Altered omega-3 polyunsaturated fatty acid status in depressed post-myocardial infarction patients

How lipids may affect risk for suicidal behavior

Suicide and nonfatal suicidal behaviors are major causes of mortality and morbidity worldwide. Variability in rates of suicide and suicidal behaviors within and between countries has been attributed to population and individual risk factors, including economic status and cultural differences, both of which can have suicide risk effects mediated through a variety of factors, of which perhaps the least understood is the role of diet. We therefore review the scientific literature concerning two major dietary lipid classes, cholesterol and polyunsaturated fatty acids (PUFAs), that have been associated with higher risk of suicide attempts and suicide. We consider potential mechanistic intermediates including serotonin transporters and receptors, toll-like receptors (TLRs), nuclear factor kappa-light-chain-enhancer of activated B cells (NFκB), and peroxisome proliferator activated receptors (PPARs). Based on this review, we describe a theoretical model linking cholesterol and PUFA status to suicide risk, taking into account the effects of cholesterol-lowering interventions on PUFA balance, membrane lipid microdomains (rafts) as a nexus of interaction between cholesterol and omega-3 PUFAs, and downstream effects on serotonergic neurotransmission and specific inflammatory pathways.

Biological profiling of prospective antidepressant response in major depressive disorder: Associations with (neuro)inflammation, fatty acid metabolism, and amygdala-reactivity

BACKGROUND

A better understanding of factors underlying antidepressant non-response may improve the prediction of which patients will respond to what treatment. Major depressive disorder (MDD) is associated with alterations in fatty acid metabolism, (neuro)inflammation and amygdala-reactivity. However, their mutual relations, and the extent to which they are associated with prospective antidepressant-response, remain unknown.

PURPOSE

To test (I) alterations in (neuro)inflammation and its associations with fatty acid metabolism and amygdala-reactivity in MDD-patients compared to controls, and (II) whether these alterations are associated with prospective paroxetine response.

METHODS

We compared 70 unmedicated MDD-patients with 51 matched healthy controls at baseline, regarding erythrocyte membrane omega-6 arachidonic acid (AA), inflammation [serum (high-sensitivity) C-reactive protein (CRP)], and in a subgroup amygdala-reactivity to emotional faces using functional magnetic resonance imaging (fMRI) (N=42). Subsequently, we treated patients with 12 weeks paroxetine, and repeated baseline measures after 6 and 12 weeks to compare non-responders, early-responders (response at 6 weeks), and late-responders (response at 12 weeks).

RESULTS

Compared to controls, MDD-patients showed higher CRP (p=0.016) and AA (p=0.019) after adjustment for confounders at baseline. AA and CRP were mutually correlated (p=0.043). In addition, patients showed a more negative relation between AA and left amygdala-reactivity (p=0.014). Moreover, AA and CRP were associated with antidepressant-response: early responders showed lower AA (p=0.018) and higher CRP-concentrations (p=0.008) than non-responders throughout the study.

CONCLUSION

Higher observed CRP and AA, their mutual association, and relation with amygdala-reactivity, are corroborative with a role for (neuro)inflammation in MDD. In addition, observed associations of these factors with prospective antidepressant-response suggest a potential role as biomarkers. Future studies in independent samples are needed to replicate and test the clinical applicability of these biological predictors for treatment response to result in a precision/personalized medicine approach for treatment.

Pathways of polyunsaturated fatty acid utilization: implications for brain function in neuropsychiatric health and disease

Essential polyunsaturated fatty acids (PUFAs) have profound effects on brain development and function. Abnormalities of PUFA status have been implicated in neuropsychiatric diseases such as major depression, bipolar disorder, schizophrenia, Alzheimer's disease, and attention deficit hyperactivity disorder. Pathophysiologic mechanisms could involve not only suboptimal PUFA intake, but also metabolic and genetic abnormalities, defective hepatic metabolism, and problems with diffusion and transport. This article provides an overview of physiologic factors regulating PUFA utilization, highlighting their relevance to neuropsychiatric disease.

Role of omega-3 fatty acids in the treatment of depressive disorders: a comprehensive meta-analysis of randomized clinical trials

Background

Despite omega-3 polyunsaturated fatty acids (PUFA) supplementation in depressed patients have been suggested to improve depressive symptomatology, previous findings are not univocal.

Objectives

To conduct an updated meta-analysis of randomized controlled trials (RCTs) of omega-3 PUFA treatment of depressive disorders, taking into account the clinical differences among patients included in the studies.

Methods

A search on MEDLINE, EMBASE, PsycInfo, and the Cochrane Database of RCTs using omega-3 PUFA on patients with depressive symptoms published up to August 2013 was performed. Standardized mean difference in clinical measure of depression severity was primary outcome. Type of omega-3 used (particularly eicosapentaenoic acid [EPA] and docosahexaenoic acid [DHA]) and omega-3 as mono- or adjuvant therapy was also examined. Meta-regression analyses assessed the effects of study size, baseline depression severity, trial duration, dose of omega-3, and age of patients.

Results

Meta-analysis of 11 and 8 trials conducted respectively on patients with a DSM-defined diagnosis of major depressive disorder (MDD) and patients with depressive symptomatology but no diagnosis of MDD demonstrated significant clinical benefit of omega-3 PUFA treatment compared to placebo (standardized difference in random-effects model 0.56 SD [95% CI: 0.20, 0.92] and 0.22 SD [95% CI: 0.01, 0.43], respectively; pooled analysis was 0.38 SD [95% CI: 0.18, 0.59]). Use of mainly EPA within the preparation, rather than DHA, influenced final clinical efficacy. Significant clinical efficacy had the use of omega-3 PUFA as adjuvant rather than mono-therapy. No relation between efficacy and study size, baseline depression severity, trial duration, age of patients, and study quality was found. Omega-3 PUFA resulted effective in RCTs on patients with bipolar disorder, whereas no evidence was found for those exploring their efficacy on depressive symptoms in young populations, perinatal depression, primary disease other than depression and healthy subjects.

Conclusions

The use of omega-3 PUFA is effective in patients with diagnosis of MDD and on depressive patients without diagnosis of MDD.

Omega-3 fatty acids and depression: scientific evidence and biological mechanisms

The changing of omega-6/omega-3 polyunsaturated fatty acids (PUFA) in the food supply of Western societies occurred over the last 150 years is thought to promote the pathogenesis of many inflammatory-related diseases, including depressive disorders. Several epidemiological studies reported a significant inverse correlation between intake of oily fish and depression or bipolar disorders. Studies conducted specifically on the association between omega-3 intake and depression reported contrasting results, suggesting that the preventive role of omega-3 PUFA may depend also on other factors, such as overall diet quality and the social environment. Accordingly, tertiary prevention with omega-3 PUFA supplement in depressed patients has reached greater effectiveness during the last recent years, although definitive statements on their use in depression therapy cannot be yet freely asserted. Among the biological properties of omega-3 PUFA, their anti-inflammatory effects and their important role on the structural changing of the brain should be taken into account to better understand the possible pathway through which they can be effective both in preventing or treating depression. However, the problem of how to correct the inadequate supply of omega-3 PUFA in the Westernized countries' diet is a priority in order to set food and health policies and also dietary recommendations for individuals and population groups.

ω-3 fatty acid intakes are inversely related to elevated depressive symptoms among United States women

Evidence that depressive symptoms are inversely related to n-3 (ω-3) fatty acids is growing among United States adults. We assessed whether self-reported depressive symptoms were inversely associated with n-3 fatty acid intakes by using a cross-sectional study in 1746 adults (aged 30-65 y) in Baltimore City, MD (2004-2009). The 20-item Center for Epidemiologic Studies-Depression Scale (CES-D) was used, with a CES-D score ≥16 suggestive of elevated depressive symptoms (EDS). By using the mean of two 24-h dietary recalls, n-3 highly unsaturated fatty acids (HUFAs; ≥20 carbons), n-3 polyunsaturated fatty acids (PUFAs; ≥18 carbons), and plausible ratios with n-6 (ω6) fatty acids were estimated. EDS prevalence was 18.1% among men and 25.6% among women. In women, the uppermost tertile (tertile 3) of n-3 PUFAs (compared with tertile 1) was associated with reduced odds of EDS by 49%, with a substantial sex differential. The n-3 PUFA:n-6:PUFA ratio was inversely related to EDS among women (tertile 2 vs. tertile 1, OR: 0.74; 95% CI: 0.41, 1.32; tertile 3 vs. tertile 1, OR: 0.47; 95% CI: 0.27, 0.83). A similar pattern was noted for n-3 HUFA:n-6 HUFA among women. For CES-D subscales, n-3 PUFA (% of energy) was inversely related to somatic complaints, whereas positive affect was directly related to n-3 HUFA (% of energy; total population and among women), n-3 HUFA:n-6 HUFA (women), and n-3 HUFA:n-6 PUFA (total population and among women). In sum, among United States women, higher intakes of n-3 fatty acids [absolute (n-3) and relative to n-6 fatty acids (n-3:n-6)] were associated with lower risk of elevated depressive symptoms, specifically in domains of somatic complaints (mainly n-3 PUFAs) and positive affect (mainly n-3 HUFAs).

Omega-3 polyunsaturated fatty acid (PUFA) status in major depressive disorder with comorbid anxiety disorders

BACKGROUND

Although lower levels of omega-3 polyunsaturated fatty acids (PUFAs) are found in major depressive disorder, less is known about PUFA status and anxiety disorders.

METHOD

Medication-free participants with DSM-IV-defined major depressive disorder (MDD), with (n = 18) and without (n = 41) comorbid DSM-IV anxiety disorders, and healthy volunteers (n = 62) were recruited from October 2006 to May 2010 for mood disorder studies at the New York State Psychiatric Institute. Participants were 18-73 years of age (mean age, 35.8 ± 12.6 years). Depression and anxiety severity was assessed using depression and anxiety subscales from the 17-item Hamilton Depression Rating Scale. Plasma PUFAs eicosapentaenoic acid (EPA; 20:5n-3) and docosahexaenoic acid (DHA; 22:6n-3) and the ratio of arachidonic acid (AA; 22:4n-6) to EPA (AA:EPA) were quantified. This secondary analysis employed analysis of variance with a priori planned contrasts to test for diagnostic group differences in log-transformed PUFA levels (logDHA, logEPA, and logAA:EPA).

RESULTS

Plasma levels of logDHA (F(2,118) = 4.923, P = .009), logEPA (F(2,118) = 6.442, P = .002), and logAA:EPA (F(2,118) = 3.806, P = .025) differed across groups. Participants with MDD had lower logDHA (t(118) = 2.324, P = .022) and logEPA (t(118) = 3.175, P = .002) levels and higher logAA:EPA levels (t(118) = -2.099, P = .038) compared with healthy volunteers. Lower logDHA (t(118) = 2.692, P = .008) and logEPA (t(118) = 2.524, P = .013) levels and higher logAA:EPA levels (t(118) = -2.322, P = .022) distinguished anxious from nonanxious MDD. Depression severity was not associated with PUFA plasma levels; however, anxiety severity across the entire sample correlated negatively with logDHA (r(p) = -0.22, P = .015) and logEPA (r(p) = -0.25, P = .005) levels and positively with logAA:EPA levels (r(p) = 0.18, P = .043).

CONCLUSIONS

The presence and severity of comorbid anxiety were associated with the lowest EPA and DHA levels. Further studies are needed to elucidate whether omega-3 PUFA supplementation may preferentially alleviate MDD with more severe anxiety.

Emerging risk factors for postpartum depression: serotonin transporter genotype and omega-3 fatty acid status

OBJECTIVE

Depression is a leading cause of disability and hospitalization. Women are at the highest risk of depression during their childbearing years, and the birth of a child may precipitate a depressive episode in vulnerable women. Postpartum depression (PPD) is associated with diminished maternal somatic health as well as health and developmental problems in their offspring. This review focuses on 2 PPD risk factors of emerging interest: serotonin transporter (5-HTT) genotype and omega-3 polyunsaturated fatty acid (n-3 PUFA) status.

METHOD

The MEDLINE, PubMed, and Web of Science databases were searched using the key words postpartum depression, nutrition, omega-3 fatty acids, and serotonin transporter gene. Studies were also located by reviewing the reference lists of selected articles.

RESULTS

Seventy-five articles were identified as relevant to this review. Three carefully conducted studies reported associations between the 5-HTT genotype and PPD. As well, there is accumulating evidence that n-3 PUFA intake is associated with risk of PPD. Preliminary evidence suggests that there could be an interaction between these 2 emerging risk factors. However, further studies are required to confirm such an interaction and to elucidate the underlying mechanisms.

CONCLUSIONS

Evidence to date supports a research agenda clarifying the associations between n-3 PUFAs, the 5-HTT genotype, and PPD. This is of particular interest owing to the high prevalence of poor n-3 PUFA intake among women of childbearing age and the consequent potential for alternative preventive measures and treatments for PPD.

Fish consumption and severely depressed mood, findings from the first national nutrition follow-up study

The evidence obtained from prospective studies to support the hypothesis that fish consumption may improve mental status remains limited. The current study prospectively assessed a low frequency of fish consumption as a risk factor for depressed mood. Included were 5068 adults aged 25-74 years examined in 1971-1975 as the baseline of the First National Health and Nutrition Examination Survey Follow-up Study. Frequency of eating fish at baseline was obtained using a 3-month food frequency questionnaire. Severely depressed mood (SDM) was defined as the Center for Epidemiologic Studies Depression Scale scores ≥22 or taking anti-depressants. After an average of 10.6 years of follow-up, among men (n=2039), the percentage of individuals with SDM was 11.7%. Compared with frequent consumers (more than once a week), the odds ratios (ORs) were 1.43 (95%CI=0.66-3.11) and 2.08 (1.08-4.09) respectively for the men eating fish once a week and less than once a week (p for trend=0.03). Among women (n=3029), the percentage of individuals with SDM was 17.89%. The ORs were 1 (reference), 0.91 (0.68-1.22) and 1.15 (0.83-1.59) respectively for the women eating fish more than once, once, and less than once a week. These estimates were obtained after adjustment for indicators of social deprivation and major physical diseases. The study concluded that independently from social deprivation and physical diseases, low fish consumption was a risk factor for SDM among men. Further studies are needed to confirm these findings and elucidate mechanisms for the difference between men and women.

A meta-analytic review of polyunsaturated fatty acid compositions in patients with depression

BACKGROUND

On the basis of evidence from studies showing the antidepressant effects of omega-3 polyunsaturated fatty acids and the inverse relation between fish consumption and the prevalence of depression, the phospholipid hypothesis seems promising in ascertaining the etiology and treatment of depression. Although several studies have shown lower levels of omega-3 (n-3) polyunsaturated fatty acids in depressive patients, the results of individual polyunsaturated fatty acids, including docosahexaenoic acid (DHA), eicosapentaenoic acid (EPA), and the omega-6 (n-6) polyunsaturated fatty acid arachidonic acid (AA), were inconsistent.

METHODS

We conducted the meta-analyses of 14 studies comparing the levels of polyunsaturated fatty acids between depressive patients and control subjects. The effect size of each study was synthesized by using a random effects model.

RESULTS

Compared with control subjects, the levels of EPA, DHA, and total n-3 polyunsaturated fatty acids were significantly lower in depressive patients. There was no significant change in AA or total n-6 polyunsaturated fatty acids.

CONCLUSIONS

The results showed lower levels of EPA, DHA, and total n-3 polyunsaturated fatty acids in patients with depression, thus implying that n-3 polyunsaturated fatty acids play a role in the pathogenesis of depression. Our findings provide further support to the phospholipid hypothesis of depression and a rationale for using n-3 polyunsaturated fatty acids as an alternative treatment for depression. With these results, future studies examining specific roles of DHA and EPA in different clusters of depressive symptoms are warranted.

Oiling the brain: a review of randomized controlled trials of omega-3 fatty acids in psychopathology across the lifespan

Around one in four people suffer from mental illness at some stage in their lifetime. There is increasing awareness of the importance of nutrition, particularly omega-3 polyunsaturated fatty acids (n-3 PUFA), for optimal brain development and function. Hence in recent decades, researchers have explored effects of n-3 PUFA on mental health problems over the lifespan, from developmental disorders in childhood, to depression, aggression, and schizophrenia in adulthood, and cognitive decline, dementia and Alzheimer's disease in late adulthood. This review provides an updated overview of the published and the registered clinical trials that investigate effects of n-3 PUFA supplementation on mental health and behavior, highlighting methodological differences and issues.

Nutrition and late-life depression: etiological considerations

Depression is a debilitating mental disorder that frequently occurs in older adults, especially in those with vascular diseases. Nutritional factors have the potential to decrease the occurrence of late-life depression but have not been adequately studied. Low folate levels, disturbed omega-3 fatty acid metabolism and obesity have been associated with depression, and may be causal factors. Longitudinal studies are urgently needed in order to examine the potential of dietary factors to prevent late-life depression.

Association of n-3 long-chain PUFA and fish intake with depressive symptoms and low dispositional optimism in older subjects with a history of myocardial infarction

Individuals with CHD are at increased risk of poor mental well-being. Dietary intake of EPA and DHA, the main n-3 fatty acids from fish, may be beneficial to mental well-being. We examined the association of EPA+DHA and fish intake with mental well-being in 644 participants, aged 60–80 years, with a history of myocardial infarction. Habitual food intake was assessed with a 203-item FFQ. Depressive symptoms were assessed with the self-report geriatric depression scale, and dispositional optimism was assessed with the revised life orientation test (LOT-R) and a four-item questionnaire (4Q). In Cox-regression models modified for cross-sectional analyses, we adjusted for sex, age, energy intake, BMI, family history of depression, education, marital status, smoking, physical activity and intake of saturated fat, alcohol and fibre. Compared with the lower tertile, subjects in the higher tertile of EPA+DHA intake had a lower prevalence of depressive symptoms, but this association was not statistically significant (prevalence ratio (PR) 0·78; 95 % CI 0·50, 1·22, P-trend 0·27). The higher tertile of EPA+DHA intake was positively associated with dispositional optimism measured with the 4Q (PR 0·69; 95 % CI 0·46, 1·03, P-trend 0·05), but not according to the LOT-R. Fish intake was not related to either depressive symptoms or dispositional optimism. In conclusion, intake of EPA+DHA was positively associated with dispositional optimism assessed with the 4Q, but not with optimism assessed with the LOT-R or with depressive symptoms.

Nutrition, mood and behaviour: a review

OBJECTIVE

To conduct a critical review of recent empirical research regarding mood, behaviour and nutrition factors including essential fatty acids, macronutrients, micronutrients and food additives.

METHOD

A literature search of databases Medline, PsycInfo, CINAHL and Embase up to October 2008. The search emphasised empirical research published in the last 10 years and also included older literature. Studies in both adults and children were addressed.

RESULTS

Research into omega-3 fatty acids has been substantial but evidence for their potential in treating mood and behaviour is modest. In comparison, there has been much less research into carbohydrate and protein intakes and little evidence for their ability to influence mood and behaviour. Recent trials with food additives suggest their removal from the diet may benefit susceptible children with hyperactivity disorders. Micronutrient supplementation appears to improve mood only in those who were initially deficient in micronutrients.

CONCLUSIONS

More stringent research designs such as longitudinal studies and the use of biologically inert placebos within randomised controlled trials are needed before supplemental use of omega-3 fatty acids to treat disorders of mood and behaviour can be recommended. Caution is advised regarding the indiscriminate use of diets free of artificial food additives in managing hyperactivity disorders, as they may place an undue burden on individuals and their families. Should omega-3 fatty acid supplementation or the elimination of certain food additives be established as effective, they may provide cost-effective, accessible and well-tolerated adjuncts to standard psychiatric treatments for mood and behavioural disturbances.

Considerations regarding neuropsychiatric nutritional requirements for intakes of omega-3 highly unsaturated fatty acids

BACKGROUND

Adverse neurodevelopmental and neuropsychiatric outcomes have been established as signs of nutrient deficiencies and may be applicable to insufficient dietary intakes of omega-3 highly unsaturated fatty acids (n-3 HUFAs).

OBJECTIVE

Consider if statistical definitions for Daily Reference Intakes can be applied to n-3 HUFAs intakes during pregnancy for maternal and neurodevelopmental deficiencies.

DESIGN

Data were prospectively collected from women during pregnancy and children up to age 8 years participating in the Avon Longitudinal Study of Parents and Children (ALSPAC). Statistical analyses took social and lifestyle factors into account.

RESULTS

During pregnancy, n-3 HUFA intakes from seafood that putatively meet statistical definitions of an estimated average requirement ranged from 0.05 to 0.06 en% (111-139 mg/d/2000 Cal) for suboptimal fine motor control at 42 m and 0.065-0.08 en% (114-181 mg/d/2000 Cal) for suboptimal verbal IQ at age 8 years and 0.18-0.22 en% (389-486 mg/d/2000 Cal) for maternal depression at 32 weeks. Intakes of n-3 ranging from 0.2 to 0.41 en% (445-917 mg/d/2000 Cal) prevented both increased risk of maternal depression and adverse neurodevelopmental outcomes for children among 97.5% of the population. No upper limit for safety was found.

CONCLUSION

During pregnancy, a n-3 HUFA intake of 0.40 en% (900 mg/d/2000 Cal) from seafood is likely to meet the nutritional requirements for 97.5% of the mothers and children of this population. These considerations do not constitute DRI's for docosahexaenoic acid and n-3 HUFAs, but may contribute to their formulation.

Is there a role for n-3 long-chain polyunsaturated fatty acids in the regulation of mood and behaviour? A review of the evidence to date from epidemiological studies, clinical studies and intervention trials

Selected biochemical evidence suggests a potential role for n-3 long-chain PUFA (n-3PUFA) in the regulation of mood and behaviour. The present paper reviews the relevant evidence, to date, from epidemiological studies, clinical studies and intervention trials. Most evidence is available investigating a role for n-3PUFA in depression, depressive illness and suicidal behaviour, but work is also available on anxiety and anxiety-related disorders, fatigue and fatigue-related disorders, aggression, hostility and anti-social behaviour, inattention, impulsivity and attention deficit hyperactivity disorder and schizophrenic disorders. For all these aspects of mood and behaviour, the evidence available is currently limited and highly inconsistent, both in terms of study methodology and study findings. There is a clear need for further work in this area.

Treatment of post-myocardial infarction depressive disorder

Both major and minor depressive disorder post-myocardial infarction (MI) are associated with an increased risk of all-cause mortality, cardiac mortality and new cardiovascular events. Post-MI depressive disorder predicts slow recovery and poor quality of life. This review attends to post-MI depressive disorder, its underlying mechanisms and options for and effects of treatment. Evidence has been found for several mechanisms to be involved in the pathophysiology, including hypothalamus-pituitary-adrenal axis activity, immune activity, polyunsaturated fatty acids, serotonin, platelet activation, type D personality and negative health behavior. Five leading randomized controlled trials are discussed, showing safety and efficacy of antidepressive treatment in post-MI patients. Effects on cardiac outcome remain unclear.

The role of fatty acids in the development and treatment of mood disorders

PURPOSE OF REVIEW

There is increasing evidence from epidemiological, case-control and randomized clinical trials for a link between omega-3 deficiency and the development of mood disorders. This article examines recent evidence for this association.

RECENT FINDINGS

During the past year our understanding of the effect of omega-3 depletion on the structure and function of the brain has been furthered by research examining human brain tissue and by studies utilizing animal models of depression. Human and animal research has also provided further evidence for omega-3 affecting mood via its anti-inflammatory effects. Previous clinical trials indicated that omega-3 can be effective as an adjunctive treatment for those with treatment-resistant depression. More recent clinical trial data indicate that omega-3 may also be an effective monotherapy for childhood depression and for depressed mood in patients who engage in recurrent self-harm. The recent clinical trial data regarding omega-3 as a treatment for bipolar disorder are inconclusive, however, and clinical trials in postnatal depression are still lacking.

SUMMARY

This article reviews the most important recent papers in this burgeoning and interesting research area.