depressive disorder (MDD) and schizophrenia (SCH) are limited. Materials and Methods: Clinical symptoms were assessed and the level of Trp metabolites and MCFAs and LCFAs for plasma samples from patients with MDD (n = 24) or SCH (n = 22) and healthy controls (HC, n = 23) were obtained and analyzed. Results: We observed changes in Trp metabolites and MCFAs and LCFAs with MDD and SCH and found that Trp and its metabolites, such as N-formyl-kynurenine (NKY), 5-hydroxyindole-3-acetic acid (5-HIAA), and indole, as well as omega-3 polyunsaturated fatty acids (N3) and the ratio of N3 to omega-6 polyunsaturated fatty acids (N3: N6), decreased in both MDD and SCH patients. Meanwhile, levels of saturated fatty acids (SFA) and monounsaturated fatty acids (MUFA) decreased in SCH patients, and there was a significant difference in the composition of MCFAs and LCFAs between MDD and SCH patients. Moreover, the top 10 differential molecules could distinguish the two groups of diseases from HC and each other with high reliability. Conclusions: This study provides a further understanding of dysfunctional Trp and FA metabolism in adult patients with SCH or MDD and might develop combinatorial classifiers to distinguish between these disorders.

Dietary Fats and Depressive Symptoms in Italian Adults

BACKGROUND

Depression represents one of the major causes of disability worldwide, with an important socioeconomic cost. Although many risk factors have been considered in its pathogenesis, nutrition seems to play a determinant role in its prevention. With regard to individual macronutrients, dietary fats and especially n-3 polyunsaturated fatty acids (n-3 PUFA) are the most studied. However, previous data about other dietary fatty acids, such as n-6 PUFA, are conflicting, and little is known about saturated fatty acids (SFA), especially when considering carbon chain length. Thus, we investigated whether single types and subtypes of dietary fats are related to depressive symptoms in Italian individuals living in the Mediterranean area.

METHODS

Dietary and socio-demographic data of 1572 individuals were analyzed. Food frequency questionnaires (FFQs) were used to determine the consumption of total dietary fat and each specific class of dietary fat, such as SFA, monounsaturated fatty acid (MUFA), and PUFA. The intake of fatty acids was also assessed according to the carbon-chain length of each single class. The Center for Epidemiologic Studies Depression Scale (CES-D) was used as a screening tool for depressive symptoms.

RESULTS

After adjustment for potential confounding factors, a significant inverse association between low/moderate levels of PUFA intake and depressive symptoms (Q2 vs. Q1, odds ratio (OR) = 0.60, 95% CI: 0.44, 0.84) was found. On the other hand, moderate saturated fat consumption was associated with depressive symptoms (Q3 vs. Q1, OR = 1.44, 95% CI: 1.02, 2.04). However, when considering carbon chain length, individuals with a lower to moderate intake of short-chain saturated fatty acids (SCSFA) and medium-chain saturated fatty acids (MCSFA) were less likely to have depressive symptoms (Q3 vs. Q1, OR = 0.48, 95% CI: 0.31, 0.75), while moderate intake of arachidic acid (C20:0) was directly associated with depressive symptoms (Q3 vs. Q1, OR = 1.87, 95% CI: 1.26, 2.77). Among single MUFAs, higher myristoleic acid (C14:1) intake was directly associated with depressive symptoms (Q4 vs. Q1, OR = 1.71, 95% CI: 1.12, 2.61), while moderate intake of erucic acid (C22:1) was associated with lower odds of having depressive symptoms (Q3 vs. Q1, OR = 0.54, 95% CI: 0.33, 0.86). When considering individual PUFAs, individuals with moderate and higher intakes of arachidonic acid (C20:4) were less likely to have depressive symptoms (OR = 0.64, 95% CI: 0.45, 0.91; OR = 0.59, 95% CI: 0.38, 0.91, respectively). Similarly, higher eicosapentaenoic acid (C20:5) intake was inversely associated with depressive symptoms (Q4 vs. Q1, OR = 0.35, 95% CI: 0.12, 0.98), while a significant association for docosahexaenoic acid (C22:6) was retrieved only for low intakes (Q2 vs. Q1, OR = 0.33, 95% CI: 0.12, 0.88).

CONCLUSIONS

Dietary fat intake may be associated with depressive symptoms, underlying the importance of distinguishing between different fat types. This study confirms the pivotal role of PUFAs and reopens the debate on the role of saturated fatty acids, suggesting plausible effects of moderate intakes of short-chain fatty acids.

Anti-Inflammatory Treatment Efficacy in Major Depressive Disorder: A Systematic Review of Meta-Analyses

Purpose

Immune imbalances in major depressive disorder (MDD) have been targeted by anti-inflammatory treatment approaches in clinical trials to increase responsiveness to therapy. However, even after several meta-analyses, no translation of evidence into clinical practice has taken place. We performed a systematic review to evaluate meta-analytic evidence of randomized controlled trials on the use of anti-inflammatory agents for MDD to summarize efficacy estimates and elucidate shortcomings.

Methods

Pooled effect estimates and heterogeneity indices were primary outcomes. Characteristics of the included meta-analyses were extracted. Scientific quality of meta-analyses was assessed using the Revised Assessment of Multiple Systematic Reviews (R-AMSTAR).

Results

N=20 meta-analyses met the eligibility criteria. Study characteristics like outcome scales, composition of patient populations, and add-on or monotherapy regimen varied very little for celecoxib studies, varied little for minocycline studies, and were rather variable for omega 3 fatty acids studies. R-AMSTAR scores ranged from 26 to 39 out of 44 points indicating variable quality, where a comprehensive literature search was the strongest and the consideration of scientific quality in the conclusions was the weakest domain across all meta-analyses. For minocycline and celecoxib, superiority was demonstrated with medium to large effect size with substantial heterogeneity and with large to very large effect size with negligible heterogeneity, respectively. For omega 3 fatty acids, superiority was also demonstrated with mainly small and medium effect sizes with substantial heterogeneity. However, for minocycline and omega 3 fatty acids, non-significant meta-analyses were found also.

Conclusion

Even in our synthesized approach, no clear recommendations could be derived on the use of anti-inflammatory treatment for MDD due to several critical aspects like heterogeneity, diversity of patient populations, treatment regimen, and outcomes, and limited scientific quality. However, we observed clear inter-substance differences with meta-analytic evidence being strongest for celecoxib and weakest for omega 3 fatty acids.

The association of dietary macronutrient quality indices with depression and anxiety symptoms and quality of life in Iranian adults: The LipoKAP study

BACKGROUND

Macronutrients' quality may impact differently on mental health and quality of life (QOL). This study aimed to investigate the potential relationship between the carbohydrate quality index (CQI), fat quality index (FQI), protein quality index (PQI), the affective mental symptoms and QOL among Iranian adults.

METHODS

The LipoKAP is a cross-sectional study, conducted with 2456 adults in Iran. A validated food frequency questionnaire was used to evaluate usual dietary intakes. A validated Iranian version of the Hospital Anxiety and Depression Scale was used to assess the severity of anxiety and depression. QOL was assessed by EQ-5D.

RESULT

In the fully adjusted model, participants in the highest tertile of CQI had lower QOL than those in the lowest tertile (OR = 1.35; 95 % CI: 1.06, 1.73). Individuals in the top tertile of FQI (OR = 0.71; 95 % CI: 0.55, 0.91) and PQI (OR = 0.78; 95 % CI: 0.60; 1.01) were less likely to report lower QOL than those in the bottom tertile. An inverse association was found between PQI and depressive symptoms (OR = 0.72, 95 % CI: 0.55, 0.95), but not for CQI and FQI.

LIMITATIONS

The cross-sectional design of the study and the use of a memory-based dietary tool may limit the generalizability of our findings.

CONCLUSION

Higher PQI was associated with lower risk of depressive symptoms and having a low-quality life. Although CQI and FQI were not related to depressive and anxiety symptoms, higher values of FQI were associated with better QOL, while CQI showed an inverse association.

Genome-Wide Association Analysis of Over 170,000 Individuals from the UK Biobank Identifies Seven Loci Associated with Dietary Approaches to Stop Hypertension (DASH) Diet

Diet is a modifiable risk factor for common chronic diseases and mental health disorders, and its effects are under partial genetic control. To estimate the impact of diet on individual health, most epidemiological and genetic studies have focused on individual aspects of dietary intake. However, analysing individual food groups in isolation does not capture the complexity of the whole diet pattern. Dietary indices enable a holistic estimation of diet and account for the intercorrelations between food and nutrients. In this study we performed the first ever genome-wide association study (GWA) including 173,701 individuals from the UK Biobank to identify genetic variants associated with the Dietary Approaches to Stop Hypertension (DASH) diet. DASH was calculated using the 24 h-recall questionnaire collected by UK Biobank. The GWA was performed using a linear mixed model implemented in BOLT-LMM. We identified seven independent single-nucleotide polymorphisms (SNPs) associated with DASH. Significant genetic correlations were observed between DASH and several educational traits with a significant enrichment for genes involved in the AMP-dependent protein kinase (AMPK) activation that controls the appetite by regulating the signalling in the hypothalamus. The colocalization analysis implicates genes involved in body mass index (BMI)/obesity and neuroticism (ARPP21, RP11-62H7.2, MFHAS1, RHEBL1). The Mendelian randomisation analysis suggested that increased DASH score, which reflect a healthy diet style, is causal of lower glucose, and insulin levels. These findings further our knowledge of the pathways underlying the relationship between diet and health outcomes. They may have significant implications for global public health and provide future dietary recommendations for the prevention of common chronic diseases.

DHA/EPA supplementation decreases anxiety-like behaviour, but it does not ameliorate metabolic profile in obese male rats

Obesity is a major public health problem that predisposes to several diseases and higher mortality in patients with COVID-19. Obesity also generates neuroinflammation, which predisposes to the development of neuropsychiatric diseases. Since there is a lack of effective treatments for obesity, the search for new strategies to reverse its consequences is urgent. In this perspective, the anti-inflammatory properties of omega-3 polyunsaturated fatty acids such as DHA/EPA might reduce the harmful effects of obesity. Here, we used the cafeteria diet (CAF) model to induce obesity in Wistar rats. Animals received ultra-processed food for 20 weeks, and DHA/EPA supplementation (500 mg/kg per d) was performed between the 16th and the 20th week. At the end of the experiment, it was evaluated: body weight, visceral fat deposition, plasma glucose, insulin and triglycerides, and it was also measured the levels of inflammatory cytokines TNF-α and IL-6 in plasma and liver, and TNF-α in the prefrontal cortex. The elevated plus maze test was performed to analyse anxiety-like behaviour. Our results demonstrated that DHA/EPA could not reverse weight and fat gain and did not modify plasma dosages. However, there was a decrease in IL-6 in the liver (DHA/EPA effect: P = 0.023) and TNF-α in the brain (CAF compared with CAF + DHA/EPA, P < 0.05). Also, there was a decrease in the anxiety index in CAF + DHA/EPA compared with the CAF group (P < 0.01). Thus, DHA/EPA supplementation is helpful to reverse the consequences of obesity in the brain.

Vegan nutrition: a preliminary guide for health professionals

Since the beginning of the 21st century, interest in vegan diets has been rapidly increasing in most countries. Misconceptions about vegan diets are widespread among the general population and health professionals. Vegan diets can be health-promoting and may offer certain important advantages compared to typical Western (and other mainstream) eating patterns. However, adequate dietary sources/supplements of nutrients of focus specific to vegan diets should be identified and communicated. Without supplements/fortified foods, severe vitamin B12 deficiency may occur. Other potential nutrients of focus are calcium, vitamin D, iodine, omega-3 fatty acids, iron, zinc, selenium, vitamin A, and protein. Ensuring adequate nutrient status is particularly important during pregnancy, lactation, infancy, and childhood. Health professionals are often expected to be able to provide advice on the topic of vegan nutrition, but a precise and practical vegan nutrition guide for health professionals is lacking. Consequently, it is important and urgent to provide such a set of dietary recommendations. It is the aim of this article to provide vegan nutrition guidelines, based on current evidence, which can easily be communicated to vegan patients/clients, with the goal of ensuring adequate nutrient status in vegans.

Omega-3 Polyunsaturated Fatty Acids Supplementation Alleviate Anxiety Rather Than Depressive Symptoms Among First-Diagnosed, Drug-Naïve Major Depressive Disorder Patients: A Randomized Clinical Trial

Background

Omega-3 polyunsaturated fatty acids (n-3 PUFAs) augmentation of antidepressants has shown great potential in the prevention and treatment of major depressive disorders (MDD).

Objective

To investigate the effect of n-3 PUFAs plus venlafaxine in patients with first-diagnosed, drug-naïve depression.

Method

A total of 72 outpatients with first-diagnosed depression were recruited. The daily dose of 2.4 g/day n-3 PUFAs or placebo plus venlafaxine was used for over 12 weeks. The outcomes were assessed by the Hamilton depression scale (HAMD), Hamilton anxiety scale (HAMA), Beck depression inventory (BDI), and Self-rating anxiety scale (SAS).

Results

Both groups exhibited improvement on clinical characteristics at week 4 and week 12 compared with baseline. The rate of responders for anxiety in n-3 PUFAs group (44.44%) was significantly higher than that in placebo group (21.21%) at week 4 (χ² = 4.182, p = 0.041), while week 12 did not show a difference (χ² = 0.900, p = 0.343). The rate of responders for depression at both week 4 (χ² = 0.261, p = 0.609) and week 12 (χ² = 1.443, p = 0.230) showed no significant difference between two groups. Further analysis found that Childhood Trauma Questionnaire (CTQ) had positive correlation with HAMA (r = 0.301, p = 0.012), SAS (r = 0.246, p = 0.015), HAMD (r = 0.252, p = 0.038) and BDI (r = 0.233, p = 0.022) with Pearson correlation analysis. Social Support Rating Scale (SSRS) had negative correlation with SAS (r = -0.244, p = 0.015) and BDI (r = -0.365, p = 0.000).

Conclusion

This trial found that n-3 PUFAs supplementation in favor of venlafaxine alleviated the anxiety symptoms rather than depressive symptoms at the early stage of treatment (4 weeks) for first-diagnosed, drug-naïve depressed patients. However, the advantage disappeared in long-term treatment. Furthermore, childhood abuse and social support are closely related to the clinical and biological characteristics of depression. Both childhood trauma and lack of social support might be predictors of poor prognosis in depression.

Clinical Trial Registration

[clinicaltrials.gov], identifier [NCT03295708].

Dietary Long-Chain n-3 Polyunsaturated Fatty Acid Supplementation Alters Electrophysiological Properties in the Nucleus Accumbens and Emotional Behavior in Naïve and Chronically Stressed Mice

Long-chain (LC) n-3 polyunsaturated fatty acids (PUFAs) have drawn attention in the field of neuropsychiatric disorders, in particular depression. However, whether dietary supplementation with LC n-3 PUFA protects from the development of mood disorders is still a matter of debate. In the present study, we studied the effect of a two-month exposure to isocaloric diets containing n-3 PUFAs in the form of relatively short-chain (SC) (6% of rapeseed oil, enriched in α-linolenic acid (ALA)) or LC (6% of tuna oil, enriched in eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA)) PUFAs on behavior and synaptic plasticity of mice submitted or not to a chronic social defeat stress (CSDS), previously reported to alter emotional and social behavior, as well as synaptic plasticity in the nucleus accumbens (NAc). First, fatty acid content and lipid metabolism gene expression were measured in the NAc of mice fed a SC (control) or LC n-3 (supplemented) PUFA diet. Our results indicate that LC n-3 supplementation significantly increased some n-3 PUFAs, while decreasing some n-6 PUFAs. Then, in another cohort, control and n-3 PUFA-supplemented mice were subjected to CSDS, and social and emotional behaviors were assessed, together with long-term depression plasticity in accumbal medium spiny neurons. Overall, mice fed with n-3 PUFA supplementation displayed an emotional behavior profile and electrophysiological properties of medium spiny neurons which was distinct from the ones displayed by mice fed with the control diet, and this, independently of CSDS. Using the social interaction index to discriminate resilient and susceptible mice in the CSDS groups, n-3 supplementation promoted resiliency. Altogether, our results pinpoint that exposure to a diet rich in LC n-3 PUFA, as compared to a diet rich in SC n-3 PUFA, influences the NAc fatty acid profile. In addition, electrophysiological properties and emotional behavior were altered in LC n-3 PUFA mice, independently of CSDS. Our results bring new insights about the effect of LC n-3 PUFA on emotional behavior and synaptic plasticity.

Diet and Anxiety: A Scoping Review

Anxiety disorders are the most common group of mental disorders. There is mounting evidence demonstrating the importance of nutrition in the development and progression of mental disorders such as depression; however, less is known about the role of nutrition in anxiety disorders. This scoping review sought to systematically map the existing literature on anxiety disorders and nutrition in order to identify associations between dietary factors and anxiety symptoms or disorder prevalence as well as identify gaps and opportunities for further research. The review followed established methodological approaches for scoping reviews. Due to the large volume of results, an online program (Abstrackr) with artificial intelligence features was used. Studies reporting an association between a dietary constituent and anxiety symptoms or disorders were counted and presented in figures. A total of 55,914 unique results were identified. After a full-text review, 1541 articles met criteria for inclusion. Analysis revealed an association between less anxiety and more fruits and vegetables, omega-3 fatty acids, "healthy" dietary patterns, caloric restriction, breakfast consumption, ketogenic diet, broad-spectrum micronutrient supplementation, zinc, magnesium and selenium, probiotics, and a range of phytochemicals. Analysis revealed an association between higher levels of anxiety and high-fat diet, inadequate tryptophan and dietary protein, high intake of sugar and refined carbohydrates, and "unhealthy" dietary patterns. Results are limited by a large percentage of animal and observational studies. Only 10% of intervention studies involved participants with anxiety disorders, limiting the applicability of the findings. High quality intervention studies involving participants with anxiety disorders are warranted.

Normobaric oxygen treatment for mild-to-moderate depression: a randomized, double-blind, proof-of-concept trial

Oxygen enriched air may increase oxygen pressure in brain tissue and have biochemical effects even in subjects without lung disease. Consistently, several studies demonstrated that normobaric oxygen treatment has clinical benefits in some neurological conditions. This study examined the efficacy of normobaric oxygen treatment in subjects with depression. In a randomized, double-blind trial, 55 participants aged 18-65 years with mild to moderate depression (had a Hamilton Rating Scale for Depression [HRSD] score of ≥ 8) were recruited to the study from the Southern district in Israel. Participants underwent a psychiatric inclusion assessment at baseline and then were randomly assigned to either normobaric oxygen treatment of 35% fraction of inspired oxygen or 21% fraction of inspired oxygen (room air) through a nasal tube, for 4 weeks, during the night. Evaluations were performed at baseline, 2 and 4 weeks after commencement of study interventions, using the following tools: HRSD; Clinical Global Impression (CGI) questionnaire; World Health Organization-5 questionnaire for the estimation of Quality of Life (WHO-5-QOL); Sense of Coherence (SOC) 13-item questionnaire; and, Sheehan Disability Scale (SDS). A multivariate regression analysis showed that the mean ± standard deviation [SD] changes in the HRSD scores from baseline to week four were - 4.2 ± 0.3 points in the oxygen-treated group and - 0.7 ± 0.6 in the control group, for a between-group difference of 3.5 points (95% confidence interval [CI] - 5.95 to - 1.0; P = 0.007). Similarly, at week four there was a between-group difference of 0.71 points in the CGI score (95% CI - 1.00 to - 0.29; P = 0.001). On the other hand, the analysis revealed that there were no significant differences in WHO-5-QOL, SOC-13 or SDS scores between the groups. This study showed a significant beneficial effect of oxygen treatment on some symptoms of depression.Trial registration: NCT02149563 (29/05/2014).

Role of dietary factors in the prevention and treatment for depression: an umbrella review of meta-analyses of prospective studies

The role of diet in depression is becoming increasingly acknowledged. This umbrella review aimed to summarize comprehensively the current evidence reporting the effects of dietary factors on the prevention and treatment of depression. PubMed, Embase, and the Cochrane Library were searched up to June 2021 to identify relevant meta-analyses of prospective studies. Twenty-eight meta-analyses, with 40 summary estimates on dietary patterns (n = 8), food and beverages (n = 19), and nutrients (n = 13) were eligible. The methodological quality of most meta-analyses was low (50.0%) or very low (25.0%). Quality of evidence was moderate for inverse associations for depression incidence with healthy diet [risk ratio (RR): 0.74, 95% confidential interval (CI), 0.48-0.99, I2 = 89.8%], fish (RR: 0.88, 95% CI, 0.79-0.97, I2 = 0.0%), coffee (RR: 0.89, 95% CI, 0.84-0.94, I2 = 32.9%), dietary zinc (RR: 0.66, 95% CI 0.50-0.82, I2 = 13.9%), light to moderate alcohol (<40 g/day, RR: 0.77, 95% CI, 0.74-0.83, I2 = 20.5%), as well as for positive association with sugar-sweetened beverages (RR: 1.05, 95% CI, 1.01-1.09, I2 = 0.0%). For depression treatment, moderate-quality evidence was identified for the effects of probiotic [standardized mean difference (SMD): -0.31, 95% CI, -0.56 to -0.07, I2 = 48.2%], omega-3 polyunsaturated fatty acid (SMD: -0.28, 95% CI, -0.47 to -0.09, I2 = 75.0%) and acetyl-L-carnitine (SMD: -1.10, 95% CI, -1.65 to -0.56, I2 = 86.0%) supplementations. Overall, the associations between dietary factors and depression had been extensively evaluated, but none of them were rated as high quality of evidence, suggesting further studies are likely to change the summary estimates. Thus, more well-designed research investigating more detailed dietary factors in association with depression is warranted.

Long-term effects of increasing omega-3, omega-6 and total polyunsaturated fats on inflammatory bowel disease and markers of inflammation: a systematic review and meta-analysis of randomized controlled trials

BACKGROUND AND AIM

Effects of long-chain omega-3 (LCn3) and omega-6 fatty acids on prevention and treatment of inflammatory bowel diseases (IBD, including Crohn's Disease, CD and ulcerative colitis, UC), and inflammation are unclear. We systematically reviewed long-term effects of omega-3, omega-6 and total polyunsaturated fats (PUFA) on IBD diagnosis, relapse, severity, pharmacotherapy, quality of life and key inflammatory markers.

METHODS

We searched Medline, Embase, Cochrane CENTRAL, and trials registries, including RCTs in adults with or without IBD comparing higher with lower omega-3, omega-6 and/or total PUFA intake for ≥ 24 weeks that assessed IBD-specific outcomes or inflammatory biomarkers.

RESULTS

We included 83 RCTs (41,751 participants), of which 13 recruited participants with IBD. Increasing LCn3 may reduce risk of IBD relapse (RR 0.85, 95% CI 0.72-1.01) and IBD worsening (RR 0.85, 95% CI 0.71-1.03), and reduce erythrocyte sedimentation rate (ESR, SMD - 0.23, 95% CI - 0.44 to - 0.01), but may increase IBD diagnosis risk (RR 1.10, 95% CI 0.63-1.92), and faecal calprotectin, a specific inflammatory marker for IBD (MD 16.1 μg/g, 95% CI - 37.6 to 69.8, all low-quality evidence). Outcomes for alpha-linolenic acid, omega-6 and total PUFA were sparse, but suggested little or no effect where data were available.

CONCLUSION

This is the most comprehensive meta-analysis of RCTs investigating long-term effects of omega-3, omega-6 and total PUFA on IBD and inflammatory markers. Our findings suggest that supplementation with PUFAs has little or no effect on prevention or treatment of IBD and provides little support for modification of long-term inflammatory status.

Beneficial Outcomes of Omega-6 and Omega-3 Polyunsaturated Fatty Acids on Human Health: An Update for 2021

Oxidative stress and inflammation have been recognized as important contributors to the risk of chronic non-communicable diseases. Polyunsaturated fatty acids (PUFAs) may regulate the antioxidant signaling pathway and modulate inflammatory processes. They also influence hepatic lipid metabolism and physiological responses of other organs, including the heart. Longitudinal prospective cohort studies demonstrate that there is an association between moderate intake of the omega-6 PUFA linoleic acid and lower risk of cardiovascular diseases (CVDs), most likely as a result of lower blood cholesterol concentration. Current evidence suggests that increasing intake of arachidonic acid (up to 1500 mg/day) has no adverse effect on platelet aggregation and blood clotting, immune function and markers of inflammation, but may benefit muscle and cognitive performance. Many studies show that higher intakes of omega-3 PUFAs, especially eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), are associated with a lower incidence of chronic diseases characterized by elevated inflammation, including CVDs. This is because of the multiple molecular and cellular actions of EPA and DHA. Intervention trials using EPA + DHA indicate benefit on CVD mortality and a significant inverse linear dose-response relationship has been found between EPA + DHA intake and CVD outcomes. In addition to their antioxidant and anti-inflammatory roles, omega-3 fatty acids are considered to regulate platelet homeostasis and lower risk of thrombosis, which together indicate their potential use in COVID-19 therapy.

Omega-3 nutraceuticals, climate change and threats to the environment: The cases of Antarctic krill and Calanus finmarchicus

The nutraceutical market for EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid) is promoting fishing for Euphasia superba (Antarctic krill) in the Southern Ocean and Calanus finmarchicus in Norwegian waters. This industry argues that these species are underexploited, but they are essential in their ecosystems, and climate change is altering their geographical distribution. In this perspective, we advocate the cessation of fishing for these species to produce nutraceuticals with EPA and DHA. We argue that this is possible because, contrary to what this industry promotes, the benefits of these fatty acids only seem significant to specific population groups, and not for the general population. Next, we explain that this is desirable because there is evidence that these fisheries may interact with the impact of climate change. Greener sources of EPA and DHA are already available on the market, and their reasonable use would ease pressure on the Arctic and Antarctic ecosystems.

Plasma polyunsaturated fatty acids and mental disorders in adolescence and early adulthood: cross-sectional and longitudinal associations in a general population cohort

Polyunsaturated fatty acids (PUFAs) may be pertinent to the development of mental disorders, for example via modulation of inflammation and synaptogenesis. We wished to examine cross-sectional and longitudinal associations between PUFAs and mental disorders in a large cohort of young people. Participants in the Avon Longitudinal Study of Parents and Children were interviewed and provided blood samples at two sampling periods when approximately 17 and 24 years old. Plasma PUFA measures (total omega-6 [n-6], total omega-3 [n-3], n-6:n-3 ratio and docosahexaenoic acid [DHA] percentage of total fatty acids) were assessed using nuclear magnetic resonance spectroscopy. Cross-sectional and longitudinal associations between standardised PUFA measures and three mental disorders (psychotic disorder, moderate/severe depressive disorder and generalised anxiety disorder [GAD]) were measured by logistic regression, adjusting for age, sex, body mass index and cigarette smoking. There was little evidence of cross-sectional associations between PUFA measures and mental disorders at age 17. At age 24, the n-6:n-3 ratio was positively associated with psychotic disorder, depressive disorder and GAD, while DHA was inversely associated with psychotic disorder. In longitudinal analyses, there was evidence of an inverse association between DHA at age 17 and incident psychotic disorder at age 24 (adjusted odds ratio 0.44, 95% confidence interval 0.22-0.87) with little such evidence for depressive disorder or GAD. There was little evidence for associations between change in PUFA measures from 17 to 24 years and incident mental disorders at 24 years. These findings provide support for associations between PUFAs and mental disorders in early adulthood, and in particular, for DHA in adolescence in relation to prevention of psychosis.