Dose-Response Association of Dietary Inflammatory Potential with All-Cause and Cause-Specific Mortality

Although the association of dietary inflammatory potential, evaluated by the dietary inflammatory index (DII), with all-cause and cause-specific mortality has been reported, evidence remains equivocal, with no relevant dose-response meta-analysis having been conducted. To examine the dose-response association of dietary inflammatory potential with risk of all-cause, cancer, and cardiovascular disease (CVD) mortality, PubMed, Embase, and Web of Science were systematically searched up to August 9, 2021. Cohort studies were included if DII was reported as ≥3 levels or per incremental increase, and if the associations of DII with all-cause, cancer, and CVD mortality were assessed. Generalized least squares regression was used to estimate study-specific dose-response associations, and the random effect model was used to pool the RRs and 95% CIs of all-cause, cancer, and CVD mortality per 1-unit increase in DII. Restricted cubic splines were used to intuitively display the dose-response association between dietary inflammatory potential and mortality. Of the 1415 studies retrieved, 15 articles (17 cohort studies involving 397,641 participants) were included in this meta-analysis. With per 1-unit increase in DII, the risks were significantly increased for all-cause mortality (RR: 1.04; 95% CI: 1.03, 1.05, I2 = 51.8%; P-heterogeneity = 0.009), cancer mortality (RR: 1.02; 95% CI: 1.00, 1.04, I2 = 58.6%; P-heterogeneity = 0.013), and CVD mortality (RR: 1.04; 95% CI: 1.02, 1.06, I2 = 85.7%; P-heterogeneity <0.001), respectively. Restricted cubic splines showed significant positive linear associations between DII and the above 3 outcomes. Our study indicated that proinflammatory diets can increase the risk of all-cause, cancer, and CVD mortality in a linear manner.