Marine omega-3 fatty acids and mood disorders--linking the sea and the soul. 'Food for Thought' I

Macronutrients and the state of happiness and mood in undergraduate youth of a military training course

BACKGROUND AND AIMS

Previous studies have reported a high prevalence of mental disorders among military organizations. Depression and anxiety are among the most important mental disorders, and depression, suicidal ideation, and violence have been found to be negatively associated with happiness and social support. Therefore, improving mood and increasing happiness can reduce the prevalence of mental disorders in military centers. Diet can improve happiness through specific molecular mechanisms and change our mood by affecting the chemical composition of the brain. Therefore, the present study examined the relationship between the quality and quantity of macronutrients in soldiers' diets with their mood and happiness.

METHODS

In the current cross-sectional study, 300 healthy soldiers were selected. Food intake data was collected using 168-item semi-quantitative food frequency questionnaire during the last year of their military training 2-year period. Then, we calculated the quality and quantity of macronutrients. Mood was assessed using the Profile of Mood States (POMS) questionnaire and happiness with the Oxford Happiness Questionnaire (OHQ).

RESULTS

The mean ± standard deviation of participants' age was 23.70 ± 1.76 years. A significant relationship was observed between mood score and carbohydrate quantity (OR: 0.32, 95% CI: 0.12-0.88, P-value for trend = 0.03). This suggests that increasing carbohydrate intake improved the participants' mood. No association was found between mood score with protein quantity (OR: 2.15, 95% CI: 0.80-5.75; P-value for trend = 0.12), and gram of fat intake (OR: 1.95, 95% CI: 0.74-5.13; P-value for trend = 0.15). None of the indicators related to macronutrient quality were significantly associated with happiness and mood scores in young soldiers (P ≥ 0.05).

CONCLUSIONS

Findings presented in this study showed that increased carbohydrate intake was significantly associated with better mood. However, mood is not related to the amount of proteins and fats and none of the parameters of macronutrient quality. Also, there was no significant relationship between the quantity and quality of macronutrients with happiness score.

Dietary Inflammatory Index and Health Outcomes: An Umbrella Review of Systematic Review and Meta-Analyses of Observational Studies

Background and Aims: The dietary inflammatory index (DII) is associated with non-communicable disease. We conducted an umbrella review to systematically evaluate meta-analyses of observational studies on DII and diverse health outcomes.

Methods: We comprehensively searched the PubMed, Web of Science, and Embase databases to identify related systematic reviews and meta-analyses of observational studies. Those investigating the association between DII and a wide range of health outcomes in humans were eligible for inclusion. For each meta-analysis, we estimated the summary effect size by using fixed and random effects models, the 95% confidence interval, and the 95% prediction interval. We assessed heterogeneity, evidence of small-study effects, and excess significance bias.

Results: The umbrella review identified 35 meta-analyses assessing associations between DII and various health outcomes: cancer (n = 24), mortality (n = 4), metabolic (n = 4), and other (n = 3). The methodological quality was high or moderate. Of the 35 meta-analyses, we observed highly suggestive evidence for harmful associations between digestive tract cancer, colorectal cancer, overall cancer, pharyngeal cancer, UADT cancer, and CVD mortality. Moreover, 11 harmful associations showed suggestive evidence: hormone-dependent cancer, rectal cancer, colon cancer, breast and prostate cancer, gynecological cancer, breast cancer, ovarian cancer, colorectal cancer, prostate cancer, all-cause mortality, and depression.

Conclusion: DII is likely to be associated with harmful effects in multiple health outcomes. Robust randomized controlled trials are warranted to understand whether the observed results are causal.

Systematic Review Registration: CRD42021218361

A Pro-Inflammatory Diet Is Associated With an Increased Odds of Depression Symptoms Among Iranian Female Adolescents: A Cross-Sectional Study

Background: The relation between dietary inflammation and risk of depression has not been widely explored. We examined the association between the inflammatory effect of the diet and the odds of depression among Iranian female adolescents. Methods: Using a stratified cluster sampling technique, 300 female adolescents aged 15-18 years were recruited from schools in Tehran between years 2014-2015. Depression was assessed using the Depression, Anxiety and Stress Scale (DASS)- a 21-point scale. The dietary inflammatory index (DII®) was used to evaluate the inflammatory potential of the diet. Dietary intake was assessed using a validated food frequency questionnaire. In addition to descriptive statistics, multivariable linear and logistic regression were used to calculate confounder-adjusted beta estimates and odds ratios. Results: In total, 88 females (30%) had at least a moderate level of depressive symptoms (DASS > 6). Females with the most pro-inflammatory diet had higher DASS depression score (β = 1.67; 95% CI = 0.03, 3.31) and were at 3.96 (95% CI = 1.12, 13.97) times higher odds of having at least moderate depressive symptoms, compared to females with the least anti-inflammatory diets. Conclusion: These data suggest that Iranian adolescent females eating a pro-inflammatory diet, as indicated by higher DII scores, had greater odds of having at least moderate depressive symptoms.

Association between inflammatory potential of diet and risk of depression in middle-aged women: the Australian Longitudinal Study on Women's Health

Dietary factors and inflammation markers have been shown to play a role in the development of depression. However, there are very few studies that have explored the association between inflammatory potential of diet and risk of depression. In this study, we examined the association between the dietary inflammatory index (DII), which was developed specifically to measure the inflammatory potential of diet, and risk of depression in the middle-aged cohort of the Australian Longitudinal Study on Women's Health. A total of 6438 women with a mean age of 52·0 (sd 1·4) years at baseline were followed-up at five surveys over 12 years (2001-2013). Depression was defined as a score of ≥10 on the Center for Epidemiologic Studies Depression-10 scale. The DII score, a literature-derived, population-based dietary index that has been validated against several inflammatory markers, was computed on the basis of dietary intake assessed using a validated FFQ. Generalised estimating equations were used to estimate relative risk (RR) of depression according to DII score. Models were adjusted for energy intake, highest education completed, marital status, menopause status and symptoms, personal illness or injury, smoking status, physical activity, BMI and depression diagnosis or treatment. In total, 1156 women (18 %) had scores≥10 on the CESD scale over the course of 9 years. Women with the most anti-inflammatory diet had an approximately 20 % lower risk of developing depression compared with women with the most pro-inflammatory diet (RRDII quartile 1 v. 4: 0·81; 95 % CI 0·69, 0·96; P trend=0·03). These results suggest that an anti-inflammatory diet is associated with lower risk of depression in middle-aged Australian women.

Is essential fatty acid status in late pregnancy predictive of post-natal depression?

OBJECTIVE

We tested the hypothesis that abnormal levels of omega-3 and omega-6 polyunsaturated fatty acids (PUFAs) during late pregnancy are associated with antenatal and post-natal depression.

METHOD

We interviewed a sample of more than 900 women in late pregnancy. We assessed whether they met criteria for depression on a standardized measure of post-natal depression [the Edinburgh Post-natal Depression Scale (EPDS)] and met DSM-IV criteria for major depression and/or were in receipt of antidepressant medication. Blood was collected at that time to generate data on nine PUFA variables. Sample members were re-interviewed post-natally to determine depressive experience in the 3 months following the birth of their baby.

RESULTS

Univariate associations were demonstrated between pre-natal depression categorized using DSM criteria and measures of blood fatty acids including total omega-3, the ratio of omega-6 to omega-3, docosahexaenoic acid (DHA) omega-3 and DHA plus eicosapentaenoic acid (EPA) omega-3. Such associations were not found post-natally, but different associations were quantified between EPDS-diagnosed depression and total omega-6, total omega-3 and EPA omega-3. In multivariate analyses, slight associations were maintained between EPDS and lower omega-3, lower EPA and higher omega-6 when neuroticism, stress during pregnancy, a lifetime episode of depression and older age were included in the analysis.

CONCLUSION

Findings in such a large sample indicate that PUFA status in late pregnancy is only slightly linked with the risk of post-natal depression when depression was quantified by the EPDS. There were no associations between post-natal depression diagnosed by DSM criteria and any fatty acid variables.

Effects of oxidative stress on fatty acid- and one-carbon-metabolism in psychiatric and cardiovascular disease comorbidity

OBJECTIVE

Cardiovascular disease (CVD) is the leading cause of death in severe psychiatric disorders (depression, schizophrenia). Here, we provide evidence of how the effects of oxidative stress on fatty acid (FA) and one-carbon (1-C) cycle metabolism, which may initially represent adaptive responses, might underlie comorbidity between CVD and psychiatric disorders.

METHOD

We conducted a literature search and integrated data in a narrative review.

RESULTS

Oxidative stress, mainly generated in mitochondria, is implicated in both psychiatric and cardiovascular pathophysiology. Oxidative stress affects the intrinsically linked FA and 1-C cycle metabolism: FAs decrease in chain length and unsaturation (particularly omega-3 polyunsaturated FAs), and lipid peroxidation products increase; the 1-C cycle shifts from the methylation to transsulfuration pathway (lower folate and higher homocysteine and antioxidant glutathione). Interestingly, corresponding alterations were reported in psychiatric disorders and CVD. Potential mechanisms through which FA and 1-C cycle metabolism may be involved in brain (neurocognition, mood regulation) and cardiovascular system functioning (inflammation, thrombosis) include membrane peroxidizability and fluidity, eicosanoid synthesis, neuroprotection and epigenetics.

CONCLUSION

While oxidative-stress-induced alterations in FA and 1-C metabolism may initially enhance oxidative stress resistance, persisting chronically, they may cause damage possibly underlying (co-occurrence of) psychiatric disorders and CVD. This might have implications for research into diagnosis and (preventive) treatment of (CVD in) psychiatric patients.

Suicide mortality in relation to dietary intake of n-3 and n-6 polyunsaturated fatty acids and fish: equivocal findings from 3 large US cohort studies

Intake of n-3 and n-6 polyunsaturated fatty acids (PUFAs) has been implicated in the pathogenesis of depression. We sought to estimate the association between intake of fish and n-3 and n-6 PUFAs and suicide mortality over the course of long-term follow-up. In this prospective cohort study, biennial questionnaires were administered to 42,290 men enrolled in the Health Professionals Follow-up Study (1988-2008), 72,231 women enrolled in the Nurses' Health Study (1986-2008), and 90,836 women enrolled in Nurses' Health Study II (1993-2007). Dietary fish and n-3 and n-6 PUFA intakes were assessed every 4 years using a validated food-frequency questionnaire. Suicide mortality was ascertained through blind physician review of death certificates and hospital or pathology reports. Adjusted relative risks of suicide mortality were estimated with multivariable Cox proportional hazards models and pooled across cohorts using random-effects meta-analysis. The pooled multivariable relative risks for suicide among persons in the highest quartile of intake of n-3 or n-6 PUFAs, relative to the lowest quartile, ranged from 1.08 to 1.46 for n-3 PUFAs (Ptrend = 0.11-0.52) and from 0.68 to 1.19 for n-6 PUFAs (Ptrend = 0.09-0.54). We did not find evidence that intake of n-3 PUFAs or fish lowered the risk of completed suicide.

Fish oil as a management component for mood disorders - an evolving signal

PURPOSE OF REVIEW

To overview the theoretical relevance of omega-3 and omega-6 fatty acids in the cause of mood disorders, and focus on evaluating the potential therapeutic role of omega-3 fatty acids.

RECENT FINDINGS

Numerous studies have documented low omega-3 fatty acid levels in those with depressive disorders, and there are plausible biological explanations as to why reduced omega-3 status may predispose to mood disorders as well as to a range of other conditions. Although early studies evaluating the role of omega-3 preparations as treatments of depression were generally positive, the rate of negative or nondifferential studies has increased in recent years. Recent meta-analyses provide an explanation in suggesting that docosahexaenoic acid-weighted preparations may be ineffective while finding support for eicosapentaenoic acid (EPA)-weighted preparations.

SUMMARY

There is sufficient indicative data favouring EPA-weighted omega-3 supplementation for those with a depressive mood disorder, particular when fish oil is viewed by patients as 'natural,' it has few side effects and is neuroprotective. Recent meta-analyses inform us that intervention studies should focus on EPA-weighted preparations.

Effects of omega 3 fatty acids supplementation in behavior and non-neurodegenerative neuropsychiatric disorders

This work provides a systematic review of all published randomised, controlled clinical trials (RCT) investigating the effects ofn-3 PUFA intake on the prevention and treatment of non-neurodegenerative neuropsychiatric disorders. Five databases (PubMed, EMBASE, LILACS, CINAHL and The Cochrane Database) were searched for RCT in this area published up to April 2011. The selected studies all involved human participants and included a comparison group. Thirty eight studies were identified, which examined the influence ofn-3 PUFA supplementation on the prevention/treatment of depression (non-perinatal) (n23), perinatal depression (n6) and attention deficit hyperactivity disorder (ADHD) (n9). Great heterogeneity was noticed in terms of study design, the doses ofn-3 PUFA administered, and study duration. Some benefit was noted with respect to the treatment of hyperactivity and depression in over half the examined studies, although the evidence was not conclusive. For any firm conclusions to be drawn, further studies will be needed that take into account the initialn-3 PUFA status of the subjects. Excessiven-3 PUFA intakes might be associated with a greater risk of peroxidation events and therefore neuropsychiatric deterioration. Indeed, some studies only recorded benefits when lower doses were administered. It is therefore important that the dose required to achieve any potential benefit be determined.

Mood effects of the amino acids tryptophan and tyrosine: 'Food for Thought' III

OBJECTIVE

Reflecting increased scientific interest in any nutritional contribution to the onset and treatment of mood disorders, we overview research into two neurotransmitter precursors - the amino acids tryptophan and tyrosine - particularly examining whether any deficiency increases risk to depression and whether those amino acids have any antidepressant properties.

METHOD

The theoretical relevance of the two amino acids was overviewed by considering published risk and intervention studies, technical papers and reviews.

RESULTS

There is some limited evidence, suggesting that depressed patients, especially those with a melancholic depression, have decreased tryptophan levels. Whether such findings reflect a causal contribution or are a consequence of a depressed state remains an open question. There is a small database supporting tryptophan preparations as benefitting depressed mood states. There is no clear evidence as to whether tyrosine deficiency contributes to depression, while the only randomized double-blind study examining tyrosine supplementation did not show antidepressant benefit.

CONCLUSION

Acute tryptophan depletion continues to provide a research tool for investigating the relevance of serotonin to depression onset. There is limited evidence that tryptophan loading is effective as a treatment for depression through its action of increasing serotonin production. Most clinical studies are dated, involve small sample sizes and/or were not placebo controlled. The development of the new serotonin reuptake inhibitor drugs seemingly signalled an end to pursuing such means of promoting increased serotonin as a treatment for depression. The evidence for tyrosine loading promoting catecholamine production as a possible treatment for depression appears even less promising, and depletion studies less informative.

'D' for depression: any role for vitamin D? 'Food for Thought' II

OBJECTIVE

While there has long been interest in any nutritional contribution to the onset and treatment of mood disorders, there has been increasing scientific evaluation of several candidate nutritional and dietary factors in recent years. In this paper, we overview research into any vitamin D insufficiency and deficiency contribution to depression.

METHOD

The relevant literature was reviewed.

RESULTS

Cross-sectional studies have identified associations between depression and low vitamin D levels, but studies have failed to clarify whether vitamin D deficiency is an antecedent cause, correlate or consequence of depression. While vitamin D deficiency and insufficiency have been linked with seasonal affective disorder, suggested associations have not been rigorously tested. There has been insufficient research to establish whether and when vitamin D supplementation should be considered as an augmentation strategy with antidepressant drugs.

CONCLUSION

There is currently insufficient evidence to argue strongly for vitamin D supplementation in patients with depression, but such a strategy is worthy of consideration in depressed patients whose lifestyle and geographical residence may indicate a risk of vitamin D insufficiency--or where low vitamin D levels have been quantified.