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.

Efficacy of low carbohydrate and ketogenic diets in treating mood and anxiety disorders: systematic review and implications for clinical practice.

BACKGROUND: There is mounting interest in the potential efficacy of low carbohydrate and very low carbohydrate ketogenic diets in various neurological and psychiatric disorders. AIMS: To conduct a systematic review and narrative synthesis of low carbohydrate and ketogenic diets (LC/KD) in adults with mood and anxiety disorders. METHOD: MEDLINE, Embase, PsycINFO and Cochrane databases were systematically searched for articles from inception to 6 September 2022. Studies that included adults with any mood or anxiety disorder treated with a low carbohydrate or ketogenic intervention, reporting effects on mood or anxiety symptoms were eligible for inclusion. PROSPERO registration CRD42019116367. RESULTS: The search yielded 1377 articles, of which 48 were assessed for full-text eligibility. Twelve heterogeneous studies (stated as ketogenic interventions, albeit with incomplete carbohydrate reporting and measurements of ketosis; diet duration: 2 weeks to 3 years; n = 389; age range 19 to 75 years) were included in the final analysis. This included nine case reports, two cohort studies and one observational study. Data quality was variable, with no high-quality evidence identified. Efficacy, adverse effects and discontinuation rates were not systematically reported. There was some evidence for efficacy of ketogenic diets in those with bipolar disorder, schizoaffective disorder and possibly unipolar depression/anxiety. Relapse after discontinuation of the diet was reported in some individuals. CONCLUSIONS: Although there is no high-quality evidence of LC/KD efficacy in mood or anxiety disorders, several uncontrolled studies suggest possible beneficial effects. Robust studies are now needed to demonstrate efficacy, to identify clinical groups who may benefit and whether a ketogenic diet (beyond low carbohydrate) is required and to characterise adverse effects and the risk of relapse after diet discontinuation.

Associations between total dairy, high-fat dairy and low-fat dairy intake, and depressive symptoms: findings from a population-based cross-sectional study.

PURPOSE: Evidence on the association between dairy intake and depression is conflicting. Given numerous dietary guidelines recommend the consumption of low-fat dairy products, this study examined associations between total dairy, high-fat dairy, and low-fat dairy intake and the prevalence of elevated depressive symptoms. Associations between dairy products, which differed in both fat content and fermentation status, and depressive symptoms were also explored. METHODS: This cross-sectional study included 1600 Finnish adults (mean age 63 ± 6 years; 51% female) recruited as part of the Kuopio Ischaemic Heart Disease Risk Factor Study. Dairy intake was assessed using 4-day food records. Elevated depressive symptoms were defined as having a score ≥ 5 on the Diagnostic and Statistical Manual of Mental Disorders-III Depression Scale, and/or regularly using one or more prescription drugs for depressive symptoms. RESULTS: In total, 166 participants (10.4%) reported having elevated depressive symptoms. Using multivariate logistic regression models, intake in the highest tertile of high-fat dairy products (OR 0.64, 95% CI 0.41-0.998, p trend = 0.04) and high-fat non-fermented dairy products (OR 0.60, 95% CI 0.39-0.92, p trend = 0.02) were associated with reduced odds for having elevated depressive symptoms. Whereas no significant association was observed between intake of total dairy, low-fat dairy, or other dairy products, and depressive symptoms. CONCLUSION: Higher intake of high-fat dairy and high-fat non-fermented dairy products were associated with reduced odds for having elevated depressive symptoms in middle-aged and older Finnish adults. Given the high global consumption of dairy products, and widespread burden of depression, longitudinal studies that seek to corroborate these findings are required.

The effect of vitamin D supplementation on depressive symptoms in adults: A systematic review and meta-analysis of randomized controlled trials.

Neurosteroid and immunological actions of vitamin D may regulate depression-linked physiology. Meta-analyses investigating the effect of vitamin D on depression have been inconsistent. This meta-analysis investigated the efficacy of vitamin D in reducing depressive symptoms among adults in randomized placebo-controlled trials (RCT). General and clinical populations, and studies of ill individuals with systemic diseases were included. Light therapy, co-supplementation (except calcium) and bipolar disorder were exclusionary. Databases Medline, PsycINFO, CINAHL and The Cochrane Library were searched to identify relevant articles in English published before April 2022. Cochrane risk-of-bias tool (RoB 2) and GRADE were used to appraise studies. Forty-one RCTs (n = 53,235) were included. Analyses based on random-effects models were performed with the Comprehensive Meta-analysis Software. Results for main outcome (n = 53,235) revealed a positive effect of vitamin D on depressive symptoms (Hedges' g = -0.317, 95% CI [-0.405, -0.230], p < 0.001, I2 = 88.16%; GRADE: very low certainty). RoB assessment was concerning in most studies. Notwithstanding high heterogeneity, vitamin D supplementation ≥ 2,000 IU/day appears to reduce depressive symptoms. Future research should investigate possible benefits of augmenting standard treatments with vitamin D in clinical depression. PROSPERO registration number: CRD42020149760. Funding: Finnish Medical Foundation, grant 4120 and Juho Vainio Foundation, grant 202100353.

Nonfermented Dairy Intake, but Not Fermented Dairy Intake, Associated with a Higher Risk of Depression in Middle-Age and Older Finnish Men.

BACKGROUND: Despite the putative health benefits of fermented dairy products, evidence on the association between fermented dairy and nonfermented dairy intake, and depression incidence is limited. OBJECTIVES: This study examined cross-sectional and prospective associations between total dairy, fermented dairy, and nonfermented dairy intake with 1) the presence of elevated depressive symptoms and 2) the risk of a future hospital discharge or outpatient diagnosis of depression. METHODS: Data from 2603 Finnish men (aged 42-60 y), recruited as part of the Kuopio Ischaemic Heart Disease Risk Factor Study, were included. Multivariable logistic regression models were used to examine ORs and 95% CIs for elevated depressive symptoms (Human Population Laboratory scale ≥5 points) at baseline. Cox proportional hazards regression models were used to estimate HRs and 95% CIs between dairy categories and risk of depression diagnoses. RESULTS: In cross-sectional analyses, fermented dairy intake in the highest (compared with lowest) tertile was associated with lower odds of having elevated depressive symptoms (adjusted OR: 0.70; 95% CI: 0.52, 0.96). Each 100-g increase in nonfermented dairy intake was associated with higher odds of having elevated depressive symptoms (adjusted OR: 1.06; 95% CI: 1.01, 1.10). During a mean follow-up time of 24 y, 113 males received a diagnosis of depression. After excluding cheese intake, higher fermented dairy intake was associated with a lower risk of depression diagnosis (adjusted HR: 0.62; 95% CI: 0.38, 1.03), which was strengthened after excluding those with elevated depressive symptoms at baseline (adjusted HR: 0.55; 95% CI: 0.31, 0.99), whereas nonfermented dairy intake in the highest tertile was associated with a 2-fold higher risk of depression (adjusted HR: 2.02; 95% CI: 1.20, 3.42). CONCLUSIONS: Fermented dairy and nonfermented dairy intake were differentially associated with depression outcomes when examined cross-sectionally and over a mean period of 24 y. These findings suggest that dairy fermentation status may influence the association between dairy intake and depression in Finnish men. The KIHD study was registered at clinicaltrials.gov as NCT03221127.

Evaluating telehealth lifestyle therapy versus telehealth psychotherapy for reducing depression in adults with COVID-19 related distress: the curbing anxiety and depression using lifestyle medicine (CALM) randomised non-inferiority trial protocol.

BACKGROUND: There is increasing recognition of the substantial burden of mental health disorders at an individual and population level, including consequent demand on mental health services. Lifestyle-based mental healthcare offers an additional approach to existing services with potential to help alleviate system burden. Despite the latest Royal Australian New Zealand College of Psychiatrists guidelines recommending that lifestyle is a 'first-line', 'non-negotiable' treatment for mood disorders, few such programs exist within clinical practice. Additionally, there are limited data to determine whether lifestyle approaches are equivalent to established treatments. Using an individually randomised group treatment design, we aim to address this gap by evaluating an integrated lifestyle program (CALM) compared to an established therapy (psychotherapy), both delivered via telehealth. It is hypothesised that the CALM program will not be inferior to psychotherapy with respect to depressive symptoms at 8 weeks. METHODS: The study is being conducted in partnership with Barwon Health's Mental Health, Drugs & Alcohol Service (Geelong, Victoria), from which 184 participants from its service and surrounding regions are being recruited. Eligible participants with elevated psychological distress are being randomised to CALM or psychotherapy. Each takes a trans-diagnostic approach, and comprises four weekly (weeks 1-4) and two fortnightly (weeks 6 and 8) 90-min, group-based sessions delivered via Zoom (digital video conferencing platform). CALM focuses on enhancing knowledge, behavioural skills and support for improving dietary and physical activity behaviours, delivered by an Accredited Exercise Physiologist and Accredited Practising Dietitian. Psychotherapy uses cognitive behavioural therapy (CBT) delivered by a Psychologist or Clinical Psychologist, and Provisional Psychologist. Data collection occurs at baseline and 8 weeks. The primary outcome is depressive symptoms (assessed via the Patient Health Questionnaire-9) at 8 weeks. Societal and healthcare costs will be estimated to determine the cost-effectiveness of the CALM program. A process evaluation will determine its reach, adoption, implementation and maintenance. DISCUSSION: If the CALM program is non-inferior to psychotherapy, this study will provide the first evidence to support lifestyle-based mental healthcare as an additional care model to support individuals experiencing psychological distress. TRIAL REGISTRATION: Australia and New Zealand Clinical Trials Register (ANZCTR): ACTRN12621000387820 , Registered 8 April 2021.

Psychological distress as a risk factor for all-cause, chronic disease- and suicide-specific mortality: a prospective analysis using data from the National Health Interview Survey.

PURPOSE: The risk psychological distress (PD) confers on mortality due to specific chronic diseases compared to suicide is unclear. Using the National Health Interview Survey (NHIS), we investigated the association between PD levels and risk of all-cause and chronic disease-specific mortality and compared the contribution of chronic disease-related mortality to that of suicide. METHODS: Data from 195, 531 adults, who participated in the NHIS between 1997 and 2004, were linked to the National Death Index records through to 2006. Multivariable Cox regression models were used to estimate hazard ratios (HRs) and their 95% confidence intervals (CIs) across four levels of PD, measured using the Kessler-6 scale. Outcomes included all-cause mortality, and mortality due to all CVDs and subtypes, all cancers and subtypes, diabetes mellitus, alcoholic liver disease and suicide. RESULTS: During a mean follow-up time of 5.9 years, 7665 deaths occurred. We found a dose-response association between levels of PD and all-cause mortality, with the adjusted HRs (95% CI) elevated for all levels of PD, when compared to asymptomatic levels: subclinical 1.10 (1.03-1.16), symptomatic 1.36 (1.26-1.46) and highly symptomatic 1.57 (1.37-1.81). A similar association was found for all CVDs and certain CVD subtypes, but not for cancers, cerebrovascular diseases diabetes mellitus. Excess mortality attributable to suicide and alcoholic liver disease was evident among those with levels of PD only. CONCLUSION: PD symptoms, of all levels, were associated with an increased risk of all-cause and CVD-specific mortality while higher PD only was associated with suicide. These findings emphasise the need for lifestyle interventions targeted towards improving physical health disparities among those with PD.

The Moo'D Study: protocol for a randomised controlled trial of A2 beta-casein only versus conventional dairy products in women with low mood.

BACKGROUND: Beta-casein is a major protein in cow's milk, of which A1 and A2 are the most frequent variants. Recent evidence implicates A1 beta-casein consumption in mechanisms that are of potential importance to mental health, yet its possible effects on psychological endpoints remains unknown. The primary aim of the study is to evaluate the comparative effects of consumption of dairy products containing A2 beta-casein versus conventional dairy (i.e. containing both A1 and A2 beta-casein) on symptoms of psychological distress in women with low mood. METHODS: 'The Moo'D Study' is a 16-week, superiority, 1:1 parallel group, triple-blinded, randomised controlled trial. Ninety women with low mood (Patient Health Questionnaire score ≥ 5) will be randomised to consume either A2 beta-casein only or conventional dairy products. The primary outcome, symptoms of psychological distress, will be measured by the 21-item Depression, Anxiety and Stress Scale. Secondary outcomes will include symptoms of depression, anxiety and stress, severity of low mood, cognition, gut microbiota composition, gut symptomatology, markers of immune function, gut inflammation, systemic metabolites, endothelial integrity and oxidative stress, body composition, perceived wellbeing, sleep, quality of life, resource use and cost-effectiveness. DISCUSSION: This study will advance our understanding of the possible impact of milk proteins on psychological distress in women as well as elucidate mechanisms underpinning any association. Given dairy products form a substantial component of traditional and Western diets, the implications of these findings are likely to be of clinical and public health importance. TRIAL REGISTRATION: The trial protocol has been prospectively registered with the Australia and New Zealand Clinical Trials Registry, ACTRN12618002023235 . Registered on 17 December 2018.

The Dietary Inflammatory Index and Human Health: An Umbrella Review of Meta-Analyses of Observational Studies.

Numerous observational studies have investigated the role of the Dietary Inflammatory Index (DII®) in chronic disease risk. The aims of this umbrella review and integrated meta-analyses were to systematically synthesize the observational evidence reporting on the associations between the DII and health outcomes based on meta-analyses, and to assess the quality and strength of the evidence for each associated outcome. This umbrella review with integrated meta-analyses investigated the association between the DII and a range of health outcomes based on meta-analyses of observational data. A credibility assessment was conducted for each outcome using the following criteria: statistical heterogeneity, 95% prediction intervals, evidence for small-study effect and/or excess significance bias, as well as effect sizes and P values using calculated random effects meta-analyses. In total, 15 meta-analyses reporting on 38 chronic disease-related outcomes were included, incorporating a total population of 4,360,111 subjects. Outcomes (n = 38) were examined through various study designs including case-control (n = 8), cross-sectional (n = 5), prospective (n = 5), and combination (n = 20) study designs. Adherence to a pro-inflammatory dietary pattern had a significant positive association with 27 (71%) of the included health outcomes (P value < 0.05). Using the credibility assessment, Class I (Convincing) evidence was identified for myocardial infarction only, Class II (Highly suggestive) evidence was identified for increased risk of all-cause mortality, overall risk of incident cancer, and risk of incident site-specific cancers (colorectal, pancreatic, respiratory, and oral cancers) with increasing (more pro-inflammatory) DII score. Most outcomes (n = 31) presented Class III (Suggestive) or lower evidence (Weak or No association). Pro-inflammatory dietary patterns were nominally associated with an increased risk of many chronic disease outcomes. However, the strength of evidence for most outcomes was limited. Further prospective studies are required to improve the precision of the effect size.

Diet and depression: exploring the biological mechanisms of action.

The field of nutritional psychiatry has generated observational and efficacy data supporting a role for healthy dietary patterns in depression onset and symptom management. To guide future clinical trials and targeted dietary therapies, this review provides an overview of what is currently known regarding underlying mechanisms of action by which diet may influence mental and brain health. The mechanisms of action associating diet with health outcomes are complex, multifaceted, interacting, and not restricted to any one biological pathway. Numerous pathways were identified through which diet could plausibly affect mental health. These include modulation of pathways involved in inflammation, oxidative stress, epigenetics, mitochondrial dysfunction, the gut microbiota, tryptophan-kynurenine metabolism, the HPA axis, neurogenesis and BDNF, epigenetics, and obesity. However, the nascent nature of the nutritional psychiatry field to date means that the existing literature identified in this review is largely comprised of preclinical animal studies. To fully identify and elucidate complex mechanisms of action, intervention studies that assess markers related to these pathways within clinically diagnosed human populations are needed.

Possible use of fermented foods in rehabilitation of anorexia nervosa: the gut microbiota as a modulator.

Anorexia nervosa is a serious psychiatric disorder with high morbidity and mortality rate. Evidence for the optimal psychopharmacological approach to managing the disorder remains limited, with nutritional treatment, focused on weight restoration through the consumption of high energy diet, regarded as one of the fundamental steps in treatment. The human gut microbiome is increasingly recognised for its proposed role in gastrointestinal, metabolic, immune and mental health, all of which may be compromised in individuals with anorexia nervosa. Dietary intake plays an important role in shaping gut microbiota composition, whilst the use of fermented foods, foods with potential psychobiotic properties that deliver live bacteria, bacterial metabolites, prebiotics and energy, have been discussed to a lesser extent. However, fermented foods are of increasing interest due to their potential capacity to affect gut microbiota composition, provide beneficial bacterial metabolites, and confer beneficial outcomes to host health. This review provides an overview of the role of the gut microbiota in relation to the disease pathology in anorexia nervosa and especially focuses on the therapeutic potential of fermented foods, proposed here as a recommended addition to the current nutritional treatment protocols warranting further investigation.

Prebiotics, probiotics, fermented foods and cognitive outcomes: A meta-analysis of randomized controlled trials.

This systematic review and meta-analysis aimed to evaluate randomized controlled trials that investigated the use of probiotic, prebiotic, and fermented food interventions for cognitive performance. In total, 22 studies (n = 1551) were included that investigated probiotics (11 studies, n = 724), prebiotics (5 studies, n = 355), and fermented foods (6 studies, n = 472). Despite several individual studies (14 of 22) reporting significant improvements in specific cognitive domains, results of the pooled meta-analysis found no significant effect for any intervention for global cognition (Probiotics: g = 0.115, 95 %CI -0.041, 0.270, p = 0.148; Prebiotics: g = 0.077, 95 %CI -0.091, 0.246, p = 0.369; Fermented food: g = 0.164 95 %CI -0.017, 0.345, p = 0.076) or any individual cognitive domain. Most studies (16 of 22) had low risk of bias. These results do not support the use of probiotic, prebiotic, and fermented food interventions for cognitive outcomes. This may be due to the limited number of small and short-term studies as well clinical heterogeneity relating to the population, cognitive tests, and intervention. Therefore, further trials that investigate these interventions in clinical populations using adequately powered samples are warranted. PROSPERO: CRD42019137936.

The effect of ultra-processed very low-energy diets on gut microbiota and metabolic outcomes in individuals with obesity: A systematic literature review.

This systematic review investigated the effects of ultra-processed very low-energy diets on gut microbiota and metabolic outcomes in individuals with obesity. MEDLINE complete, EMBASE, Scopus, Cochrane and CINAHL were searched between date of inception and October 2019. Seven trials were reviewed (a total of 130 participants, with 10 to 44 participants in each trial). Of these, five were single-arm interventions and included very low-energy diets adjunctive to comprehensive lifestyle interventions such as nutritional counselling, behavioural therapy and exercise programmes. Changes to taxa within the Firmicutes phylum were found, including reduced abundance of potentially beneficial butyrogenic microbes (Roseburia, Faecalbacterium prausnitzii, Lactobacillus, Bifidobacterium and Lachnospiraeceae). Conversely, increased abundance of potentially pathogenic or opportunistic microbes from the Bacteroidetes phylum was reported, including increases in Alistipes and Bacteroides taxa. However, outcomes were inconsistent, with some trials also showing decreases in Bacteroides taxa and increases in commensal microbiota, such as Lachnospiraceae and Bifidobacteriaceae. The changes in metabolic parameters observed from baseline to after the ultra-processed very low-energy diets were mostly beneficial or were not significantly altered. Although the selected articles were deemed to have satisfactory methodological quality, to understand the possible direct effects of these regimens on gut microbiota, further rigorously designed trials, with more standardised microbiological sequencing techniques and detailed reporting, are required. Study registration: Prospero ID: CRD42019124436.

Is dairy consumption associated with depressive symptoms or disorders in adults? A systematic review of observational studies.

Diet quality is associated with depression risk, however the possible role of dairy products in depression risk is unclear. A number of epidemiological studies have examined associations between dairy consumption and depressive symptoms, but results have been inconsistent. Therefore, this systematic review aimed to examine whether an association exists between dairy consumption and depressive symptoms or disorders in adults. Anxiety symptoms were also explored as a secondary outcome. CINAHL, Cochrane, MEDLINE complete, EMBASE, Scopus and PsycINFO databases were searched from database inception to December 2018. Studies were included if they used a case-control, cross-sectional, or cohort study design, and included community dwelling or institutionalized adults (≥18 years). Seven prospective and six cross-sectional studies (N = 58,203 participants) reported on the association between dairy consumption and depressive symptoms or disorders. Findings were mixed, with one study reporting a positive association; five studies reporting no association; and seven studies reporting mixed associations depending on dairy type, gender or population group. We found conflicting and inconsistent associations in studies that were generally of fair quality. Future longitudinal and intervention studies that employ more rigorous dietary assessment methods are warranted.

The effect of emerging nutraceutical interventions for clinical and biological outcomes in multiple sclerosis: A systematic review.

BACKGROUND: Due to the considerable burden of multiple sclerosis (MS)-related symptoms and the need to identify effective interventions to prevent disease progression, various nutraceutical interventions have been trialed as adjunctive treatments. The aim of this review was to investigate the efficacy and safety of nutraceutical interventions for clinical and biological outcomes in people with MS. METHODS: In accordance with PRISMA reporting guidelines, a systematic literature search was conducted using three electronic literature databases. Risk of bias was assessed using the Jadad scale. RESULTS: Thirty-seven randomized controlled trials, investigating fourteen nutraceuticals, were included in the review. Trials that investigated alpha lipoic acid (n = 4/6), ginkgo biloba (n = 3/5), vitamin A (n = 2/2), biotin (n = 1/2), carnitine (n = 1/2), green tea (n = 1/2), coenzyme Q10 (n = 1/1), probiotics (n = 1/1), curcumin (n = 1/1), Andrographis paniculata (n = 1/1), ginseng (n = 1/1), and lemon verbena (n = 1/1) were reported to improve biological (e.g. MRI brain volume change, antioxidant capacity) and/or clinical (e.g. fatigue, depression, Expanded Disability Status Scale) outcomes in multiple sclerosis compared to control. However, most trials were relatively small (average study sample size across included studies, n = 55) and there were few replicate studies per nutraceutical to validate the reported results. Furthermore, some nutraceuticals (e.g. green tea and inosine) should be used with caution due to reported adverse events. Risk of bias across most studies was low, with 31 studies receiving a score between 4 and 5 (out of 5) on the Jadad Scale. CONCLUSION: The existing literature provides preliminary support for the use of a number of nutraceutical interventions in MS. However, sufficiently powered long-term trials are required to expand the currently limited literature and to investigate unexplored nutraceuticals that may target relevant pathways involved in MS such as the gut microbiome and mitochondrial dysfunction. Prospero ID: CRD42018111736.

Does Fruit and Vegetable Consumption During Adolescence Predict Adult Depression? A Longitudinal Study of US Adolescents.

The relationship between better diet quality and decreased depression across the life span is consistent and compelling. Fruit and vegetable consumption has been of particular interest. The nutritional benefits from the consumption of fruits and vegetables may mitigate non-communicable diseases and promote brain and mental health. This study aimed to determine whether fruit and vegetable consumption during adolescence was associated with a reduced risk of developing depression in adulthood in a large, representative sample of US individuals. Data from the Add Health Study were analyzed, which included 3,696 participants who were aged approximately 17 years at baseline (1994-1995), and 29 years at follow-up (2007-2008). The Center for Epidemiologic Studies Depression Scale was used to assess depression and a self-report item asked how many times the participant consumed fruit/vegetables on the previous day. Individuals who were depressed at both times points had the highest proportion who failed to consume any fruit (31%) or vegetables (42%) on the previous day. Fruit and vegetable consumption did not predict of adult depression in fully adjusted models. Cross sectional associations existed for diet and adolescent depression only. Our initial findings supported fruit and vegetable consumption as being protective against adult depression, but this association was subsequently attenuated on adjustment for other relevant factors. Future research will benefit from more precise measures of dietary intakes.