The associations between diet-induced inflammation and health outcomes: a population-based phenome-wide association study

Evidence linking the dietary inflammatory index (DII) to health outcomes remains inconsistent and limited. This study assessed the associations between DII and 845 health outcomes (N = 78,390 to 207,832), identifying 133 outcomes significantly associated with DII after multiple comparison correction (P_FDR < 0.05). Most of these health outcomes pertained to the digestive, circulatory, and endocrine/metabolic systems. Using the genetic instrument rs7910002, significantly associated with DII at the genome-wide level (P < 5 × 10^-8), Mendelian randomization (MR) phenome-wide association analysis (N = 121,978 to 315,586) revealed significant associations between DII and 25 health outcomes (P_FDR < 0.05). Consistent effects of DII on seven health outcomes were observed in the above analyses. Subsequently, two-sample MR analysis confirmed that higher DII increased the risk of abdominal hernia, cholelithiasis, and back pain. Our study comprehensively assessed the health effects of DII and highlighted the importance of anti-inflammatory diets for disease prevention.