The effect of cinnamon supplementation on cardiovascular risk factors in adults: a GRADE assessed systematic review, dose–response and meta-analysis of randomized controlled trials

BACKGROUND: Numerous clinical studies have suggested that cinnamon supplementation may be effective for cardiovascular disease risk factors, but the findings are controversial. This comprehensive systematic review and meta-analysis aimed to assess the impact of cinnamon supplementation on cardiovascular disease risk factors. METHODS: Relevant studies were identified through electronic searches of databases, including Web of Science, PubMed, Central, Scopus, and Embase, up to July 2024. RESULTS: Forty-nine studies were included. Cinnamon supplementation significantly reduced WC (SMD = - 0.40; 95% (CI): - 0.73, - 0.06), DBP (SMD = - 1.04; 95% CI: - 1.54, - 0.55), SBP (SMD = - 0.85; 95% CI: - 1.54, - 0.16), fasting glucose (SMD = - 1.28; 95% CI: - 1.65, - 0.90), fasting insulin (SMD = - 0.26; 95% CI: - 0.50, - 0.02), HbA1c (SMD = - 0.71; 95% CI: - 1.02, - 0.40), HOMA-IR (SMD = - 0.54; 95% CI: - 0.82, - 0.26), postprandial blood glucose (SMD = - 2.28; 95% CI: - 3.48, - 1.08), CRP (SMD = - 0.78; 95% CI: - 1.28, - 0.27), LDL-C (SMD = - 0.71; 95% CI: - 1.02, - 0.40), total cholesterol (TC) (SMD = - 1.15; 95% CI: - 1.55, - 0.75), triglycerides (TG) (SMD = - 0.91; 95% CI: - 1.25, - 0.56), and MDA (SMD = - 0.76; 95% CI: - 1.07, - 0.45). Additionally, cinnamon supplementation significantly elevated HDL-C levels (SMD = 0.56; 95% CI: 0.23, 0.89). CONCLUSION: Cinnamon supplementation demonstrated significant benefits in improving cardiovascular risk factors. These findings suggest its potential as an adjunct therapy for improving cardiovascular disease risk factors.