Increased Dietary Inflammatory Index Is Associated with Schizophrenia: Results of a Case–Control Study from Bahrain

Abstract

Background: Several studies have indicated that chronic low-grade inflammation is associated with the development of schizophrenia. Given the role of diet in modulating inflammatory markers, excessive caloric intake and increased consumption of pro-inflammatory components such as calorie-dense, nutrient-sparse foods may contribute toward increased rates of schizophrenia. This study aimed to examine the association between dietary inflammation, as measured by the dietary inflammatory index (DII®), and schizophrenia. Methods: A total of 120 cases attending the out-patient department in the Psychiatric Hospital/Bahrain were recruited, along with 120 healthy controls matched on age and sex. The energy-adjusted DII (E-DII) was computed based on dietary intake assessed using a comprehensive food frequency questionnaire (FFQ). Logistic regression was used to estimate odds ratios and 95% confidence intervals, adjusting for potential confounders including age, sex, body mass index, education, employment, diabetes, hypertension, and cardiovascular disease with E-DII expressed both as a continuous variable and categorized as quartiles. Results: The mean E-DII score for the entire sample was 1.79 ± 1.52, indicating a generally pro-inflammatory diet. The cases with schizophrenia appeared to have a higher E-DII score compared to controls: 1.99 ± 1.39 vs. 1.60 ± 1.38, respectively (p = 0.009). For every one unit increase in the E-DII score, the odds of having schizophrenia increased by 62% (OR 1.62; 95% CI 1.17–2.26). Similarly, increased risk was observed when the E-DII was used as quartiles, with participants in most pro-inflammatory quartile 4 being nearly 6 times more likely to be schizophrenic than participants in the most anti-inflammatory group quartile 1 (OR 5.96; 1.74–20.38; p-trend = 0.01). Conclusions: The data suggest that a pro-inflammatory diet, as indicated by increasing E-DII score, is associated with schizophrenia. This is the first study to examine the association between the DII and schizophrenia in a Middle Eastern population. Although these results are consistent with findings from research conducted in depression, additional studies are required before generalizing the findings to other populations.

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

“…This has significant clinical implications in the sense that for best protective results, lifestyle modifications should be well-timed and offered as comprehensive interventions to address various components. Thus, we recommend that offering smoking cessation therapy, exercise education, and nutritional interventions by qualified health-care professionals should be prioritized in daily clinical practice to maintain an active lifestyle by the patient with depression and other SPMI (Jahrami et al, 2019).…”

“…Over the past three decades, Bahrain has undergone significant improvements in health care status, including increased life expectancy (~75 years), reductions in child mortality, and the prevalence of communicable diseases (Charara et al, 2017). Nonetheless, as people in Bahrain are living longer, the burden of chronic diseases, including mental disorders, are on the rise (Jahrami et al, 2019(Jahrami et al, , 2014.…”

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

“…The process of literature selection is shown in Figure 1. A total of 16 articles with 92,242 participants were included in this metaanalysis, including five cohort studies, one case-control study, and 10 cross-sectional studies (16,(26)(27)(28)(29)(30)(31)(32)(33)(34)(35)(36)(37)(38)(39)(40)(41). All studies assessed the DII score based on interviewed food-frequency questionnaires or 24-h diet recalls.…”

Anti-Inflammatory Diets and Schizophrenia

“…A case-control study conducted in Bahrain aimed to examine the association between dietary inflammatory potential and schizophrenia using DII [ 65 ]. This study was performed using a 1:1 ratio matched design including 120 cases and 120 controls.…”