Effect of stevia on blood glucose and HbA1C: A meta-analysis

Background: The study investigates substituting non-nutritive sweeteners (NNS) for sugar to address health concerns related to excess sugar intake. It specifically examines how stevia affects insulin and blood glucose levels. The systematic review and meta-analysis aim to evaluate stevia's impact on glycemic indices. Methods: We conducted a systematic review and meta-analysis following PRISMA guidelines, including 26 studies with 1439 participants. The PROSPERO registration number for this research is CRD42023414411. We systematically searched PubMed (MEDLINE), Scopus, Web of Science, and Google Scholar. Additionally, we thoroughly reviewed the reference lists of the articles we extracted and relevant reviews. Two evaluators independently carried out screening, quality assessment, and data extraction. The GRADE (grading of recommendations, assessment, development, and evaluation) approach was utilized to evaluate the certainty of the evidence. Results: Stevia consumption was associated with significantly reducing blood glucose levels (WMD: -3.84; 95 % CI: -7.15, -0.53; P = 0.02, low certainty), especially in individuals with higher BMI, diabetes, and hypertension. Dose-response analysis revealed a decrease in blood glucose for >= 3342 mg/day of stevia consumption. Stevia consumption has been shown to reduce blood glucose levels within 1-4 months, as evidenced by dose-response analysis (less than 120 days) and subgroup analysis (more than four weeks). However, stevia did not significantly affect insulin concentration or HbA1C levels (very low and low certainty, respectively). Conclusions: Low certainty evidence showed that stevia improved blood glucose control, especially when consumed for less than 120 days. However, more randomized trials with higher stevia dosages are required.