Nutrient Intake Differences Among Ethnic Groups and Risks 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.

Dietary Nutrient Deficiencies and Risk of Depression (Review Article 2018-2023)

Depression is classified as one of the most common mental disorders. Its prevalence has recently increased, becoming a growing public health threat. This review focuses on clarifying the role and importance of individual nutrients in the diet and the impact of nutrient deficiencies on the risk of depression. Deficiencies in nutrients such as protein, B vitamins, vitamin D, magnesium, zinc, selenium, iron, calcium, and omega-3 fatty acids have a significant impact on brain and nervous system function, which can affect the appearance of depressive symptoms. However, it is important to remember that diet in itself is not the only factor influencing the risk of or helping to treat depression. There are many other aspects, such as physical activity, sleep, stress management, and social support, that also play an important role in maintaining mental health. The data review observed that most of the available analyses are based on cross-sectional studies. Further studies, including prospective cohort, case-control studies, are recommended to draw more reliable conclusions.

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.

Cross-Sectional Associations of Intakes of Starch and Sugars with Depressive Symptoms in Young and Middle-Aged Japanese Women: Three-Generation Study of Women on Diets and Health

The relationship between the intakes of saccharide subtypes and depressive symptoms is unclear in Asian countries. This cross-sectional study aimed to investigate this association among 3963 young (age of 18 years) and 3826 middle-aged (mean age of 47.8 years) Japanese women. The intakes of starch, total sugars, free sugars, sucrose, lactose, glucose, and total fructose were assessed using a validated diet history questionnaire. The prevalence of depressive symptoms was 22.0% and 16.8% among young and middle-aged women, assessed using the Center for Epidemiologic Studies Depression (CES-D) score. After adjusting for potential confounding factors, higher starch intake was associated with a lower prevalence of depressive symptoms in young women with an odds ratio (OR) of the fourth to the first quintiles of 0.75 (95% confidence interval (CI): 0.57, 0.99). Moreover, higher intakes of sugars (except for lactose) were associated with a higher prevalence of depressive symptoms in young women, with ORs (95% CI) of the fifth to the first quintiles ranging from 1.30 (0.995, 1.69) for glucose to 1.47 (1.12, 1.93) for sucrose. These associations were not observed in middle-aged women. Future prospective studies are needed to confirm these findings.

Biopsychosocial and Nutritional Factors of Depression among Type 2 Diabetes Mellitus Patients: A Systematic Review

The rising prevalence of depression among Type 2 Diabetes Mellitus (T2DM) patients has triggered an alarming situation, and further actions need to be taken by health care professionals and policymakers to curb the issue. There is a lack of evidence review in terms of the biopsychosocial and nutritional factors that are related to depression among T2DM. Hence, this review aimed to identify available evidence on the biopsychosocial and nutritional factors associated with depression among T2DM patients based on the existing literature. Articles were systematically searched from four databases, namely PubMed, Scopus, Web of Science, and EBSCOHost. The approach for the identification of the final articles followed PRISMA guidelines. The selected full-text articles were published between 2017 and 2021 in the English language, and included studies focused on depression among T2DM patients. Using AXIS tools, the eligible articles were evaluated to assess the quality of studies. A total of 19 studies were included in the review, and information related to research questions and associated factors was extracted. Biological, psychological, social, and nutritional factors were shown to be linked with depression among T2DM patients. Future studies need to considered using the biopsychosocial model and incorporating nutritional factors to manage the issues of depression among T2DM patients.