A meta-analysis of dietary inflammatory index and bone health status.

Background: The inflammatory potential of diets is associated with several diseases and can affect bone health. We aimed to systematically review and pool the current evidence on the association of DII with bone health in observational studies.
Methods: We searched PubMed and NLM Gateway (for Medline), Web of Science, Scopus and EMBASE up to December 16, 2020 for studies that examined the relationship between DII score and bone mineral density (BMD) or fracture. All observational studies were included in this meta-analysis. Heterogeneity between studies was evaluated using Cochran Q-statistic and I2 statistics. Random effect meta-analysis method was used to pool the effect size. Stratified meta-analysis according to the type of study (cohort/ non-cohort) was performed to assess the relationship of DII with BMD and fracture.
Results: In total, 13 articles were included in the present systematic review, including five cohorts, five cross-sectional, and three case-control studies. The total sample size of these studies was 211,938 individuals aged 5 to 85 years. According to random-effect meta-analysis, DII was associated with increased odds of fracture in non-cohort studies (pooled OR=1.42, 95%CI: 1.17, 1.67), but this association was not statistically significant in cohort studies (pooled OR=1.03, 95%CI: 0.97, 1.09). Moreover, only in non-cohort studies, the mean of BMD in subjects in the highest DII category was significantly lower than those in the lowest DII category (SMD: -9.59, 95%CI: -10.84,-8.33). Conclusions: Our findings showed that high score of DII can have devastating effects on bone health. Further longitudinal studies are necessary to confirm these findings among more diverse populations. © Springer Nature Switzerland AG 2021.