Gut Health = Mental Health? The Impact of Diet and Dietary Supplements on Mood Disorders

Does fruit and vegetable consumption impact mental health? Systematic review and meta-analyses of published controlled intervention studies

Associations between fruit and vegetable (FV) consumption and mental health are suggested, largely from observational studies. This systematic review aimed to identify and summarise all published controlled intervention studies investigating the effects of FV consumption on mental health in adults. Four academic databases (Medline, PsycINFO, PubMed, Web of Science) were searched on 16 September 2022, over all years, for studies that used an intervention design; included FV consumption; included an appropriate non-FV-consumption control; used a validated measure of mental health and were conducted in healthy adults or adults with solely a depressive or anxiety-related condition. Study details were tabulated and combined using meta-analyses. Risk of bias was assessed using the domains of the Cochrane Collaboration. Six studies, enrolling 691 healthy adults and reporting on one or more mental health outcomes, were found. Meta-analyses found small and imprecise effects of FV consumption for: psychological well-being (4 studies, 289 participants) standardised mean difference (SMD) = 0·07 (95 % CI -0·17, 0·30), P = 0·58, I2 = 0 %; depressive symptomology (3 studies, 271 participants) SMD = -0·15 (95 % CI -0·40, 0·10), P = 0·23, I2 = 47 % and anxiety-related symptomology (4 studies, 298 participants) SMD = -0·15 (95 % CI -0·39, 0·08), P = 0·20, I2 = 71 %. Some benefit for psychological well-being was found in change-from-baseline data: SMD = 0·28 (95 % CI 0·05, 0·52), P = 0·02, I2 = 0 %. Risk of bias was high in many studies. Limitations include the consideration only of published studies and stem from the studies found. Given the few, limited studies available and the small size of effects, stronger evidence is needed before recommending FV consumption for mental health.

The association between gut-health promoting diet and depression: A mediation analysis

BACKGROUND

Recent research has highlighted the relevance of a gut-health promoting diet as a possible treatment and prevention for depression. A dietary pattern with consumption of fermented food and high consumption of dietary fiber can promote gut health, physical health, and might even improve mental health. This study aimed to investigate the interrelationship among diet, physical health, and depression.

METHODS

This study used a nationally representative sample (N = 16,572) from the National Health and Nutrition Examination Survey (2011-2018). Dietary information was collected by dietary recall interviews. Depression was assessed by the 9-item Patient Health Questionnaire. Subjective physical health was indicated by self-reported Body Mass Index (BMI). Objective physical health was indicated by BMI measured by trained health technicians. Path analysis was used to test the association between diet and depression, and the mediating roles of self-reported BMI and BMI measured by technicians.

RESULTS

Consumption of probiotic foods and higher intake of fiber were significantly associated with lower levels of depressive symptoms. Both subjective and objective physical health significantly mediated the relationship between variables of diet and mild depressive symptoms. Subjective physical health also significantly mediated the relationship between high intake of dietary fiber and lower likelihood of reporting severe depressive symptoms.

CONCLUSION

Despite being cross-sectional in nature, this study presented evidence that gut-health promoting diets may reduce depressive symptoms through improving physical health. These findings provide preliminary support to diet programs for preventing depression and diet programs as an alternative or supplementary treatment of depression.

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

BACKGROUND AND AIMS

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Patient-reported exposures and outcomes link the gut-brain axis and inflammatory pathways to specific symptoms of severe mental illness

We developed a "gut-brain-axis questionnaire" (GBAQ) to obtain standardized person-specific "review of systems" data for microbiome-gut-brain-axis studies. Individual items were compared to PANSS symptom measures using dimensional, transdiagnostic and traditional categorical approaches.

METHOD

Forty psychotic participants, independent of diagnoses, and 42 without psychosis (18 nonpsychotic affective disorders, 24 healthy controls) completed the GBAQ and underwent research diagnostic and symptom assessments. The PANSS scales and its dysphoric mood, autistic preoccupation and activation factors were computed.

RESULTS

Transdiagnostic analyses robustly linked psychosis severity to constipation (p<.001), and Negative (p=.045) and General Psychopathology scores (p=.016) with bowel hypomotility. Activation factor scores predicted numbers of psychiatric (p=.009) and medical conditions (p=.003), BMI (p=.003), skin (p<.001) and other conditions. Categorical analyses comparing psychotic, nonpsychotic and control groups revealed behavioral differences: cigarette smoking (p=.013), alcohol use (p=.007), diet (p's <.05), exercise (p<.001). All subjects accurately self-reported their diagnosis.

CONCLUSIONS

The GBAQ is a promising tool. Transdiagnostic analyses associated psychotic symptoms to gut hypomotility, indicative of low gut vagal tone, consistent with reduced cardiovagal activity in psychosis. Activation, similar to delirium symptoms, predicted medical comorbidity and systemic inflammatory conditions. Group level comparisons only showed behavioral differences. Underpinnings of psychiatric disorders may include reduced gut vagal function, producing psychosis, and systemic inflammation, impacting risks for psychotic and nonpsychotic conditions.

Psychological distress resulting from the COVID-19 confinement is associated with unhealthy dietary changes in two Italian population-based cohorts

Purpose

To examine the relationship between psychological distress resulting from the COVID-19 lockdown and dietary changes.

Methods

Cross-sectional analysis from 2 retrospective Italian cohorts recruited from May to September 2020: (1) The Moli-LOCK cohort consists of 1401 participants from the Moli-sani Study (n = 24,325) who were administered a telephone-based questionnaire to assess lifestyles and psychological factors during confinement; (2) the ALT RISCOVID-19 is a web-based survey of 1340 individuals distributed throughout Italy who self-responded to the same questionnaire using Google® forms.

Psychological distress was measured by assessments of depression (PHQ-9 and depressive items from the Screening Questionnaire for Disaster Mental Health- SQD-D), anxiety (GAD-7), stress (PSS-4), and post-traumatic stress disorder (SQD-P). Diet quality was assessed either as changes in consumption of ultra-processed foods (UPF) or adherence to Mediterranean diet (MD).

Results

In ALT RISCOVID-19, increased UPF intake was directly associated with depression (both PHQ-9 and SQD-D; p < 0.0001), anxiety (p < 0.0001), stress (p = 0.001) and SQD-P (p = 0.001); similar results were obtained in the Moli-LOCK cohort except for perceived stress. When psychometric scales were analysed simultaneously, only depression (SQD-D) remained associated with UPF (both cohorts). In both cohorts, psychological distress poorly influenced changes toward an MD, except for depression (SQD-D) that resulted inversely associated in the ALT RISCOVID-19 participants (β = − 0.16; 95% CI − 0.26, − 0.06).

Conclusions

Psychological distress from the COVID-19 confinement is directly associated with unhealthy dietary modifications in two Italian cohorts. In view of possible future restrictive measures to contain pandemic, public health actions are warranted to mitigate the impact of psychological distress on diet quality.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00394-021-02752-4.

Vegetarian diet and depression scores: A meta-analysis

BACKGROUND

Several studies have suggested an association between vegetarian diet and higher depression scores. However, some studies have also shown an effect in the opposite direction, indicating lower depression scores in vegetarians. Given this discrepancy in the literature, this meta-analysis was aimed to determine whether there is a significant association between vegetarian diet and depression scores across different published studies.

METHODS

A keyword search in major databases was conducted. Studies reporting depression scores in vegetarians and a non-vegetarian control group were included. Meta-analysis following a conditional random-effects procedure was conducted in R.

RESULTS

After duplicates were removed and studies were analyzed for inclusion criteria, k=13 studies with an overall n of 49889 participants (8057 vegetarians and 41832 non-vegetarian controls) were included in the analysis. Random-effects meta-analysis revealed a significant difference between vegetarians and non-vegetarians, with vegetarians showing higher depression scores than non-vegetarians.

LIMITATIONS

The heterogeneity between studies was high and geographical variation in study location was low, limiting cross-cultural insights.

CONCLUSIONS

Vegetarians show higher depression scores than non-vegetarians. However, due to high heterogeneity of published studies, more empirical research is needed before any final conclusions can be drawn. Also, empirical studies from a higher number of different countries would be desirable.

Pharmacological Activities of Sulfated Fucose-Rich Polysaccharides after Oral Administration: Perspectives for the Development of New Carbohydrate-Based Drugs

Marine organisms are a source of active biomolecules with immense therapeutic and nutraceutical potential. Sulfated fucose-rich polysaccharides are present in large quantities in these organisms with important pharmacological effects in several biological systems. These polysaccharides include sulfated fucan (as fucoidan) and fucosylated chondroitin sulfate. The development of these polysaccharides as new drugs involves several important steps, among them, demonstration of the effectiveness of these compounds after oral administration. The oral route is the more practical, comfortable and preferred by patients for long-term treatments. In the past 20 years, reports of various pharmacological effects of these polysaccharides orally administered in several animal experimental models and some trials in humans have sparked the possibility for the development of drugs based on sulfated polysaccharides and/or the use of these marine organisms as functional food. This review focuses on the main pharmacological effects of sulfated fucose-rich polysaccharides, with an emphasis on the antidislipidemic, immunomodulatory, antitumor, hypoglycemic and hemostatic effects.

[Perception of loneliness, happiness, and health, and quality of diet. The moderator role of weight status]

Introduction

Aim: to determine the relationship between perceived loneliness, happiness, and health, and quality of diet, observing the moderator role of weight status in elementary school children during the state of alarm decreed for COVID-19. Methods: a descriptive, cross-sectional study in a sample of 116 Spanish schoolchildren. The perception of loneliness, happiness, and health was assessed using three items of the Health Behavior in School-aged Children questionnaire. The quality of their Mediterranean diet was assessed using the Mediterranean Diet Quality Index quetsionnaire for children and adolescents. Anthropometric variables were collected through a self-reported questionnaire, and for the calculation of body mass index the Quetelet index (kg/m2) was used. Results: the descriptive analysis showed no differences in the perception of loneliness, happiness, or health, quality of diet, or anthropometric variables (p > 0.005), except for weight (p < 0.005), according to sex. The inferential analysis showed that higher values in quality of diet are correlated with higher scores in perceived happiness and health (p < 0.005). In turn, the linear regression test showed an association between quality of diet and perception of happiness after the model was adjusted for normal weight (R2 = 0.382; p < 0.005). Likewise, it showed a significant association between quality of diet and perception of health after the model was adjusted for overweight schoolchildren (R2 = 0.455; p < 0.005). Conclusion: the association between perceived health and happiness with quality of diet seems to be moderated by weight status.

Associations between depression, nutrition, and outcomes among individuals with coronary artery disease

OBJECTIVES

Depression and malnutrition are prevalent among people with coronary artery disease (CAD) and can affect their prognosis, but the relationship between depression and malnutrition and its co-effect on prognosis is not clear. We sought to explore that relationship and its effects.

METHODS

In this study, the nutritional and emotional statuses of 547 people with CAD were assessed using the Controlling Nutritional Status (CONUT) score and the Patient Health Questionnaire-9. The average follow-up period was 2.1 y, after which we explored the relationship between depression and nutrition and prognosis.

RESULTS

A total of 41% of the participants were found to have mild malnutrition, 10% moderate to severe malnutrition, 26% had mild depression, and 11% had moderate to severe depression. A total of 20.6% of the participants were found to have comorbidities of depression and malnutrition; and both moderate to severe depression (adjusted hazard ratio [HR], 1.674; 95% confidence interval [CI], 1.098-2.551) and moderate to severe malnutrition (adjusted HR, 1.686; 95% CI, 1.073-2.648) were observed to be risk factors for the composite end point. Participants with comorbidities of depression and malnutrition were found to have increased risk of cardiovascular death (HR, 5.390; 95% CI, 1.483-19.589) and composite end point (adjusted HR, 1.791; 95% CI, 1.133-2.833) compared to those without both depression and malnutrition.

CONCLUSIONS

Depression and malnutrition were found to be risk factors for adverse outcomes in people with CAD. People with CAD should pay attention to their emotional and nutritional statuses, and interventions must be timely and efficient.