Dietary intervention in depression - a review

The association between the number of food kinds and risk of depression in U.S. adults

BACKGROUND

The association between the number of food kinds and the risk of depression in adults was examined.

METHODS

According to the inclusion and exclusion criteria, a total of 4593 adults were included in the study. The number of food kinds was collected via 24‒hour dietary recalls. Depression was assessed using the Patient Health Questionnaire‒9. Logistic regression and restricted cubic spline models were applied to assess the association between the number of food kinds and the risk of depression.

RESULTS

This study included 4593 study participants, 451 of whom were diagnosed with depression. The revised advantage ratios (with corresponding confidence intervals) for the prevalence of depression among individuals in the fourth quartiles of the number of food kinds (Q4) in comparison to the lowest quartile (Q1) were determined to be 0.59 (0.36‒0.96), respectively. According to our subgroup analyses, the number of food kinds was negatively associated with the risk of depression in females, participants aged 18‒45 and 45‒65 years, and participants with a body mass index (BMI) of 25 to 24.9 kg/m2. According to our dose‒response analysis, the number of food kinds was linearly associated with the risk of depression (Pfor nonlinear=0.5896).

CONCLUSION

The risk of depression exhibited a linear and negative correlation with the number of food kinds. The results indicated that a diversified diet was an effective nonpharmacological approach that deserved further generalization.

Effects of chronic exposure to a high fat diet, nutritive or non-nutritive sweeteners on hypothalamic-pituitary-adrenal (HPA) and -gonadal (HPG) axes of male Sprague-Dawley rats

PURPOSE

Diet-related factors are of great significance in the regulation of hypothalamic-pituitary-adrenal (HPA) and hypothalamic-pituitary-gonad (HPG) axes. In this study, we aimed to investigate the effects of chronic exposure to a high fat diet (HFD), fructose or sucralose on the endocrine functions.

METHODS

Male, Sprague-Dawley rats received a normal chow diet, HFD, 10% fructose or 0.02% sucralose for 10 weeks. Behavioral changes were assessed by open field (OFT) and elevated plus-maze (EPM) tests at week 8. H&E staining was used to observe pathological changes in adrenal cortex, testis and perirenal adipose tissue. Serum hormone concentrations were quantified via enzyme-linked immunosorbent assay (ELISA). The mRNA expression levels of genes along the HPA and HPG axes were determined using real-time PCR.

RESULTS

All types of dietary interventions increased body weight and disturbed metabolic homeostasis, with anxiogenic phenotype in behavioral tests and damage to cell morphology of adrenal cortex and testis being observed. Along the HPA axis, significantly increased corticotropin releasing hormone (CRH), adrenocorticotropic hormone (ACTH) and corticosterone (CORT) concentrations were observed in the HFD or 0.02% sucralose group. For HPG axis, gonadotropin-releasing hormone (GnRH) and estradiol (E2) concentrations were significantly increased in all dietary intervention groups, while decreased concentrations of follicle-stimulating hormone (FSH) and testosterone (T) were also detected. Moreover, transcriptional profiles of genes involved in the synthesis of hormones and corresponding hormone receptors were significantly altered.

CONCLUSION

Long-term consumption of HFD, fructose or sucralose manifested deleterious effects on endocrine system and resulted in the dysregulation of HPA and HPG axes.

The role of dietary intake of live microbes in the association between leisure-time physical activity and depressive symptoms: a population-based study

Current research has shown promising associations between factors such as diet, total physical activity, and mental health outcomes, acknowledging the intricate interplay between these variables. However, the role of dietary intake of live microbes, coupled with leisure-time physical activity (LTPA), in their relationship to depressive symptoms necessitates further exploration. The present study examined a cohort of 25 747 individuals who participated in the National Health and Nutrition Examination Survey between the years 2007 and 2018. Patient's Health Questionnaire (PHQ-9) was employed, whereby individuals scoring ≥ 10 were classified as exhibiting symptoms of depression. LTPA status was reported by the Global Physical Activity Questionnaire and calculated by metabolic equivalent-minutes/week. Foods consumed by participants were evaluated by live microbes per gram, which were categorized into three groups: low, medium, and high. After controlling for all covariates, findings indicated that LTPA was negatively associated with depressive symptoms (OR (95% confidence interval (CI): 0.983 (0.976, 0.990), p < 0.001). Participating in more LTPA was positively correlated with consuming all three levels of dietary live microbes (low, β (95% CI): 0.086 (0.063, 0.109); medium, β (95% CI): 0.009 (0.007, 0.012); high, β (95% CI): 0.002 (0.001, 0.002)). Moreover, taking more foods with medium live microbes was associated with lower depressive likelihood (OR (95% CI): 0.931(0.882, 0.982), p = 0.010). Intake of medium and high levels of live microbes mediated the association between LTPA and depressive symptoms by 4.15% and 0.83%, respectively. Dietary intake of foods containing medium and high levels of live microbes may be a mediator of LTPA's negative association with depressive symptoms.

Diet Overall and Hypocaloric Diets Are Associated With Improvements in Depression but Not Anxiety in People With Metabolic Conditions: A Systematic Review and Meta-Analysis

The risk of depression and anxiety is higher in people with metabolic conditions, but whether dietary approaches, which are central to the management of metabolic conditions, can also improve depression and anxiety is uncertain. The primary aim of this systematic review and meta-analysis was to evaluate the effects of dietary interventions on depression and anxiety in adults with metabolic conditions. The secondary aim was to evaluate the effects of hypocaloric and isocaloric dietary interventions on these outcomes. Four databases (MEDLINE, PsychINFO, EMBASE, and CINAHL) were searched from inception to March 2023. Randomized controlled trials (RCTs) including dietary interventions in adults with metabolic conditions (type 2 diabetes mellitus, hyperlipidemia, hypertension, and/or overweight/obesity) that assessed depression and/or anxiety as outcomes were included. Overall, 13 RCTs were included in the systematic review, ≤13 of which were included in the meta-analysis. Estimates were pooled using random-effect meta-analysis for dietary interventions compared with controls. Improvements in depression scores were found in meta-analytic models including all dietary interventions [pooled estimate for the standardized mean difference (SMD) = -0.20 (95% CI: -0.35, -0.05); P = 0.007] and hypocaloric only diets [SMD = -0.27 (95% CI: -0.44, -0.10); P = 0.002]. There were no improvements in depression scores with isocaloric dietary interventions only [SMD = -0.14 (95% CI: -0.38, 0.10); P = 0.27]. In addition, there were no significant effects of any dietary interventions on anxiety scores. In adults with metabolic conditions, all dietary interventions and hypocaloric diets improved depression, but not anxiety. These findings suggest that dietary interventions including hypocaloric diets can play an important role in the management of depression in people with metabolic conditions. This systematic review and meta-analysis has been registered with PROSPERO (CRD42021252307).