The effect of pomegranate (Punica granatum) supplementation on metabolic status in patients with type 2 diabetes: A systematic review and meta-analysis

Objective: Several randomized controlled clinical trials (RCTs) have investigated the effect of pomegranate (Punica granatum) supplementation in patients with type 2 diabetes mellitus (T2DM), with conflicting results. Therefore, the present study assessed the effect of pomegranate on metabolic status and oxidative stress in patients with T2DM. Methods: A comprehensive search was conducted in Pubmed, EMBASE, ISI web of science, Cochrane library and Scopus databases until April 2020, to identify RCTs investigating the effect of pomegranate supplementation on glycemic markers (fasting blood glucose (FBG), homeostasis model assessment-estimated insulin resistance index (HOMA-IR), glycosylated hemoglobin percentage (HbA1c) and insulin levels), anthropometric indices (body mass index (BMI) and body weight (BW)), blood lipids (triglycerides (TG), total cholesterol (TC), high lipoprotein cholesterol (HDL-C) and low lipoprotein cholesterol (LDL-C)), inflammatory markers (high sensitive creactive protein (Hs-CRP)) and markers of oxidative stress (total antioxidant capacity (TAC)) in adults with T2DM. Mean difference was pooled using a random-effects model. Results: Seven trials, comprising 350 participants, were included in the present systematic review and meta-analysis. The results of the meta-analysis revealed that pomegranate supplementation did not have any significant effects on metabolic status and oxidative stress biomarkers of subjects with T2DM. There were no evidence of publication bias regarding to selected outcomes. Conclusion: There were no significant favorable effects of pomegranate supplementation on metabolic parameters in patients with T2DM. Future well-designed, large scale RCTs, with longer duration are needed in this field.