Dietary Inflammatory Index in relation to bone mineral density, osteoporosis risk and fracture risk: a systematic review and meta-analysis

Summary Our systematic review and meta-analysis indicated that pro-inflammatory diets, as measured by higher Dietary Inflammatory Index scores, are significantly associated with lower BMD of lumbar spine and total hip as well as elevated risk of osteoporosis and fractures. These findings may contribute to the development of public health strategies. Introduction Inflammatory Index (DII) is a method to assess the inflammatory potential of diets; it has been reported to be associated with several diseases. However, the relation between DII and bone health remains controversial for the inconsistent findings from previous studies. This systematic review and meta-analysis aimed to ascertain the underlying relationships between DII and bone mineral density (BMD), osteoporosis risk, and fracture risk. Methods We systematically searched PubMed and Web of Science for all relevant epidemiological studies published up to May 1, 2020. Fixed-effects model or random-effects model was employed to pool the study-specific effect sizes (ESs) and 95% confidence intervals (CIs). Results Eleven studies with a total of 127,769 participants were included. We found that continuous DII was negatively associated with BMD of lumbar spine (odds ratios [OR]: 0.990; 95% CI: 0.984, 0.995) and total hip (OR: 0.995; 95% CI: 0.990, 0.999), but not femoral neck (OR: 0.998; 95% CI: 0.994, 1.002). Moreover, the highest category of DII displayed significantly associations to increased risk of osteoporosis (ES: 1.31; 95% CI: 1.16, 1.48) and fractures (ES: 1.28; 95% CI: 1.03, 1.59) compared with the lowest category of DII, respectively. Conclusion Our analysis indicated that diets with high pro-inflammatory components might increase the risk of osteoporosis and fractures and lower BMD of lumbar spine and total hip. More prospective studies involving populations of diverse ages and genders are expected to further verify the universality of the results.