Effectiveness of Passion Fruit Peel Flour (Passiflora edulis L.) versus Turmeric Flour (Curcuma longa L.) on Glycemic Control: Systematic Review and Meta-Analysis

Background: It is undeniable that diabetes may cause several health complications for the population. Many of these complications are associated with poor glycemic control. Due to this, strategies to handle this problem are of great clinical importance and may contribute to reducing the various complications from diabetes. Objective: The aim of this study was to compare the effectiveness of the passion fruit peel flour versus turmeric flour on glycemic control. Methods: This is a systematic review and meta-analysis following the PRISMA protocol. The following inclusion criteria were applied: (1) Case-control studies, cohort studies, and clinical trials, due to the improved statistical analysis and, in restrict cases, cross-sectional studies; (2) Articles published in any language. The databases used for the search were PubMed, Scopus, Web of Science, Cochrane, and LILACS. A bias analysis and a meta-analyses were undertaken using R Studio (version 3.3.1) using effect- size models. Results: A total of 565 studies were identified from which 11 met the inclusion and exclusion criteria. Through isolated analysis, the effectiveness of turmeric flour on glycemic control was in the order of 0.73 CI (Confidence Interval) (from 0.68 to 0.79) and the effectiveness of passion fruit peel flour was 0.32 CI (0.23 to 0.45). The joint analysis resulted in 0.59 CI (0.52 to 0.68). The assessment of blood glucose was by glycated hemoglobin levels. All values were significant at a p < 0.05 level. Conclusion: Both interventions showed significant effects on glycemic control.