The Association of Adherence to the Mediterranean Diet with Depression in Older Adults Longitudinally Taking into Account Cognitive Status: Results from the HELIAD Study

Diet quality and depression risk: A systematic review and meta-analysis of prospective studies

BACKGROUND

The association between diet and the onset and treatment of depression is unclear. This study aims to estimate the evidence for the prospective association between diet quality and depression.

METHODS

Systematic searches in PubMed, Web of Science and Embase up to 2024/01/04 of propective studies on the potential relationship between diet quality and depression identified 21 randomized clinical trials (RCT) and 92 prospective cohorts (PC) (>700,000 participants), that were pooled in random-effects frequentist and Bayesian meta-analyses.

RESULTS

Treatment-RCT yielded anecdotal-to-moderately strong support for the hypothesis that dietary interventions improve depression (d = -0.80, 95 % CI = -1.46 to -0.14), though their internal validity was low. Interventional effects were observed in nonpatient samples (d = -0.17, -0.29 to -0.08). Prevention-RCT yielded strong evidence indicating no association. Data from PC showed that adherence to some dietary patterns/food groups was associated with depression, e.g., adherence to the Mediterranean-diet was associated to fewer self-reported symptoms (OR = 0.91, 95%CI = 0.88-0.96), with anecdotal-to-moderate strength of evidence but no dose-response relationship. For most dietary patterns and food-groups (e.g., fish), data supported the null-hypothesis of no effect. Effect moderation was present: associations were evident when depression was self-reported but not when diagnosed. Postpartum-depression studies yielded evidence showing dose-response associations between fish (OR = 0.84, 95%CI = 0.78-0.91) and dietary DHA/EPA/Omega3 consumption (OR = 0.84, 95%CI = 0.77-0.92) with self-reported depression-scores.

CONCLUSIONS

The strength of the current evidence on the hypothesis that dietary quality influences depression outcome is very low, due to reverse causation and low internal and construct validity. The clinical significance of fish/dietary DHA/EPA/Omega3 intake to reduce the risk of postpartum-depression should be further investigated.

Rethinking Depression-Beyond Neurotransmitters: An Integrated Psychoneuroendocrineimmunology Framework for Depression's Pathophysiology and Tailored Treatment

It is known that the effectiveness of drug treatment for depression, ammine deficit based, is largely unsatisfactory. In this review, we examine the proposal of a precision therapy has emerged and has received a strong push by the identification of the role of inflammation in depression. However, precision psychiatry risks being caught in the reductionist trap of searching for the molecular switch that resets the whole system and switches off the disease. This is an illusion since the human being is complex and depression is a systemic and variable disorder. In this study, we show the inadequacy of the reductionist paradigm, and, at the same time, illustrate the superiority of the systemic paradigm centered on psychoneuroendocrineimmunology (PNEI). According to the PNEI paradigm, depression is a disease of the whole human being, caused by different sources working together: psychological, biological, and behavioral. This means knowing the biological and psychological history of the subject, identifying relational and biological crisis factors, and building personalized treatments targeting those factors with the tools of medicine and psychology, which are not reducible to the combination of drugs and psychotherapy. Our proposal presents a paradigm shift that is both theoretical and practical, which enables clinicians to assess patients experiencing depression in a unified way and treat them in an integrated manner.

Depression and Diet Quality, US Adolescents and Young Adults: National Health and Nutrition Examination Survey, 2015-March 2020

BACKGROUND

Depression is a common mental health disorder.

OBJECTIVE

The objective of this study was to explore the association between diet quality, as measured by the Healthy Eating Index 2020 (HEI-2020), and depression symptoms among US adolescents and young adults aged 12 to 29 years.

DESIGN

The study design was a cross-sectional secondary data analysis.

PARTICIPANTS

Data from the first 24-hour dietary recall for adolescents and young adults aged 12 to 29 years in the National Health and Nutrition Examination Survey from 2015 to March 2020 (n = 4750) were analyzed.

MAIN OUTCOME MEASURE

Depression was defined as a score ≥10 on the Patient Health Questionnaire, reflecting moderate or severe symptoms in the previous 2 weeks.

STATISTICAL ANALYSES PERFORMED

HEI-2020 total (range, 0-100) and component scores were calculated for those with and without depression. Predicted HEI-2020 scores were estimated from linear regression models, adjusting for age, gender, race and Hispanic origin, family income, and seeing a mental health professional in the past year. Statistical analyses accounted for the complex sample design.

RESULTS

The prevalence of depression among adolescents and young adults was 7.8% (95% CI 6.3% to 9.5%). Total HEI-2020 score was 45.9 (95% CI 45.0 to 46.7) out of 100 on a given day during 2015 to March 2020. Among young people with depression, total HEI-2020 score was lower than among those without depression (41.7 vs 46.2; P < .001). After adjustment for covariates, the difference was attenuated, but remained significant. In adjusted analyses, HEI-2020 component scores were lower for those with depression compared with those without depression for the adequacy components: total fruits (1.4 vs 1.7; P = .03), whole fruits (1.2 vs 1.7; P < .01), total vegetables (2.1 vs 2.6; P < .01), greens and beans (0.8 vs 1.2; P < .01), and total protein foods (3.6 vs 4.0; P = .02) out of a maximum score of 5. There were no statistically significant differences observed for whole grains, dairy, seafood and plant proteins, fatty acids, saturated fats, refined grains, sodium, or added sugars.

CONCLUSIONS

Overall diet quality is low among young people. Diet quality, especially consumption of fruits, vegetables, and protein foods was lower among young people with depression compared with those without depression.

The impact of the Mediterranean diet on alleviating depressive symptoms in adults: a systematic review and meta-analysis of randomized controlled trials

CONTEXT

High adherence to the Mediterranean diet (MD) has been associated with a reduced risk of depression in prospective cohort studies, but whether MD interventions are effective among adults with depression is uncertain.

OBJECTIVE

This study aimed to synthesize findings on the effects of MD interventions on the severity of depressive symptoms in adults with depression.

DATA SOURCES

PubMed, Cochrane CENTRAL, PsycINFO, Scopus, and Web of Science were systematically searched from database inception to March 2023. The Preferred Reporting Items for Systematic Review and Meta-Analyses guidelines and the Cochrane recommendations were followed. We included randomized controlled trials (RCTs) comparing outcomes after MD interventions with outcomes for control conditions in adults with depressive disorders or depressive symptoms.

DATA EXTRACTION

Two authors extracted the data independently. The Sidik-Jonkman estimator, the I2 metric, and the prediction interval were used to estimate between-study heterogeneity. To determine the risk of bias and the certainty of evidence from RCTs, we used the Cochrane Collaboration's Risk of Bias 2 and Grades of Recommendation, Assessment, Development, and Evaluation tools, respectively.

DATA ANALYSIS

In total, 1507 participants (mean age range: 22.0 years-53.3 years) with depression were initially included in the 5 RCTs of this review. Compared with control conditions, MD interventions significantly reduced depressive symptoms among young and middle-aged adults with major depression or mild to moderate depressive symptoms (standardized mean difference: -0.53; 95% confidence interval: -0.90 to -0.16; I2 = 87.1%). The prediction interval ranged from -1.86 to 0.81. The overall risk of bias was within the range of "some concerns" to "high," while the certainty of evidence was low.

CONCLUSION

MD interventions appear to have substantial potential for alleviating depressive symptoms in people experiencing major or mild depression. However, to establish robust recommendations, there remains a need for high-quality, large-scale, and long-term RCTs.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration no. CRD42022341895.

Mediterranean diet-based intervention to improve depressive symptoms: analysis of the PREDIDEP randomized trial

BACKGROUND

The effect of an intervention based on Mediterranean diet on reducing recurrence risk or subsyndromal depressive symptoms in recovered depressed patients has not been explored.

METHODS

The PREDIDEP study was a two-year randomized trial designed to assess the effect of the Mediterranean Diet enriched with extra virgin olive oil on depression recurrence. At baseline and at four, eight, 16, 20, and 24 months of follow-up, depressive symptoms were evaluated through the Beck Depression inventory. Cox regression analysis was fitted to assess the role of dietary intervention on the risk of depression recurrence. Mixed effects linear models were used to assess changes in depressive subsyndromal symptoms according to the intervention.

RESULTS

After two years of intervention, the dietary intervention group (n = 103) compared to the control group (n = 93) showed no differences regarding depression recurrence risk as main outcome. As secondary outcomes, an improvement of depressive symptoms was yielded at four (-2.15; 95% CI = -4.00 to -0.29) and eight months (-2.42; 95% CI = -4.17 to -0.67) in the intervention group, with no changes in control group. Moreover, at 20 months, significant differences were found between groups (-3.35; 95% CI = -6.08 to -0.61).

CONCLUSIONS

An intervention with Mediterranean diet in patients with previous depressive episodes might contribute to the reduction of depressive subsyndromal symptoms.

Associations between fruit and vegetable intakes and incident depression in middle-aged and older adults from 10 diverse international longitudinal cohorts

BACKGROUND

Emerging observational evidence supports a role for higher fruit and vegetable intake in protecting against the development of depression. However, there is a scarcity of research in older adults or in low- to middle-income countries (LMICs).

METHODS

Participants were 7801 community-based adults (mean age 68.6 ± 8.0 years, 55.8 % female) without depression, from 10 diverse cohorts, including four cohorts from LMICs. Fruit and vegetable intake was self-reported via comprehensive food frequency questionnaire, short food questionnaire or diet history. Depressive symptoms were assessed using validated measures, and depression defined applying validated cut-offs. The associations between baseline fruit and vegetable intakes and incident depression over a follow-up period of three to nine years were examined using Cox regression. Analyses were performed by cohort with results meta-analysed.

RESULTS

There were 1630 cases of incident depression (21 % of participants) over 40,258 person-years of follow-up. Higher intake of fruit was associated with a lower risk of incident depression (HR 0.87, 95%CI [0.77, 0.99], I2 = 4 %). No association was found between vegetable intake and incident depression (HR 0.93, 95%CI [0.84, 1.04], I2 = 0 %).

LIMITATIONS

Diverse measures used across the different cohorts and the modest sample size of our study compared with prior studies may have prevented an association being detected for vegetable intake.

CONCLUSIONS

Our study supports a role for fruit, but not vegetable intake in protecting against depression. Research investigating different types of fruits and vegetables using standardised measures in larger cohorts of older adults from low- and middle-income countries is warranted.

Adherence to Mediterranean diet is inversely associated with depressive symptoms in older women: findings from the NutBrain Study

Data on the association of the Mediterranean diet (MD) with depressive symptoms in older people at high risk of depression are scarce. This study aimed to investigate the cross-sectional association of the adherence to the MD and its components with depressive symptoms in an Italian cohort of older men and women. A total of 325 men and 473 women aged 65–97 years (2019–2023) answered a 102-item semi-quantitative FFQ, which was used to calculate the Mediterranean diet score (MDS). Depressive symptoms were assessed using the Centre for Epidemiological Studies Depression Scale; subjects with a score of 16 or more were considered to have depression. Multivariable logistic regression was used for statistical analysis. The occurrence of depressive symptoms was 19·8 % (8·0 % men, 27·9 % women). High adherence to MDS (highest tertile) significantly reduced the odds of having depressive symptoms by 54·6 % (OR 0·454, 95 % CI 0·266, 0·776). In sex-stratified analysis, the reduction was evident in women (OR 0·385, 95 % CI 0·206, 0·719) but not in men (OR 0·828, 95 % CI 0·254, 2·705). Looking at the association of MDS components with depressive symptoms, we found an inverse significant association with fish consumption and the MUFA:SFA ratio above the median only in women (OR 0·444, 95 % CI 0·283, 0·697 and OR 0·579, 95 % CI 0·345, 0·971, respectively). High adherence to the MDS, and a high fish intake and MUFA:SFA ratio were associated with lower depressive symptoms in women only. Future longitudinal studies are needed to confirm these findings and to explore the underlying biological mechanisms.

A randomized feasibility trial of the modified Atkins diet in older adults with mild cognitive impairment due to Alzheimer's disease

Background

Alzheimer's disease (AD) is increasing in prevalence, but effective treatments for its cognitive impairment remain severely limited. This study investigates the impact of ketone body production through dietary manipulation on memory in persons with mild cognitive impairment due to early AD and explores potential mechanisms of action.

Methods

We conducted a 12-week, parallel-group, controlled feasibility trial of a ketogenic diet, the modified Atkins diet (MAD), compared to a control diet in patients with cognitive impairments attributed to AD. We administered neuropsychological assessments, including memory tests, and collected blood samples at baseline and after 12 weeks of intervention. We performed untargeted lipidomic and targeted metabolomic analyses on plasma samples to detect changes over time.

Results

A total of 839 individuals were screened to yield 38 randomized participants, with 20 assigned to receive MAD and 18 assigned to receive a control diet. Due to attrition, only 13 in the MAD arm and nine in the control arm were assessed for the primary endpoint, with two participants meeting ketosis levels used to define MAD adherence criteria. The average change from baseline in the Memory Composite Score was 1.37 (95% CI: -0.87, 4.90) points higher in the MAD group compared to the control group. The effect size of the intervention on baseline MAD change was moderate (Cohen's D = 0.57, 95% CI: -0.67, 1.33). In the 15 participants (nine MAD, six control) assessed for lipidomic and metabolomic-lipidomics and metabolomics, 13 metabolites and 10 lipids showed significant changes from baseline to 12 weeks, including triacylglycerols (TAGs, 50:5, 52:5, and 52:6), sphingomyelins (SM, 44:3, 46:0, 46:3, and 48:1), acetoacetate, fatty acylcarnitines, glycerol-3-phosphate, and hydroxy fatty acids.

Conclusions

Attrition was greatest between baseline and week 6. All participants retained at week 6 completed the study. Despite low rates of adherence by criteria defined a priori, lipidomic and metabolomic analyses indicate significant changes from baseline in circulating lipids and metabolites between MAD and control participants at 12-week postrandomization, and MAD participants showed greater, albeit nonsignificant, improvement in memory.

Association between healthy eating and depression symptoms among Chinese older adults: A cross-sectional study based on the Chinese Longitudinal Healthy Longevity survey

Introduction

This study aimed to assess the relationship between the healthy eating index (HEI) and depression symptoms in an older adult population using the Chinese Longevity Health Survey.

Methods

The HEI was constructed based on the frequency of intake of 13 dietary variables, with higher scores indicating better diet quality. Depression symptoms was assessed by the Center for Epidemiologic Studies Depression-10 scale. We used multivariate binary logistic regression to explore the association between the HEI and depression symptoms and reported as odds ratio (OR) and 95 % confidence interval (95 % CI).

Results

A total of 12,078 older adults were included. The average HEI for this group of older adults was 26.4 ± 7.1. After adjusting for covariates, compared with participants in the lowest quartile of a healthy eating index, those in the second to the fourth quartile group had a 0.93- (95 % CI: 0.83 to 1.03), 0.84- (95 % CI: 0.75 to 0.95) and 0.69- (95 % CI: 0.62 to 0.77) fold risk of depression symptoms, respectively. Restricted cubic spline curves showed that the risk of depression symptoms decreased with increasing HEI, especially above 26, and for each unit increase in the HEI, the risk of depression symptoms in older adults decreased by 3 % (OR = 0.97; 95 % CI: 0.96 to 0.99).

Conclusions

This study found an association between higher levels of the HEI and reduced risk of depression symptoms in older Chinese adults. This result emphasizes the need to focus on dietary diversity in older adults to promote healthy aging.

Adherence to a Mediterranean Diet Is Inversely Associated with Anxiety and Stress but Not Depression: A Cross-Sectional Analysis of Community-Dwelling Older Australians

Diet quality may be an important modifiable risk factor for mental health disorders. However, these findings have been inconsistent, particularly in older adults. We explored the independent associations between adherence to a Mediterranean diet (MedDiet) and severity of symptoms related to depression, anxiety and stress in older adults from Australia. This was a cross-sectional analysis of older Australians ≥ 60 years. MedDiet adherence was assessed using the Mediterranean Diet Adherence Screener (MEDAS), and the Depression, Anxiety and Stress Scale (DASS-21) was used to assess the severity of negative emotional symptoms. A total of n = 294 participants were included in the final analyses (70.4 ± 6.2 years). Adherence to a MedDiet was inversely associated with the severity of anxiety symptoms (β = -0.118; CI: -0.761, -0.012; p = 0.043) independent of age, gender, BMI, physical activity, sleep, cognitive risk and ability to perform activities of daily living. Furthermore, MedDiet adherence was inversely associated with symptoms of stress (β = -0.151; CI: -0.680, -0.073; p = 0.015) independent of age, gender, BMI, physical activity and sleep. However, no relationship between MedDiet adherence and depressive symptoms was observed. We showed that adherence to a MedDiet is inversely associated with the severity of symptoms related to anxiety and stress but not depression. Exploring these findings with the use of longitudinal analyses and robust clinical trials are needed to better elucidate these findings in older adults.

Composition of healthy diets for older persons

PURPOSE OF REVIEW

This study aims to review recent evidence (2022-2023) on the role of diet in promoting healthy aging in older adults.

RECENT FINDINGS

Current evidence of diet and healthy aging is limited to epidemiological studies. A healthy diet is beneficial for individual domains of intrinsic capacity, that is, cognition, locomotion, vitality, psychological, and/or sensory functions, with sex-specific differences reported. Only a few studies used the multidimensional concept of intrinsic capacity as an outcome. This review supports that a healthy diet for older adults consists of plenty of plant-based foods, adequate protein-rich foods, and healthy fats. Next to quantity, improving the quality and variety within food groups play a role in optimizing health. Data on the associations between adherence to national food-based dietary guidelines and intrinsic capacity are scarce.

SUMMARY

A healthy diet, centered on plant-based foods, adequate protein-rich foods and healthy fats, potentially promotes healthy aging. Future studies may evaluate the association between adherence to healthy dietary patterns (particularly national food-based dietary guidelines) and the multidimensional concept of intrinsic capacity, with consideration of sex-specific differences. Clinical trials are warranted to inform the causal effects of diet and outcomes related to intrinsic capacity.

The Brain-Gut-Microbiota Interplay in Depression: a key to design innovative therapeutic approaches

Depression is the most prevalent mental disorder in the world associated with huge socio-economic consequences. While depressive-related symptoms are well known, the molecular mechanisms underlying disease pathophysiology and progression remain largely unknown. The gut microbiota (GM) is emerging as a key regulator of the central nervous system homeostasis by exerting fundamental immune and metabolic functions. In turn, the brain influences the intestinal microbial composition through neuroendocrine signals, within the so-called gut microbiota-brain axis. The balance of this bidirectional crosstalk is important to ensure neurogenesis, preserve the integrity of the blood-brain barrier and avoid neuroinflammation. Conversely, dysbiosis and gut permeability negatively affect brain development, behavior, and cognition. Furthermore, although not fully defined yet, changes in the GM composition in depressed patients are reported to influence the pharmacokinetics of common antidepressants by affecting their absorption, metabolism, and activity. Similarly, neuropsychiatric drugs may shape in turn the GM with an impact on the efficacy and toxicity of the pharmacological intervention itself. Consequently, strategies aimed at re-establishing the correct homeostatic gut balance (i.e., prebiotics, probiotics, fecal microbiota transplantation, and dietary interventions) represent an innovative approach to improve the pharmacotherapy of depression. Among these, probiotics and the Mediterranean diet, alone or in combination with the standard of care, hold promise for clinical application. Therefore, the disclosure of the intricate network between GM and depression will give precious insights for innovative diagnostic and therapeutic approaches towards depression, with profound implications for drug development and clinical practice.

Longitudinal Examination of Body Mass Index and Cognitive Function in Older Adults: The HELIAD Study

Given the increase in the aging population and thus in the prevalence of dementia, the identification of protective factors against cognitive decline is necessary. In a cohort of 1076 non-demented adults ≥ 65 years old (59.7% women) from the HELIAD study, we assessed whether changes in body mass index (BMI) were associated with changes in cognition over a 3-year follow-up period separately for those ≤ 75 and >75 years old. We identified six BMI trajectory groups based on participants' BMI status at baseline and at the first follow-up visit; normal to normal BMI was the reference group. Major cognitive domains were evaluated, and a composite index reflecting global cognition was calculated. In participants aged ≤75 years, weight loss-moving from obesity to overweight or normal BMI-was associated with less decline in the memory composite score over time (β = 0.141; p = 0.035), while 3-year maintenance of a BMI ≥ 25 kg/m² was related to greater reduction in the visuospatial composite score over time (β = -0.093; p = 0.020). Regarding participants aged >75 years, 3-year maintenance of a BMI ≥ 30 kg/m² contributed to a slower rate of decline in the memory composite score over time (β = 0.102; p = 0.042), whereas weight loss-from overweight to normal BMI-was associated with a decreased attention/processing speed composite score longitudinally (β = -0.275; p = 0.043). Our findings indicated that the association between changes in BMI and cognitive functioning was modified by age. Weight management may have the potential to delay cognitive decline in older adults.

Co-Expression Network Analysis Identifies Molecular Determinants of Loneliness Associated with Neuropsychiatric and Neurodegenerative Diseases

Loneliness and social isolation are detrimental to mental health and may lead to cognitive impairment and neurodegeneration. Although several molecular signatures of loneliness have been identified, the molecular mechanisms by which loneliness impacts the brain remain elusive. Here, we performed a bioinformatics approach to untangle the molecular underpinnings associated with loneliness. Co-expression network analysis identified molecular 'switches' responsible for dramatic transcriptional changes in the nucleus accumbens of individuals with known loneliness. Loneliness-related switch genes were enriched in cell cycle, cancer, TGF-β, FOXO, and PI3K-AKT signaling pathways. Analysis stratified by sex identified switch genes in males with chronic loneliness. Male-specific switch genes were enriched in infection, innate immunity, and cancer-related pathways. Correlation analysis revealed that loneliness-related switch genes significantly overlapped with 82% and 68% of human studies on Alzheimer's (AD) and Parkinson's diseases (PD), respectively, in gene expression databases. Loneliness-related switch genes, BCAM, NECTIN2, NPAS3, RBM38, PELI1, DPP10, and ASGR2, have been identified as genetic risk factors for AD. Likewise, switch genes HLA-DRB5, ALDOA, and GPNMB are known genetic loci in PD. Similarly, loneliness-related switch genes overlapped in 70% and 64% of human studies on major depressive disorder and schizophrenia, respectively. Nine switch genes, HLA-DRB5, ARHGAP15, COL4A1, RBM38, DMD, LGALS3BP, WSCD2, CYTH4, and CNTRL, overlapped with known genetic variants in depression. Seven switch genes, NPAS3, ARHGAP15, LGALS3BP, DPP10, SMYD3, CPXCR1, and HLA-DRB5 were associated with known risk factors for schizophrenia. Collectively, we identified molecular determinants of loneliness and dysregulated pathways in the brain of non-demented adults. The association of switch genes with known risk factors for neuropsychiatric and neurodegenerative diseases provides a molecular explanation for the observed prevalence of these diseases among lonely individuals.