Dietary patterns and depression risk: A meta-analysis

Association between the dietary inflammatory index and common mental health disorders profile scores

BACKGROUND & AIMS

The association between diet and mental health disorders might be mediated by inflammatory properties of the diet. We evaluated the association between the dietary inflammatory index (DII) and the risk of a worsened mental health disorders profile.

METHODS

A total of 3363 Iranian adults were included in this cross-sectional study. A mental health disorders profile score was calculated using regression analysis, within the framework of factor analysis, based on anxiety, depression and psychological distress, with a higher scores indicating greater severity of mental problems. Dietary intakes were assessed using a validated dish-based food frequency questionnaire (DFQ). Twenty-seven macro- and micro-nutrients, onions, tea and caffeine were included in the calculation of DII. Each of them received a score based on their inflammatory ability, thus, a greater DII indicated a more pro-inflammatory diet. The odds of being in the highest tertile of mental health disorders profile across the tertiles of DII was assessed using multinomial logistic regression.

RESULTS

Either in the crude or fully-adjusted multinomial logistic regression models, participants in the lowest tertile of DII had a lower risk for being in the top tertile of mental health disorders profile (adjusted model: OR: 0.45; 95% CI: 0.33, 0.60; P trend<0.001). In a stratified analysis by sex, similar findings were observed in both genders, although there was only a trend for the associations to be significant in men (men: OR: 0.53; 95% CI: 0.31, 0.90; P trend = 0.070; women: OR: 0.40; 95% CI: 0.27, 0.58; P trend<0.0001).

CONCLUSIONS

Our findings suggest a direct association between the pro-inflammatory properties of the diet and an increased risk of higher mental health disorders profile scores. Prospective dietary intervention studies and observational prospective cohorts are required to confirm these findings.

A review of dietary and microbial connections to depression, anxiety, and stress

Objective: Pre-clinical evidence suggests that the gastrointestinal microbiota contributes to mood and behavior disorders. Among humans, diet quality and patterns, which also impact the gastrointestinal microbiota, have been linked to depression, anxiety, and stress. This review summarizes findings from clinical studies using dietary intervention to improve depression, anxiety, or stress and the role the gastrointestinal microbiota may have in these disorders.Methods: A literature search was conducted using the keywords microbiome, microbiota, depression, anxiety, stress, diet, dietary pattern, diet quality, fiber, prebiotics, probiotics, and mood.Results: Mood was improved by enhancing diet quality. Fructooligosaccharide and galactooligosaccharide improved anxiety and depression in participants consuming ≥ 5 g/day. Additionally, bifidobacteria were enriched in subjects consuming ≥ 5 g/day. Probiotic consumption improved psychological or biological measures of depression, anxiety, or stress in individuals predisposed to a mood disorder. Probiotics suppressed biological markers of stress in healthy individuals in a strain-dependent manner.Discussion: High-quality diets, prebiotics, and probiotics may beneficially affect mood. Habitual diets rich in dietary fiber and omega-3-polyunsaturated fatty acids may be linked to reduced risk of developing symptoms of depression, anxiety, and stress; however, additional studies are necessary. Certain probiotics may enhance mood, but their influence on the gastrointestinal microbiota requires further investigation.

Egg consumption and prevalence of psychological disorders in adults

PURPOSE

No previous study has examined the associations between egg consumption and prevalence of psychological disorders. The present study was conducted to determine the association between egg consumption and depression in a large sample of Iranian adults.

METHODS

This cross-sectional study was conducted on 3172 adults in Isfahan, Iran. Egg consumption was assessed by using a validated, self-administered, dish-based, semi-quantitative food frequency questionnaire. The Iranian validated version of Hospital Anxiety and Depression Scale was used to screen for anxiety and depression. The Iranian validated version of General Health Questionnaire with 12 items was used to assess psychological distress. Depression, anxiety and psychological distress were defined according to standard criteria.

RESULTS

The mean age of the study participants was 36.5 ± 7.9 years. Depression, anxiety and psychological distress were prevalent among 28.4, 13.6 and 23% of the study subjects, respectively. After controlling for potential confounders, no significant association was observed between egg intake and depression (OR for comparing extreme quartiles: 1.08; 95% CIs 0.80-1.45) and anxiety (OR 0.79; 95% CIs 0.54-1.16), as well as psychological distress (OR 1.03; 95% CIs 0.76-1.41) in the whole population. In men, significant positive associations were observed between egg intake and depression before controlling for BMI (OR 1.68; 95% CIs 1.01-2.80); however, the associations became non-significant after taking BMI into account (OR 1.62; 95% CIs 0.96-2.72).

CONCLUSIONS

We found no significant association between egg intake and psychological disorders. Further studies, in particular of prospective design, are warranted.

Prospective association between adherence to dietary recommendations and incident depressive symptoms in the French NutriNet-Santé cohort

A posteriorihealthier dietary patterns and several nutrients have been associated with lower risks of depression in various studies; however, evidence is lacking with regard to the prospective association between adherence to nutritional recommendations (food-based and nutrient-based recommendations) and incident depression or depressive symptoms. In this study, we investigate such associations in the NutriNet Santé cohort. The study sample included 26 225 participants (aged 18–86 years) who were initially free of depressive symptoms. Adherence to nutritional recommendations was measured by four scores namely modified French Programme National Nutrition Santé-Guideline Score (mPNNS-GS), Alternative Healthy Eating Index-2010 (AHEI-2010), Probability of Adequate Nutrient Intake Dietary Score (PANDiet) and Diet Quality Index-International (DQI-I), using non-consecutive dietary record data during the first 2 years of follow-up (mean number of recording days=8,sd2). Depressive symptoms were defined by a Center for Epidemiologic Studies Depression Scale (CES-D) score ≥17 for men and ≥23 for women. We used Cox proportional hazards models to estimate hazard ratios and 95 % CI, modelling the dietary scores as standardised continuous variables and as tertiles. Over a mean follow-up of 6 years, we identified 2166 incident cases of depressive symptoms. All dietary scores with the exception of the AHEI-2010 were significantly inversely associated with incident depressive symptoms. In the fully adjusted model, an increase of 1sdin the mPNNS-GS, PANDiet and DQI-I was, respectively, associated with an 8 % (95 % CI 4, 13), 5 % (95 % CI 1, 9) and 9 % (95 % CI 5, 13) reduction in the risk of depressive symptoms. Overall, these findings suggest that diet in accordance with national or international guidelines could have beneficial effects with regard to mental health.

Dietary Polyphenol Intake and Depression: Results from the Mediterranean Healthy Eating, Lifestyle and Aging (MEAL) Study

Background: The epidemiological evidence for a relation between dietary polyphenol intake and depression is limited. Therefore, the aim of this study was to assess the association between habitual dietary intake of total polyphenols, their classes, subclasses and individual compounds and depressive symptoms among the participants of the Mediterranean healthy Eating, Lifestyle and Aging (MEAL) study. Methods: Demographic and dietary characteristics of 1572 adults living in southern Italy were analyzed. Food frequency questionnaires and Phenol-Explorer were used to calculate habitual dietary intakes of polyphenols. The Center for Epidemiologic Studies Depression Scale (CES-D-10) was used as screening tool for depressive symptoms. Multivariate logistic regression analyses were used to test associations and were expressed as odds ratio (OR) and 95% confidence intervals (CI). Results: A total of 509 individuals reported having depressive symptoms. Based on multivariate logistic regression analyses, total polyphenol intake was not associated with depressive symptoms. After adjustment for potential confounding factors, dietary intake of phenolic acid (OR = 0.64, 95% CI: 0.44, 0.93), flavanones (OR = 0.54, 95% CI: 0.32, 0.91), and anthocyanins (OR = 0.61, 95% CI: 0.42, 0.89) showed significant inverse association with depressive symptoms, when comparing the highest with the lowest quartile. Moreover, flavanones and anthocyanins, were associated with depressive symptoms in a dose-response manner. Among individual compounds, inverse association was observed for quercetin (OR = 0.53, 95% CI: 0.32, 0.86) and naringenin (OR = 0.51, 95% CI: 0.30, 0.85), for the highest versus lowest quartile of intake. When taking into consideration the major sources of the polyphenols, only citrus fruits and wine consumption was inversely associated with depressive symptoms (Q4 vs. Q1: OR= 0.51, 95% CI: 0.35, 0.75; Q4 vs. Q1: OR = 0.53, 95% CI: 0.38, 0.74, respectively). Conclusions: Higher dietary intake of flavonoid may be inversely associated with depressive symptoms. Further studies are needed to definitively confirm these observed associations.

Intake of Raw Fruits and Vegetables Is Associated With Better Mental Health Than Intake of Processed Fruits and Vegetables

Background: Higher intakes of fruits and vegetables, rich in micronutrients, have been associated with better mental health. However, cooking or processing may reduce the availability of these important micronutrients. This study investigated the differential associations between intake of raw fruits and vegetables, compared to processed (cooked or canned) fruits and vegetables, and mental health in young adults.

Methods: In a cross-sectional survey design, 422 young adults ages 18–25 (66.1% female) living in New Zealand and the United States completed an online survey that assessed typical consumption of raw vs. cooked/canned/processed fruits and vegetables, negative and positive mental health (depressive symptoms, anxiety, negative mood, positive mood, life satisfaction, and flourishing), and covariates (including socio-economic status, body mass index, sleep, physical activity, smoking, and alcohol use).

Results: Controlling for covariates, raw fruit and vegetable intake (FVI) predicted reduced depressive symptoms and higher positive mood, life satisfaction, and flourishing; processed FVI only predicted higher positive mood. The top 10 raw foods related to better mental health were carrots, bananas, apples, dark leafy greens like spinach, grapefruit, lettuce, citrus fruits, fresh berries, cucumber, and kiwifruit.

Conclusions: Raw FVI, but not processed FVI, significantly predicted higher mental health outcomes when controlling for the covariates. Applications include recommending the consumption of raw fruits and vegetables to maximize mental health benefits.

High prevalence of depressive symptoms in a national sample of adults in Indonesia: Childhood adversity, sociodemographic factors and health risk behaviour

BACKGROUND

The aim of this study was to investigate depressive symptoms and their association with sociodemographic factors, stressors and support, including childhood adversity, health status risk and behaviour in Indonesia.

METHOD

In a cross-sectional national population survey in 2014-15 in Indonesia, 31442 adults (mean age 37.3 years, SD = 14.9, age range 15-101 years) responded to the Centers for Epidemiologic Studies Depression Scale (CES-D-10) and various other measures.

RESULTS

Overall, 15.0% of participants reported moderate and 6.9% severe depressive symptoms, or 21.8% moderate or severe depressive symptoms (21.4% among men and 22.3% among women). In multivariable logistic regression among both men and women, sociodemographic factors (younger age, poor subjective economic background, being unemployed, residing in Java and main island groups), stressors (childhood hunger and poor or fair self-rated health status and having experienced disasters), lack of social trust and religiosity, having one or more chronic conditions, tobacco use and soft drink consumption were positively and obesity negatively associated with moderate or severe depressive symptoms.

CONCLUSION

High rates (21.8%) of depressive symptoms were found. Several risk factors including sociodemographic factors such as younger age, stressors, lack of social support, health risk status and behaviour variables were identified which can be utilized in guiding interventions.

Association between dietary patterns and depressive symptoms among middle-aged adults in China in 2016-2017

The purpose of this study was to explore the associations of dietary patterns with depressive symptoms in middle-aged Chinese adults. The cross-sectional study participants were 1360 Chinese adults (45-59 years, 659 males and 701 females) who participated in a Health Survey at the time of periodic checkup. Dietary intakes were assessed via a semi-quantitative food frequency questionnaire (FFQ). Binary logistic regression analysis was used to estimate odds ratio(OR) and 95% confidence interval(CI) for depressive symptoms according to quartiles of each dietary pattern score. Four major dietary patterns were identified by factor analysis: traditional Chinese, Western, grains-vegetables and high-salt patterns. After controlling for potential confounders, participants in the highest quartile of the Western pattern scores had greater odds of depressive symptoms than those in the lowest quartile. In contrast, participants in the highest quartile of the grains-vegetables pattern had lower odds of depressive symptoms than those in the lowest quartile. Nevertheless, no significant associations were observed between the traditional Chinese and high-salt patterns and the risk of depressive symptoms, even after adjusting for potential confounders. The findings indicate that the Western pattern is associated with an increased risk, and the grains-vegetables pattern is associated with a reduced risk of depressive symptoms.

Fish consumption and depression in Korean adults: the Korea National Health and Nutrition Examination Survey, 2013-2015

BACKGROUND/OBJECTIVES

There is a growing body of evidence that supports the potential role of fish consumption in relation to depression, but the data in Korean population is scarce. Thus, we examined the association between fish consumption and depression in Korean adults.

SUBJECTS/METHODS

We conducted a cross-sectional study in 9183 Korean adults aged 19-64 years who participated in the 6TH Korea National Health and Nutrition Examination Survey (2013-2015), which is a large nationally representative study of Korean population. Fish consumption and depression status were assessed using questionnaires. Multivariable logistic regression models were used to compute odds ratios (ORs) and 95% confidence intervals (CIs) for physician-diagnosed clinical depression.

RESULTS

Out of the 9183 subjects, 389 (4.2%) were diagnosed with depression. After adjusting for potential confounders, the multivariable-adjusted ORs for clinical depression across fish consumption were 1.00 (reference) for <1 time/week, 0.76 (95% CI: 0.56-1.04) for 1-3 times/week and 0.52 (95% CI: 0.37-0.74) for ≥4 times/week (P for trend = 0.0005). The inverse association for ≥4 times/week of fish consumption was stronger in women (OR = 0.44, 95% CI: 0.29-0.67, P for trend < .0001), but there was no significant association in men.

CONCLUSIONS

Our findings suggest that high consumption of fish is associated with lower odds of depression in Korean adults, particularly in women. These results warrant further prospective studies to verify the association between fish consumption and risk of depression in Korean adults.

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

BACKGROUND

It has been claimed that the quality of a diet is associated with the incidence of depressive disorders. We sought to investigate the evidence for this claim.

METHODS

Systematic searches were performed up to March 6th, 2017 in order to identify prospective cohort studies that reported on exposure to dietary patterns or food groups and the incidence of depression/depressive symptoms. Data from 24 independent cohorts (totalling 1,959,217 person-years) were pooled in random-effects meta-analyses.

RESULTS

Adherence to a high-quality diet, regardless of type (i.e., healthy/prudent or Mediterranean), was associated with a lower risk of depressive symptoms over time (odds ratios ranged 0.64-0.78 in a linear dose-response fashion [P < 0.01]). A relatively low dietary inflammatory index was also associated with a somewhat lower incidence of depressive symptom (odds ratio = 0.81), although not in a dose-response fashion. Similar associations were found for the consumption of fish and vegetables (odds ratios 0.86 and 0.82 respectively) but not for other high quality food groups (e.g., fruit). Studies that controlled for depression severity at baseline or that used a formal diagnosis as outcome did not yield statistically significant findings. Adherence to low quality diets and food groups was not associated with higher depression incidence.

LIMITATIONS

Our ability to detect confounders was only limited.

CONCLUSION

There is evidence that a higher quality of a diet is associated with a lower risk for the onset of depressive symptoms, but not all available results are consistent with the hypothesis that diet influences depression risk. Prospective studies that control for relevant confounders such as obesity incidence and randomized controlled prevention trials are needed to increase the validity of findings in this field.

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.

Fasting Plasma Glucose, Self-Appraised Diet Quality and Depressive Symptoms: A US-Representative Cross-Sectional Study

Depression and type 2 diabetes (T2D) contribute significantly to global burden of disease and often co-occur. Underpinning type 2 diabetes is poor glycaemic control and glucose is also an obligatory substrate for brain metabolism, with potential implications for cognition, motivation and mood. This research aimed to examine the relationships between fasting plasma glucose and depressive symptoms in a large, population representative sample of US adults, controlling for other demographic and lifestyle behavioural risk factors. Using the 2013–2014 National Health and Nutrition Examination Survey (NHANES) data, this study first investigated the relationship between fasting plasma glucose and mental disorders at a population-level, accounting for demographic, health behavioural and weight-related factors known to co-occur with both type 2 diabetes and mental disorders. Depressive symptoms were derived from the 9-item Patient Health Questionnaire. Fasting plasma glucose was obtained through medical examination and demographic (age, household income, sex) and health characteristics (perceived diet quality, daily time sedentary) were self-reported. Body mass index was calculated from objectively measured height and weight. In the univariate model, higher fasting plasma glucose was associated with greater depressive symptoms among females (b = 0.24, 95% CI = 0.05, 0.43, p < 0.05), but not males. In the final fully adjusted model, the relationship between fasting plasma glucose and depressive symptoms was non-significant for both males and females. Of all independent variables, self-appraised diet quality was strongly and significantly associated with depressive symptoms and this remained significant when individuals with diabetes were excluded. Although diet quality was self-reported based on individuals’ perceptions, these findings are consistent with a role for poor diet in the relationship between fasting plasma glucose and depressive symptoms.

Impact of adherence to antidepressants on healthcare outcomes and costs among patients with type 2 diabetes and comorbid major depressive disorder

OBJECTIVE

To evaluate the association between adherence to antidepressants and an effect on clinical outcomes and healthcare costs in patients with major depressive disorder (MDD) and comorbid type 2 diabetes (T2D).

METHODS

This retrospective study used MarketScan claims data from January 2012 to March 2014. Study entry was the first claim for an antidepressant and a diagnosis code for MDD and T2D in the prior 6 months. Adherence and persistence with antidepressant therapy in the first 180 days were defined as medication possession ratio (MPR) ≥ 80% and length of therapy (LOT), with no treatment gap of >15 days, respectively. T2D control (HbA1c <7%), oral diabetes medication adherence, and healthcare costs were measured in the 12 month post-index period. The impact of antidepressant adherence and persistence on outcomes was assessed using multivariable analyses.

RESULTS

Among the 1361 patients included, the mean age was 59 years and 55% were women. About one-third of the patients were adherent (35.9%, mean MPR = 40%), persistent (32.0%, average LOT = 100 days), and adherent/persistent (31.2%) on antidepressants. Being adherent, persistent, or adherent/persistent to antidepressants was associated with a two-fold improvement in adherence to oral diabetes medications. Of those with HbA1c data (n = 121), adherence or adherence/persistence to antidepressants was associated with patients being five times more likely to have T2D control (odds ratio [OR]: 4.95; 95% confidence interval [CI]: 1.39, 17.59, p = .0134). Comparison between antidepressant-persistent and non-persistent patients was not significant. Mean difference in adjusted all-cause annual costs showed lower costs among antidepressant-adherent and adherent/persistent patients (adherent: -$350, 95% CI: -$462, -$247; adherent/persistent: -$1165; 95% CI: -$1280, -$1060).

CONCLUSIONS

Patients with better antidepressant adherence and adherence/persistence demonstrated better HbA1c control, with lower all-cause total and medical costs. Adherence, persistence, or adherence/persistence to antidepressants was associated with improved adherence to oral diabetes medications.

Nutritional psychiatry: the present state of the evidence

Mental illness, including depression, anxiety and bipolar disorder, accounts for a significant proportion of global disability and poses a substantial social, economic and heath burden. Treatment is presently dominated by pharmacotherapy, such as antidepressants, and psychotherapy, such as cognitive behavioural therapy; however, such treatments avert less than half of the disease burden, suggesting that additional strategies are needed to prevent and treat mental disorders. There are now consistent mechanistic, observational and interventional data to suggest diet quality may be a modifiable risk factor for mental illness. This review provides an overview of the nutritional psychiatry field. It includes a discussion of the neurobiological mechanisms likely modulated by diet, the use of dietary and nutraceutical interventions in mental disorders, and recommendations for further research. Potential biological pathways related to mental disorders include inflammation, oxidative stress, the gut microbiome, epigenetic modifications and neuroplasticity. Consistent epidemiological evidence, particularly for depression, suggests an association between measures of diet quality and mental health, across multiple populations and age groups; these do not appear to be explained by other demographic, lifestyle factors or reverse causality. Our recently published intervention trial provides preliminary clinical evidence that dietary interventions in clinically diagnosed populations are feasible and can provide significant clinical benefit. Furthermore, nutraceuticals including n-3 fatty acids, folate, S-adenosylmethionine, N-acetyl cysteine and probiotics, among others, are promising avenues for future research. Continued research is now required to investigate the efficacy of intervention studies in large cohorts and within clinically relevant populations, particularly in patients with schizophrenia, bipolar and anxiety disorders.