Abstract
BACKGROUND: The relationship between dietary inflammatory potential and depression in middle-aged and older populations has not been fully elucidated. This study aimed to examine this association and its potential mechanisms.
METHODS: Data from 194,246 UK Biobank participants without depression at baseline were analyzed. The Dietary Inflammatory Index (DII) was used to classify diets as anti-inflammatory (DII < 0) or pro-inflammatory (DII ≥ 0). During a median follow-up time of 11.52 years, 5937 participants developed depression. Cox proportional-hazards models were used to estimate the association in terms of hazard ratio (HR) and 95 % confidence interval (CI). Mediation analyses were conducted to examine the role of inflammation-related indicators and chronic diseases, while disease correlation network analysis was used to explore the relationships between chronic diseases and depression.
RESULTS: A pro-inflammatory diet was associated with an increased depression risk (hazard ratio [HR] = 1.099, 95 % CI: 1.043-1.158). Stratified analyses showed stronger associations in females, participants younger than 60 years at baseline, non-smokers, current smokers, non-drinkers, current drinkers, and those with moderate or high levels of physical activity. Mediation analysis revealed that the neutrophil to high-density lipoprotein cholesterol ratio and obesity mediated 13.69 % and 5.94 % of the relationship, respectively. Disease network analysis highlighted the central role of diabetes and hypertension, with obesity most strongly linked to depression.
CONCLUSION: This study suggests that adopting an anti-inflammatory diet may help prevent depression in middle-aged and older adults. Inflammation-related indicators and chronic disease partially mediated the association between dietary inflammatory potential and depression.