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

Ultra-Processed Foods and Mental Health: Where Do Eating Disorders Fit into the Puzzle?

Ultra-processed foods (UPFs) like pastries, packaged snacks, fast foods, and sweetened beverages have become dominant in the modern food supply and are strongly associated with numerous public health concerns. While the physical health consequences of UPF intake have been well documented (e.g., increased risks of cardiometabolic conditions), less empirical discussion has emphasized the mental health consequences of chronic UPF consumption. Notably, the unique characteristics of UPFs (e.g., artificially high levels of reinforcing ingredients) influence biological processes (e.g., dopamine signaling) in a manner that may contribute to poorer psychological functioning for some individuals. Importantly, gold-standard behavioral lifestyle interventions and treatments specifically for disordered eating do not acknowledge the direct role that UPFs may play in sensitizing reward-related neural functioning, disrupting metabolic responses, and motivating subsequent UPF cravings and intake. The lack of consideration for the influences of UPFs on mental health is particularly problematic given the growing scientific support for the addictive properties of these foods and the utility of ultra-processed food addiction (UPFA) as a novel clinical phenotype endorsed by 14-20% of individuals across international samples. The overarching aim of the present review is to summarize the science of how UPFs may affect mental health, emphasizing contributing biological mechanisms. Specifically, the authors will (1) describe how corporate-sponsored research and financial agendas have contributed to contention and debate about the role of UPFs in health; (2) define UPFs and their nutritional characteristics; (3) review observed associations between UPF intake and mental health conditions, especially with depression; (4) outline the evidence for UPFA; and (5) describe nuanced treatment considerations for comorbid UPFA and eating disorders.

Association of dietary saturated fatty acid intake with depression: mediating effects of the dietary inflammation index

Background

Diet and dietary inflammation play an important role in depression. The aim of this study was to assess the association of SFAs with depression risk and the mediating role of DII.

Method

Among 22, 478 U.S. adults (≥ 20, years old) according to the National Health and Nutrition Examination Survey (NHANES), univariate logistic regression, and multivariate logistic regression were used to evaluate the association between dietary intake of SFAs and the risk of depression. Dietary inflammation levels were evaluated using the DII. Mediation analysis was used to investigate the risk of DII and depression. The nonlinear relationship between SFAs and depression was assessed using restricted cubic spline (RCS).

Results

There was a significant difference in SFA 6.0 dietary intake between depression and non-depression individuals. After adjusting for potential confounders, multifactorial logistic regression results showed that SFA 8.0 (Q3 1.58 (1.09, 2.30), p-value = 0.017; Q4 1.55 (1.00, 2.42), p-value = 0.050) may increase the prevalence factor for depression, SFA 14.0 (Q3 0.67 (0.47, 0.94), p-value = 0.020) may decrease the risk of depression. There were sex and age differences in the effects of different subtypes of SFAs on depression. Dietary intake of SFA 12.0 content showed a nonlinear relationship with the risk of depression (p-value = 0.005). Furthermore, DII was recognized as a mediator of the association between SFAs and the risk of depression.

Conclusion

The findings suggest that dietary intake of SFAs is associated with the risk of depression in relation to the chain length of SFAs, and this may be due to the mediating effect of DII.

Autophagy in Its (Proper) Context: Molecular Basis, Biological Relevance, Pharmacological Modulation, and Lifestyle Medicine

Autophagy plays a critical role in maintaining cellular homeostasis and responding to various stress conditions by the degradation of intracellular components. In this narrative review, we provide a comprehensive overview of autophagy's cellular and molecular basis, biological significance, pharmacological modulation, and its relevance in lifestyle medicine. We delve into the intricate molecular mechanisms that govern autophagy, including macroautophagy, microautophagy and chaperone-mediated autophagy. Moreover, we highlight the biological significance of autophagy in aging, immunity, metabolism, apoptosis, tissue differentiation and systemic diseases, such as neurodegenerative or cardiovascular diseases and cancer. We also discuss the latest advancements in pharmacological modulation of autophagy and their potential implications in clinical settings. Finally, we explore the intimate connection between lifestyle factors and autophagy, emphasizing how nutrition, exercise, sleep patterns and environmental factors can significantly impact the autophagic process. The integration of lifestyle medicine into autophagy research opens new avenues for promoting health and longevity through personalized interventions.

Is a plant-based diet effective to maintain a good psycho-affective status in old age? Results of a survey of a long-lived population from Sardinia

BACKGROUND

Depression is common among the elderly, resulting in poor quality of life and elevated healthcare expenditure. Among other factors, dietary habits could also affect this condition, although the specific food patterns involved remain to be established. The present study aimed to assess the role of plant- versus animal-dominant foods consumption on the affective state of nonagenarians from a Sardinian population, Italy, well known for its longevity (Blue Zone).

METHODS

Data, including demographic, education, anthropometric parameters, monthly income, and comorbidity were recorded and analyzed. Symptomatic depression was assessed using the Geriatric Depression Scale (GDS) during a comprehensive home geriatric assessment; nutritional status was evaluated by a validated food frequency questionnaire.

RESULTS

A total of 200 elderly subjects living in the Sardinian Blue Zone (mean age 93.9 ± 3.9 years) participated in the study; symptomatic depression was present in 51% of the whole cohort and was more common among women. Multivariable logistic regression showed a significantly greater risk of depression in people consuming plantbased foods (OR = 1.42, 95% CI 1.04-1.93), whereas moderate animal-derived foods consumption was associated with a better affective state (OR = 0.79, 95% CI 0.62-0.98).

CONCLUSIONS

These findings indicate that a more balanced diet, including animal-derived foods, instead of an exclusive plant-dominant diet, may be more appropriate in the elderly, and abstention from animal-based food intake should not be recommended in advanced age to prevent depression.

Mood and microbes: a comprehensive review of intestinal microbiota's impact on depression

Depression is considered a multifaceted and intricate mental disorder of growing concern due to its significant impact on global health issues. The human gut microbiota, also known as the "second brain," has an important role in the CNS by regulating it through chemical, immunological, hormonal, and neurological processes. Various studies have found a significant bidirectional link between the brain and the gut, emphasizing the onset of depression therapies. The biological and molecular processes underlying depression and microbiota are required, as the bidirectional association may represent a novel study. However, profound insights into the stratification and diversity of the gut microbiota are still uncommon. This article investigates the emerging evidence of a bacterial relationship between the gut and the brain's neurological system and its potential pathogenicity and relevance. The interplay of microbiota, immune system, nervous system neurotransmitter synthesis, and neuroplasticity transitions is also widely studied. The consequences of stress, dietary fibers, probiotics, prebiotics, and antibiotics on the GB axis are being studied. Multiple studies revealed the processes underlying this axis and led to the development of effective microbiota-based drugs for both prevention and treatment. Therefore, the results support the hypothesis that gut microbiota influences depression and provide a promising area of research for an improved knowledge of the etiology of the disease and future therapies.

Cool the Inflamed Brain: A Novel Anti-inflammatory Strategy for the Treatment of Major Depressive Disorder

BACKGROUND

Abundant evidence suggests that inflammatory cytokines contribute to the symptoms of major depressive disorder (MDD) by altering neurotransmission, neuroplasticity, and neuroendocrine processes. Given the unsatisfactory response and remission of monoaminergic antidepressants, anti-inflammatory therapy is proposed as a feasible way to augment the antidepressant effect. Recently, there have been emerging studies investigating the efficiency and efficacy of anti-inflammatory agents in the treatment of MDD and depressive symptoms comorbid with somatic diseases.

METHODS

In this narrative review, prospective clinical trials focusing on anti-inflammatory treatment for depression have been comprehensively searched and screened. Based on the included studies, we summarize the rationale for the anti-inflammatory therapy of depression and discuss the utilities and confusions regarding the anti-inflammatory strategy for MDD.

RESULTS

This review included over 45 eligible trials. For ease of discussion, we have grouped them into six categories based on their mechanism of action, and added some other anti-inflammatory modalities, including Chinese herbal medicine and non-drug therapy. Pooled results suggest that anti-inflammatory therapy is effective in improving depressive symptoms, whether used as monotherapy or add-on therapy. However, there remain confusions in the application of anti-inflammatory therapy for MDD.

CONCLUSION

Based on current clinical evidence, anti-inflammatory therapy is a promisingly effective treatment for depression. This study proposes a novel strategy for clinical diagnosis, disease classification, personalized treatment, and prognostic prediction of depression. Inflammatory biomarkers are recommended to be assessed at the first admission of MDD patients, and anti-inflammatory therapy are recommended to be included in the clinical practice guidelines for diagnosis and treatment. Those patients with high levels of baseline inflammation (e.g., CRP > 3 mg/L) may benefit from adjunctive anti-inflammatory therapy.

Association between Western Dietary Patterns, Typical Food Groups, and Behavioral Health Disorders: An Updated Systematic Review and Meta-Analysis of Observational Studies

Western dietary patterns (WDP) and typical food groups may play a major role in the risk of behavioral health disorders. Nevertheless, the relationships between WDP, common food categories, and mental health disorders lack consistency and remain incompletely understood in relation to potential mechanisms. Therefore, the objective of the present study was conducted to synthesize available evidence linking WDP and typical food groups to these outcomes. Web of Science, PubMed, EMBASE, and MEDLINE were searched up to August 2023. Random effect meta-analyses were performed to obtain pooled odds ratio and the relative risk for the prevalence of outcomes and the incidence of outcomes, respectively. A total of 54 articles were included. WDP was associated with increased risk of both depression (1.19; 95% CI: 1.06-1.32) and depressive symptoms (1.20; 95% CI: 1.08-1.34). Except for high-fat dairy products, food groups are associated with an increased risk of anxiety, depression, and depressive symptoms. This review presents evidence to further understand the relationship between WDP, typical food groups, and the incidence of behavioral health disorders, and more randomized controlled trials and cohort studies are urgently required to confirm these findings and elucidate potential mechanisms.

DHA and EPA Alleviate Epileptic Depression in PTZ-Treated Young Mice Model by Inhibiting Neuroinflammation through Regulating Microglial M2 Polarization and Improving Mitochondrial Metabolism

Depression is the most common complication of childhood epilepsy, leading to a poor prognosis for seizure control and poor quality of life. However, the molecular mechanisms underlying epileptic depression have not been completely elucidated. Increasing evidence suggests that oxidative stress and neuroinflammation are major contributors to depression. The positive effects of dietary supplementation with docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) on depression have been previously reported. However, knowledge regarding the effects of EPA and DHA in managing depressive symptoms in pediatric patients with epilepsy is limited. Therefore, this study aims to investigate the effects of EPA and DHA on epileptic depression in a pentylenetetrazole (PTZ)-treated young mouse model. Three-week-old mice were fed a DHA- or EPA-enriched diet for 21 days and treated with PTZ (35 mg/kg, i.p.) every other day for a total of 10 times. EPA was more effective than DHA at alleviating PTZ-induced depressive symptoms. Pathological results revealed that DHA and EPA significantly improved neuronal degeneration in the hippocampus. Analysis of the mechanism revealed that DHA and EPA mitigated PTZ-induced myelin damage by increasing the protein levels of CNPase, Olig2, and MBP. Furthermore, both DHA and EPA reduced neuroinflammation by promoting microglial M2 polarization and suppressing the LCN2-NLRP3 inflammasome pathway. Notably, EPA polarized microglia towards the M2 phenotype. In addition, DHA and EPA decreased oxidative stress by inhibiting NOX2 and enhancing mitochondrial metabolism through the increased expression of mitochondrial respiratory chain complex I-V proteins. These findings suggest that DHA and EPA can be used as effective interventions to improve depression in children with epilepsy, with EPA being a particularly favorable option.

Depressive symptoms among adolescents in six sub-Saharan African countries: A pooled analysis of associated factors

There is a need to identify risk factors, including nutrition-related factors, for depressive disorders among sub-Saharan African (SSA) adolescents. We examined the association of multiple measures with depressive symptoms among adolescents living across six SSA countries. Building on previous analyses, we used data from a cross-sectional study conducted from 2015 to 2017 among adolescents aged 10-19 years in six SSA countries (N = 7512). Depressive symptoms were defined as highest tertile of the 6-item Kutcher Adolescent Depression Scale score. Using mixed-effects Poisson regression models, we pooled data across sites and examined the association of sociodemographic, nutrition, and other indices with depressive symptoms. We additionally assessed effect modification by sex, age, and school-going status. We observed higher risk of depressive symptoms among girls (adjusted risk ratio [RR]: 1.29, 95 % confidence interval [95 % CI]: 1.05-1.58, P = 0.016), older adolescents (RR for 18-19 years: 1.59, 95 % CI: 1.44-1.76, P < 0.001), and adolescents experiencing bullying (RR: 1.43, 95 % CI: 1.26-1.62, P < 0.001) or violence (RR: 1.34, 95 % CI: 1.24-1.45, P < 0.001). Adolescents experiencing food insecurity also had a higher risk of depressive symptoms (RR: 1.90, 95 % CI: 1.64-2.19, P < 0.001) along with those consuming ≥ 5 servings of fruit and vegetables per day (RR: 1.18, 95 % CI: 1.03-1.34, P = 0.015); conversely, those who consumed grains, roots and tubers in the past day were at decreased risk (RR: 0.73, 95 % CI: 0.69-0.77, P < 0.001). There was no strong evidence of effect modification of associations. This study reinforces the potential role of multiple sociodemographic and nutrition-related measures on risk of depressive symptoms in these populations.

Exploring the Relationship between Mood Disorders and Coexisting Health Conditions: The Focus on Nutraceuticals

Major depressive disorder and bipolar disorder are the leading causes of global disability. Approximately 50% of patients fail to attain remission, prompting a pronounced focus on the significance of dietary patterns and specific nutrients within the pathophysiology of mood disorders. The connection between chronic diseases and mood disorders follows a bidirectional pattern: physical ailments are interrelated with affective disorders, and, concurrently, mood symptoms often precede chronic diseases and have the potential to worsen their prognosis. Nutraceuticals affect factors that could potentially impact the onset of mood disorders: monoamines and brain-derived neurotrophic factor (BDNF) concentrations, neuroinflammation, oxidative stress, and sleep quality. Furthermore, mood disorders rarely manifest in isolation. Typically, such patients concurrently experience other mental disorders or somatic comorbidities: obesity, hypertension, diabetes, polycystic ovary syndrome (PCOS), etc., where providing nutritional support is also pertinent. To optimize the therapeutic approach for individuals with mood disorders, incorporating nutritional support may not solely ameliorate symptoms stemming directly from the mental condition, but also indirectly through interventions targeting comorbidities.

Microbiota-gut-brain axis mechanisms in the complex network of bipolar disorders: potential clinical implications and translational opportunities

Bipolar disorders (BD) represent a severe leading disabling mental condition worldwide characterized by episodic and often progressive mood fluctuations with manic and depressive stages. The biological mechanisms underlying the pathophysiology of BD remain incompletely understood, but it seems that there is a complex picture of genetic and environmental factors implicated. Nowadays, gut microbiota is in the spotlight of new research related to this kind of psychiatric disorder, as it can be consistently related to several pathophysiological events observed in BD. In the context of the so-called microbiota-gut-brain (MGB) axis, it is shown to have a strong influence on host neuromodulation and endocrine functions (i.e., controlling the synthesis of neurotransmitters like serotonin or mediating the activation of the hypothalamic-pituitary-adrenal axis), as well as in modulation of host immune responses, critically regulating intestinal, systemic and brain inflammation (neuroinflammation). The present review aims to elucidate pathophysiological mechanisms derived from the MGB axis disruption and possible therapeutic approaches mainly focusing on gut microbiota in the complex network of BD. Understanding the mechanisms of gut microbiota and its bidirectional communication with the immune and other systems can shed light on the discovery of new therapies for improving the clinical management of these patients. Besides, the effect of psychiatric drugs on gut microbiota currently used in BD patients, together with new therapeutical approaches targeting this ecosystem (dietary patterns, probiotics, prebiotics, and other novelties) will also be contemplated.

Prevalence of Depression and Fish Consumption among First Year Spanish University Students: UniHcos Project

The World Health Organization estimates that one fifth of university students have experienced major depressive disorder at some point in their lives. Nutrition may be one of the modifiable factors that influence the development of depression. Specifically, low omega-3 fatty acid and vitamin D levels, both nutrients found in high quantities in fish, have been linked to depressive disorders. The main objective of this study was to evaluate the prevalence of depression among young Spanish university students, in addition to the pattern of fish consumption among students and the possible relationship between fish consumption and the presence of depression. Data were collected retrospectively from a nationally representative sample of 11,485 Spanish university students aged 18 years or older in 11 Spanish universities, from 2012 to 2022. The respondents were analyzed according to frequency of consumption and compliance with weekly recommendations for fish intake and the presence of depression. Regression models were also performed to determine students' odds of depression as a function of compliance with recommendations according to selected sociodemographic variables. The prevalence of depression was 10.5%; it was more prevalent in women, older students and in those with both high and low BMIs. In addition, it was also more prevalent in those that lived outside the family home, with roommates and those who were employed. Sixty-seven percent of the students met the fish intake recommendations. The most common frequency of fish consumption was 1-2 times/week (44.2%), and the least frequent was 2.3% daily fish consumption. Students from northern universities were more likely to consume fish (68.4%) than those from southern universities (66.4%). Non-consumption of fish was found to increase the risk of depression (ORa = 1.45 (1.28-1.64); AF = 31.0% (21.9-39.0)), but it was the student's own conditions that had the greatest influence on the development of the disorder. In summary, a lower consumption of fish seems to be associated with a higher incidence of depression in Spanish university students; however, other social factors of the student may influence the development of the disorder, and all of this should be taken into account for the development of prevention strategies.

Depression and Its Phytopharmacotherapy-A Narrative Review

Depression is a mental health disorder that develops as a result of complex psycho-neuro-immuno-endocrinological disturbances. This disease presents with mood disturbances, persistent sadness, loss of interest and impaired cognition, which causes distress to the patient and significantly affects the ability to function and have a satisfying family, social and professional life. Depression requires comprehensive management, including pharmacological treatment. Because pharmacotherapy of depression is a long-term process associated with the risk of numerous adverse drug effects, much attention is paid to alternative therapy methods, including phytopharmacotherapy, especially in treating mild or moderate depression. Preclinical studies and previous clinical studies confirm the antidepressant activity of active compounds in plants, such as St. John's wort, saffron crocus, lemon balm and lavender, or less known in European ethnopharmacology, roseroot, ginkgo, Korean ginseng, borage, brahmi, mimosa tree and magnolia bark. The active compounds in these plants exert antidepressive effects in similar mechanisms to those found in synthetic antidepressants. The description of phytopharmacodynamics includes inhibiting monoamine reuptake and monoamine oxidase activity and complex, agonistic or antagonistic effects on multiple central nervous system (CNS) receptors. Moreover, it is noteworthy that the anti-inflammatory effect is also important to the antidepressant activity of the plants mentioned above in light of the hypothesis that immunological disorders of the CNS are a significant pathogenetic factor of depression. This narrative review results from a traditional, non-systematic literature review. It briefly discusses the pathophysiology, symptomatology and treatment of depression, with a particular focus on the role of phytopharmacology in its treatment. It provides the mechanisms of action revealed in experimental studies of active ingredients isolated from herbal antidepressants and presents the results of selected clinical studies confirming their antidepressant effectiveness.

Is a Genetic Diathesis for Poor Nutrition Becoming More Crucial Due to the Uniformity of COVID Social Stress?

The important role of nutrition in proper neural functioning and mental health has seen wider acceptance, but is still sadly under recognized given the existent body of research. This Special Issue was designed to unite authoritative information on this topic in one volume. This editorial provides an overview of the issue, and suggests that the combination of social isolation, lack of exercise, and remaining indoors that overtook industrialized societies during 2020 are specific factors expected to change the Gene × Environment interactions for anxiety and depression. Importantly, the recent environmental changes may make biological diatheses for nutritional deficiencies even more problematic. The concept of G × E interaction is dissected to clarify a non-intuitive scenario: heritability may increase, even when a sharp increase in prevalence is entirely the result of an environmental change (e.g., COVID anxiety and isolation). Key research is highlighted, specific genetic examples are noted, and theoretical implications regarding natural selection are discussed.

Dietary Fats and Depressive Symptoms in Italian Adults

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Phenolic Acids as Antidepressant Agents

Depression is a psychiatric disorder affecting the lives of patients and their families worldwide. It is an important pathophysiology; however, the molecular pathways involved are not well understood. Pharmacological treatment may promote side effects or be ineffective. Consequently, efforts have been made to understand the molecular pathways in depressive patients and prevent their symptoms. In this context, animal models have suggested phytochemicals from medicinal plants, especially phenolic acids, as alternative treatments. These bioactive molecules are known for their antioxidant and antiinflammatory activities. They occur in some fruits, vegetables, and herbal plants. This review focused on phenolic acids and extracts from medicinal plants and their effects on depressive symptoms, as well as the molecular interactions and pathways implicated in these effects. Results from preclinical trials indicate the potential of phenolic acids to reduce depressive-like behaviour by regulating factors associated with oxidative stress, neuroinflammation, autophagy, and deregulation of the hypothalamic-pituitary-adrenal axis, stimulating monoaminergic neurotransmission and neurogenesis, and modulating intestinal microbiota.