Dietary inflammatory index, cardiometabolic conditions and depression in the Seguimiento Universidad de Navarra cohort study

Accelerated biological aging as potential mediator mediates the relationship between pro-inflammatory diets and the risk of depression and anxiety: A prospective analysis from the UK biobank

BACKGROUND

The relationship between inflammatory dietary patterns and the risk of depression/anxiety has not been clearly established due to differences in study populations, geographic regions, sex, and methods of calculating the inflammatory index.

METHODS

We drew upon a prospective cohort in the UK Biobank and calculated the energy-adjusted dietary inflammatory index (E-DII). The follow-up time was defined from the date of completing the last dietary survey questionnaire to the date of diagnosis of depression, anxiety, phobic anxiety, other types of anxiety, death, loss to follow-up, or the respective censoring dates for England (September 30, 2021), Scotland (July 31, 2021), and Wales (February 28, 2018). The final follow-up times end on September 30, 2021, July 31, 2021, and February 28, 2018, for England, Scotland, and Wales, respectively. During the follow-up process, if a participant develops the condition, dies, or is lost to follow-up, the follow-up is terminated. We used Cox regression to evaluate the connection between E-DII and depression/anxiety. We employed restricted cubic spline curves for nonlinear relationships. We also conducted mediation analyses to explore whether biological age mediated the relationship between E-DII and depression. Additionally, we investigated whether genetic susceptibility modified the relationship between E-DII and depression through interaction modeling.

RESULTS

In the final analysis, we included a total of 151,295, 159,695, 165,649, and 160,097 participants for the analysis of depression, all types of anxiety, specific phobia anxiety, and other types of anxiety, respectively. For every one-unit increase in E-DII, the risk of experiencing depression and anxiety increased by 5 % and 4 %, respectively. We identified a "J"-shaped nonlinear relationship (P for nonlinear = 0.003) for both depression and anxiety. A significant association with an elevated risk of depression was observed when E-DII exceeded 0.440, and an increased risk of anxiety was noted when E-DII was more than -0.196. Mediation analysis demonstrated that PhenoAge age acceleration (AA) (For depression, proportion of mediation = 9.6 %; For anxiety, proportion of mediation = 10.1 %) and Klemera-Doubal method Biological Age (KDM AA) (For depression, proportion of mediation = 2.9 %; For anxiety, proportion of mediation = 5.1 %) acted as mediators between E-DII and the development of depression and anxiety (P < 0.05).

CONCLUSIONS

Diets with pro-inflammatory characteristics are associated with a heightened risk of depression and anxiety. Furthermore, the association of pro-inflammatory diets and depression is mediated by biological age.

Associations of a proinflammatory diet, habitual salt intake, and the onset of type 2 diabetes: A prospective cohort study from the UK Biobank

AIM

To explore the relationship between proinflammatory diet, habitual salt intake and the onset of type 2 diabetes.

METHODS

This prospective study was conducted among 171 094 UK Biobank participants who completed at least one 24-h dietary questionnaire and were free of diabetes at baseline. Participants were followed up until 1 March 2023 for type 2 diabetes incidence, with diagnosis information obtained from linked medical records. An Energy-adjusted Diet Inflammatory Index (E-DII) was calculated based on 28 food parameters. Habitual salt intake was determined through the self-reported frequency of adding salt to foods. The associations between E-DII, habitual salt intake and type 2 diabetes incidence were tested by the Cox proportional hazard regression model.

RESULTS

Over a median follow-up period of 13.5 years, 6216 cases of type 2 diabetes were documented. Compared with participants with a low E-DII (indicative of an anti-inflammatory diet), participants with a high E-DII (indicative of a proinflammatory diet) had an 18% heightened risk of developing type 2 diabetes. The association between E-DII and type 2 diabetes tends to be linear after adjustment for major confounders. Participants with a proinflammatory diet and always adding salt to foods had the highest risk of type 2 diabetes incidence (hazard ratio 1.60, 95% confidence interval 1.32-1.94).

CONCLUSIONS

Our findings indicate that a proinflammatory diet and higher habitual salt intake were associated with an increased risk of type 2 diabetes. These results support the public health promotion of an anti-inflammatory diet and reducing salt intake to prevent the onset of type 2 diabetes.

The higher dietary inflammation is associated with a higher burden of multimorbidity of cardio-metabolic and mental health disorders in an urbanizing community of southern India: A cross-sectional analysis for the APCAPS cohort

Background & aims

Habitual dietary pattern has been shown to be a major modulator of systemic inflammation and is considered a modifiable risk factor for cardio-metabolic diseases (CMDs) and mental health disorders. We examined whether dietary-inflammation is associated with the multimorbidity of CMDs and mental health disorders in urbanizing-villages in southern India. We hypothesized that the participants with higher dietary-inflammation would have a higher burden of multimorbidity.

Materials & methods

We conducted a cross-sectional analysis of 5984 adults (53% male) participating in the Andhra Pradesh Children and Parents' Study. We assessed dietary-inflammation using dietary inflammatory index (DII®) based on intake of 27 micro- and macro-nutrients which were measured using a validated food-frequency-questionnaires. The CMDs and mental health disorders were assessed using standardized clinical procedures and validated questionnaires. 'Multimorbidity' was defined as a co-existence of one or more CMDs (hypertension, diabetes, myocardial infarction, heart failure, angina and stroke) and one or more mental health disorders (depression and anxiety). The association of multimorbidity with dietary-inflammation was examined using robust Poisson regression.

Results

The prevalence of multimorbidity was 3.5% and ∼75% of participants were consuming a pro-inflammatory diet (DII >0.0). As compared to the 1st DII-quartile (least dietary-inflammatory group), the adjusted prevalence ratio (95% confidence interval) for the presence of multimorbidity was 1.46(0.87, 2.46) for 2nd, 1.75(1.05, 2.89) for 3rd, and 1.77(1.06, 2.96) for 4th DII-quartile (p-trend = 0.021). There was no evidence of an interaction between DII and sex on multimorbidity.

Conclusions

Dietary-inflammation had a positive linear association with the multimorbidity, which suggest that even modest reduction in dietary-inflammation may reduce the multimorbidity burden.

Association of disaster-related damage with inflammatory diet among older survivors of the Great East Japan Earthquake and Tsunami

Traumatic experiences from disasters have enduring effects on health, both directly and indirectly by influencing health behaviours. Among potential pathways, the impact of disaster-related trauma on dietary patterns has been understudied. This study investigated the relationship between disaster-related trauma and dietary inflammatory index (DII®), and how these relationships differed by gender and whether they prepare meal by themselves or not among older survivors of the 2011 Great East Japan Earthquake and Tsunami (n 1375). Dietary data were collected in 2020 using a brief-type self-administered diet history questionnaire, from which we derived a dietary inflammatory index (DII®) based on twenty-six food/nutrient items, where higher scores indicate pro-inflammatory (i.e. unhealthy) diet. We found that the experience of housing damage due to the earthquake and tsunami was associated with slightly higher DII scores (coef. = 0·38, 95 % CI -0·05, 0·81). Specifically, women who cooked by themselves tended to have higher DII when they experienced housing damage (coef. = 1·33, 95 %CI -0·63, 3·28). On the other hand, loss of friends was associated with a lower DII score (coef. = -0·28, 95 % CI -0·54, -0·01). These findings highlight the importance of providing support to groups who are at increased risk of deterioration in dietary quality in the aftermath of disasters.

Is there a link between the inflammatory potential of a diet and mental health among patients with migraine? Findings from a cross-sectional survey

AIMS

In this study, we aimed to evaluate the relationship between the dietary inflammatory index (DII) and mental health outcomes among patients with migraine headaches.

METHODS

In this cross-sectional study, 262 subjects were included. The dietary intakes were collected using a validated 168-item semi-quantitative food frequency questionnaire. Items were scored according to their inflammatory potential, so a higher DII indicated a more pro-inflammatory diet. The association between DII and the mental health of participants was investigated using multinomial logistic regression and odds ratio (OR) with a corresponding 95% confidence interval (CI) was reported.

RESULTS

Overall, 224 women and 38 men, with a mean (standard error) DII of -2.96 (0.06), age of 36.1 (0.53) years, and BMI of 25.55 (0.21) kg/m2, comprised our study population. DII was positively associated with a higher risk of depression in patients with the highest adherence to a pro-inflammatory diet compared to those with the lowest adherence (OR = 1.76; 95%CI: 1.04, 3.00; Ptrend = 0.035). Adjustments for age, sex, marital status, smoking status, migraine headache index score, number of family members, mean arterial pressure, medication, physical activity, and BMI intensified the association in a way that the risk of depression was 2.03 times higher in patients with the highest adherence to a pro-inflammatory diet compared to those with the lowest adherence to a pro-inflammatory diet (OR = 2.03; 95%CI: 1.18, 3.49; Ptrend = 0.011).

CONCLUSION

Our findings suggest that depression was positively associated with adherence to a pro-inflammatory diet. However, no significant association was observed between anxiety and stress with DII.

Dietary Inflammatory Potential, Inflammation-Related Lifestyle Factors, and Incident Anxiety Disorders: A Prospective Cohort Study

It is unclear whether diet-associated inflammation is related to the development of anxiety disorders. We aimed to investigate the association between energy-adjusted dietary inflammatory index (E-DII) scores and the incidence of anxiety disorders, and explore the joint effects of E-DII scores with other inflammatory lifestyles in enhancing anxiety risk. In the UK Biobank Study of 96,679 participants, baseline E-DII scores were calculated from the average intake of at least two 24 h dietary recalls. Multivariable-adjusted Cox models were used to evaluate the associations between E-DII scores and the incidence of total anxiety disorders, and primary types and subtypes; additive and multiplicative interactions of a pro-inflammatory diet and seven inflammatory lifestyles were examined. After a median follow-up of 9.4 years, 2785 incident cases of anxiety disorders occurred. Consuming a pro-inflammatory diet was significantly associated with a higher risk of total anxiety disorders (HRQ4vsQ1 = 1.12, 95% CI = 1.00-1.25), and positive associations were consistently identified for primary types and subtypes of anxiety disorders, with HRs ranging from 1.08 to 1.52, and were present in women only. Both additive and multiplicative interactions of current smoking and a proinflammatory diet on total anxiety risk were identified. A proinflammatory diet was associated with a higher incidence of anxiety disorders, and current smoking may synergize with a proinflammatory diet to promote anxiety risk, particularly among women.

Nutritional considerations in major depressive disorder: current evidence and functional testing for clinical practice

Depression is a multifaceted condition with diverse underlying causes. Several contributing and inter-related factors such as genetic, nutritional, neurological, physiological, gut-brain-axis, metabolic and psychological stress factors play a role in the pathophysiology of depression. This review aims to highlight the role that nutritional factors play in the aetiology of depression. Secondly, we discuss the biomedical and functional pathology tests which measure these factors, and the current evidence supporting their use. Lastly, we make recommendations on how practitioners can incorporate the latest evidence-based research findings into clinical practice. This review highlights that diet and nutrition greatly affect the pathophysiology of depression. Nutrients influence gene expression, with folate and vitamin B12 playing vital roles in methylation reactions and homocysteine regulation. Nutrients are also involved in the tryptophan/kynurenine pathway and the expression of brain-derived neurotrophic factor (BDNF). Additionally, diet influences the hypothalamic-pituitary-adrenal (HPA) response and the composition and diversity of the gut microbiome, both of which have been implicated in depression. A comprehensive dietary assessment, combined with appropriate evaluation of biochemistry and blood pathology, may help uncover contributing factors to depressive symptoms. By employing such an approach, a more targeted and personalised treatment strategy can be devised, ultimately leading to improved patient outcomes.

Construct Validation of the Dietary Inflammatory Index (DII) among Young College-Aged Women

The Dietary Inflammatory Index (DII) is designed to assess the inflammatory potential of the diet. While previous research has utilized DII among college-aged women, no study to date has validated it in this population. We conducted a construct validation of DII among 393 healthy women aged 18-31 years against a robust panel of 14 inflammatory biomarkers, including CRP, IL-1β, IL-4, IL-6, IL-10, and TNF-α, which were used in the development of DII. Three linear regression models were constructed: (1) an age-adjusted model, (2) the most parsimonious model based on likelihood ratio tests, and (3) a fully adjusted model for age, race, body mass index, waist circumference, physical activity, smoking status, and nonsteroidal anti-inflammatory drug use. DII was derived from the Harvard food frequency questionnaire and categorized into quartiles. Consistent with our hypothesis, DII was negatively and significantly associated with back-transformed IL-10 levels, confirming that a more pro-inflammatory diet was associated with lower levels of an anti-inflammatory cytokine (Model 3: Q4 vs. Q1 β = 0.62; 95% CI: 0.42, 0.93; p-trend = 0.04). While validated in other populations, DII may not be a suitable tool for assessing the inflammatory potential of the diet among college-aged women.

The role of dietary inflammatory index and physical activity in depressive symptoms: Results from NHANES 2007-2016

BACKGROUND

Depression is a major public health problem. This study was aimed to analyze the relationship between dietary inflammation index (DII), physical activity, and depressive symptoms, and to explore the effect of different lifestyles on depressive symptoms by combining DII and physical activity to form four lifestyle groups.

METHODS

This study analyzed data from the National Health and Nutrition Examination Survey (NHANES) from 2007 to 2016. A total of 21,785 subjects were involved. Depressive symptoms and dietary inflammation were measured by the Patient Health Questionnaire (PHQ-9) and Energy-adjusted Dietary Inflammatory Index, respectively. The participants were divided subgroups by different physical activity combined pro-inflammatory or anti-inflammatory diet groups.

RESULTS

Both pro-inflammatory diet and inactivity were positively associated with depressive symptoms. Compared with the anti-inflammatory diet & active group, the risk of depressive symptoms was 2.061 times higher in the pro-inflammatory diet & inactive group, 1.351 times higher in the pro-inflammatory diet & active group, and 1.603 times higher in the anti-inflammatory diet & inactive group. Physical inactivity was associated with a higher risk of depressive symptoms than a pro-inflammatory diet. Females and the 20-39 age group showed a strong association between lifestyles and depressive symptoms.

LIMITATIONS

Because of the cross-sectional study, no causal conclusions could be drawn. Moreover, PHQ-9 is a relatively basic method of identifying depressive symptoms, more and further research is needed.

CONCLUSIONS

Both a pro-inflammatory diet and physical inactivity were associated with higher risk of depressive symptoms, especially for young and female population.

Inflammatory properties of diet mediate the effect of epilepsy on moderate to severe depression: Results from NHANES 2013-2018

BACKGROUND

Depression is a major public health problem, and epilepsy and a high-inflammatory diet are important causes of depression. We aimed to explore the level of dietary inflammation in epileptic patients and its relationship with moderate to severe depression (MSD).

METHODS

This cross-sectional study included 12,788 participants aged 20-80 years from the NHANES database from 2013 to 2018. Depressive symptoms were evaluated using the nine-item Patient Health Questionnaire (PHQ-9), and epilepsy was diagnosed based on the use of antiepileptic drugs within the previous 30 days. Dietary inflammatory index (DII) scores and energy-adjusted DII (E-DII) scores were calculated based on dietary recalls of the past 24 h, and average DII (ADII) and energy-adjusted ADII (E-ADII) were calculated based on two 24-hour dietary recalls.

RESULTS

The DII, E-DII, and ADII scores and prevalence of MSD were significantly increased in epileptic patients compared with non-epilepsy subjects. The E-ADII score (P = 0.078) was weakly associated with comorbid MSD in patients with epilepsy. Mediation models showed that dietary inflammation scores mediated 2.31 % to 12.25 % of epilepsy-related MSD. In stratified analysis, an increased prevalence of MSD was present in the Quartile 2 subgroup based on DII and E-ADII scores and in the Quartile 3 subgroup of epileptic patients based on DII, E-DII, and ADII scores.

CONCLUSIONS

Epileptics consume more proinflammatory foods and nutrients than control subjects. MSD in patients with epilepsy is associated with their high inflammatory diet. Suggesting an urgent need for rational dietary management in the epileptic population.

Does Better Diet Quality Offset the Association between Depression and Metabolic Syndrome?

Several studies have shown that depression increases the risk of metabolic syndrome (MetS), which is often exacerbated by the fact that both exist concurrently. People with depression are more likely to have unhealthy eating habits, which can eventually trigger the development of MetS. This study was to investigate whether diet quality modifies the association between depression and MetS in a total of 13,539 Korean adults aged 19 to 80 from 2014, 2016 and 2018 Korean National Health and Nutrition Examination Surveys. Depression was assessed by the Patient Health Questionnaire-9 (PHQ-9) and subjects were divided into subgroups according to the PHQ-9 scores: normal (<5), mild (5-9), and moderate-to-severe (≥10) groups. Diet quality was measured by the Korean Healthy Eating Index (KHEI). A complex sample multiple logistic regression stratified by tertiles of KHEI scores was used to explore whether diet quality modifies an association between depression severity and metabolic syndrome. Depression severity was positively associated with the risk of MetS (p trend = 0.006) after adjustment for potential confounders. Only the lowest diet quality, moderately-to-severely depressed group, showed a higher risk of MetS (OR: 1.72, 95% CI: 1.24-2.40) compared to the normal group. Our results suggest that healthy diet quality could offset the positive relationship between depression and MetS in the general Korean adult population. Encouraging a healthy diet regime can improve not only physical health but also the mental state of the general public.

A J-shaped association between Dietary Inflammatory Index (DII) and depression: A cross-sectional study from NHANES 2007-2018

BACKGROUND

Growing evidence indicates that depression is more common in people who partake in a pro-inflammatory diet. The objective of our study was to assess the association between the Dietary Inflammatory Index (DII) and depression through a cross-sectional study of the National Health and Nutrition Examination Survey from 2007 to 2018.

METHODS

We used weighted multivariable logistic regression models with subgroup analysis to explore the relationship between DII and depression. Generalized additive models were used to test whether there was a nonlinear association. Then, we constructed a two-piece linear regression model and performed a recursive algorithm to calculate the inflection point.

RESULTS

The study enrolled a total of 30,627 individuals from the United States. In the regression model with full confounding variables adjusted, the OR (95 % CI) for the association between DII and depression was 1.05 (1.04, 1.06). A J-shaped association was found between DII and depression, with a turning point of 2.74. After the turning point, the OR (95 % CI) was 1.60 (1.51, 1.69). Only the interaction in the cardiovascular disease (CVD) analysis was statistically significant.

CONCLUSION

Our study highlighted a J-shaped association between DII and depression in a nationally representative sample of adults from the United States.

Association between an oxidative balance score and mortality: a prospective analysis in the SUN cohort

PURPOSE

We aimed to prospectively investigate the association of an overall oxidative balance score (OBS) with all-cause death and cause-specific mortality among participants in the Seguimiento Universidad de Navarra (SUN) Study, a Mediterranean cohort of Spanish graduates.

METHODS

Using baseline information on 12 a priori selected dietary and non-dietary lifestyle pro- and antioxidants exposures-vitamins C and E, β-carotenes, selenium, zinc, heme iron, polyphenols, total antioxidant capacity, body mass index, alcohol, smoking, and physical activity-we constructed an equally weighted OBS categorized into quartiles, with higher scores representing greater antioxidant balance. Cox proportional hazards models were fitted to evaluate the association between the OBS and mortality.

RESULTS

A total of 18,561 participants (mean [SD] age, 38.5 [12.4] years; 40.8% males) were included in the analysis. During a median follow-up of 12.2 years (interquartile range 8.3-14.9), 421 deaths were identified, including 80 deaths from cardiovascular disease (CVD), 215 from cancer, and 126 from other causes. After adjustment for potential confounders, the hazard ratios and 95% confidence interval (CIs) between the highest quartile (predominance of antioxidants) vs. the lowest quartile (reference category) were 0.35 (95% CI 0.22-0.54, P-trend < 0.001) for all-cause mortality, 0.18 (95% CI 0.06-0.51, P-trend = 0.001) for CVD mortality, 0.35 (95% CI 0.19-0.65, P-trend = 0.002) for cancer mortality, and 0.45 (95% CI 0.20-1.02, P-trend = 0.054) for other-cause mortality.

CONCLUSION

Our findings suggest a strong inverse association between the OBS and all-cause, CVD, and cancer mortality. Individuals exposed to both antioxidant dietary and lifestyle factors may potentially experience the lowest mortality risk.

STUDY REGISTRY NUMBER

Dynamic Mediterranean Prospective Cohort: the SUN Project; NCT02669602. https://clinicaltrials.gov/ct2/show/NCT02669602 . https://proyectosun.es.

Dietary inflammatory potential and the incidence of depression and anxiety: a meta-analysis

The potential modifiable role of diet in common psychological disorders, including depression and anxiety, has attracted growing interest. Diet may influence the occurrence of mental disorders through its inflammatory characteristics. The purpose of this meta-analysis was to explore whether dietary inflammatory potential is associated with the risk of depression and anxiety. A systematic literature search was conducted in PubMed, Web of Science, and Embase databases up to February 2021. Articles related to dietary inflammatory potential and risk of depression or anxiety were included. After the elimination of repetitive and irrelevant literature, we conducted quality assessment, publication bias, and sensitivity analysis. In total, 17 studies with a total of 157,409 participants were included in the final analysis. Compared with the lowest inflammatory diet group, the highest group was significantly associated with the incidence of depression and anxiety, with the following pooled odds ratios (ORs) and 95% confidence intervals (95% CIs): 1.45 (1.30 ~ 1.62) for depression and 1.66 (1.41 ~ 1.96) for anxiety. A subgroup analysis by gender showed that this association was more prominent in women. For depression, the increased risk was 49% in women (OR 1.49, 95% CI 1.28 ~ 1.74) and 27% in men (OR 1.27, 95% CI 1.06 ~ 1.52). As for anxiety, the increased risk was 80% in women (OR 1.80, 95% CI 1.30 ~ 2.49) and 47% in men (OR 1.53, 95% CI 0.81 ~ 2.89). As a result, long-term anti-inflammatory eating patterns may prevent depression and anxiety, whereas pro-inflammatory eating patterns may promote these conditions. People should add more fish, fish oil, fresh fruit, walnuts, and brown rice to their diet.

Proinflammatory dietary pattern and depression risk in older adults: Prospective analyses from the Seniors-ENRICA studies

BACKGROUND & AIMS

Only a few studies have assessed the association between a proinflammatory diet and the risk of depression in older adults, and they have rendered weak results. The present study analysed the association between the Dietary Inflammatory Index (DII) and incident self-reported diagnosis or symptoms of depression in two cohorts of community-dwelling older adults in Spain.

METHODS

We used data from the Seniors-ENRICA-I (SE-I) and Seniors-ENRICA-II (SE-II) cohorts. In both cohorts, the baseline DII was calculated from habitual food consumption estimated with a validated computer-based diet history. The incidence of both physician self-reported diagnosis of depression and mild-to-major depressive symptoms (≥3 on the 10-item Geriatric Depression Scale) was analysed. Logistic regression models were adjusted for the main potential confounders, such as sociodemographics, lifestyles, and comorbidities. The results of both cohorts were pooled using a random effects model.

RESULTS

Among the 1627 participants in SE-I (mean age 71.5 ± 5.5 y, 53.1% women) and the 1579 in SE-II (mean age 71.4 ± 4.2, 46.7% women), 86 (5.3%) and 140 (8.9%) incident cases of depression were identified after a mean 3.2-y and 2.3-y follow-up, respectively. The fully adjusted odds ratio (95% confidence interval) of incident depression for the highest (the highest proinflammatory diet) versus the lowest quartile of DII was 2.76 (1.25-6.08, p-for-trend = 0.005) in the SE-I, 1.90 (1.04-3.40, p-for-trend = 0.005) in the SE-II and 2.07 (1.01-3.13) in the pooled cohorts. The results were consistent across strata defined by sex, age, physical activity, loneliness/poor social network, and morbidity.

CONCLUSIONS

A proinflammatory dietary pattern is associated with depression risk in older adults. Future research should evaluate whether reducing the inflammatory component of diet leads to reduced depression symptoms in this population.

Anti-Inflammatory Dietary Diversity and Depressive Symptoms among Older Adults: A Nationwide Cross-Sectional Analysis

The purpose of this study was to associate the anti-inflammatory dietary diversity and depressive symptoms among a nationwide sample of Chinese older adults. We used data from the 2018 wave of Chinese longitudinal healthy longevity survey (CLHLS). We assessed depressive symptoms using the 10 items of the center for epidemiologic studies depression scale (CES-D-10). Based on the dietary diversity index (DDI) generated by previous studies, we construct two novel indicators: the protein-enriched dietary diversity index diet (PEDDI) and the anti-inflammatory dietary diversity index diet (AIDDI). We used multivariate logistic models to evaluate the associations of DDI, PEDDI, and AIDDI with depressive symptoms, statistically adjusted for a range of potential confounders. A total of 12,192 participants (mean age 83.6 years) were included in the analysis. We found that participants with a higher score of DDI (OR = 0.91, 95% CI: 0.89-0.92) and PEDDI (OR = 0.91, 95% CI: 0.88-0.93) showed lower odds of having depressive symptoms, while the association between AIDDI and depressive symptoms was more marked (OR = 0.80, 95% CI: 0.78-0.83). The associations remained in subgroup analyses and sensitivity analyses. The results indicate that intaking diversified diet, particularly anti-inflammatory foods, may be associated with a lower risk of depressive symptoms. The findings of this study, if confirmed as causal, provide evidence that an intervention of adopting an anti-inflammatory diversified diet may reduce the burden of depression among older adults.

Correlation between dietary score and depression in cancer patients: Data from the 2005–2018 National Health and Nutrition Examination Surveys

Aim

To investigate the correlation between dietary score and depression in patients with cancer.

Methods

In this cross-sectional study, data were collected from the National Health and Nutrition Examination Survey (NHANES) 2005–2018, a cross-sectional and nationally representative database, to compare 322 patients with depression to 2,868 with no depression. Mediterranean (MEDS) diet, Dietary Approaches to Stop Hypertension (DASH) diet, and the Healthy Eating Index 2015 (HEI-2015) score were calculated. Depression was assessed using the Patient Health Questionnaire-9 (PHQ-9). Weighted logistic regression models were used to explore the relationship between dietary scores and depression in patients with cancer. Subgroup analysis was performed by sleep disorders, sex, cancer type, number of tumors, and pain relief prescription treatment.

Results

The final study sample included 3,190 adults, with 56.94% of them being women, representing 2,177 (86.51%) non-Hispanic white adults. After multivariable adjustment, the MEDS score was correlated with a reduced risk of depression in patients with cancer [odds ratio (OR): 0.90, 95% confidence interval (CI): 0.82–0.97, p = 0.010]. Moreover, the MEDS score was correlated with depression in cancer patients with sleep disorders (OR: 0.84, 95% CI: 0.76–0.93, p = 0.001), in female patients with cancer (OR: 0.83, 95% CI: 0.74–0.92, p &lt; 0.001), particularly in female cancer reproductive system patients (OR: 0.69, 95% CI: 0.57–0.82, p &lt; 0.001). MEDS score also showed a decreased risk of depression in patients with 1 cancer (OR: 0.90, 95% CI: 0.82–0.98, p = 0.019). MEDS score (OR: 0.86, 95% CI: 0.86–0.98, p = 0.024) and DASH (OR: 0.91, 95% CI: 0.84–0.98, p = 0.015) score were related to a decreased risk of depression in patients with cancer using pain relief prescription.

Conclusion

Good diet quality is significantly correlated with decreased risk of depression in patients with cancer. Aligning with the Dietary Guidelines, such as the MEDS diet, may be beneficial to the reduced risk of depression in patients with cancer.

Prospective association between ultra-processed food consumption and incidence of elevated symptoms of common mental disorders

BACKGROUND

Our aim was to investigate the association between ultra-processed food (UPF) consumption and the incidence of elevated symptoms of common mental disorders (CMD) in two Brazilian birth cohorts.

METHODS

We analyzed data from the 1993 (n = 3130) and 1982 (n = 3165) Pelotas Birth Cohorts. In the 1993 cohort, the 18y wave provided the first wave data and the 22y wave the second wave data. In the 1982 cohort, the first and the second waves data came from the 22y and the 30y waves, respectively. The self-reporting questionnaire (SRQ-20) was used to assess CMD symptoms and determine the incidence of elevated symptoms of CMD over time. UPF consumption was assessed using food frequency questionnaires, and it was expressed as % of the total energy and % of g/d intake and coded into quartiles according to sex. Poisson and Cox regression models were used to estimate the association between UPF consumption and incidence of elevated symptoms of CMD.

RESULTS

There were no associations between first wave quartiles of UPF consumption and incidence of elevated symptoms of CMD (quartiles based on % of total energy:Q2: HR = 1.15, 95%CI: 0.93-1.42; Q3 = 0.91, 0.73-1.14; Q4 = 0.97, 0.77-1.21. Quartiles based on % of g/d: Q2 = 1.03, 0.83-1.27; Q3 = 1.05, 0.85-1.31; Q4 = 0.97, 0.78-1.21).

LIMITATIONS

Recall bias and only two time-points in each cohort study.

CONCLUSIONS

The consumption of ultra-processed food was not associated with the incidence of elevated CMD symptoms over time.

The relationship between ultra-processed food consumption and internalising symptoms among adolescents from São Paulo city, Southeast Brazil

OBJECTIVE

To investigate the association between ultra-processed food (UPF) consumption and internalising symptoms (IS) among adolescents.

DESIGN

It is a cross-sectional study. Paper-pencil survey was completed in classroom with information on UPF consumption, IS and selected covariates. IS were assessed with the Internalizing Symptoms sub-scale from the Social Behaviour Questionnaire (IS-SBQ). UPF was evaluated with a FFQ extracted from the Brazilian National School Health Survey. Crude and adjusted association between UPF and IS was investigated with structural equation models.

SETTING

São Paulo, SP, Brazil.

PARTICIPANTS

A total of 2680 students, M_age = 14·85; (95 % CI 14·81, 14·88).

RESULTS

UPF consumption was associated with higher scores in IS in the crude (β = 0·14; P < 0·001) and adjusted (β = 0·12; P < 0·001) models. The higher the consumption of UPF, the higher is the IS score. The following variables were associated with a lower risk of UPF consumption: male sex, public school and having more meals with parents. The change in the magnitude of the standardised score was almost negligible, but the model was significantly improved with the inclusion of covariates.

CONCLUSIONS

Our results provide evidence about the positive association between UPF consumption and IS among adolescents. The association, despite its low magnitude, remained significant after adjusting for potential confounders. These results are relevant considering the increase in UPF consumption worldwide and in low- and middle-income countries. Also, our study emphasises the importance of a healthy diet with a reduction in UPF consumption among adolescents.

Dietary Inflammatory Index and Cardiometabolic Risk in Ecuadorian School-Age Children

BACKGROUND

Cardiometabolic diseases and metabolic syndrome (MetS) are becoming increasingly prevalent in low- and middle-income countries (LMICs). Cardiometabolic diseases and MetS are closely associated with low-grade systemic inflammation, which may be modified by diet. Previous studies have focused on the association of dietary inflammation with MetS and cardiometabolic risk in adult populations, but few studies have examined this issue in children, especially in LMICs.

METHODS

We conducted a cross-sectional study to explore the association of dietary inflammation with cardiometabolic risk components and MetS in urban Ecuadorian children aged 6-12 years old (n = 276). A semi-quantitative food frequency questionnaire (FFQ) was used to collect data on child dietary intake. Dietary inflammation was evaluated using an energy-adjusted Dietary Inflammatory Index (DII), divided into quartiles. Data were also collected on cardiometabolic risk indicators including blood lipids, blood pressure (BP), blood glucose, body mass index, and waist circumference. Data were analyzed using multivariable linear and logistic regression.

RESULTS

Child DII scores ranged from -4.87 (most anti-inflammatory) to 4.75 (most pro-inflammatory). We transformed the continuous scores into quartiles (Q): Q1 was the most anti-inflammatory (-4.87 to -3.35), Q2 was anti-inflammatory (-3.34 to -1.45), Q3 was pro-inflammatory (-1.44 to 1.08), and Q4 was the most pro-inflammatory (1.09 to 4.75). In the covariate-adjusted model, DII scores were positively associated with total blood cholesterol (p = 0.027), triglycerides (p = 0.034), and diastolic BP (p = 0.013). In addition, for every one-unit increase in DII score, MetS increased by 1.20 in the covariate-adjusted model (95% CI = 1.01,1.43).

CONCLUSIONS

The findings suggest that more pro-inflammatory diets may contribute to poorer cardiometabolic health in school-age children. This is important because even small increases in child blood pressure, blood cholesterol, and glucose levels over time can damage health and lead to earlier progression to conditions such as hypertension and atherosclerosis.

The association between dietary inflammatory index, dietary antioxidant index, and mental health in adolescent girls: an analytical study

BACKGROUND

Diet is considered as one of the modifiable factors that appears to exert a vital role in psychological status. In this way, we designed this study to examine the association between dietary inflammatory index (DII), dietary antioxidant index (DAI), and mental health in female adolescents.

METHODS

This cross-sectional study included 364 female adolescents selected from high schools in the five regions of Tabriz, Iran. A 3-day food record was used to extract the dietary data and calculate DII/DAI scores. DII and DAI were estimated to assess the odds of depression, anxiety, and stress based on the Depression Anxiety Stress Scales-21. Adjusted relationships of the DII and DAI with depression, anxiety, and stress were determined using multiple regression after adjusting for age, energy intake, BMI, family income and mother and father education. Overweight was defined as body mass index (BMI)-for-age >  + 1 z-score relative to world health organization standards.

RESULTS

Depression, anxiety, and stress were observed in 21.4%, 26.6%, and 25.7% of subjects, respectively. The percentage of overweight among adolescents was 19.4%. The association between DII and score of mental health profile was positive among subjects in the third tertile of DII compared to subjects in the first tertile. However, this association was not statistically significant after adjusting for confounding variables. Moreover, there was a significant inverse association between DAI and depression and anxiety; and a statistically insignificant association between DAI and stress after adjusting for confounders.

CONCLUSIONS

Our results highlighted the importance of a healthy and anti-inflammatory diet on mental health in female adolescents. Therefore, modifying unhealthy dietary habits are likely to be effective in the management of psychosocial disorders.

Association of the Dietary Inflammatory Index with Depressive Symptoms among Pre- and Post-Menopausal Women: Findings from the National Health and Nutrition Examination Survey (NHANES) 2005-2010

During their lifetime, 20% of US women experience depression. Studies have indicated that a high Dietary Inflammatory Index (DII) score is associated with high C-reactive protein (CRP) levels and depression. No previous study has compared the association of the DII with different measures of depression (e.g., somatic, cognitive) among pre- and post-menopausal women. We used data from 2512 pre-menopausal and 2392 post-menopausal women from the National Health and Nutrition Examination Survey (NHANES) 2005−2010 database. We ran linear and logistic regression models to compare the association of the DII with survey-measured depression among pre- and post-menopausal women. We further assessed the mediation effect of CRP on the association of the DII and depression, using structural equation modeling. The odds of experiencing depression among pre-menopausal women was higher for all DII quartiles compared to the reference group (i.e., DII Q1), with an odds ratio (OR) of 3.2, 5.0, and 6.3 for Q2, Q3, and Q4, respectively (p < 0.05). Among post-menopausal women, only Q4 had 110% higher odds of experiencing depression compared to Q1 (p = 0.027). No mediation effect of CRP was found between DII and any of our depression outcome measures. Our findings suggest that lifestyle habits, such as diet, may have a stronger influence on mental health among pre-menopausal women than post-menopausal women.

Dietary Inflammatory Index in relation to Type 2 Diabetes: A Meta-Analysis

BACKGROUND AND AIMS

Epidemiologic studies show a strong association between chronic inflammation and type 2 diabetes (T2D). Diet may also affect the risk of T2D by modulating inflammation. This meta-analysis aimed to assess the relation of dietary inflammatory index (DII) and risk of T2D.

METHODS

PubMed and Scopus were systematically searched from their inception to September 2020 to identify relevant studies. Relative risks, hazard ratios, or odds ratios (OR), with their corresponding 95% confidence intervals (95% CI), were calculated and pooled using a random-effects model.

RESULTS

A total of 48 different studies, with a total sample size of 1,687,424 participants, were eligible to be included in this meta-analysis. In the overall analysis, no significant association was observed between DII and risk of T2D (OR = 1.03, 95% CI: 0.91 to 1.15), with significant evidence for heterogeneity (I ²  = 96.5%, P < 0.001); however, higher DII was identified as being significantly related to increased risk of T2D in high quality studies (OR = 1.58, 95% CI: 1.15 to 2.17). In the stratified analysis by the dietary assessment tool, background disease, and sex of participants, DII showed no significant association with T2D.

CONCLUSIONS

Higher DII might be associated with an increased risk of T2D. Additional well-designed studies are required to confirm this finding.

The dietary inflammatory index, obesity, type 2 diabetes, and cardiovascular risk factors and diseases

An unhealthy diet is a recognized risk factor in the pathophysiology of numerous chronic noncommunicable diseases (NCD), including obesity, type 2 diabetes (T2DM), and cardiovascular diseases (CVD). This is, at least in part, due to unhealthy diets causing chronic low-grade inflammation in the gut and systemically. To characterize the inflammatory potential of diet, we developed the Dietary Inflammatory Index (DII®). Following this development, around 500 papers have been published, which examined the association between the DII, energy-adjusted DII (E-DII™), and the children's DII (C-DII™) and many chronic NCDs including obesity and cardiometabolic diseases. Although a previous narrative review published in 2019 briefly summarized the evidence in this area, there was a significant increase in papers on this topic since 2020. Therefore, the purpose of this narrative review is to provide an in-depth updated review by including all papers until July 2021 on DII and its relationship with obesity, T2DM, and CVD. Furthermore, we aim to identify potential gaps in the literature and provide future directions for research. Most studies found that DII was associated with an increased risk of obesity, T2DM, and CVD with some relationships being sex-specific. However, we identified the paucity of papers describing associations between dietary inflammation and T2DM and its risk factors. Few studies used gold-standard measures of cardiometabolic risk factors. We also identified the lack of interventional studies designed to change the inflammatory potential of diets and study its effect on cardiometabolic risk factors and diseases. We recommend that such interventional studies are needed to assess if changes in DII, representing the inflammatory potential of diet, independently of changes in body composition can modulate cardiometabolic risk factors and diseases.

Association of Dietary Inflammatory Index (DII) and Depressive Disorders

A lot of evidence shows that inflammation is related to the development of depression. However, the heterogeneity of depression hinders efforts to understand, prevent and treat this disease. The purpose of this comprehensive review is to summarize the links between inflammation and the established core features of depression, which show more homogeneity than the syndrome itself: overreaction to negative information, changes in reward processing, and cognitive control decline, and somatic syndrome. For each core feature, we first briefly outline its relevance to depression and neurobiological basis, and then review the evidence to investigate the potential role of inflammation. We mainly focus on the discovery of the experimental paradigm of exogenous inflammation. We concluded that inflammation may play a role in overreaction to negative information, altered reward responses, and physical symptoms. There is less evidence to support the effect of inflammation on cognitive control by standard neuropsychological measures. Finally, we discussed the implications for future research and recommendations on how to test the role of inflammation in the pathogenesis of heterogeneous mental illness.

Role of BMI in the Relationship Between Dietary Inflammatory Index and Depression: An Intermediary Analysis

Introduction: This study investigated this association and the role of BMI in the inflammatory process in a large population-based observational study.

Methods: A total of 1,865 elderly people (≥55 years) were followed from the Community Cohort Study of Nervous System Diseases (CCSNSD) cohort study from 2018 to 2019 (Mean [SD] age, 66.31 [0.32] years; 716 [38.4%] males). The semi-quantitative FFQ and geriatric depression scale (GDS) were used to evaluate the diet and depressive symptoms of the elderly, respectively. The multivariable logistic regression model estimated the OR and 95% CI between Empirical Dietary Inflammatory Index (E-DII) and depression. The interaction of E-DII and BMI on depressive events was tested, and the mediation analysis of BMI was performed.

Results: As measured by E-DII, the mean (SE) value of the inflammatory potential of the diet in our study was 1.56 (0.12). E-DII ranged from 5.23 to 5.58. In comparison with the first quartile, the elderly from the second quartile (OR: 1.15 [95% CI: 1.09, 1.28]) to the fourth quartile (OR: 1.31 [95% CI: 1.16, 1.42]) have a higher risk of depression before adjustment for BMI. An interaction was observed between E-DII and BMI in terms of the risk of depression (P_Interaction < 0.001). The whole related part is mediated by BMI (31.06%).

Conclusion: Our findings indicate that the higher pro-inflammatory potential of diet is associated with a higher risk of depression, and this association may be mediated by BMI. Further research is needed to verify our findings and clarify the latent mechanism.

The dietary inflammatory index is inversely associated with depression, which is minimally mediated by C-reactive protein

Depression affects 8% of adults in America and is one of the leading causes of disability in Western countries. The dietary inflammatory index (DII) has previously been reported to be associated with inflammation and depression. However, no study to date has looked at the potential mediating effect of inflammation on the association of DII and depression. We hypothesized that the association of DII and depression would be both statistically and clinically mediated substantially by inflammation. We assessed these associations using the cross-sectional National Health and Nutrition Examination Survey (NHANES) 2005-2010 database. Our analysis included 10,022 participants aged 20 years and older. Inflammation was assessed with C-reactive protein (CRP) levels. Diet was measured using two 24 hour dietary recalls. Depression was assessed using the 9-item Patient Health Questionnaire (PHQ-9), which has a score range of 0 to 27, with the higher score showing more severe depressive symptoms. Comparing the highest to lowest DII quartiles, the mean score difference for depression was 0.47 units (95% CI 0.24-0.70, P-trend <.001) in the multivariable adjusted model. In the sex-stratified models, the results remained significant only among females, with the mean score difference of 0.72 (95% CI 0.34-1.10, P-trend <.001). CRP mediated 3.6% of the association between DII and depression in the total population in the fully adjusted model, which was statistically significant (P-trend <.001) but not clinically significant. No mediation association was found in the sex-stratified models. Further studies are needed to assess the associations with various inflammatory biomarkers in larger and more diverse populations.

Healthy diet, depression and quality of life: A narrative review of biological mechanisms and primary prevention opportunities

Unipolar depressive disorder (UDD) affects more than 264 million people worldwide and was projected well before the severe acute respiratory syndrome coronavirus 2 pandemic to be the leading cause of disability-adjusted life years lost in 2030. It is imperative for leading economies to implement preventive strategies targeted towards UDD, given consistent policies are currently lacking. Recently established similarities between the aetiological hypotheses of depression and cardiometabolic diseases are shifting paradigms within this field. It is believed that dietary practices could potentially reduce the incidence of depression; similar to their effects on metabolism. Thus, the aim of this review was to compile current evidence on healthy dietary patterns as suitable contributors towards primary prevention strategies against UDD. Most of the well-known biological mechanisms behind depression have been positively associated with healthful diets and dietary patterns to varying degrees. Interestingly, a common factor of UDD is the production and overall effects of inflammatory cytokines, such as interleukin-6, tumor necrosis factor-α, and C-reactive protein. These compounds have been associated with depressive symptoms, disturbances in neuroendocrine function, leaky gut, monoamine activity and brain function, while also being key factors in the development of cardiometabolic diseases. The Mediterranean diet (MD) in particular, is well supported by first-level evidence regarding its preventive qualities against metabolic and cardiovascular diseases and thus considered a model for healthy eating by various organizations. In one of the few clinical trials investigating these associations, the PREDIMED trial, individuals with diabetes assigned to a MD supplemented with mixed tree nuts experienced a 41% relative risk reduction for developing depression. Lastly, there is a need to include health related quality of life as an indicator of physical and mental well-being, considering its putative associations with depression and suicide risk. Going forward, focusing on clinical trials, using precise nutritional assessments, and identifying nutritional biomarkers which may be related to depression are needed to fully support the implementation of dietary recommendations in the field of psychiatry.

Associations between nutrition and the incidence of depression in middle-aged and older adults: A systematic review and meta-analysis of prospective observational population-based studies

AIM

To systematically examine the longitudinal observational evidence between diet and the incidence of depression in adults aged 45 years and older.

METHOD

Three electronic databases were searched for cohort studies published up to December 2020 that investigated the association between baseline dietary intake and incidence of depression in community-dwelling adults aged 45+years. Combined odds ratios (OR) and 95% confidence intervals (95%CI) were calculated. Random-effects models were used.

RESULTS

In total 33 articles were included, with 21 combined in meta-analyses. Both the Dietary Inflammatory Index and the Western diet were associated with an increased odds of incident depression (Dietary Inflammatory Index: OR 1.33; 95%CI 1.04, 1.70; P = 0.02; Western: OR 1.15 95%CI 1.04, 1.26; P = 0.005). Higher fruit and vegetable intakes were associated with a reduced risk of incident depression (vegetables: OR 0.91; 95%CI 0.87, 0.96; P < 0.001; fruit: OR 0.85; 95%CI 0.81, 0.90; P < 0.001). No association was observed between the Mediterranean diet, "healthy" diet, fish intake and incident depression.

CONCLUSIONS

Results suggest an association between higher consumption of pro-inflammatory diets and Western diets and increased incidence of depression, while higher intake of fruit and vegetables was associated with decreased incidence of depression. These results are limited by the observational nature of the evidence (results may reflect residual confounding) and the limited number of studies. More high-quality intervention and cohort studies are needed to confirm these associations and to extend this work to other food groups and dietary patterns.

Higher Dietary Inflammation in Patients with Schizophrenia: A Case-Control Study in Korea

Inflammation is a risk factor for the onset and progression of schizophrenia, and dietary factors are related to chronic inflammation. We investigated whether the dietary inflammatory index (DII) is associated with schizophrenia in the Korean population. Of the 256 subjects who responded to the questionnaire, 184 subjects (117 controls; 67 individuals with schizophrenia) were included in this case-control study. A semi-quantitative food frequency questionnaire was used to evaluate the dietary intakes of the study participants. The energy-adjusted DII (E-DII) was used to assess the inflammatory potential of the participants' diets. Dietary intakes of vitamin C, niacin, and folate were significantly reduced in the patients with schizophrenia. The patients with schizophrenia had higher E-DII scores than the controls (p = 0.011). E-DII was positively associated with schizophrenia (odds ratio = 1.254, p = 0.010). The additional analysis confirmed that E-DII was significantly associated with schizophrenia, especially in the third tertile group of E-DII scores (odds ratio = 2.731, p = 0.016). Our findings suggest that patients with schizophrenia have more pro-inflammatory diets.

Association Between Dietary Inflammatory Index and Mental Health: A Systematic Review and Dose-Response Meta-Analysis

Objective: We aimed to systematically evaluate the association between Dietary Inflammatory Index (DII) and mental health.

Methods: We searched PubMed, Embase, and Web of Science from their inception to December 31, 2020. Categorical meta-analysis and dose–response meta-analysis were performed to evaluate the association between DII and mental health.

Results: A total of 16 studies were included in this meta-analysis. Compared with the lowest DII category, the highest category was significantly associated with a variety of mental health outcomes, with the following pooled odds ratios (ORs) and 95% confidence intervals (95% CIs): 1.28 (1.17–1.39) for symptoms of depression, 1.27 (1.08–1.49) for symptoms of anxiety, 1.85 (1.43–2.40) for distress, and 4.27 (1.27–14.35) for schizophrenia. Furthermore, there was a linear dose–response relationship between DII and symptoms of depression in that a 1-unit increment in DII was associated with an increased risk of 6% for symptoms of depression (OR: 1.06, 95% CI: 1.03–1.19).

Conclusion: The present study indicates that more pro-inflammatory diet, as estimated by the higher DII score, is associated with symptoms of mental disorder. It may be of clinical and public health significance regarding the development of novel nutritional psychiatry approaches to promote good mental health.

Breakfast skipping alone and in interaction with inflammatory based quality of diet increases the risk of higher scores of psychological problems profile in a large sample of Iranian adults

The authors investigate the association of breakfast skipping and its interaction with a dietary inflammatory index (DII) with the severity of psychological disorders. A total of 2876 Iranian general adults were enrolled in this cross-sectional study. Psychological problems profile score was calculated using the regression method in the framework of factor analysis based on depression, anxiety and psychological distress. The higher scores indicate more severity of mental problem. The frequency of breakfast eating in a week was assessed. Dietary intakes were assessed using a food-frequency questionnaire and twenty-seven items were included in the calculation of DII. In the crude model, individuals who ate breakfast seldom had the highest odds for having worse psychological problems profile (OR 3⋅59; 95 % CI 2⋅52, 5⋅11). Adjustment for various confounders did not change the associations (OR 3⋅35; 95 % CI 2⋅11, 5⋅32). In the adjusted multinomial logistic regression model, participants with high DII (>median) who skipped breakfast had highest risk of being in the higher tertiles of psychological problems profile compared with those who had low DII (<median) and ate breakfast (OR 6⋅67; 95 % CI 3⋅45, 12⋅90). Similar results were observed in women and men regarding the impact of breakfast skipping alone and interaction with DII on scores of psychological problems profile. Breakfast skipping is associated with higher risk of psychological problems. Similar findings were obtained in the stratified analysis by sex. Our findings confirmed that the DII and breakfast skipping are associated with mental health, interactionally. Further longitudinal studies are needed to confirm the true link between breakfast skipping and psychological problems.

Dietary inflammatory index (DII®) and the risk of depression symptoms in adults

BACKGROUND & AIMS

Findings from observational studies investigating the association between Dietary Inflammatory Index (DII®) scores and depression symptoms (DepS) are inconsistent. This study aims to assess the association between energy-adjusted DII (E-DII™) and DepS using the North West Adelaide Health Study (NWAHS) cohort as well as update a previous meta-analysis.

METHODS

A total of 1743 (mean ± SD age: 56.6 ± 13.6 years, 51% female) study participants from NWAHS were included in the cross-sectional study and 859 (mean ± SD age: 58.4 ± 12.1 years, 52.6% female) in the longitudinal analyses. The Center for Epidemiological Studies Depression Scale (CES-D) was used for the measurement of DepS. E-DII scores were calculated from the dietary data collected using a validated food frequency questionnaire (FFQ). Data from two stages [Stage 3 (2008-10) and North West 15 (NW15) (2015)] were used. Log- and negative binomial regression were used to assess the association between quartiles of E-DII and DepS. A recent meta-analysis was updated by including 12 publications (six cross-sectional and six cohort studies) on the association between DII and DepS.

RESULTS

In the cross-sectional analysis, a higher E-DII score (i.e., more pro-inflammatory diet) was associated with a 79% increase in odds of reporting DepS [OR_Quartile4vs1: 1.79; 95% CI: 1.14-2.81; p = 0.01; p for trend (p_trend) = 0.03]. Males with higher E-DII had a more than two-fold higher odds of DepS (OR_Quartile4vs1: 2.27; 95% CI: 1.02-5.06; p = 0.045; p_trend = 0.09). Females with higher E-DII had an 81% increase in odds of DepS (OR_Quartile4vs1: 1.81; 95% CI: 1.01-3.26; p = 0.046; p_trend = 0.07). These associations were consistent in the longitudinal analysis. Comparing highest to lowest quintiles of E-DII, the updated meta-analysis showed that a pro-inflammatory diet is associated with a 45% increase in odds of having DepS (OR: 1.45; 95% CI: 1.20-1.74; p < 0.01) with higher odds in females (OR: 1.53; 95% CI: 1.16-2.01; p = 0.01) compared to their male counterparts (OR: 1.29; 95% CI: 0.98-1.69; p = 0.15).

CONCLUSION

The data from the NWAHS and the updated meta-analysis of observational studies provide further evidence that a pro-inflammatory diet is positively associated with increased risk of DepS. These findings support the current recommendation on consuming a less inflammatory diet to improve DepS.

Diet, Stress and Mental Health

Introduction: There has long been an interest in the effects of diet on mental health, and the interaction of the two with stress; however, the nature of these relationships is not well understood. Although associations between diet, obesity and the related metabolic syndrome (MetS), stress, and mental disorders exist, causal pathways have not been established. Methods: We reviewed the literature on the relationship between diet, stress, obesity and psychiatric disorders related to stress. Results: Diet and obesity can affect mood through direct effects, or stress-related mental disorders could lead to changes in diet habits that affect weight. Alternatively, common factors such as stress or predisposition could lead to both obesity and stress-related mental disorders, such as depression and posttraumatic stress disorder (PTSD). Specific aspects of diet can lead to acute changes in mood as well as stimulate inflammation, which has led to efforts to assess polyunsaturated fats (PUFA) as a treatment for depression. Bidirectional relationships between these different factors are also likely. Finally, there has been increased attention recently on the relationship between the gut and the brain, with the realization that the gut microbiome has an influence on brain function and probably also mood and behavior, introducing another way diet can influence mental health and disorders. Brain areas and neurotransmitters and neuropeptides that are involved in both mood and appetite likely play a role in mediating this relationship. Conclusions: Understanding the relationship between diet, stress and mood and behavior could have important implications for the treatment of both stress-related mental disorders and obesity.

Association between the Inflammatory Potential of Diet and Stress among Female College Students

A pro-inflammatory diet may have an adverse influence on stress and inflammatory biomarker levels among college students. The dietary inflammatory index (DII®) is a tool used to assess the inflammatory potential of a diet. However, evidence for the association between DII and stress is limited. We examined the association between energy-adjusted DII (E-DIITM), high sensitivity-C-reactive protein [hs-CRP], and stress among female college students. This cross-sectional study included 401 randomly selected female students, aged 19-35 years. Data collection included blood, anthropometric measurements, a healthy-history questionnaire, the perceived stress scale (PSS-10), the Saudi food frequency questionnaire (FFQ), and E-DII. Multiple linear regression analyses were used to examine the association between FFQ-derived E-DII score, hs-CRP, and PSS. A higher E-DII score per 1SD (1.8) was associated with a 2.4-times higher PSS score (95% CI: 1.8, 3.1). Higher hs-CRP per 1SD (3.3 mg/L) was associated with a 0.9 (95% CI: 0.7-1.1) times higher PSS score, independent of lifestyle and dietary factors. Our findings indicate that pro-inflammatory diets were highly prevalent among Saudi college students and were associated with higher stress levels. Consideration of the role of stress and focusing on anti-inflammatory foods may be key for healthier dietary habits.

Associations between healthy Japanese dietary patterns and depression in Japanese women

OBJECTIVE

Higher quality dietary patterns such as healthy/prudent and Mediterranean dietary patterns have been protectively associated with depression. This study examined whether healthy Japanese dietary patterns, which differ from dietary patterns derived from Western areas, are associated with depressive symptoms among Japanese women.

DESIGN

A cross-sectional study (the Nagano Nutrition and Health Study). Depressive symptoms were assessed using the Center for Epidemiologic Studies Depression Scale. Dietary patterns were derived with a principal component analysis of the consumption of fifty-six food and beverage items, which were assessed by a validated brief diet history questionnaire.

SETTING

Nagano, Japan.

PARTICIPANTS

Japanese women (n 1337) aged 20-72 years.

RESULTS

We identified three dietary patterns: 'healthy Japanese', 'sweets-fat' and 'seafood-alcohol'. The highest quality dietary pattern was 'healthy Japanese'. It is characterised by a high intake of vegetables, mushrooms, seaweed, soyabean products, potatoes, fish/shellfish and fruit. The age- and multivariate-adjusted OR (95 % CI) of depressive symptoms for the highest quartiles of the 'healthy Japanese' pattern score were 0·58 (95 % CI 0·41, 0·82) and 0·69 (95 % CI 0·45, 1·06), respectively. Meanwhile, no associations were observed for 'sweets-fat' and 'seafood-alcohol' patterns.

CONCLUSIONS

The 'healthy Japanese' pattern may be inversely associated with depressive symptoms with an exposure-response association. The specific Japanese food groups in the 'healthy Japanese' pattern included mushrooms, seaweed, soyabean products and potatoes, as well as vegetables, fish/shellfish and fruit. These seem to create an anti-inflammation-prone dietary pattern, and this factor might be associated with better mental health.

Association between Dietary Inflammatory Index (DII®) and depression and anxiety in the Mashhad Stroke and Heart Atherosclerotic Disorder (MASHAD) Study population

BACKGROUND

Systemic inflammation is emerging as an important factor in the etiology of psychiatric disorders such as depression and anxiety. Therefore, the inflammatory potential of the diet may also be an etiological factor for these conditions, and this may be estimated by calculating the dietary inflammatory index (DII®) score. We aimed to investigate the association between DII score and incidence of depression and anxiety among a representative sample in northeastern Iran.

METHODS

This cross-sectional study undertook in a sub-sample of 7083 adults aged 35 to 65 years recruited as part of Mashhad stroke and heart atherosclerotic disorder (MASHAD) cohort study population, and after excluding subjects with incomplete data. All participants completed the Beck Anxiety Inventory (BAI), the Beck Depression Inventory II (BDI-II), and a validated 65-item food frequency questionnaire (FFQ). Logistic regression was used to evaluate the association between DII score and depression/anxiety score.

RESULTS

Of the study participants, 37.1% (n = 2631) were found to have mild to severe depression, and 50.5% (n = 3580) were affected by mild to severe anxiety. After adjusting for confounding factors, in women, the third (OR: 1.41, 95% CI: 1.06-1.88, p-values< 0.05) and fourth quartiles (OR: 1.37, 95% CI: 1.03-1.83, p-values< 0.05) of DII score were associated with increased risk of a high depression score compared to the first quartile of DII score.

CONCLUSION

There was a significant association between DII score and severe depression among women but not men in this Iranian population. In order to confirm the association between DII food score, depression, and anxiety, further research is required in different populations, and perhaps an intervention study.

Dietary inflammatory index potentially increases blood pressure and markers of glucose homeostasis among adults: findings from an updated systematic review and meta-analysis

OBJECTIVE

In the current meta-analysis, we aimed to systematically review and summarize eligible studies for the association between dietary inflammatory index (DII) and blood pressure, hypertension (HTN) and glucose homeostasis biomarkers.

DESIGN/SETTING

In a systematic search of PubMed, Scopus and Google Scholar electronic databases up to February 2019, relevant studies were included in the literature review. Observational studies evaluating the association between DII and HTN, hyperglycaemia, systolic blood pressure (SBP), diastolic blood pressure (DBP), fasting blood glucose (FBG), insulin, homeostatic model assessment of insulin resistance (HOMA-IR) and glycated Hb (HbA1c) were included.

PARTICIPANTS

Not applicable.

RESULTS

Total numbers of studies were as follows: OR for DII and HTN (n 12), OR for DII and hyperglycaemia (n 9), HTN prevalence (n 9), mean (sd) of SBP and DII (n 12), mean (sd) of DBP and DII (n 10), mean (sd) of FBS and DII (n 13), mean (sd) of HbA1c and DII (n 3), mean (sd) of insulin and DII (n 6), mean (sd) of HOMA-IR and DII (n 7). Higher DII scores were associated with higher odds of HTN (OR = 1·13; 95 % CI 1·01, 1·27; P < 0·001), SBP (weighted mean difference (WMD) = 1·230; 95 % CI 0·283, 2·177; P = 0·011), FBS (WMD = 1·083; 95 % CI 0·099, 2·068; P = 0·031), insulin (WMD = 0·829; 95 % CI 0·172, 1·486; P = 0·013), HbA1c (WMD = 0·615; 95 % CI 0·268, 0·961; P = 0·001) and HOMA-IR (WMD = 0·192; 95 % CI 0·023, 0·361; P = 0·026) values compared with lowest DII categories.

CONCLUSIONS

Lower inflammatory content of diets for prevention of cardiovascular risk factors is recommended.

Assessing dietary and lifestyle risk behaviours and their associations with disease comorbidities among patients with depression: A case-control study from Bahrain

OBJECTIVES

In Western populations, patients with depression die 10-25 years prematurely compared to controls, mainly due to lifestyle-related diseases. Tobacco smoking, excessive alcohol intake, poor diets and physical inactivity are among the major contributors to disease comorbidities. The objective of this research is to assess the dietary and lifestyle behaviours for Bahraini patients with depression and to determine their associations with different medical comorbidities.

METHODS

A case-control study was conducted from March to December 2019. A sample of 96 diagnosed patients with depression was recruited from the Psychiatric Hospital/Bahrain, and 96 age- and sex-matched controls were recruited from primary health centres. Assessment of anthropometrics, dietary and alcohol intakes, tobacco smoking and physical activity levels were undertaken for both cases and controls. National electronic medical records were reviewed retrospectively for medical comorbidities for the recruited cases. Logistic regression analysis was used to identify associations between lifestyle behaviours and medical comorbidities after controlling for confounding factors.

RESULTS

Patients with depression reported higher intakes of energy and energy-yielding macronutrients (e.g., carbohydrates, protein, and fat); three-fold higher rates of tobacco smoking; and significantly lower levels of physical activity. Cases appeared to be at a doubled risk for developing obesity, diabetes type 2, hypertension, and musculoskeletal disorders. The risk for cardiovascular problems was similar for cases and controls.

CONCLUSIONS

Poor dietary intakes, increased prevalence of smoking, and low levels of physical activity were evident in patients with depression in Bahrain; these factors were associated with some medical comorbidities.

Is there a relationship between the dietary inflammatory index and metabolic syndrome among adolescents?

Background Dietary patterns have a crucial role in modulating chronic inflammation. This study aimed to determine the relationship between the Dietary Inflammatory Index (DII) and inflammation markers and metabolic syndrome components in adolescents (n = 343). Methods Fasting glucose, fasting insulin and lipid profile were analyzed and blood pressures were measured. Analysis of inflammation markers such as sedimentation, leukocyte, C-reactive protein (CRP), tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6) was also performed. The DII scores were calculated based on the adolescent's 3-day food consumption records. Results The dietary inflammatory score varied between 1.04 and 5.11 (3.6 ± 0.82). There was no significant difference in leukocyte and CRP levels between quartiles (p > 0.05). Those in the fourth quartile were observed to have higher levels of TNF-α and IL-6 compared to the others (p < 0.05). In the multiple regression analysis, a positive correlation existed only between IL-6 and DII, independent of other inflammatory markers (β = 0.272; p < 0.05). The DII was associated with glucose intolerance (odds ratio [OR] for DII quartile 4 compared to 1 = 3.5, 95% confidence interval [CI] = 1.2-10.4) and dyslipidemia (OR for DII quartile 4 compared to 1 = 5.3, 95% CI = 1.7-16.8). Conclusions These data suggest that a higher DII score was significantly associated with an increased risk of metabolic syndrome and some metabolic syndrome components in adolescents. Hence, DII can be used to determine the inflammatory potential of a diet and a healthy diet with anti-inflammatory properties that may be conducive to the prevention of metabolic disorders.

Association of poorer dietary quality and higher dietary inflammation with greater symptom severity in depressed individuals with appetite loss

BACKGROUND

Major depressive disorder (MDD) is the leading cause of years lived with disability; however, little is known about its etiology to inform treatment. For a subset of MDD patients, appetite change and/or bodily inflammation may play a role in exacerbating symptoms. The goal of this study is to examine whether, relative to healthy comparisons (HC), MDD individuals with increased versus decreased appetite symptoms show a differential relationship between diet quality and inflammation.

METHODS

Unmedicated current MDD (n = 61) varying in appetite change (decrease (MDD-DE): n = 39; increase (MDD-IN): n = 22) and HC (n = 42) completed 24-hour dietary recall and state depression/anxiety measures. Healthy eating and dietary inflammatory indices were calculated from dietary reports. Blood samples measured five inflammation-related biomarkers. Analyses investigated between- and within-group differences in the Healthy Eating Index (HEI), the Dietary Inflammatory Index (DII), inflammation-related blood biomarkers, and symptom severity.

RESULTS

While both MDD-DE and MDD-IN exhibited lower HEI scores than HC, only MDD-IN showed higher plasma interleukin-1 receptor antagonist (IL-1RA) and interleukin-6 (IL-6) levels than HC. In contrast, MDD-DE exhibited higher DII scores than MDD-IN and HC. Within MDD-DE, greater symptom severity was associated with lower HEI and higher DII.

LIMITATIONS

Modest sample sizes and the cross-sectional study design limited power to detect within-MDD effects.

CONCLUSIONS

Although MDD, regardless of appetite change, is linked to poorer dietary quality, depression severity was related to dietary characteristics only in subjects who reported appetite loss. Thus, increasing the quality of dietary intake could be a treatment target for some individuals with depression.

The relationship between inflammatory dietary pattern in childhood and depression in early adulthood

BACKGROUND

Inflammation may be a hidden process in the relationship between dietary intake and depression, but no study has evaluated the role of diet and inflammation jointly in explaining depression risk in early life. The current study aims to investigate the relationship between inflammatory dietary pattern (IDP) in childhood and depression in early adulthood.

METHODS

This study used data prospectively collected over 10 years from the Avon Longitudinal Study of Parents and Children (ALSPAC) cohort (n ​= ​6939) free from depression at baseline (age 8.5 years). An IDP score was empirically derived via reduced rank regression and stepwise linear regression based on dietary intake data from the food frequency questionnaire at 8.5 years and levels of inflammatory biomarkers, C-reactive protein and interleukin-6, at 9.5 years. At age 18 years, depression cases were identified via the International Statistical Classification of Diseases, 10th Revision (ICD-10) diagnosis and the Clinical Interview Schedule-Revised (CIS-R) depression score. Logistic regression models were constructed to examine the relationship between the IDP score and risk of depression adjusted for potential confounders. Analyses stratified by weight status were also conducted. Multiple imputations were utilized to minimize bias due to loss-to-follow-up.

RESULTS

Participants in the highest tertile of IDP score had 1.34 times odds to develop depression compared to those in the lowest tertile (95% CI, 1.08-1.66; P-trend<0.01), after dietary misreporting status and energy intake were adjusted. After all covariates were adjusted, the relationship between IDP tertiles and depression was attenuated (highest tertile vs. lowest tertile: OR ​= ​1.21; 95% CI, 0.96-1.51); in addition, the relationship was marginally significant among participants who were not overweight or obese (p ​< ​0.10) but not significant among participants who were overweight or obese.

CONCLUSIONS

Higher IDP in childhood seems to be associated with higher depression risk in early adulthood. The study provides preliminary evidence that chronic inflammation may underlie the relationship between diet and depression even for children, especially those who are not overweight or obese.

Dietary Patterns and Depression: First Results in a Cross-Sectional Study from the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil)

Background: Relations between diet and mental health continue to be a subject for controversy and an increasing numbers of studies. Recent literature is represented by papers that examine overall diet by way of dietary patterns and its association with depression, replacing previous studies about nutrients. The aim of this cross-sectional study is to evaluate the relation between dietary patterns and depressive episode in the baseline (2008–2010) population of the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil). We analyzed 14,798 participants of ELSA-Brasil. Methods: We constructed dietary patterns based on the Food Frequency Questionnaire using multiple correspondence and cluster analysis; to evaluate depressive episodes, we used the Clinical Interview Schedule-Revised (CIS-R). As an independent variable, we used the patterns: Traditional, Low-Sugar/Low-Fat, Fruit-Vegetables, and Bakery Products. We used multiple logistic regression models to evaluate relations between the dietary patterns and depressive episodes. Results: The Traditional pattern showed the highest percentages of consumption. After adjusting, the Bakery Products (OR = 1.33; 95%CI 1.05–1.70) was associated positively and significantly with depressive episodes only for women. Conclusions: International studies corroborated this finding, suggesting that the Bakery Products pattern could be a marker of a specific population group in which depressive episodes are frequent.

The relationship between dietary inflammatory index and psychosomatic complaints profiles: results from SEPAHAN cross-sectional study

Background

Although the dietary inflammatory index (DII) has been evaluated in relation to psychological disorders risk, the association between DII and psychosomatic complaints is unclear. This study aimed to determine the association between DII, as a proxy measure of the inflammatory potential of the diet, and psychosomatic complaints.

Methods

This cross-sectional study included 2818 people from the general population, aged 19 to 69 years, of Isfahan province in Iran. Dietary intake was assessed using a validated dish-based food-frequency questionnaire. Psychosomatic complaints were assessed using a self-administered validated Persian questionnaire. Twenty-seven nutrients or foods were included in the calculation of DII. Each of them received a score based on their inflammatory ability, thus, a higher DII score indicated a more pro-inflammatory diet. The risk of being in the top median of a psychosomatic complaints profile across the tertiles of DII was assessed using logistic regression.

Results

Four psychosomatic complaints profiles (psychological, gastrointestinal, neuro-skeletal and pharyngeal- respiratory) were identified. After controlling for potential confounders, individuals in the top tertile of DII had higher odds for experiencing high somatic complaints scores for the psychological (odds ratio (OR) = 1.44, 95% confidence interval (CI): 1.10, 1.89; P trend = 0.009), gastrointestinal (OR = 1.22, 95% CI: 0.99, 1.75; P = 0.058) or neuro-skeletal (OR = 1.56, 95% CI: 1.10, 2.22; P = 0.013) profile. The association for pharyngeal-respiratory complaints did not remain significant after adjustment for stressful life events, medical condition, and anti-psychotropic medicine use.

Conclusion

The significant positive link between DII and the various psychosomatic complaints profiles suggests that a diet with anti-inflammatory potential might be favourably related to psychosomatic complaints. Further studies, particularly clinical trials and longitudinal studies, are warranted to investigate the inflammatory potential of diet in relation to psychosomatic complaints.

Dietary Inflammatory Index and Non-Communicable Disease Risk: A Narrative Review

There are over 1,000,000 publications on diet and health and over 480,000 references on inflammation in the National Library of Medicine database. In addition, there have now been over 30,000 peer-reviewed articles published on the relationship between diet, inflammation, and health outcomes. Based on this voluminous literature, it is now recognized that low-grade, chronic systemic inflammation is associated with most non-communicable diseases (NCDs), including diabetes, obesity, cardiovascular disease, cancers, respiratory and musculoskeletal disorders, as well as impaired neurodevelopment and adverse mental health outcomes. Dietary components modulate inflammatory status. In recent years, the Dietary Inflammatory Index (DII®), a literature-derived dietary index, was developed to characterize the inflammatory potential of habitual diet. Subsequently, a large and rapidly growing body of research investigating associations between dietary inflammatory potential, determined by the DII, and risk of a wide range of NCDs has emerged. In this narrative review, we examine the current state of the science regarding relationships between the DII and cancer, cardiometabolic, respiratory and musculoskeletal diseases, neurodevelopment, and adverse mental health outcomes. We synthesize the findings from recent studies, discuss potential underlying mechanisms, and look to the future regarding novel applications of the adult and children's DII (C-DII) scores and new avenues of investigation in this field of nutritional research.

Empirically derived food-based dietary inflammatory index is associated with increased risk of psychological disorders in women

Purpose/introduction: There is no study on the association of empirically derived food-based dietary inflammatory index (FDII) and risk of psychological disorders. We investigated the association between FDII and odds of psychological disorders in Iranian adults.Methods and materials: In this cross-sectional study, data on dietary intakes of 3363 Iranian adult participants were collected using a validated dish-based 106-item semi-quantitative food frequency questionnaire. FDII score was constructed based on participants' dietary intakes of 28 pre-defined food groups. The Iranian validated version of Hospital Anxiety and Depression Scale (HADS) and General Health Questionnaire (GHQ) was used to assess psychological disorders. Depression, anxiety and psychological distress were defined based on standard criteria.Results: After controlling for potential confounders, participants in the top quintile of FDII score had a greater odds of depression (OR: 1.49; 95% CI: 1.08-2.06), anxiety (OR: 1.92; 95% CI: 1.24-2.96), and psychological distress (OR: 1.55; 95% CI: 1.10-2.19) compared with those in the bottom quintile. When we did the analyses stratified by gender, we found a significant positive association between FDII score and depression (OR: 1.57; 95% CI: 1.04-2.35), anxiety (OR: 1.99; 95% CI: 1.19-3.34), and psychological distress (OR: 1.68; 95% CI: 1.10-2.56) among women comparing the highest and the lowest quintiles. We found no significant association between FDII score and psychological disorders in men.Conclusion: We found that greater FDII score was positively associated with psychological disorders. In the gender-stratified analysis, this was seen in women but not in men.

The Inflammatory Potential of the Diet is Directly Associated with Incident Depressive Symptoms Among French Adults

BACKGROUND

Low-grade chronic inflammation has been suggested to play a substantial role in the etiology of depression; however, studies on the prospective association between the inflammatory potential of the diet and depression are limited.

OBJECTIVE

The aim of this study was to investigate the association between the inflammatory potential of the diet (measured using the Alternate Dietary Inflammatory Index, ADII) and incident depressive symptoms. We also tested the potential modulating effect of sex, age, BMI, and lifestyle indicators.

METHODS

The study sample consisted of 26,730 participants (aged 18-86 y) from the NutriNet-Santé study. Baseline ADII was computed using repeated 24-h dietary records collected during the first 2 y of the follow-up. Incident cases of depressive symptoms were defined by a Center for Epidemiologic Studies Depression scale ≥17 for men and ≥23 for women at least once during follow-up. HR and 95% CI were estimated using multivariable Cox proportional hazards models.

RESULTS

A total of 2221 incident cases of depressive symptoms were identified over a mean follow-up of 5.4 y. After accounting for a wide range of potential confounders, the highest quartile of the ADII was associated with a 15% (95% CI: 2, 31) increase in the risk of depressive symptoms compared with the lowest quartile. In the stratified analyses, associations were statistically significant only among women (HRquartile4 vs. quartile1: 1.19; 95% CI: 1.02, 1.37), middle-age adults (HRquartile4 vs. quartile1: 1.16; 95% CI: 1.00, 1.35), and participants with a BMI ≥25 (HRquartile4 vs. quartile1: 1.29; 95% CI: 1.04, 1.60).

CONCLUSIONS

Overall, a proinflammatory diet was associated with a higher risk of depressive symptoms, especially among women, middle-age adults, and participants with overweight or obesity. These findings contribute to the increasing scientific evidence showing a detrimental role of the proinflammatory diet. The NutriNet-Santé study is registered at clinicaltrials.gov as NCT03335644.

Healthy dietary indices and risk of depressive outcomes: a systematic review and meta-analysis of observational studies

With depression being the psychiatric disorder incurring the largest societal costs in developed countries, there is a need to gather evidence on the role of nutrition in depression, to help develop recommendations and guide future psychiatric health care. The aim of this systematic review was to synthesize the link between diet quality, measured using a range of predefined indices, and depressive outcomes. Medline, Embase and PsychInfo were searched up to 31st May 2018 for studies that examined adherence to a healthy diet in relation to depressive symptoms or clinical depression. Where possible, estimates were pooled using random effect meta-analysis with stratification by observational study design and dietary score. A total of 20 longitudinal and 21 cross-sectional studies were included. These studies utilized an array of dietary measures, including: different measures of adherence to the Mediterranean diet, the Healthy Eating Index (HEI) and Alternative HEI (AHEI), the Dietary Approaches to Stop Hypertension, and the Dietary Inflammatory Index. The most compelling evidence was found for the Mediterranean diet and incident depression, with a combined relative risk estimate of highest vs. lowest adherence category from four longitudinal studies of 0.67 (95% CI 0.55-0.82). A lower Dietary Inflammatory Index was also associated with lower depression incidence in four longitudinal studies (relative risk 0.76; 95% CI: 0.63-0.92). There were fewer longitudinal studies using other indices, but they and cross-sectional evidence also suggest an inverse association between healthy diet and depression (e.g., relative risk 0.65; 95% CI 0.50-0.84 for HEI/AHEI). To conclude, adhering to a healthy diet, in particular a traditional Mediterranean diet, or avoiding a pro-inflammatory diet appears to confer some protection against depression in observational studies. This provides a reasonable evidence base to assess the role of dietary interventions to prevent depression. This systematic review was registered in the PROSPERO International Prospective Register of Systematic Reviews under the number CRD42017080579.