Diet and depression: exploring the biological mechanisms of action

Associations of breakfast habits and breakfast quality with depression symptoms: A cross-sectional study based on NHANES 2007-2018

BACKGROUND

Breakfast, often considered the most important meal of the day, affects both physical and mental health. While most studies focused on the effects of skipping breakfast on depression, few explored the roles of breakfast quality and breakfast time. The study aimed to investigate the association of breakfast habits and breakfast quality with depression symptoms.

METHODS

This study included 23,839 participants aged 20 and older from the 2007-2018 National Health and Nutrition Examination Survey (NHANES). Breakfast habits were assessed using two 24-h dietary recalls, capturing both whether and when breakfast was consumed. Breakfast quality was assessed by calculating the Breakfast Quality Score (BQS). Depression symptoms was diagnosed using the Patient Health Questionnaire (PHQ-9). Binary logistic regression was used to explore the associations.

RESULTS

Compared to participants who did not report breakfast, the ORs of participants who reported breakfast on both one recall and both recalls were 0.737(0.591,0.919) and 0.766(0.624,0.939) for depression symptoms. Compared to participants in the BQS T1 subgroup, the ORs of participants in the T2 subgroup and T3 subgroup were 0.895(0.723,1.108) and 0.716(0.564,0.908) for depression symptoms (P for trend = 0.013). Compared to participants who had breakfast before 8:00 AM, the ORs for depression symptoms were 1.104 (95 % CI: 0.888, 1.371) for those who had breakfast between 8:00-9:00 AM and 1.278 (95 % CI: 1.030, 1.587) for those who had breakfast after 9:00 AM.

CONCLUSIONS

Skipping breakfast, low breakfast quality, and late breakfast are independently associated with depression symptoms.

In silico bioprospecting of receptors for Oligoventin: An antimicrobial peptide isolated from spider eggs of Phoneutria nigriventer

BACKGROUND

Irresponsible and wholesale use of antimicrobial agents is the principal cause of the emergence of strains of resistant microorganisms to traditional drugs. Oligoventin is a neutral peptide isolated from spider eggs of Phoneutria nigriventer, with antimicrobial activity against Gram-positive, Gram-negative, and yeast organisms. However, the molecular target and pathways of antimicrobial activity are still unknown. Thus, the aim of the present study is to prospect receptors associated with the antimicrobial activity of Oligoventin using in silico tools.

METHODS

The PharmMapper and PDB server was used to prospect targets originating from microorganisms. Additionally, the PatchDock server was utilized to perform molecular docking between Oligoventin and the targets. Subsequently, the I-TASSER server was adopted to predict the ligand site. Finally, the docking results and predicted sites were compared with literature sites of each target.

RESULTS

Over 100 potential receptors for oligoventin have been identified. Among these, enoyl-ACP reductase (Idpdb1LXC) and thymidylate synthase ThyX (Idpdb 1O28) from bacteria and N-acetylglucosamine phosphate mutase (Idpdb 2DKD) showed superior interaction with oligoventin, exhibiting colocalization between docked residues and cofactor/active sites. These enzymes play a crucial role in fatty acid and DNA biosynthesis in prokaryotes and in cell wall synthesis in yeast.

CONCLUSION

Therefore, in silico results suggest that Oligoventin can impair fatty acid DNA, cell wall synthesis, thereby reducing microbial proliferation and causing microorganism death.

Factors influencing mental health outcomes among university students: a cross-sectional study in Bangladesh

INTRODUCTION

Mental health issues, particularly anxiety and depression, are on the rise among university students globally, including in Bangladesh. However, comprehensive data on the factors influencing mental health outcomes in this group remain limited, hindering the development of effective programmes and interventions.

OBJECTIVES

This study aims to assess the mental health status of university students in Bangladesh and examine the key factors influencing mental health outcomes.

DESIGN

A cross-sectional online survey was conducted in Bangladesh from December 2022 to March 2023.

SETTING

Universities in Bangladesh.

PARTICIPANTS

University students aged 18 and older.

OUTCOME MEASURES

Data were collected through a structured survey that assessed depression and anxiety using the Patient Health Questionnaire and the Generalized Anxiety Disorder scale, as well as dietary diversity through the Individual Dietary Diversity Score.

RESULTS

The results showed that while female students exhibited greater dietary diversity, they also had higher obesity rates, whereas male students reported more physical activity. Mental health assessments revealed that 36.1% of participants experienced mild anxiety, 11.5% severe anxiety, 39.8% mild depression and 8.3% severe depression. Binary logistic regression analysis identified significant predictors of anxiety and depression, including gender, personal income, body mass index and screen time. Females were less likely to experience anxiety (crude odds ratios (COR): 0.531, p =0.034) and depression (COR: 0.591, p =0.023) compared with males. Furthermore, low intake of wheat, rice (COR: 2.123, p=0.050) and pulses (COR: 1.519, p=0.050), as well as high consumption of fats, oils (COR: 2.231, p=0.024) and sugary foods (COR: 2.277, p=0.001), were associated with anxiety, while inadequate intake of vitamin A- and C-rich fruits (COR: 1.435, p =0.018) was linked to depression. Overweight students were found to be more susceptible to depression.

CONCLUSION

The findings of the study emphasise the necessity for targeted interventions that promote healthier lifestyles to enhance mental health outcomes among university students in Bangladesh.

Policy Actions Required to Improve Nutrition for Brain Health

Brain health is a pressing global concern. Poor diet quality is a recognized major environmental risk factor for brain disorders and one of the few that is modifiable. There is substantial evidence that nutrition impacts brain development and brain health across the life course. So why then is the full potential of nutrition not utilized to improve brain function? This commentary, which is based on discussions of the European Brain Research Area BRAINFOOD cluster, aims to highlight the most urgent research priorities concerning the evidence base in the area of nutrition and brain health and identifies 3 major issues that need to be addressed: (1) increase causal and mechanistic evidence on the link between nutrition and brain health, (2) produce effective messages/education concerning the role of food for brain health, and (3) provide funding to support collaborative working across diverse stakeholders.

Depressive symptoms mediate the association between dietary inflammatory index and sleep: A cross-sectional study of NHANES 2005-2014

BACKGROUND

Sleep pattern (sleep duration, trouble sleeping, sleep disorder) is associated with both energy density dietary inflammatory index (EDII) and depression. However, whether depression mediates the EDII-sleep pattern relationship is unclear.

METHODS

14,305 participants from the National Health and Nutrition Examination Survey (NHANES) from 2005 to 2014 were included in this study. Weighted multivariable logistic regression and mediated effect analysis were conducted to analyze the associations between EDII, depression and sleep pattern.

RESULTS

In the regression model with full confounding variables adjusted, the OR (95 % CI) for the association between EDII and sleep pattern was 2.11 (1.44, 3.08). Similarly, comparing the highest to the lowest EDII scores, the association with depression yielded an identical OR of 2.62 (1.89, 3.64). Mediation models showed depressive symptoms mediated 24.06 % of the EDII-sleep pattern link. Analysis by sleep pattern subtypes found depressive symptoms mediated 18.22 % for sleep duration, 30.53 % for sleep disorder (both with substantial direct EDII effects), and 93.73 % for trouble sleeping, where EDII's direct impact was not considerable.

CONCLUSION

Positive association of EDII with unhealthy sleep pattern is partly mediated by depression, and anti-inflammatory diet could be beneficial.

The association between plant and animal protein intake with depression, anxiety, and stress

BACKGROUND

Recent evidence suggests that diet composition is a key biological factor related to the development of depressive disorders. The present study was conducted to investigate the animal and plant protein intake and their replacement in association with depression, anxiety, and stress in Iranian adults.

METHOD

In this cross-sectional study, the dietary intake of 7169 subjects were assessed using a validated food frequency questionnaire. The depression, anxiety, and stress Scale - 21 (DASS-21) questionnaire was used to psychological disorders. Logistic regression was used to obtain odds ratios for depression, anxiety, and stress across quintiles of animal and plant protein.

RESULTS

The participants' age range was 20-69 years. Individuals with the highest animal protein consumption had a lower chance for developing depression compared to those with the lowest intakes (OR = 0.73, 95%CI: 0.59-0.90; Ptrend < 0.01). Results also showed a significant association between animal protein intake and anxiety, such that subjects in the highest quintile of animal protein intake had 24% lower odds for anxiety compared to those in the lowest quintile (p < 0.05). We found a significant association between highest quintiles of animal protein intake and a 40% lower risk for stress among female individuals (Ptrend = 0.05). The multivariable-adjusted non-linear analyses also revealed that the replacement of plant protein with animal protein was significantly associated with the likelihood of depression and anxiety (P < 0.05).

CONCLUSION

Animal protein intake might lower the odds of depression and anxiety particularly. Future prospective investigations are proposed to confirm these findings.

A menu for microbes: unraveling appetite regulation and weight dynamics through the microbiota-brain connection across the lifespan

Appetite, as the internal drive for food intake, is often dysregulated in a broad spectrum of conditions associated with over- and under-nutrition across the lifespan. Appetite regulation is a complex, integrative process comprising psychological and behavioral events, peripheral and metabolic inputs, and central neurotransmitter and metabolic interactions. The microbiota-gut-brain axis has emerged as a critical mediator of multiple physiological processes, including energy metabolism, brain function, and behavior. Therefore, the role of the microbiota-gut-brain axis in appetite and obesity is receiving increased attention. Omics approaches such as genomics, epigenomics, transcriptomics, proteomics, and metabolomics in appetite and weight regulation offer new opportunities for featuring obesity phenotypes. Furthermore, gut-microbiota-targeted approaches such as pre-, pro-, post-, and synbiotic, personalized nutrition, and fecal microbiota transplantation are novel avenues for precision treatments. The aim of this narrative review is 1) to provide an overview of the role of the microbiota-gut-brain axis in appetite regulation across the lifespan and 2) to discuss the potential of omics and gut microbiota-targeted approaches to deepen understanding of appetite regulation and obesity.

MUSAE: Fusion of art and technology to address challenges in food and health

There is an urgent need to transform our current food system to improve population health/wellbeing and planetary health. A number of challenges exist in order to achieve this. Artists, with their innate ability to use imagination to envision future needs and solve problems, represent a key group in this transformation. The project MUSAE brings together artists with experts from different disciplines to define an innovative model to integrate artistic collaboration in the (European) Digital innovation hubs (E-DIHs). They will employ the Design Futures Art-Driven (DFA) methods to enable artists and a range of companies involved in food production and distribution to develop innovative products and services that address key issues in the food system. MUSAE will run two residencies involving 23 artists and 11 SMEs working with three main technologies-Artificial Intelligence, Wearables and Robotics-to envision the future scenarios for societal needs and technology applications, as well as develop future-driven prototypes, thus opening new markets and innovations in the area of food.

Association between dietary patterns and suicide ideation among depressed adults: Insights from NHANES 2007-2020

BACKGROUND

Dietary patterns are strongly linked to the risk of major depressive disorder (MDD). However, research on the relationship between dietary patterns and MDD with suicidal ideation (MDD + SI) are limited. The Healthy Eating Index (HEI)-2015, Dietary Inflammatory Index (DII), Comprehensive Dietary Antioxidant Index (CDAI), Oxidative Balance Score (OBS), and Dietary Index for Gut Microbiota (DI-GM) are five validated tools for assessing dietary patterns based on inflammation, antioxidant capacity, and gut microbiota diversity. This study aims to investigate the association between these dietary indices and MDD + SI.

METHODS

A total of 23,621 participants from the 2007-2020 National Health and Nutrition Examination Survey were included in this study. MDD and SI were assessed using the PHQ-9. Weighted multivariable logistic regression, subgroup analyses, and restricted cubic spline (RCS) models were applied to analyze the relationships between five dietary indices and the risks of MDD and MDD + SI.

RESULTS

All five dietary indices showed associations with MDD to varying degrees; however, only DI-GM exhibited a significant negative association with MDD + SI after adjustment for confounding factors. Subgroup and stratified linear trend analyses revealed that this association was stronger among former smokers, obese individuals and those with hypertension or diabetes. RCS analysis showed a significant non-linear relationship between DI-GM and MDD, while a significant linear dose-response relationship was observed for DI-GM and MDD + SI.

LIMITATIONS

Cross-sectional study designs cannot establish causality.

CONCLUSION

The findings of this study revealed a significant association between DI-GM and MDD + SI. Dietary interventions that promote gut microbiota diversity may help reduce the risk of MDD + SI.

The relationship between depression and nutritional status among the elderly adults with cardiovascular diseases in Northern Iran

BACKGROUND

Malnutrition and depression among the elderly people with cardiovascular diseases are important public health concerns. This study made an attempt to determine the relationship between these people's depression and their nutritional status in northern Iran.

METHODS

This analytical cross-sectional study was conducted on 190 elderly patients hospitalized with cardiovascular diseases in Dr. Heshmat Heart Hospital in Rasht (Iran) in the 2022-2023. The research instruments included demographic information questionnaire, mini-nutritional assessment questionnaire, and geriatric depression scale. Data were analyzed by SPSS-21 software and using Chi-Square tests and ordinal logistic regression.

RESULTS

The participants' mean age was 68.4 ± 6.5 and 50.5% of the participants were women.56.3% of the elderly participants suffered from malnutrition and 96.3% of them suffered from various degrees of depression. Additionally, there was a relationship between the participants' severity of depression and their nutritional status. Significant relationships were also observed between the participants' depression (OR = 1.28 and p < 0.001), marital status (OR = 1.52 and p = 0.006), and underlying diseases (OR = 0.814, p = 0.035) with nutritional status.

CONCLUSION

Given the significant relationship depression with nutritional status in cardiovascular patients, early diagnosis and treatment of depression in these patients is essential to prevent the effects of depression on nutritional status and disease course.

Omnivore, vegan and vegetarian diet quality associations with depressive symptoms: A comparative cross-sectional analysis of the Australian Longitudinal Study on Women's Health

BACKGROUND

Depressive symptoms are experienced by >350 million people globally. Research suggests that a diet rich in plant foods could be protective against depressive symptoms, but vegans and vegetarians who eat a predominant plant-based diet are known to have higher depressive symptoms than omnivores.

METHODS

This study aims to explore a secondary analysis of the association between diet quality and depressive symptoms in women born between 1973 and 1978 who follow vegan, vegetarian, and omnivore diets from the Australian Longitudinal Study of Women's Health at baseline (1996) and at three time points (2000, 2003 and 2009).

RESULTS

After controlling for covarying factors, there was a significant association between diet quality and depressive symptoms in both the plant-based and omnivore groups at both time points F(9, 4851) = 106.90, p < .001. There was no significant difference between diet quality and depressive symptoms between diet type.

CONCLUSIONS

Despite diet type (plant-based or omnivore), adhering to a high-quality diet may decrease depressive symptoms and a low-quality diet may increase depressive symptoms in Australian women.

LIMITATIONS

Caution should be exercised when interpreting these results due to the small sample sizes and small resulting coefficients, there is uncertainty that coefficients this small can be associated with any meaningful change in an individual being treated for depressive symptoms in a clinical setting.

Diet interventions for depression: Review and recommendations for practice

OBJECTIVE

this paper aims to present the evidence for the role of diet in the prevention and treatment of depression, review the potential underlying mechanisms and provide practice recommendations for mental health clinicians.

METHODS

A literature review was conducted through searches of PubMed with the search terms 'depression', 'diet', 'prevention', 'treatment' and 'mechanisms' and combinations thereof. Additional articles were identified through hand searching.

RESULTS

Greater adherence to several healthy dietary patterns, traditional diets such as the Mediterranean diet and other diets such as the DASH diet are associated with or can treat symptoms of depression. Several limitations of the research were noted, many of which relate to inherent challenges of studying diet. Mechanisms by which dietary intervention can influence mood include the gut microbiome, modulation of inflammatory processes, reduction in oxidative stress and modulation of hypothalamic-pituitary-adrenal axis function. Recommendations for mental health clinicians to enable translation of the evidence into practice are provided.

CONCLUSION

Diet can play an important role in preventing and treating depression. Mental health clinicians are well placed to provide dietary counselling and to use clinical judgement in choosing the specific approach that reflects the needs of the patient but are encouraged to refer to a specialist dietitian where necessary.

Prevalence and Factors Associated With Depression and Depressive Symptoms Among Chinese Older Persons: An Integrative Review

China is the country with the largest population of older persons. Depression is the most common mental health issue among older adults, a trend expected to increase as societies continue to age. With the global increase in depression and depressive symptoms among this demographic, the resulting disease burden poses a significant challenge to health and social care systems in China. To map, summarise and examine the empirical literature on the prevalence and factors associated with depression and depressive symptoms in Chinese older adults, an integrative literature review was conducted informed by the guidelines of Whittemore and Knafl. The literature search encompassed EMBASE, SCOPUS, CINAHL, Web of Science, PubMed, PsycINFO, SocINDEX, China National Knowledge Infrastructure Database and Wanfang Database. The review included 65 studies, 29 in English and 36 in Chinese. The reported prevalence of depression or depressive symptoms in Chinese older adults was 3.78%-84.3%. Based on the biopsychosocial model, the associated factors were clustered as follows: biological factors (physical health, disability, drug effects, gender, age, diets, physical activities), psychological factors (self-esteem, coping skills, trauma, emotions, beliefs, hobbies, lifestyle) and social factors (family relationships, peers, family circumstances, school, residential areas, social support, social structure). This review synthesised research on depression among older adults in China, highlighting varying prevalence across diverse geographical locations. Given the high prevalence among certain older Chinese cohorts, the early identification and assessment of the factors associated with depression is essential to reducing disease burden. The use of the biopsychosocial model provided a theoretical lens to examine depression in this population in an integrative and holistic way. Thus, furthering understanding of the factors that require close consideration in future research and practice innovations on depression in older persons.

The effect of fruits and vegetables on children's mental and cognitive health: A systematic review of intervention studies and perspective for future research

OBJECTIVES

To synthesize evidence from fruit and vegetable intervention studies investigating mental or cognitive health outcomes (or both) in children ≤10 y. Our aim was to understand the efficacy of such interventions in improving measures of cognitive performance or mental health and to identify successful intervention elements to inform future research.

METHODS

We conducted a systematic search of the Cochrane, Embase, PubMed, and CINAHL databases for articles published before August 2022 (PROSPERO registration no. CRD42022356571). A narrative synthesis was conducted according to the Synthesis Without Meta-Analysis guidelines.

RESULTS

Of the 4686 articles identified, only 7 of the 17 full texts screened were included in the final review. No studies investigated the efficacy of interventions using "whole" fruits or vegetables. Six studies examined the effects of blueberries using drinks made from fresh (1 cup) or freeze-dried (30 g) blueberries and one study evaluated a mulberry powder-based drink. Sample sizes ranged from 14 to 54, and most studies were acute interventions with outcomes measured in a 2- to 3-h window (n = 6). Through a narrative synthesis of direction of responses, measures of executive function appeared sensitive to intervention effects in both acute and longer-term settings. Some concerns of risk of bias were evident, according to the RoB 2 tool, related to incomplete reporting of methodological aspects.

CONCLUSIONS

The studies identified through this systematic review could not directly address the planned research question, resulting in poor certainty of evidence. Future research with whole fruit and vegetable interventions could better inform population health strategies for improved mental and cognitive health outcomes in children.

Impact of ultra-processed food consumption during pregnancy on maternal and child health outcomes: A comprehensive narrative review of the past five years

BACKGROUND & AIMS

Ultra-processed foods (UPF) are increasingly prevalent in modern diets and are associated with negative health outcomes such as chronic diseases due to their high processing and low nutrient density. Despite the potential impact of UPF intake during pregnancy on maternal and child health, studies in this area are limited. Therefore, this narrative comprehensive review aimed to identify associations between UPF consumption, categorized by the NOVA system, during pregnancy and maternal and child health outcomes over the past five years (2019-2024).

METHODS

Following PRISMA-ScR criteria (2018), MedLine/PubMed, Scopus, and Embase databases were searched for articles on maternal and child health outcomes associated with UPF consumption categorized by the NOVA system during pregnancy, out of 767 studies identified, 22 were eligible.

RESULTS

Overall, high UPF consumption during pregnancy was positively associated with various adverse maternal-child outcomes, including gestational diabetes mellitus, gestational weight gain, poor glycemic control, negative nutrition biomarkers, inflammatory markers, and hypertensive disorders during pregnancy. It also negatively impacted child growth and development, and was associated with adiposity gain, potential adverse mental disorders, indicators of poor nutrition, and poor overall diet quality.

CONCLUSIONS

Despite the limited data, high consumption of UPF during pregnancy adversely affected the health outcomes of both mothers and children, impacting nutrition indicators and diet quality. Further studies on this topic are needed. Promoting healthy eating habits among pregnant women is crucial for achieving optimal health outcomes.

Adherence to unhealthy diets is associated with altered frontal gamma-aminobutyric acid and glutamate concentrations and grey matter volume: preliminary findings

OBJECTIVES

Common mental disorders (CMD) are associated with impaired frontal excitatory/inhibitory (E/I) balance and reduced grey matter volume (GMV). Larger GMV (in the areas that are implicated in CMD-pathology) and improved CMD-symptomatology have been observed in individuals who adhere to high quality diets. Moreover, preclinical studies have shown altered neurometabolites (primarily gamma-aminobutyric acid: GABA and glutamate: GLU) in relation to diet quality. However, neurochemical correlates of diet quality and how these neurobiological changes are associated with CMD and with its transdiagnostic factor, rumination, is unknown in humans. Therefore, in this study, we examined the associations between diet quality and frontal cortex neuro-chemistry and structure, as well as CMD and rumination in humans.

METHODS

Thirty adults were classified into high and low diet quality groups and underwent 1H-MRS to measure medial prefrontal cortex (mPFC) metabolite concentrations and volumetric imaging to measure GMV.

RESULTS

Low (vs High) diet quality group had reduced mPFC-GABA and elevated mPFC-GLU concentrations, as well as reduced right precentral gyrus (rPCG) GMV. However, CMD and rumination were not associated with diet quality. Notably, we observed a significant negative correlation between rumination and rPCG-GMV and a marginally significant association between rumination and mPFC-GLU concentrations. There was also a marginally significant association between mPFC-GLU concentrations and rPCG-GMV.

DISCUSSION

Adhering to unhealthy dietary patterns may be associated with compromised E/I balance, and this could affect GMV, and subsequently, rumination.

The Interplay of Nutrition, the Gut Microbiota and Immunity and Its Contribution to Human Disease

Nutrition, the gut microbiota and immunity are all important factors in the maintenance of health. However, there is a growing realization of the complex interplay between these elements coalescing in a nutrition-gut microbiota-immunity axis. This regulatory axis is critical for health with disruption being implicated in a broad range of diseases, including autoimmune disorders, allergies and mental health disorders. This new perspective continues to underpin a growing number of innovative therapeutic strategies targeting different elements of this axis to treat relevant diseases. This review describes the inter-relationships between nutrition, the gut microbiota and immunity. It then details several human diseases where disruption of the nutrition-gut microbiota-immunity axis has been identified and presents examples of how the various elements may be targeted therapeutically as alternate treatment strategies for these diseases.

Intimate Partner Violence and Women's Dietary Diversity: A Population-Based Investigation in 8 Low- and Middle-Income Countries

BACKGROUND

Intimate partner violence (IPV) poses a significant threat to the well-being of women and girls and is a highly prevalent form of gender-based violence. Evidence regarding the nutritional implications of IPV has focused primarily on intergenerational relationships with child nutrition and growth. There remains a knowledge gap regarding the association with women's own dietary intake.

OBJECTIVES

We investigated relationships between past-year IPV (physical, emotional, and sexual) and women's dietary habits, using the Minimum Dietary Diversity for Women tool.

METHODS

The data sources analyzed were the cross-sectional Demographic and Health Surveys conducted in Cambodia (2021, N = 5618), Nepal (2022, N = 4155), Sierra Leone (2019, N = 3808), Nigeria (2018, N = 8313), Tajikistan (2017, N = 4792), Cote D'Ivoire (2022, N = 3654), Kenya (2022, N = 10,717), and the Philippines (2022, N = 12,240). Utilizing multivariable generalized linear models, we assessed the overall relationship between women's exposure to IPV and 1) the number of food groups consumed and 2) minimum dietary diversity.

RESULTS

Our results reveal heterogeneous relationship patterns between IPV and women's diet. Although none of the pooled estimates were significant and there were a large number of nonsignificant associations, IPV was associated with consuming a lower number of total food groups and reduced consumption of a diverse diet in Nigeria, Kenya, and the Philippines. There is evidence that in Tajikistan, physical violence relates to an increased number of food groups consumed.

CONCLUSIONS

IPV is associated with altered dietary intake patterns within certain low- and middle-income countries. The directionality of associations may depend on local food environments and food access. Further research is needed to clarify the pathways underlying these findings. These pathways may involve impacts of IPV that influence diet and food access, for example, mental health symptoms and disorders and related coping mechanisms.

Gut-brain axis as a bridge in obesity and depression: Mechanistic exploration and therapeutic prospects

A recent study by Wang et al, published in the World Journal of Psychiatry, provided preventative and therapeutic strategies for the comorbidity of obesity and depression. The gut-brain axis, which acts as a two-way communication system between the gastrointestinal tract and the central nervous system, plays a pivotal role in the pathogenesis of these conditions. Evidence suggests that metabolic byproducts, such as short-chain fatty acids, lipopolysaccharide and bile acids, which are generated by the gut microbiota, along with neurotransmitters and inflammatory mediators within the gut-brain axis, modulate the host's metabolic processes, neuronal regulation, and immune responses through diverse mechanisms. The interaction between obesity and depression via the gut-brain axis involves disruptions in the gut microbiota balance, inflammatory immune responses, and alterations in the neuroendocrine system. Modulating the gut-brain axis, for example, through a ketogenic diet, the use of probiotics, and the supplementation of antioxidants, offers new remedial approaches for obesity and depression. Future research that explores the mechanisms of the gut-brain axis is needed to provide more evidence for clinical treatment.

The Association Between Adherence to the Mediterranean Diet and Depression and Anxiety Symptoms in University Students: The Mediating Role of Lean Mass and the Muscle Strength Index

BACKGROUND/OBJECTIVES

recent studies have suggested that components typical of the Mediterranean diet (MedDiet) are associated with depression and anxiety prevention. In this sense, the main objective of this study was to analyse the associations between adherence to the MedDiet and depression and anxiety symptoms and to examine whether this relationship is mediated by lean mass and the muscle strength index (MSI).

METHODS

a cross-sectional study (based on data obtained from the Nuts4Brain-Z study) was conducted from 2023-2024, involving 428 university students, aged 18-30 years, from a Spanish public university. Depression was assessed using the Beck Depression Inventory (BDI-II), and anxiety was assessed via the General Anxiety Disorder-7 (GAD-7) tool. Adherence to the MedDiet was assessed using the MEDAS questionnaire. Lean mass was assessed via bioimpedance, and MSI was measured via a dynamometer. ANCOVA models were used to test the mean differences in depression and anxiety scores using MEDAS categories (low adherence < 9 points vs high adherence ≥ 9 points). Serial multiple mediation models, adjusted for the main confounders, were used to explore the role of lean mass and MSI in the relationships between adherence to the MedDiet and depression and anxiety symptoms.

RESULTS

university students with high adherence to the MedDiet exhibited lower scores for depression and anxiety symptoms (p < 0.05) than did students with low adherence to the MedDiet. The mediation analysis preliminarily revealed that both lean mass and MSI acted as mediators of the relationships between adherence to the MedDiet and depression and anxiety.

CONCLUSION

adherence to the MedDiet in university students per se does not appear to have a direct effect on depression and anxiety symptoms because these associations are partially (for depression) or entirely (for anxiety) explained by lean mass and MSI.

Long-chain omega-3 polyunsaturated fatty acids are associated with brain connectivity and mood in young adults with subthreshold depression: A preliminary study

BACKGROUND

The long-chain omega-3 polyunsaturated fatty acids (PUFAs) docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) have beneficial effects in depression, and these effects may be mediated via changes in functional brain connectivity. However, little is known about these effects in those with subthreshold depression.

METHODS

15 Participants aged 18-29 years with Patient Health Questionnaire-8 (PHQ-8) scores ≥ 4 and Generalised Anxiety Disorder Assessment-7 (GAD-7) scores ≥ 5, underwent resting-state functional magnetic resonance imaging. Whole-brain, seed-based connectivity analyses were performed using bilateral orbitofrontal cortex (OFC) and amygdala seeds. Omega-3 and -6 PUFA status was assessed from dried bloodspot analysis of %DHA, %EPA, Omega-3 Index (calculated as the sum of DHA plus EPA expressed as a percentage of the total measured fatty acids and a correction applied as dried blood spot samples were used instead of erythrocytes) and ratio of the omega-6 PUFA arachidonic acid (ARA) to EPA (ARA/EPA).

RESULTS

PHQ-8 scores indicated subthreshold depression (mean = 10.0; SD = 4.2) and were negatively associated with DHA levels and Omega-3 Index. Significant negative associations were also identified between connectivity of the OFC with the angular gyrus and DHA and Omega-3 Index, while weaker connectivity of these regions was associated with lower PHQ-8 and GAD-7 scores. DHA and Omega-3 Index values were significantly associated with greater connectivity of the amygdala with the posterior cingulate cortex, which was also associated with lower PHQ-8 scores.

CONCLUSIONS

Higher omega-3 PUFA status in young adults with moderate, but mean subthreshold depression was associated with lower depression rating scores and altered functional connectivity of brain regions shown to play a role in the neurobiology of depression.

The associations of cardiovascular health and all-cause mortality among individuals with depression

The association between the recently updated cardiovascular health (CVH) assessment algorithm, the Life's Essential 8 (LE8), and all-cause mortality among adults with depression remains unknown. From the National Health and Nutrition Examination Survey (NHANES) spanning 2005-2018, a cohort of 2,935 individuals diagnosed with depression was identified. Their CVH was evaluated through the LE8 score system. The investigation of mortality status utilized connections with the National Death Index up to December 31, 2019. To assess the impact of CVH on mortality risk, Kaplan-Meier survival analysis and Cox proportional hazards models, adjusting for variables related to demographics and socioeconomic status, were applied. Among 2,935 participants, those with higher CVH levels had significantly lower all-cause mortality compared to those with lower CVH levels. Cox regression analyses demonstrated that each 1-point increase in CVH score was associated with a lower risk of all-cause mortality [HR = 0.97, 95%CI:0.96-0.98]. The inverse association between CVH and mortality persisted across different demographic and socioeconomic subgroups. Higher CVH levels were associated with a significantly lower risk of all-cause mortality in individuals with depression. These findings underscore the importance of comprehensive CVH management as part of healthcare strategies for people with depression, suggesting that improving CVH may contribute to longer life expectancy in this vulnerable population.

Developing a translational research framework for MDD: combining biomolecular mechanisms with a spiraling risk factor model

Objective

The global incidence and burden of Major Depressive Disorder (MDD) are increasing annually, with current antidepressant treatments proving ineffective for 30-40% of patients. Biomolecular mechanisms within the microbiota-gut-brain axis (MGBA) may significantly contribute to MDD, potentially paving the way for novel treatment approaches. However, integrating the MGBA with the psychological and environmental aspects of MDD remains challenging. This manuscript aims to: 1) investigate the underlying biomolecular mechanisms of MDD using a modeling approach, and 2) integrate this knowledge into a comprehensive 'spiraling risk factor model' to develop a biopsychosocial translational research framework for the prevention and treatment of MDD.

Methods

For the first aim, a systematic review (PROSPERO registration) was conducted using PubMed, Embase, and Scopus to query literature published between 2016-2020, with select additional sources. A narrative review was performed for the second aim.

Results

In addition to genetics and neurobiology, research consistently indicates that hyperactivation of the HPA axis and a pro-inflammatory state are interrelated components of the MGBA and likely underlying mechanisms of MDD. Dysregulation of the MGBA, along with imbalances in mental and physical conditions, lifestyle factors, and pre-existing treatments, can trigger a downward spiral of stress and anxiety, potentially leading to MDD.

Conclusions

MDD is not solely a brain disorder but a heterogeneous condition involving biomolecular, psychological, and environmental risk factors. Future interdisciplinary research can utilize the integrated biopsychosocial insights from this manuscript to develop more effective lifestyle-focused multimodal treatment interventions, enhance diagnosis, and stimulate early-stage prevention of MDD.

Systematic Review Registration

https://www.crd.york.ac.uk/PROSPERO/, identifier CRD42020215412.

Processed and ultra-processed foods are associated with depression and anxiety symptoms in a cross-sectional sample of urban Lebanese adults

While low dietary quality has been linked to poor mental health, evidence on more direct relations of specific dietary quality indicators, namely degrees of food processing, with mental health disorders remains limited. This study aims to investigate the association between food groups' intakes, defined based on their degree of food processing, with depression and anxiety symptoms in a sample of Lebanese adults. We hypothesized that higher intakes of ultra-processed foods (UPF) will be related to higher risk of depression and anxiety while an opposite association will be observed for unprocessed or minimally processed foods (MPF). Data come from a Lebanese cross-sectional study (n = 188 adults). The NOVA classification was adopted for evaluating the intakes of the 4 food groups: unprocessed or minimally processed foods (MPF); processed culinary ingredients (PCI); processed foods (PF) and ultra-processed foods (UPF). Associations between food group intakes in quartiles with depression and anxiety symptoms were analyzed using multivariable regression analyses adjusted for several confounders. Median energy intake was 2481.65 (2617.2) kcal/d, with 36.12% of Total Energy Intakes coming from MPF, 29.71% from PF, 25.25% from UPF, and 5.75% from PCI. Among participants, 33% and 27.7% had elevated depression and anxiety symptoms, respectively. Higher PF intake was associated with significantly lower odds of both depression and anxiety symptoms while a higher UPF intake was associated with higher odds of depression. Results confirm the hypothesized links between UPF and adverse mental health outcomes and highlight the need for further studies on PF intakes and mental health given the culture-specific nature of foods constituting this group.

Effect of dietary live microbe intake on the prevalence and mortality risks of depression and suicidal ideation in adults: Evidence from a nationwide population-based study

BACKGROUND

Gut microbial dysbiosis has been implicated in the pathogenesis of depression. Dietary interventions offer promising microbial-targeted therapeutics for depression. However, limited evidence exists regarding the associations between dietary live microbe intake and the prevalence of depression, as well as its impact on mortality risks.

METHODS

This study included 28,133 participants from the U.S. National Health and Nutrition Examination Survey (2005-2018), and ascertained their underlying causes of death. Weighted logistic regression was utilized to assess the relationships between live microbe intake and risks of depression and suicidal ideation. Independent and joint associations between live microbe and mortality outcomes were evaluated using multivariable Cox regression and Kaplan-Meier survival curves to calculate relative risks.

RESULTS

In the fully adjusted model, participants with high dietary live microbe intake had a significantly lower prevalence of depression (OR = 0.727, 95%CI: 0.627,0.844) and suicidal ideation (OR = 0.778, 95%CI: 0.648,0.935) than those with low intake. The multivariable-adjusted HRs for individuals in the G1 were 1.217 (95%CI, 1.081, 1.370) for all-cause mortality and 1.307 (95%CI, 1.029,1.661) for cardiovascular disease mortality, compared to participants in the G3. Kaplan-Meier survival analysis revealed that cumulative hazard of cardiovascular mortality was progressively lower among participants with depression in the G3 than those without depression.

CONCLUSIONS

Higher live microbe intake was associated with a lower prevalence of depression and suicidal ideation, and was linked to significantly decreased risks of all-cause and cardiovascular mortality. Further larger prospective studies are essential to verify the health effects of live microbes, and personalized dietary recommendations are necessary.

Mechanisms of change in digital interventions for depression: A systematic review and meta-analysis of six mediator domains

BACKGROUND

While the efficacy of digital interventions for the treatment of depression is well established, comprehensive knowledge on how therapeutic changes come about is still limited. This systematic review aimed to provide an overview of research on change mechanisms in digital interventions for depression and meta-analytically evaluate indirect effects of potential mediators.

METHODS

The databases CENTRAL, Embase, MEDLINE, and PsycINFO were systematically searched for randomized controlled trials investigating mediators of digital interventions for adults with depression. Two reviewers independently screened studies for inclusion, assessed study quality and categorized potential mediators. Indirect effects were synthesized with a two-stage structural equation modeling approach (TSSEM).

RESULTS

Overall, 25 trials (8110 participants) investigating 84 potential mediators were identified, of which attentional (8 %), self-related (6 %), biophysiological (6 %), affective (5 %), socio-cultural (2 %) and motivational (1 %) variables were the scope of this study. TSSEM revealed significant mediation effects for combined self-related variables (ab = -0.098; 95 %-CI: [-0.150, -0.051]), combined biophysiological variables (ab = -0.073; 95 %-CI: [-0.119, -0.025]) and mindfulness (ab = -0.042; 95 %-CI: [-0.080, -0.015]). Meta-analytical evaluations of the other three domains were not feasible.

LIMITATIONS

Methodological shortcomings of the included studies, the considerable heterogeneity and the small number of investigated variables within domains limit the generalizability of the results.

CONCLUSION

The findings further the understanding of potential change mechanisms in digital interventions for depression and highlight recommendations for future process research, such as the consideration of temporal precedence and experimental manipulation of potential mediators, as well as the application of network approaches.

The impact of the Mediterranean diet on alleviating depressive symptoms in adults: a systematic review and meta-analysis of randomized controlled trials

CONTEXT

High adherence to the Mediterranean diet (MD) has been associated with a reduced risk of depression in prospective cohort studies, but whether MD interventions are effective among adults with depression is uncertain.

OBJECTIVE

This study aimed to synthesize findings on the effects of MD interventions on the severity of depressive symptoms in adults with depression.

DATA SOURCES

PubMed, Cochrane CENTRAL, PsycINFO, Scopus, and Web of Science were systematically searched from database inception to March 2023. The Preferred Reporting Items for Systematic Review and Meta-Analyses guidelines and the Cochrane recommendations were followed. We included randomized controlled trials (RCTs) comparing outcomes after MD interventions with outcomes for control conditions in adults with depressive disorders or depressive symptoms.

DATA EXTRACTION

Two authors extracted the data independently. The Sidik-Jonkman estimator, the I2 metric, and the prediction interval were used to estimate between-study heterogeneity. To determine the risk of bias and the certainty of evidence from RCTs, we used the Cochrane Collaboration's Risk of Bias 2 and Grades of Recommendation, Assessment, Development, and Evaluation tools, respectively.

DATA ANALYSIS

In total, 1507 participants (mean age range: 22.0 years-53.3 years) with depression were initially included in the 5 RCTs of this review. Compared with control conditions, MD interventions significantly reduced depressive symptoms among young and middle-aged adults with major depression or mild to moderate depressive symptoms (standardized mean difference: -0.53; 95% confidence interval: -0.90 to -0.16; I2 = 87.1%). The prediction interval ranged from -1.86 to 0.81. The overall risk of bias was within the range of "some concerns" to "high," while the certainty of evidence was low.

CONCLUSION

MD interventions appear to have substantial potential for alleviating depressive symptoms in people experiencing major or mild depression. However, to establish robust recommendations, there remains a need for high-quality, large-scale, and long-term RCTs.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration no. CRD42022341895.

Human gut microbiome, diet, and mental disorders

Diet is one of the most important external factor shaping the composition and metabolic activities of the gut microbiome. The gut microbiome plays a crucial role in host health, including immune system development, nutrients metabolism, and the synthesis of bioactive molecules. In addition, the gut microbiome has been described as critical for the development of several mental disorders. Nutritional psychiatry is an emerging field of research that may provide a link between diet, microbial function, and brain health. In this study, we have reviewed the influence of different diet types, such as Western, Mediterranean, vegetarian, and ketogenic, on the gut microbiota composition and function, and their implication in various neuropsychiatric and psychological disorders.

The involvement of the microbiota-gut-brain axis in the pathophysiology of mood disorders and therapeutic implications

INTRODUCTION

There is a growing body of evidence implicating gut-brain axis dysfunction in the pathophysiology of mood disorders. Accordingly, gut microbiota has become a promising target for the development of biomarkers and novel therapeutics for bipolar and depressive disorders.

AREAS COVERED

We describe the observed changes in the gut microbiota of patients with mood disorders and discuss the available studies assessing microbiota-based strategies for their treatment.

EXPERT OPINION

Microbiota-targeted interventions, such as symbiotics, prebiotics, paraprobiotics, and fecal microbiota transplants seem to attenuate the severity of depressive symptoms. The available results must be seen as preliminary and need to be replicated and/or confirmed in larger and independent studies, also considering the pathophysiological and clinical heterogeneity of mood disorders.

Dietary fiber intake moderates the impact of blood cadmium on depression: a nationally representative cross-sectional study

BACKGROUND

Cadmium (Cd) is a very poisonous pollutant in the environment that has harmful implications on the neurological system. While high fiber intake is beneficial for mental health, it remains unknown whether the recommended basis for dietary fiber intake (DFI) (14 g/1000 kcal per day) can alleviate Cd-induced depression.

METHODS

The investigation employed data from the National Health and Nutrition Examination Survey (NHANES) conducted between the years 2005 and 2020. The research encompassed individuals who had information on blood Cd concentrations, two 24-hour dietary recalls, and depression diagnosis. We deployed weighted logistic regression analyses to estimate the association of exposure to Cd and DFI with depression risk.

RESULTS

The adjusted ORs (95% CI) for depression were 1.33 (95% CI: 1.08, 1.65) and 1.64 (95% CI: 1.38, 1.94) for the third and fourth quartiles of blood Cd concentrations, respectively (Ptrend < 0.001). Doubling DFI was connected with a 0.78-fold (95% CI: 0.71, 0.85) decrease in the risk of depression. Participants below recommended DFI levels had a greater depression risk with higher blood Cd concentrations: OR of 1.39 (95% CI: 1.11, 1.73) for the third and 1.67 (95% CI: 1.40, 1.98) for the fourth quartile. No significant association between Cd exposure and depression was perceived for participants meeting recommended DFI levels.

CONCLUSIONS

Higher blood Cd burden was associated with elevated depression risk, while recommended DFI could alleviate this effect. High-fiber dietary pattern may counteract the deleterious effect of environmental pollutants such as Cd on depression.

CLINICAL TRIAL NUMBER

Not applicable.

The role of olive oil and its constituents in mental health: a scoping review

Mounting evidence suggests that the Mediterranean diet has a beneficial effect on mental health. It has been hypothesised that this effect is mediated by a variety of foods, nutrients and constituents; however, there is a need for research elucidating which of these components contribute to the therapeutic effect. This scoping review sought to systematically search for and synthesise the research on olive oil and its constituents and their impact on mental health, including the presence or absence of a mental illness or the severity or progression of symptoms. PubMed and OVID MEDLINE databases were searched. The following article types were eligible for inclusion: human experimental and observational studies, animal and preclinical studies. Abstracts were screened in duplicate, and data were extracted using a piloted template. Data were analysed qualitatively to assess trends and gaps for further study. The PubMed and OVID MEDLINE search yielded 544 and 152 results, respectively. After full-text screening, forty-nine studies were eligible for inclusion, including seventeen human experimental, eighteen observational and fourteen animal studies. Of these, thirteen human and four animal studies used olive oil as a comparator. Observational studies reported inconsistent results, specifically five reporting higher rates of mental illness, eight reporting lower and five reporting no association with higher olive oil intake. All human experimental studies and nine of ten animal studies that assess olive oil as an intervention reported an improvement of anxiety or depression symptoms. Olive oil may benefit mental health outcomes. However, more experimental research is needed.

Understanding immune system dysfunction and its context in mood disorders: psychoneuroimmunoendocrinology and clinical interventions

Mood disorders include a set of psychiatric manifestations of increasing prevalence in our society, being mainly represented by major depressive disorder (MDD) and bipolar disorder (BD). The etiopathogenesis of mood disorders is extremely complex, with a wide spectrum of biological, psychological, and sociocultural factors being responsible for their appearance and development. In this sense, immune system dysfunction represents a key mechanism in the onset and pathophysiology of mood disorders, worsening mainly the central nervous system (neuroinflammation) and the periphery of the body (systemic inflammation). However, these alterations cannot be understood separately, but as part of a complex picture in which different factors and systems interact with each other. Psychoneuroimmunoendocrinology (PNIE) is the area responsible for studying the relationship between these elements and the impact of mind-body integration, placing the immune system as part of a whole. Thus, the dysfunction of the immune system is capable of influencing and activating different mechanisms that promote disruption of the psyche, damage to the nervous system, alterations to the endocrine and metabolic systems, and disruption of the microbiota and intestinal ecosystem, as well as of other organs and, in turn, all these mechanisms are responsible for inducing and enhancing the immune dysfunction. Similarly, the clinical approach to these patients is usually multidisciplinary, and the therapeutic arsenal includes different pharmacological (for example, antidepressants, antipsychotics, and lithium) and non-pharmacological (i.e., psychotherapy, lifestyle, and electroconvulsive therapy) treatments. These interventions also modulate the immune system and other elements of the PNIE in these patients, which may be interesting to understand the therapeutic success or failure of these approaches. In this sense, this review aims to delve into the relationship between immune dysfunction and mood disorders and their integration in the complex context of PNIE. Likewise, an attempt will be made to explore the effects on the immune system of different strategies available in the clinical approach to these patients, in order to identify the mechanisms described and their possible uses as biomarkers.

Dietary Factors Associated with Depressive Symptoms in Midlife Women 40-50 Years of Age Living in the United States

Purpose

Women in the decade before menopause are at risk for depression. This study describes dietary factors associated with depression risk in late premenopausal women that could be modifiable with targeted interventions.

Methods

Descriptive cross-sectional study comparing a community-based sample of 342 healthy premenopausal women categorized as low-risk and high-risk for depression in a secondary analysis of dietary variables. Depression risk was estimated with the Center for Epidemiological Studies-Depression (CES-D) scale. Dietary variables were based on three random 24-hour diet recalls during a 1-week period that included an in-person visit with measures of potential covariates such as blood pressure, height, and weight for body mass index (BMI), a urine sample for follicle-stimulating hormone, demographic factors, exercise and sleep. Independent t-tests were used initially to compare groups, followed by logistic regression to adjust for covariates. Statistical significance was set at p ≤ 0.05.

Results

Depression risk (CES-D ≥ 16) was present in 30% of participants. Compared with the low-risk group, the high-risk group had significantly higher intake of polyunsaturated fat, omega-6 linoleic acid and sucrose, and lower intake of galactose, vitamin C, and omega-3 eicosapentaenoic acid. After adjusting for energy intake and significant covariates (income adequacy, education, race/ethnicity, marital status, BMI, exercise and sleep duration), only polyunsaturated fat, omega-6, and sucrose remained significant.

Conclusion

Depression prior to menopause is common and multifactorial. Findings support the importance of assessing saturated fats, omega-6 fatty acids, and sucrose. Attention to diet in addition to exercise and sleep may improve intervention outcomes for mental health in midlife women.

Association between different diet quality scores and depression risk: the REGICOR population-based cohort study

BACKGROUND

Our aim was to determine the association between diet quality and depression incidence in the population-based REGICOR cohort study, Catalonia, Spain.

METHODS

Prospective observational study using participants' baseline (2003-2006), follow-up (2007-2013) and clinical records data. Five diet quality scores were derived from a food frequency questionnaire (FFQ) at baseline: the relative Mediterranean Diet Score (rMED), the Modified Mediterranean Diet Score (ModMDS), a Dietary Approaches to Stop Hypertension (DASH) score, a Healthful Plant-based Diet Index (HPDI) and the World Health Organization Healthy Diet Indicator (WHO-HDI). Participants using pharmacological antidepressant treatment were excluded as a proxy for presence of depression at baseline. At follow-up, the Patient Health Questionnaire (PHQ-9) was applied to assess depressive symptoms (≥ 10 defining depressive disorder). A secondary outcome was depression diagnosis assessed through clinical records. Logistic regression and Cox proportional hazards models were used.

RESULTS

Main analysis included 3046 adults (50.3% women) with a mean age of 54.7 (SD = 11.6) years. After 6-years follow-up, 184 (6.04%) cases of depressive disorder were identified. There was 16% lower odds of depressive disorder per 1SD increase of rMED (OR = 0.84; 95%CI = 0.71-0.98). Secondary outcome analysis (n = 4789) identified 261 (5.45%) incident cases of clinical depression diagnosis over 12 years follow-up, and 19% lower risk of clinical depression was observed with the WHO-HDI (HR = 0.81; 95%CI = 0.70-0.93). Adjusting for BMI did not attenuate the findings.

CONCLUSIONS

A significant inverse association between diet quality and depression incidence was found in this population-based cohort study, independent of sociodemographic, health and lifestyle. Adherence to a healthy diet could be a complementary intervention for the prevention of depression.

Fiber intake and fiber intervention in depression and anxiety: a systematic review and meta-analysis of observational studies and randomized controlled trials

CONTEXT

Dietary fibers hold potential to influence depressive and anxiety outcomes by modulating the microbiota-gut-brain axis, which is increasingly recognized as an underlying factor in mental health maintenance.

OBJECTIVE

Evidence for the effects of fibers on depressive and anxiety outcomes remains unclear. To this end, a systematic literature review and a meta-analysis were conducted that included observational studies and randomized controlled trials (RCTs).

DATA SOURCES

The PubMed, Embase, CENTRAL, CINAHL, and PsychINFO databases were searched for eligible studies.

DATA EXTRACTION

Study screening and risk-of-bias assessment were conducted by 2 independent reviewers.

DATA ANALYSIS

Meta-analyses via random effects models were performed to examine the (1) association between fiber intake and depressive and anxiety outcomes in observational studies, and (2) effect of fiber intervention on depressive and anxiety outcomes compared with placebo in RCTs. A total of 181 405 participants were included in 23 observational studies. In cross-sectional studies, an inverse association was observed between fiber intake and depressive (Cohen's d effect size [d]: -0.11; 95% confidence interval [CI]: -0.16, -0.05) and anxiety (d = -0.25; 95%CI, -0.38, -0.12) outcomes. In longitudinal studies, there was an inverse association between fiber intake and depressive outcomes (d = -0.07; 95%CI, -0.11, -0.04). In total, 740 participants were included in 10 RCTs, all of whom used fiber supplements. Of note, only 1 RCT included individuals with a clinical diagnosis of depression. No difference was found between fiber supplementation and placebo for depressive (d = -0.47; 95%CI, -1.26, 0.31) or anxiety (d = -0.30; 95%CI, -0.67, 0.07) outcomes.

CONCLUSION

Although observational data suggest a potential benefit for higher fiber intake for depressive and anxiety outcomes, evidence from current RCTs does not support fiber supplementation for improving depressive or anxiety outcomes. More research, including RCTs in clinical populations and using a broad range of fibers, is needed.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration no. CRD42021274898.

Relationship between serum neurofilament light chain protein and depression: A nationwide survey and Mendelian randomization study

BACKGROUND

Investigating the link between serum neurofilament protein (sNfL) levels and depression remains an area of limited understanding. This study explores the correlation in US adults and employs Mendelian randomization (MR) to ascertain causality.

METHODS

Our cross-sectional study analyzed data from participants aged 20 and above in the National Health and Nutrition Examination Survey (2013-2014). We employed a weighted multiple logistic regression model to examine the relationship between ln (sNfL) and depression. Restricted cubic splines (RCS) were used to visualize non-linear relationships. Stratified analyses examined associations between ln(sNfL) and depression in different subgroups. Subsequently, we conducted a two-sample bidirectional Mendelian randomization (MR) to assess the causal relationship between sNfL and depression. The inverse variance-weighted (IVW) method was utilized as the primary analysis.

RESULTS

Among 1765 participants (mean age 45.19 years; 49.37 % male), 166 had depression with a Patient Health Questionnaire (PHQ-9) score ≥ 10. After adjusting for covariates, a positive correlation remained between sNfL and depression (OR 1.511, 95 % CI: 1.050-2.175). RCS curves indicated a non-linear association, with a turning point at 2.76 pg/ml. Stratified analyses revealed positive correlations in specific subgroups, with interactions involving age, race, family income, recreational activity, and ln(sNfL). MR using IVW found no significant causal relationship between sNfL and depression genetically (OR = 0.956, 95 % CI: 0.878-1.042), with reverse analysis yielding similar results (OR = 0.897, 95 % CI: 0.756-1.065).

CONCLUSIONS

This cross-sectional study highlights a significant correlation between ln(sNfL) and depression. However, MR results indicate no causal relationship between sNfL and depression.

Longitudinal associations between fruit and vegetable intakes and depressive symptoms in middle-aged and older adults from four international twin cohorts

Beneficial associations between higher fruit and vegetable intakes and risk of depression appear to exist but few studies have focused on adults aged 45 + years and the potential that associations are due to residual confounding has not been tested. This longitudinal study of twins (n = 3483, age 45-90 years) from Australia, Denmark, Sweden and USA, assessed the associations between baseline fruit/vegetable intake and depressive symptoms over 5-11 years using linear mixed effects models. Intakes from food frequency questionnaires were trichotomized. Depressive symptoms were assessed using validated measures. The co-twin method was used to examine familial confounding. Compared with low intakes, both high fruit and high vegetable intakes were associated with lower depressive symptoms (fruit: β -.007 [95%CI - .014, < - .001], p = .040; vegetables: β - .006 [95%CI -.011, -.002], p = .002); whereas only moderate vegetable intakes, were associated with lower depressive symptoms (vegetables: β - .005 [95%CI - .009, - .001], p = .014). No familial confounding was found for vegetables, while the results for fruit were inconclusive, likely due to smaller sample size and the marginal significance of the main result. Higher fruit and vegetable intakes may protect against depressive symptoms, presenting another argument for increasing intakes in adults aged 45 + years.

Greater resting state functional connectivity of the medial prefrontal cortex with the thalamus, caudate, and putamen in individuals who adhere to the Mediterranean style diets

PURPOSE

Healthy diets are believed to be associated with a reduced risk of experiencing common mental disorders (CMDs) and related symptomatology (such as ruminative thinking), and with healthier brain chemistry and structure, especially in the frontal regions implicated in CMDs, cognitive control, and food choice. Nevertheless, there is very limited research on the relationship between diet health/quality and brain function. In this study we assessed the associations between adherence to the Mediterranean diet and resting state functional connectivity (rs-FC) of the prefrontal cortex (PFC) with the whole brain and whether this connectivity would be associated with ruminative thinking as a transdiagnostic factor for CMDs.

METHODS

Thirty-seven adults (Mean Age = 25.57, SD = 7.18) completed the Mediterranean Diet Adherence Screener (MEDAS) and were classified into high- and low-quality diet groups and completed the Ruminative Response Scale. All participants underwent resting-state functional MRI (fMRI) to determine whole-brain rs-FC of the medial prefrontal cortex (mPFC).

RESULTS

Participants in the high MEDAS group (vs. low MEDAS group) exhibited significantly greater rs-FC of the mPFC seed with the thalamus, caudate and putamen. Additionally, the strength of rs-FC of the mPFC seed with these regions was positively associated with the MEDAS scores across groups in both crude and adjusted models. There were no significant associations between the strength of rs-FC of the mPFC seed with the cluster of voxels with the thalamus, caudate, and putamen and ruminative thinking.

DISCUSSION

This work shows that healthy dietary patterns are associated with rs-FC in the frontal-subcortical circuitry in healthy volunteers. Considering the implications of the dysregulation of this circuity, adhering to healthy dietary patterns may offer a promising alternative/complementary method to improve CMDs, cognitive control, and food choices.

Adherence to MIND Diet and Risk of Recurrent Depressive Symptoms: Prospective Whitehall II Cohort Study

BACKGROUND/OBJECTIVES

This study examined the association between adherence to the Mediterranean dietary approaches to stop hypertension Intervention for Neurodegenerative Delay (MIND) diet, its components, and recurrent depressive symptoms (DepSs).

METHODS

The analyses included 4824 participants (73% men, mean age = 61; SD = 5.9) from the British Whitehall II cohort study. The MIND diet scores were derived from a validated 127-item food frequency questionnaire in 2002-2004. DepSs were assessed by the Center for Epidemiologic Studies Depression Scale (score ≥ 16) or by use of antidepressant drugs, and recurrence was defined as having DepSs in at least two of the four repeated measurements in the 2002-2004, 2007-2009, 2012-2013, and 2015-2016 follow-up phases.

RESULTS

Recurrent DepSs were observed in 13.3% of the participants over 13 years of follow-up. After adjusting for potential confounders, participants in the highest tertile of the MIND diet score (where a higher score represents a higher diet quality) had 26% lower odds of experiencing recurrent DepSs (OR = 0.74; 95% CI 0.58-0.93) compared to those in the lowest tertile. In mutually adjusted analyses of 14 MIND diet components in relation to recurrent DepSs, independent associations were observed for green leafy vegetables (OR = 0.59, 95% CI: 0.45-0.78), other vegetables (OR = 0.43, 95% CI:0.24-0.77), and berries (OR = 0.74, 95% CI: 0.61-0.89).

CONCLUSIONS

In this British prospective cohort, good adherence to the MIND diet, particularly to the recommendations for vegetables and berries, was associated with a lower risk of recurrent depressive symptoms, independent of socio-economic, health behavior, and health status factors, including baseline cognitive impairment and antecedents of DepSs.

The Effect of Nutrients on Neurological Disorders

The prevalence of neurological disorders (NDs) is increasing, with great cost to public health [...].

The effect of vitamin D supplementation on depression: a systematic review and dose-response meta-analysis of randomized controlled trials

The impact of vitamin D supplementation on depressive symptoms remains uncertain. This study aimed to investigate the dose-dependent effects of vitamin D supplementation on depressive and anxiety symptoms in adults. We systematically searched PubMed, Scopus, and Web of Science up to December 2022 to identify randomized controlled trials evaluating the effects of vitamin D3 supplementation on depression and anxiety symptoms in adults. Using a random-effects model, we calculated the standardized mean difference (SMD) for each 1000 IU/day vitamin D3 supplementation. The GRADE tool assessed the certainty of evidence. Our analysis included 31 trials with 24189 participants. Each 1000 IU/day vitamin D3 supplementation slightly reduced depressive symptoms in individuals with and without depression (SMD: -0.32, 95% CI -0.43 to -0.22; GEADE = moderate). The effect was more pronounced in those with depressive symptoms (SMD: -0.57, 95% CI -0.69 to -0.44; n = 15). The greatest reduction occurred at 8000 IU/day (SMD: -2.04, 95% CI -3.77 to -0.31). Trials with follow-up ⩽8 weeks (SMD: -0.45, 95% CI -0.70 to -0.20; n = 8) and 8 to ⩽24 weeks (SMD: -0.47, 95% CI -0.70 to -0.24; n = 15) showed stronger effects compared to those lasting 24 to ⩽52 weeks (SMD: -0.13, 95% CI -0.28 to 0.02; n = 5) or longer than 52 weeks (SMD: 0.14, 95% CI -0.16 to 0.44; n = 3) (p group difference <0.001). Vitamin D3 supplementation had no significant effects on anxiety symptoms. In summary, this study suggests that vitamin D3 supplementation may effectively reduce depressive symptoms in short term. Further high-quality trials are warranted for a conclusive assessment of its impact on anxiety.

Adherence to the Mediterranean diet and risk of anxiety and depression in people with obesity: a cross-sectional analysis

BACKGROUND/OBJECTIVES

Anxiety and depression are common mental disorders worldwide, in particular in people with obesity. Adherence to the Mediterranean diet has been found beneficial for the prevention of anxiety and depression in the general population. We aimed to evaluate this association in a large cohort of people with obesity.

SUBJECTS/METHODS

A cross-sectional study of 4957 patients with obesity (63.1% women, median age 49 years, IQR 40-58 years and BMI 33.6 kg/m2, IQR 31.6-36.9 kg/m2) was carried out. Clinical history, anthropometric measurements and lifestyle-related information were investigated. A 14-item MEDAS questionnaire was used to assess adherence to the Mediterranean diet. The 20-item STAI2 questionnaire and the 24-item QD questionnaire were used to assess the presence of anxious and depressive symptoms, respectively. Clinical cases of anxiety and depression were identified among patients with a physician-made diagnosis of anxiety and depression or with STAI2 and QD score ≥95th percentiles of reference population.

RESULTS

Overall, 11.9% of participants were positive for anxiety and 11% for depression. Multivariate linear regression models showed a decrease in STAI2 and QD scores of 0.18 points (95%CI: -0.33, -0.03) and 0.10 points (95%CI: -0.16, -0.03), respectively, for each 1-point increase in MEDAS score. The multivariate logistic regression model showed a 7% reduction in the odds of anxiety and depression for each 1-point MEDAS increase (OR = 0.93, 95%CI: 0.89, 0.99; OR = 0.93, 95%CI: 0.88, 0.98).

CONCLUSIONS

Mediterranean diet is associated with a lower risk of anxiety and depression in people with obesity. Longitudinal studies are needed to determine causality.

Associations of childhood household dysfunction and healthy lifestyle with depressive symptoms in adolescents

OBJECTIVE

Limited understanding exists regarding the cumulative impact of childhood household dysfunction (CHD) on adolescent depressive symptoms in developing countries, as well as the role of lifestyles in this association. This study aims to explore the associations of individual and cumulative CHD indicators with depressive symptoms among Chinese adolescents. Additionally, we investigate potential interactions and joint associations of CHD and lifestyles on depressive symptoms.

METHODS

In the second phase of the Longitudinal Study of Adolescents' Mental and Behavioral Well-being Research, data on depressive symptoms, CHD indicators, lifestyle factors, and other covariates were collected from 3106 students (mean [SD] age, 15.16 [1.52] years). Linear and logistic mixed-effects models were employed, with both stratified and joint analyses conducted.

RESULTS

Except for parental death, each CHD indicator was associated with an increased risk of depressive symptoms. The accumulation of CHD indicators exhibited a positive, graded association with depressive symptoms scores (β = 3.22, 95% CI: 2.48 to 3.97 for one CHD indicator; β = 5.45, 95% CI: 4.41 to 6.49 for two or more CHD indicators, all P < 0.01). A significant interaction was found between the number of CHD indicators and the healthy lifestyle score (interaction β = -0.40, 95% CI: -0.78 to -0.03, P < 0.05), indicating that healthy lifestyles may mitigate the risk of depressive symptoms in individuals experiencing CHD. For example, the OR for having depressive symptoms among adolescents with favourable lifestyles compared with those with unfavourable lifestyles was 0.21 (95% CI: 0.10 to 0.45, P < 0.01) among those experiencing CHD. Moreover, adolescents with two or more CHD indicators and unfavourable lifestyles faced the highest risk of having depressive symptoms (OR = 8.03, 95% CI: 4.83 to 13.34, P < 0.01) compared with those with no CHD indicator and favourable lifestyles.

CONCLUSIONS

These findings underscore the importance of promoting comprehensive healthy lifestyles and reducing CHD exposure for the prevention of depressive symptoms in adolescents.

Associations between specific dietary patterns, gut microbiome composition, and incident subthreshold depression in Chinese young adults

INTRODUCTION

The interplay between influential factors and the incidence of subthreshold depression (SD) in young adults remains poorly understood.

OBJECTIVES

This study sought to understand the dietary habits, gut microbiota composition, etc. among individuals with SD in young adults and to investigate their association with SD occurrence.

METHODS

Employing a cross-sectional approach, 178 individuals with SD, aged 18-32 years, were matched with 114 healthy counterparts. SD status was evaluated using the Zung Self-rating Depression Scale (SDS), Zung Self-rating Anxiety Scale (SAS), Beck Depression Inventory 2nd version (BDI-II), the 17-item Hamilton Rating Scales of Depression (HAMD-17), and Pittsburgh Sleep Quality Index (PSQI). Metagenomic sequencing was utilized to identify fecal microbial profiles. Dietary patterns were discerned via factor analysis of a 25-item food frequency questionnaire (FFQ). Logistic regression analysis and mediation analysis were performed to explore the potential links between gut microbiota, dietary patterns, and incident SD.

RESULTS

Data on dietary habits were available for 292 participants (mean [SD] age, 22.1 [2.9] years; 216 [73.9 %] female). Logistic regression analysis revealed that dietary patterns Ⅰ (odds ratio [OR], 0.34; 95 % CI, 0.15-0.75) and IV (OR, 0.39; 95 % CI, 0.17-0.86 and OR, 0.39; 95 % CI, 0.18-0.84) were associated with reduced risk of SD. Distinct microbial profiles were observed in young adults with SD, marked by increased microbial diversity and taxonomic alterations. Moreover, mediation analysis suggested Veillonella atypica as a potential mediator linking SDS or BDI-II scores with a healthy dietary pattern rich in bean products, coarse grains, nuts, fruits, mushrooms, and potatoes (β = 0.25, 95 % CI: 0.02-0.78 and β = 0.18, 95 % CI: 0.01-0.54).

CONCLUSIONS

Our findings highlight the complex interplay between dietary patterns, gut microbiota, and the risk of developing SD in young adults, underscoring the potential for dietary interventions and microbiome modulation in mental health promotion.

Fibre & fermented foods: differential effects on the microbiota-gut-brain axis

The ability to manipulate brain function through the communication between the microorganisms in the gastrointestinal tract and the brain along the gut-brain axis has emerged as a potential option to improve cognitive and emotional health. Dietary composition and patterns have demonstrated a robust capacity to modulate the microbiota-gut-brain axis. With their potential to possess pre-, pro-, post-, and synbiotic properties, dietary fibre and fermented foods stand out as potent shapers of the gut microbiota and subsequent signalling to the brain. Despite this potential, few studies have directly examined the mechanisms that might explain the beneficial action of dietary fibre and fermented foods on the microbiota-gut-brain axis, thus limiting insight and treatments for brain dysfunction. Herein, we evaluate the differential effects of dietary fibre and fermented foods from whole food sources on cognitive and emotional functioning. Potential mediating effects of dietary fibre and fermented foods on brain health via the microbiota-gut-brain axis are described. Although more multimodal research that combines psychological assessments and biological sampling to compare each food type is needed, the evidence accumulated to date suggests that dietary fibre, fermented foods, and/or their combination within a psychobiotic diet can be a cost-effective and convenient approach to improve cognitive and emotional functioning across the lifespan.

Relationship of the Prime Diet Quality Score (PDQS) and Healthy Eating Index (HEI-2015) with depression and anxiety: a cross-sectional study

BACKGROUND

Previous studies have suggested a significant association between diet quality and mental health. However, a limited number of studies have utilized the Prime Diet Quality Score (PDQS) to examine this association. Additionally, no study has yet compared the PDQS and Healthy Eating Index-2015 (HEI-2015) in terms of their association with depression and anxiety.

AIM

This cross-sectional study aimed to investigate the association between diet quality, measured by the PDQS and HEI-2015, and the odds of depression and anxiety in adults.

METHODS

This study utilized data from the LIPOKAP study, which was conducted between February 2018 and July 2019 in five cities in Iran. We included 1994 adults aged 18 and above who were selected through a multistage cluster sampling method. Participants completed a validated semiquantitative food frequency questionnaire (FFQ) to evaluate their dietary intake. The FFQ was used to calculate the PDQS and HEI-2015. Depression and anxiety levels were determined using the Hospital Anxiety and Depression Scale (HADS).

RESULTS

The participants had a mean age of 39.79 ± 13.87 years, with females accounting for 1,041 (52.2%) of the total population. PDQS showed a significant inverse association with the odds of depression (OR = 0.45, 95% CI: 0.28-0.71) and anxiety (OR = 0.40, 95% CI: 0.25-0.62) in the fully adjusted model. Similarly, the highest quartile of HEI-2015 showed a significantly lower odds of depression (OR = 0.60, 95% CI: 0.40-0.90) and anxiety (OR = 0.62, 95% CI: 0.42-0.92) compared to the lowest quartile.

CONCLUSION

Both PDQS and HEI-2015 were associated with a reduced risk of depression and anxiety. However, the PDQS demonstrated a stronger inverse association with these risks compared to the HEI-2015. This suggests that the PDQS could be a more beneficial dietary pattern for preventing depression and anxiety compared to HEI-2015. Further large-scale studies are required to confirm these findings.

Gut-Brain Axis and Psychopathology: Exploring the Impact of Diet with a Focus on the Low-FODMAP Approach

BACKGROUND

The gut-brain axis (GBA) is a bidirectional communication network connecting the central nervous system with the gastrointestinal (GI) tract, influencing both mental and physical health. Recent research has underscored the significant role of diet in modulating this axis, with attention to how specific dietary patterns can impact anxiety and depression, particularly when linked to disorders of gut-brain interaction (DGBIs), like intestinal bowel syndrome (IBS).

AIMS AND METHODS

This narrative review examines the effects of specific diet regimens on the GBA and its potential role in managing psychopathology, focusing on anxiety and depression, IBS, and the low-FODMAP diet. We conducted a search on PubMed and MEDLINE by combining the following key terms: "Gut-Brain Axis", "Irritable Bowel Syndrome", "Low FODMAP diet", "Mediterranean Diet", "Psychopathology", "Anxiety and Depression", and "Gut Microbiota". We applied the following filters: "Clinical Trials", "Randomized Controlled Trials", "Reviews", "Meta-Analyses", and "Systematic Reviews". In total, 59 papers were included.

RESULTS

Low-FODMAP diet, originally developed to alleviate GI symptoms in IBS, may also positively influence mental health by modulating the GBA and improving the gut microbiota (GM) composition. New insights suggest that combining the low-FODMAP diet with the Mediterranean diet could offer a synergistic effect, enhancing both GI and psychological therapeutic outcomes.

CONCLUSIONS

Understanding the complex interactions between diet, the GM, and mental health opens new avenues for holistic approaches to managing psychopathology, particularly when linked to GI symptoms.

The association of diet quality with the mental health of students during their transition to university

University students are at risk of experiencing mental health and diet quality problems during their transition to university. This study aimed to examine the bidirectional associations between the diet quality and mental health of students during their transition to universities in the UK, and the impact of the transition on diet quality and mental health. The study adopted a cross-sectional design and took place during the first semester of year 2021-2022. Participants were first year undergraduate students at four UK universities, living at student halls. They were invited to participate by completing online surveys, including a diet quality instrument (Short Form Food Frequency Questionnaire), a mental health instrument (Depression Anxiety and Stress Scale) and a quality of transition instrument (College Adjustment Questionnaire). Results showed that a healthy diet was associated with good mental health (b = -3.46, 95% CI [-6.14, -.78]). Unfavourable mental health was associated with having an unhealthy diet (b = -.01, 95% CI [-.02, -.00]). Transition did not moderate the relationship between diet quality and mental health of students, or vice versa (ps> .05). Preliminary analyses showed a significant direct effect of good quality of transition to university on good mental health (b = -1.51, 95% CI [-1.88, -1.13]), but did not have an indirect effect via diet quality; there were no significant direct or indirect effects on diet quality, however larger studies are needed to replicate these preliminary analyses. Our current findings can inform university policies and health education research, and further research is needed to determine whether interventions to improve diet quality at the university level could reduce mental health issues, and whether interventions to support students under stress may lead to healthier dietary habits. Cross-sectional studies cannot determine the directionality of effects, hence longitudinal studies are required to enhance our understanding of the relationships between diet quality and mental health over time.

Combined healthy lifestyles and risk of depressive symptoms: A baseline survey in China

BACKGROUND

Little evidence exists about whether a combination of healthy lifestyle factors is associated with a lower risk of depressive symptoms among Chinese population. We aimed to investigate the association between combined healthy lifestyle factors and risk of depressive symptoms.

METHODS

We conducted a baseline survey from July 2021 to December 2023, including 53,642 Chinese adults from general population. A healthy lifestyle score was constructed based on six lifestyle factors (physical activity, smoking status, alcohol consumption, diet, sleep duration, and body mass index). Logistic regression models were used to estimate odds ratios (ORs) and 95 % confidence intervals (CIs) adjusted for confounding variables.

RESULTS

Each additional healthy lifestyle score was associated with a 20 % lower risk of having depressive symptoms (OR (95 % CI): 0.80 (0.78-0.81)). Compared with individuals with ≤2 healthy lifestyle factors, individuals with all the six healthy lifestyle factors had a 58 % reduced risk of having depressive symptoms (0.42 (0.37-0.47)). After stratification by gender, education and urbanization, the significant inverse association with healthy lifestyle score was stronger in women, individuals with high education, and urban residents. Besides, the significant negative association between healthy lifestyle score and depressive symptoms remained for different severity of depressive symptoms.

LIMITATIONS

Given the cross-sectional nature of data, we cannot make causal inferences.

CONCLUSIONS

Our study indicated that adherence to healthy lifestyle factors was associated with a reduced risk of having depressive symptoms among Chinese adults. The observed associations were modified by gender, education and urbanization. These findings warrant further verification in interventional studies.