The effects of capsinoids and fermented red pepper paste supplementation on Glycemic Control: A systematic review and meta-analysis of randomized controlled trials.

OBJECTIVE: The present systematic review and meta-analysis were conducted to investigate the effects of capsinoids supplementation on glycemic control.

METHODS: Relevant studies, published up to May 2020, were searched through PubMed/Medline, Scopus, ISI Web of Science, Embase, and Google Scholar. All randomized clinical trials investigating the effect of capsinoids supplementation on glycemic control were included.

RESULTS: Out of 326 citations, eight trials with nine effect sizes, that enrolled 530 subjects were included. Capsinoids and red pepper resulted in no significant reduction in glucose (Weighted mean differences (WMD): -0.27 mg/dl; 95% CI: -1.9 to 1.37, P=0.75), insulin (WMD: -0.09 µU/mL; 95% CI: -1.76 to1.57, P=0.913), homeostatic model assessment for insulin resistance (HOMA-IR) (WMD: 0.52; 95% CI: -0.29 to 1.32, P=0.208), and hemoglobin A1C (HbA1C) (WMD: 0.01 %; 95% CI: -0.04 to 0.05, P=0.712). Greater effects on glucose were detected in trials performed on both gender, using red pepper, lasted ≥ 12 weeks, and participants aged >40 years old and recruited greater sample size >50. Insulin and HOMA-IR were reduced by using red pepper.

CONCLUSION: Overall, these data suggest that capsinoids and red pepper supplementation did not have beneficial effects on glucose, insulin, HbA1C, and HOMA-IR but significantly reduce glucose in people older than 40 years.