Exploring the therapeutic potential of omega-3 fatty acids in depression

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).

Specific Foods Associated with Depressive Symptoms among Young Adults and Their Bioactive Effects

Depression represents a widespread and devastating psychiatric public health challenge globally. It is particularly prevalent among young adults in Korea. Certain foods may have medicinal properties that alleviate depressive symptoms. This study aimed to examine the association between specific foods and depressive symptoms among young adults, exploring their bioactive effects and possible mechanisms. We conducted a cross-sectional study involving 1000 Korean young adults aged 18-39 years. Food frequency questionnaires were used to assess diets and their associations with depressive symptoms. Results from multivariable logistic regression analysis indicated associations between several specific foods and their effects: milk (odds ratio = 0.58, 95% confidence interval: 0.36-0.94), eggs (0.55, 0.35-0.87), bananas (0.58, 0.36-0.94), oranges (0.62, 0.40-0.96), sweet potatoes (0.60, 0.37-0.97), mushrooms (0.53, 0.31-0.92, females only), and kimchi (0.40, 0.17-0.95, males only). Furthermore, molecular docking indicated that hesperidin had the highest docking score of 5.86 in oranges. Several bioactive compounds identified as potentially beneficial in combatting depression include calcium, casein, alpha-lactalbumin, tryptophan (TRP), vitamin B6 and B12, magnesium, flavonoids (especially hesperidin), carotenoids, ergothioneine, fiber, and probiotics. To recommend these foods in the management of depression among young adults, further clinical intervention studies are necessary.

Omega-3 long-chain polyunsaturated fatty acids: Metabolism and health implications

Recently, omega-3 long-chain polyunsaturated fatty acids (n-3 LC-PUFAs) have gained substantial interest due to their specific structure and biological functions. Humans cannot naturally produce these fatty acids (FAs), making it crucial to obtain them from our diet. This comprehensive review details n-3 LC-PUFAs and their role in promoting and maintaining optimal health. The article thoroughly analyses several sources of n-3 LC-PUFAs and their respective bioavailability, covering marine, microbial and plant-based sources. Furthermore, we provide an in-depth analysis of the biological impacts of n-3 LC-PUFAs on health conditions, with particular emphasis on cardiovascular disease (CVD), gastrointestinal (GI) cancer, diabetes, depression, arthritis, and cognition. In addition, we highlight the significance of fortification and supplementation of n-3 LC-PUFAs in both functional foods and dietary supplements. Additionally, we conducted a detailed analysis of the several kinds of n-3 LC-PUFAs supplements currently available in the market, including an assessment of their recommended intake, safety, and effectiveness. The dietary guidelines associated with n-3 LC-PUFAs are also highlighted, focusing on the significance of maintaining a well-balanced intake of n-3 PUFAs to enhance health benefits. Lastly, we highlight future directions for further research in this area and their potential implications for public health.

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.

Saturated and Polyunsaturated Fatty Acids Production by Aurantiochytrium limacinum PKU#Mn4 on Enteromorpha Hydrolysate

Thraustochytrids are unicellular marine heterotrophic protists, which have recently shown a promising ability to produce omega-3 fatty acids from lignocellulosic hydrolysates and wastewaters. Here we studied the biorefinery potential of the dilute acid-pretreated marine macroalgae (Enteromorpha) in comparison with glucose via fermentation using a previously isolated thraustochytrid strain (Aurantiochytrium limacinum PKU#Mn4). The total reducing sugars in the Enteromorpha hydrolysate accounted for 43.93% of the dry cell weight (DCW). The strain was capable of producing the highest DCW (4.32 ± 0.09 g/L) and total fatty acids (TFA) content (0.65 ± 0.03 g/L) in the medium containing 100 g/L of hydrolysate. The maximum TFA yields of 0.164 ± 0.160 g/g DCW and 0.196 ± 0.010 g/g DCW were achieved at 80 g/L of hydrolysate and 40 g/L of glucose in the fermentation medium, respectively. Compositional analysis of TFA revealed the production of equivalent fractions (% TFA) of saturated and polyunsaturated fatty acids in hydrolysate or glucose medium. Furthermore, the strain yielded a much higher fraction (2.61-3.22%) of eicosapentaenoic acid (C20:5n-3) in the hydrolysate medium than that (0.25-0.49%) in the glucose medium. Overall, our findings suggest that Enteromorpha hydrolysate can be a potential natural substrate in the fermentative production of high-value fatty acids by thraustochytrids.

Omega-3 Fatty Acids Supplementation in the Treatment of Depression: An Observational Study

Depression is a common mood disorder characterized by persistent sadness and loss of interest. Research suggests an association between the inclusion of omega-3 fatty acids in the diet and a reduced risk for depression. The present study evaluated the effectiveness of omega-3 fatty acid supplements in alleviating depressive symptoms in patients with mild to moderate depression. A total of 165 patients suffering from mild to moderated depression were randomized to receive omega-3 fatty acid supplementation, an antidepressant (single agent), or a combination of an antidepressant and omega-3 fatty acid supplementation. The clinical features of depression were assessed using the Hamilton Depression Rating Scale (HDRS) during the follow-up period. A statistically significant improvement in depressive symptoms was observed from baseline to first, second and third follow-ups within each treatment arm as measured by HRDS scores (p = 0.00001). Further, the HDRS scores at the third follow-up were significantly lower in patients on combination therapy of omega-3 fatty acid supplement and antidepressants (arm-3) than the patients on the omega-3 fatty acid supplement alone (arm-1) [Q = 5.89; p = 0.0001] or the patients taking an antidepressant alone (arm 2) [Q = 4.36; p = 0.0068]. The combination of an omega-3 fatty acid supplement and an antidepressant elicited significantly higher improvement in depressive symptoms than the supplement or the antidepressant alone.

Dietary inflammatory index, and depression and mortality risk associations in U.S. adults, with a special focus on cancer survivors

Introduction

A higher risk for depression and mortality is associated with the inflammatory potential of diet measured through the Dietary Inflammatory Index (DII). The roles of DII in the risk of depression and death in cancer survivors were unclear. We aimed to examine the association between energy-adjusted DII (E-DII) score and risk of depression, and mortality using data from the 2007-2018 National Health and Nutrition Examination Survey (NHANES), with a special focus on cancer survivors.

Methods

The 24-h dietary recall interview was used as a basis to calculate the E-DII score and the Patient Health Questionnaire-9 (PHQ-9) was used to measure the depressive outcomes. Logistic regression analyses were performed to determine the association between quartiles of E-DII score and depression. Cox proportional hazard regression and competing risk analyses were used to estimate the risks of quartiles of E-DII score or depression on mortality.

Results

A total of 27,447 participants were included; including 24,694 subjects without cancer and 2,753 cancer survivors. The E-DII score and depression were not distributed differently between the two groups. However, the E-DII scores were positively associated with within each group's depression (all P trend < 0.001) and participants with higher E-DII scores had a higher risk of depression (subjects without cancer: OR_{Q4 vs Q1}: 2.17, 95% CI: 1.75-2.70; cancer survivors: OR_{Q4 vsQ1}: 1.78, 95% CI: 1.09-2.92). The median follow-up time were 87 person-months, a total of 1,701 (4.8%) and 570 (15.2%) all-cause deaths in subjects without cancer and cancer survivors were identified by the end of 2019. The highest E-DII scores quartile was associated with the highest risk of all-cause (HR_{Q4 vsQ1}: 1.90, 95% CI: 1.54-2.35) and cardiovascular disease (CVD) cause death (HR_{Q4 vsQ1}: 2.50, 95% CI: 1.69-2.3.7) in the subjects without cancer. Moreover, participants with depressive symptoms had higher all-cause mortality (HR: 1.29, 95% CI: 1.04-1.59). No significant correlation was found for E-DII scores or depression with all-cause, cancer-cause or CVD-cause mortality in cancer survivors.

Conclusion

Our findings demonstrate that E-DII score was positively associated with depression risk. A higher E-DII score or depressive symptom may increase the risks of all-cause and CVD-cause mortality only among general subjects.

Biological Role of Nutrients, Food and Dietary Patterns in the Prevention and Clinical Management of Major Depressive Disorder

Major Depressive Disorder (MDD) is a growing disabling condition affecting around 280 million people worldwide. This complex entity is the result of the interplay between biological, psychological, and sociocultural factors, and compelling evidence suggests that MDD can be considered a disease that occurs as a consequence of an evolutionary mismatch and unhealthy lifestyle habits. In this context, diet is one of the core pillars of health, influencing multiple biological processes in the brain and the entire body. It seems that there is a bidirectional relationship between MDD and malnutrition, and depressed individuals often lack certain critical nutrients along with an aberrant dietary pattern. Thus, dietary interventions are one of the most promising tools to explore in the field of MDD, as there are a specific group of nutrients (i.e., omega 3, vitamins, polyphenols, and caffeine), foods (fish, nuts, seeds fruits, vegetables, coffee/tea, and fermented products) or dietary supplements (such as S-adenosylmethionine, acetyl carnitine, creatine, amino acids, etc.), which are being currently studied. Likewise, the entire nutritional context and the dietary pattern seem to be another potential area of study, and some strategies such as the Mediterranean diet have demonstrated some relevant benefits in patients with MDD; although, further efforts are still needed. In the present work, we will explore the state-of-the-art diet in the prevention and clinical support of MDD, focusing on the biological properties of its main nutrients, foods, and dietary patterns and their possible implications for these patients.