The effect of pomegranate products on glycemic profile in adults: a GRADE- assessed systematic review and dose-response meta-analysis of randomized controlled trials.

Abstract

Background: Pomegranate consumption may have a beneficial effect on glucose control and insulin resistance due to its bioactive compounds. However, the results of available clinical trials are inconsistent. To address these inconsistencies, we conducted a meta-analysis of 34 randomized clinical trials (RCTs) evaluating the effects of pomegranate on glycemic parameters in adults.

Methods: A thorough search was conducted across multiple databases until December 2024 to identify trials that investigated the impact of pomegranate on glucose control and insulin sensitivity. We calculated the effect size, reported as the weighted mean difference (WMD) with 95% confidence intervals (CIs), based on the net changes in fasting blood glucose (FBS), insulin, HOMA-IR, and Hemoglobin A1c (HbA1c).

Results: Among the 407 records, this meta-analysis included 34 eligible RCTs involving 1500 participants. Pomegranate consumption was significantly associated with a reduction in FBS (WMD: -3.036 mg/dl; 95% CI, -4.273 to -1.799, P < 0.001, Tau² = 6.039, I² = 89.22%), insulin (WMD: -0.967 IU/mL; 95% CI, -1.486 to -0.448, P < 0.001, Tau² = 0.761, I² = 83.82%), HOMA-IR (WMD: -0.338; 95% CI, -0.470 to -0.205, P < 0.001, Tau² = 0.031, I² = 84.96%), and QUICKI (WMD: 0.003; 95% CI, 0.001 to 0.006, P = 0.011, Tau² = 0.00, I² = 7.11%), whereas changes in HbA1c (WMD: 0.046, 95% CI: -0.207 to 0.298, P = 0.723, Tau² = 0.081, I² = 60.62%) were not statistically significant. The non-linear dose-response analysis showed a significant association between the pomegranate dose and FBS (P for non-linearity = 0.006). Also, the duration of pomegranate consumption showed a significant non-linear relationship with FBS (P for non-linearity = 0.022) and insulin (P for non-linearity = 0.030). We did not find a significant non-linear association between the dosage of pomegranate juice and FBS (P for non-linearity = 0.83), insulin (P for non-linearity = 0.51), and duration of pomegranate extract with FBS (P for non-linearity = 0.30).

Conclusion: This meta-analysis suggests that the consumption of pomegranate products can result in positive effects on FBS, insulin levels, HOMA-IR, and QUICKI in adults. More RCTs with longer duration and larger sample sizes are needed to confirm these findings.