Study eligibility criteria:
PICOS (Patient/Population, Intervention, Comparison, Outcome, Study types) framework was used as inclusion criteria for this systematic review and meta-analysis. Original investigations with randomized controlled trial design that conducted among postmenopausal women were considered for inclusion in this article. For inclusion, trials should report the effects of soy isoflavones or soy isoflavones plus soy protein on serum concentration of CRP as primary or secondary outcomes. After reading the full texts of retrieved clinical trials, we did not consider RCTs with following criteria in our systematic review and meta-analysis: 1) taking other nutrient supplements beside soy in intervention group; 2) trials without comparison group; 3) Not reporting information related to serum concentration of CRP at baseline or after intervention and any data for computing it; 4) Reporting serum concentration of CRP in figures; 5) Not reporting the dose of soy isoflavones and protein in natural soy product; 6) Non-English articles.