Dietary inflammatory index and brain disorders: a Large Prospective Cohort study

There is emerging evidence that diet plays a key contributor to brain health, however, limited studies focused on the association of dietary inflammatory potential with brain disorders. This study aimed to examine the association of dietary inflammation with brain disorders in the UK biobank. The prospective cohort study used data from 2006 to 2010 from the UK Biobank, with the median follow-up duration for different outcomes ranging between 11.37 to 11.38. Dietary inflammatory index and Energy-adjusted dietary inflammatory index [DII and EDII] were assessed through plausible dietary recalls. Outcomes included brain disorders (all-cause dementia [ACD], Alzheimer's disease [AD], Parkinson's disease [PD], stroke, sleep disorder, anxiety and depression disorder) and brain magnetic resonance imaging measures. Cox proportional-hazard models, restricted cubic spline model [RCS], Ordinary least squares regressions, and structural equation models were used to estimate associations. Of 164,863 participants with available and plausible dietary recalls, 87,761 (53.2%) were female, the mean (SD) age was 58.97 (8.05) years, and the mean (SD) education years was 7.49 (2.97) years. Vegetables and fresh fruits show significant anti-inflammatory properties, while low-fiber bread and animal fats show pro-inflammatory properties. The nonlinear associations of DII and EDII scores with ACD, AD, sleep disorder, stroke, anxiety, and depression were observed. Multivariable-adjusted HRs for participants in highest DII score VS lowest DII score were 1.165 (95% CI 1.038-1.307) for ACD, 1.172 (95% CI 1.064-1.291) for sleep disorder, 1.110 (95% CI 1.029-1.197) for stroke, 1.184 (95% CI 1.111-1.261) for anxiety, and 1.136 (95% CI 1.057-1.221) for depression. Similar results were observed with regard to EDII score. Compared with the lowest EDII score group, the highest group showed a higher risk of anxiety, depression, sleep disorder, stroke and dementia. Results from sensitivity analyses and multivariable analyses were similar to the main results. Pro-inflammatory diets were associated with a higher risk of brain disorders. Our findings suggest a potential means of diet to lower risk of anxiety, depression, sleep disorder, stroke, and dementia.