Adherence to the ultra-processed dietary pattern and risk of depressive outcomes: Findings from the NutriNet Brasil cohort study and an updated systematic review and meta-analysis

BACKGROUND & AIMS

We aimed to analyze the prospective association between adherence to the ultra-processed dietary pattern and risk of depressive outcomes using original data from the NutriNet Brasil cohort and via a systematic review and meta-analysis of observational studies that have investigated the same association.

METHODS

In our original research analysis, we used data from 15,960 adults (≥18 y) participating in the NutriNet Brasil cohort study, free of depression or depressive symptoms during the baseline (77.5% women, 45.8 ± 13.0 y). The mean dietary share of ultra-processed foods (%Kcal/d), calculated from two baseline 24-h dietary recalls, was used to measure the adherence to the ultra-processed dietary pattern. New cases of depressive symptoms were assessed using the Patient Health Questionnaire-9 over the follow-up period (mean: 18.3 months). Cox proportional hazards models were used for the main analyses. In our systematic review and meta-analysis, we incorporated effect estimates from six prospective cohort studies that have examined the same association, including ours.

RESULTS

In the adjusted model, each 10% increase in the dietary share of ultra-processed foods was associated with a 10% increase in the hazard of incident cases of depressive symptoms (HR:1.10; 95%CI: 1.07-1.14). This association was slightly attenuated in the models including potential mediators. In our meta-analysis of six prospective studies, high versus low exposure to ultra-processed foods was associated with a summary hazard ratio of depressive outcomes of 1.32; 95%CI: 1.19-1.46; I2: 71%.

CONCLUSION

A higher adherence to the ultra-processed dietary pattern was associated with a higher risk of developing depressive outcomes in the NutriNet Brasil cohort and in the meta-analysis.

The association of major dietary patterns with odds and severity of anxiety disorders: a case-control study

Background: In the present study, we explored the association between major dietary patterns, odds, and severity of anxiety disorders, which has not been clarified to date.Methods: This case-control study was conducted on 85 patients who were group-matched by gender with 170 healthy subjects. Dietary intakes were evaluated applying a 147-item validated food frequency questionnaire (FFQ). Anthropometric data collection was accomplished based on precise clinical assessments. Major dietary patterns were identified using principal component analysis (PCA). Multivariate odds ratios (OR) with 95% confidence intervals (CI) were used to investigate the association of the identified dietary patterns with anxiety disorders. Multiple linear regression analysis was used to evaluate the association between the GAD-7 score and major dietary pattern scores.Results: Three major dietary patterns were derived through PCA labeled as 'healthy', 'Western', and 'Mixed'. Those in the top tertile of the healthy dietary pattern were less likely to have anxiety disorders (OR =   0.26; 95%CI: 0.10, 0.66), while no significant relationship was found between Western and mixed dietary patterns and the odds of anxiety disorders. The severity of anxiety disorders, assessed by the GAD-7 score, was reduced by higher adherence to healthy dietary pattern (P = 0.003), and increased by greater adherence to mixed (P = 0.002) and Western (P = 0.001) dietary patterns.Conclusion: We provided evidence demonstrating an inverse association of healthy dietary pattern with odds, and severity of anxiety disorders. Also, higher adherence to Western and mixed dietary patterns resulted in greater GAD-7 scores.

Probiotic, prebiotic, synbiotic and fermented food supplementation in psychiatric disorders: A systematic review of clinical trials

The use of probiotics, prebiotics, synbiotics or fermented foods can modulate the gut-brain axis and constitute a potentially therapeutic intervention in psychiatric disorders. This systematic review aims to identify current evidence regarding these interventions in the treatment of patients with DSM/ICD psychiatric diagnoses. Forty-seven articles from 42 studies met the inclusion criteria. Risk of bias was assessed in all included studies. Major depression was the most studied disorder (n = 19 studies). Studies frequently focused on schizophrenia (n = 11) and bipolar disorder (n = 5) and there were limited studies in anorexia nervosa (n = 4), ADHD (n = 3), Tourette (n = 1), insomnia (n = 1), PTSD (n = 1) and generalized anxiety disorder (n = 1). Except in MDD, current evidence does not clarify the role of probiotics and prebiotics in the treatment of mental illness. Several studies point to an improvement in the immune and inflammatory profile (e.g. CRP, IL6), which may be a relevant mechanism of action of the therapeutic response identified in these studies. Future research should consider lifestyle and dietary habits of patients as possible confounders that may influence inter-individual treatment response.

Existing and Future Strategies to Manipulate the Gut Microbiota With Diet as a Potential Adjuvant Treatment for Psychiatric Disorders

Nutrition and diet quality play key roles in preventing and slowing cognitive decline and have been linked to multiple brain disorders. This review compiles available evidence from preclinical studies and clinical trials on the impact of nutrition and interventions regarding major psychiatric conditions and some neurological disorders. We emphasize the potential role of diet-related microbiome alterations in these effects and highlight commonalities between various brain disorders related to the microbiome. Despite numerous studies shedding light on these findings, there are still gaps in our understanding due to the limited availability of definitive human trial data firmly establishing a causal link between a specific diet and microbially mediated brain functions and symptoms. The positive impact of certain diets on the microbiome and cognitive function is frequently ascribed with the anti-inflammatory effects of certain microbial metabolites or a reduction of proinflammatory microbial products. We also critically review recent research on pro- and prebiotics and nondietary interventions, particularly fecal microbiota transplantation. The recent focus on diet in relation to brain disorders could lead to improved treatment outcomes with combined dietary, pharmacological, and behavioral interventions.

An Overview of the Potential Role of Nutrition in Mental Disorders in the Light of Advances in Nutripsychiatry

PURPOSE OF REVIEW

As research on the potential impact of nutrition on mental disorders, a significant component of global disability continues to grow the concepts of "nutritional psychiatry, psycho-dietetics/nutripsychiatry" have taken their place in the literature. This review is a comprehensive examination of the literature on the the potential mechanisms between common mental disorders and nutrition and evaluates the effectiveness of dietary interventions.

RECENT FINDINGS

Inflammation, oxidative stress, intestinal microbiota, mitochondrial dysfunction, and neural plasticity are shown as potential mechanisms in the relationship between mental disorders and nutrition. As a matter of fact, neurotrophic factors, which make important contributions to repair mechanisms throughout life, and neuronal plasticity, which plays a role in mental disorders, are affected by nutritional factors. In metabolism, the antioxidant defense system works with nutritional cofactors and phytochemicals. A balanced, planned diet that provides these components is more likely to provide nutrients that increase resilience against the pathogenesis of mental disorders. Nutrition can be considered a risk factor for mental disorders. Therefore, developing public health strategies focused on improving diet may help reduce the global burden of mental disorders and other related diseases.

The use of diet for preventing and treating depression in young men: current evidence and existing challenges

Emerging evidence suggests that diet therapy (nutrients, foods and dietary patterns) could be effective as a potential adjunctive treatment option for major depressive disorder. Numerous mechanisms have been proposed, including the role inflammation, oxidative stress, brain-derived neurotrophic factor, the gastrointestinal tract microbiome and tryptophan/serotonin metabolism. Despite known differences in depression characteristics and treatment responses between males and females, there are limited sex-specific studies examining the role of diet in young men specifically. This is important as young men are often reluctant to seek mental health support, so finding treatment strategies which appeal to this demographic is crucial. This brief report provides an overview of the most recent advances in the use of diet for preventing and treating depression in young men, highlighting existing challenges and opportunities for future research. We recommend that clinicians discuss the role of diet with depressed young men, so that diet may be used alongside current treatment options.

High ultra-processed food consumption is associated with elevated psychological distress as an indicator of depression in adults from the Melbourne Collaborative Cohort Study

BACKGROUND

Few studies have tested longitudinal associations between ultra-processed food consumption and depressive outcomes. As such, further investigation and replication are necessary. The aim of this study is to examine associations of ultra-processed food intake with elevated psychological distress as a marker for depression after 15 years.

METHOD

Data from the Melbourne Collaborative Cohort Study (MCCS) were analysed (n = 23,299). We applied the NOVA food classification system to a food frequency questionnaire (FFQ) to determine ultra-processed food intake at baseline. We categorised energy-adjusted ultra-processed food consumption into quartiles by using the distribution of the dataset. Psychological distress was measured by the ten-item Kessler Psychological Distress Scale (K10). We fitted unadjusted and adjusted logistic regression models to assess the association of ultra-processed food consumption (exposure) with significant psychological distress (outcome and defined as K10 ≥ 20). We fitted additional logistic regression models to determine whether these associations were modified by sex, age and body mass index.

RESULTS

After adjusting for sociodemographic characteristics and lifestyle and health-related behaviours, participants with the highest relative intake of ultra-processed food were at increased odds of significant psychological distress compared to participants with the lowest intake (aOR: 1.23; 95%CI: 1.10, 1.38, p for trend = 0.001). We found no evidence for an interaction of sex, age and body mass index with ultra-processed food intake.

CONCLUSION

Higher ultra-processed food intake at baseline was associated with subsequent elevated psychological distress as an indicator of depression at follow-up. Further prospective and intervention studies are necessary to identify possible underlying pathways, specify the precise attributes of ultra-processed food that confer harm, and optimise nutrition-related and public health strategies for common mental disorders.

Nutrition and bipolar disorder: a systematic review

INTRODUCTION

Individuals with bipolar disorder (BD) have higher rates of unhealthy lifestyles and risk for medical comorbidities Research currently suggests that dietary factors may play a role in the development of depression and anxiety. Therefore, nutritional approaches are potential strategies for the treatment of BD. The aim of this review is to summarize the available evidence on nutrition and BD.

MATERIALS AND METHODS

The paper was developed based on PRISMA 2020 guidelines. The search was conducted in Sep-2021 using PubMed and Cochrane Library, augmented by manually checked references lists. The search found 986 studies, of which 47 were included, combined with 13 from reference lists, totaling 60 studies.

RESULTS

There were 33 observational trials, of which 15 focused on fatty acids, 9 on micronutrients, 5 on specific foods, 4 on macro and micronutrients. The 27 interventional studies mainly focused on fatty acids, micronutrients and N-acetylcysteine (NAC).

DISCUSSION

Dietary intake or supplementation of unsaturated fatty acids, mainly Omega-3 seems to be associated with improved BD symptoms, along with seafood, folic acid and zinc. Studies found variable, mainly non-significant impacts of creatine, carnitine, vitamin D, inositol or NAC supplementation on BD. There are promising results associated with Coenzyme Q10 (Coq10) and probiotics. Taken together, these preliminary findings suggest that dietetic approaches might be included as part of BD treatment. Also considering the high risk of metabolic disorders in individuals with BD, they should be encouraged to choose healthy dietary lifestyles, including daily intake of fruits, vegetables, seafood and whole grains.

Associations of depression and intake of antioxidants and vitamin B complex: Results of the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil)

BACKGROUND

Optimum functioning of the central nervous system is dependent on a wide range of nutrients, so mental illness can be impacted by diet via several mechanisms. We aimed to investigate the associations of antioxidants (vitamin A, C and E, and selenium and zinc) and vitamin B complex (B6, folate and B12) intake with depression in 14,737 subjects of the Brazilian Longitudinal Study of Adult Health.

METHODS

Baseline cross-sectional data was analyzed. Micronutrients intake was measured using the Food Frequency Questionnaire, and depression was assessed using the Clinical Interview Schedule Revised. Logistic regression models were built using daily intake quintiles of micronutrients.

RESULTS

A significant inverse relationship was observed between depression and higher intake of selenium, zinc, vitamins B6 and B12 for the total sample. Among women, a similar pattern of associations was observed, in addition to the higher intake of vitamins A and C. Among men, a significant inverse relationship between depression was observed only with the intake of vitamins B12 and B6. Higher total antioxidant intake was significantly associated with lower odds of depression and an inverse dose-response effect between total antioxidant intake and clinical severity of depression was observed among women, in adjusted models.

LIMITATIONS

Recall bias in assessing diet. Misclassification bias regarding current depression.

CONCLUSIONS

Depression is associated with lower intake of antioxidants and B vitamins. Higher intake of selected micronutrients may contribute to reduce depression occurrence and severity.

Nutrition, nutritional deficiencies, and schizophrenia: An association worthy of constant reassessment

Schizophrenia is a mental health disorder that occurs worldwide, cutting across cultures, socioeconomic groups, and geographical barriers. Understanding the details of the neurochemical basis of schizophrenia, factors that contribute to it and possible measures for intervention are areas of ongoing research. However, what has become more evident is the fact that in targeting the neurochemical imbalances that may underlie schizophrenia, the type of response seen with currently available phamacotherapeutic agents does not provide all the answers that are needed. Therefore, the possible contribution of non-pharmacological approaches to schizophrenia management is worthy of consideration. In recent times, research is beginning to show nutrition may play a possibly significant role in schizophrenia, affecting its development, progression and management; however, while attempts had been made to examine this possible relationship from different angles, articles addressing it from a holistic point of view are not common. In this review, we examine existing scientific literature dealing with the possible relationship between nutrition and schizophrenia, with a view to elucidating the impact of diet, nutritional deficiencies and excesses on the aetiology, progression, management and outcome of schizophrenia. Secondly, the effect of nutritional supplements in prevention, as sole therapy, or adjuncts in schizophrenia management are examined.

Polyphenols as adjunctive treatments in psychiatric and neurodegenerative disorders: Efficacy, mechanisms of action, and factors influencing inter-individual response

The pathophysiology of psychiatric and neurodegenerative disorders is complex and multifactorial. Polyphenols possess a range of potentially beneficial mechanisms of action that relate to the implicated pathways in psychiatric and neurodegenerative disorders. The aim of this review is to highlight the emerging clinical trial and preclinical efficacy data regarding the role of polyphenols in mental and brain health, elucidate novel mechanisms of action including the gut microbiome and gene expression, and discuss the factors that may be responsible for the mixed clinical results; namely, the role of interindividual differences in treatment response and the potentially pro-oxidant effects of some polyphenols. Further clarification as part of larger, well conducted randomized controlled trials that incorporate precision medicine methods are required to inform clinical efficacy and optimal dosing regimens.

[Nutrition and mental health - how findings from genetic studies can support the identification of dietary effects]

Nutrition and mental health - how findings from genetic studies can support the identification of dietary effects Abstract. Introduction: Numerous studies indicate that dietary interventions could be an important approach to the prevention and treatment of mental disorders. However, conventional nutritional epidemiological approaches (e. g., observational studies and randomized controlled trials, RCTs) have specific limitations to consider when interpreting the results. This article examines whether genetic studies could help to establish a link between diet and the prevention of mental disorders. Furthermore, it examines whether it is possible to draw conclusions about causal relationships. Methods: This narrative review describes various approaches of genetic cross-phenotype studies and presents examples of their applications in nutritional psychiatry. In addition, it discusses specific requirements as well as the strengths and limitations of the respective approaches. Results: To date, in the context of nutritional psychiatry, genetic correlation analyses, look-up analyses, and Mendelian randomization (MR) studies have been used for genetic crossphenotype analyses. Genetic correlation and look-up analyses provide initial evidence of possible overlap between specific mental disorders and metabolic pathways or specific nutrients. MR studies are used for detailed analyses that aim to identify causal relationships. However, MR is based on specific assumptions that must be met and considered when results are interpreted. Conclusion: Genetic cross-phenotype analyses are a useful amendment to conventional nutritional epidemiological research. In particular, positive results from MR studies provide an important fundament for identifying and developing suitable dietary interventions, which in turn increases the chance of success upon testing in subsequent RCTs. Accordingly, genetic cross-phenotype analyses are important instruments for increasing the efficiency in nutritional psychiatric research.

Are US adults with low-exposure to methylmercury at increased risk for depression? A study based on 2011-2016 National Health and Nutrition Examination Surveys (NHANES)

OBJECTIVE

Depression is a highly-prevalent disorder among US adults and despite advancements in treatment options, prevalence rates are increasing. With the emerging recommendations of dietary interventions such as high fish intake come potential risks, for example, exposure to methylmercury (MeHg). Case reports and animal models have suggested a possible association of high doses of MeHg with psychiatric symptoms; the impact of low-dose exposure on depression remains unknown.

METHODS

In this cross-sectional study, survey-weighted logistic regression models were built to assess the relationship between low-dose MeHg blood levels and depression in a sample of n = 3930 adults from the National Health and Nutrition Examination Survey (NHANES) from 2011 to 2016.

RESULTS

9.1% (n = 1335) of the respondents screened positive for depression; all participants had MeHg blood levels below the US Environmental Protection Agency's reference dose. The adjusted multivariate logistic regression model showed no statistically significant association between MeHg blood levels and depression.

CONCLUSION

Low-dose MeHg does not seem to be associated with depression in this study. However, dietary recommendations with regards to fish intake should be made cautiously. Further studies are needed, especially considering predicted increasing environmental pollution of our food webs and the potentially higher vulnerability of subpopulations such as pregnant women.

Mental, emotional, and behavioral effects of ketogenic diet for non-epileptic neuropsychiatric conditions

Ketogenic diet (KD) is comprised of a distinct macronutrient combination: i.e. 90% fat, 8% of protein and 2% of carbohydrates, typically characterized as a high-fat low-carbohydrate diet. KD's efficacy was largely established for treatment resistant epilepsy in children, but its mental, emotional and behavioral effects remain largely unknown. Nevertheless, the efficacious effects of KD in childhood epilepsy provide rationale for repurposing this approach for other brain-based disorders. Consequently, clinicians and researchers should be aware of the evidence regarding efficacy, as well as the benefits and risks of adopting this diet. Results from animals and humans studies provide equivocal evidence across multiple domains of psychopathology. Conceptually, KD shows promise to serve as an efficacious treatment for mental disorders.

Nutritional psychiatry: Towards improving mental health by what you eat

Does it matter what we eat for our mental health? Accumulating data suggests that this may indeed be the case and that diet and nutrition are not only critical for human physiology and body composition, but also have significant effects on mood and mental wellbeing. While the determining factors of mental health are complex, increasing evidence indicates a strong association between a poor diet and the exacerbation of mood disorders, including anxiety and depression, as well as other neuropsychiatric conditions. There are common beliefs about the health effects of certain foods that are not supported by solid evidence and the scientific evidence demonstrating the unequivocal link between nutrition and mental health is only beginning to emerge. Current epidemiological data on nutrition and mental health do not provide information about causality or underlying mechanisms. Future studies should focus on elucidating mechanism. Randomized controlled trials should be of high quality, adequately powered and geared towards the advancement of knowledge from population-based observations towards personalized nutrition. Here, we provide an overview of the emerging field of nutritional psychiatry, exploring the scientific evidence exemplifying the importance of a well-balanced diet for mental health. We conclude that an experimental medicine approach and a mechanistic understanding is required to provide solid evidence on which future policies on diet and nutrition for mental health can be based.

Vegetarian diets and depressive symptoms among men

BACKGROUND

Vegetarian diets are associate with cardiovascular and other health benefits, but little is known about mental health benefits or risks.

AIMS

To determine whether self-identification of vegetarian dietary habits is associated with significant depressive symptoms in men.

METHOD

Self-report data from 9668 adult male partners of pregnant women in the Avon Longitudinal Study of Parents and Children (ALSPAC) included identification as vegetarian or vegan, dietary frequency data and the Edinburgh Post Natal Depression Scale (EPDS). Continuous and binary outcomes were assessed using multiple linear and logistic regression taking account of potential confounding variables including: age, marital status, employment status, housing tenure, number of children in the household, religion, family history of depression previous childhood psychiatric contact, cigarette and alcohol consumption.

RESULTS

Vegetarians [n = 350 (3.6% of sample)], had higher depression scores on average than non-vegetarians (mean difference 0.96 points [95%CI + 0.53, + 1.40]) and a greater risk for EPDS scores above 10 (adjusted OR = 1.67 [95% CI: 1.14,2.44]) than non-vegetarians after adjustment for potential confounding factors.

CONCLUSIONS

Vegetarian men have more depressive symptoms after adjustment for socio-demographic factors. Nutritional deficiencies (e.g. in cobalamin or iron) are a possible explanation for these findings, however reverse causation cannot be ruled out.

Integrative Therapies in Anxiety Treatment with Special Emphasis on the Gut Microbiome

Over the past decade, research has shown that diet and gut health affects symptoms expressed in stress related disorders, depression, and anxiety through changes in the gut microbiota. Psycho-behavioral function and somatic health interaction have often been ignored in health care with resulting deficits in treatment quality and outcomes. While mental health care requires the professional training in counseling, psychotherapy and psychiatry, complimentary therapeutic strategies, such as attention to a nutritional and diverse diet and supplementation of probiotic foods, may be integrated alongside psychotherapy treatment models. Development of these alternative strategies is predicated on experimental evidence and diligent research on the biology of stress, fear, anxiety-related behaviors, and the gut-brain connection. This article provides a brief overview on biological markers of anxiety and the expanding nutritional literature relating to brain health and mental disorders. A case study demonstrates an example of a biopsychosocial approach integrating cognitive psychotherapy, dietary changes, and mindfulness activities, in treating symptoms of anxiety. This case study shows a possible treatment protocol to explore the efficacy of targeting the gut-brain-axis that may be used as an impetus for future controlled studies.