Dietary Inflammatory Potential Score and Risk of Breast Cancer: Systematic Review and Meta-analysis.

Several studies have been conducted on the relationship between dietary inflammatory potential (DIP) and breast cancer. However, the findings are conflicting. This systematic review and meta-analysis summarizes the findings on the association between DIP and the risk of breast cancer. We used relevant keywords and searched online international electronic databases, including PubMed and NLM Gateway (for Medline), Institute for Scientific Information (ISI), and Scopus for articles published through February 2017. All cross-sectional, case-control, and cohort studies were included in this meta-analysis. Meta-analysis was performed using the random effects meta-analysis method to address heterogeneity among studies. Findings were analyzed statistically. Nine studies were included in the present systematic review and meta-analysis. The total sample size of these studies was 296,102, and the number of participants varied from 1453 to 122,788. The random effects meta-analysis showed a positive and significant association between DIP and the risk of breast cancer (pooled odds ratio, 1.14; 95% confidence interval, 1.01-1.27). The pooled effect size was not statistically significant because of the type of studies, including cohort (pooled relative risk, 1.04; 95% confidence interval, 0.98-1.10) and case-control (pooled odds ratio, 1.63; 95% confidence interval, 0.89-2.37) studies. We found a significant and positive association between higher DIP score and risk of breast cancer. Modifying inflammatory characteristics of diet can substantially reduce the risk of breast cancer.