The effects of green coffee bean extract on blood pressure and heart rate: A systematic review and dose-response meta-analysis of randomized controlled trials

Background and aims The existing literature on the effects of green coffee bean extract (GCBE) consumption on systolic blood pressure (SBP), diastolic blood pressure (DBP), and heart rate (HR) is equivocal. This study aimed to summarize the effects of GCBE consumption on SBP, DBP and HR in adults. Methods Data were pooled using a random-effects model and expressed as weighted mean difference (WMD) and 95% confidence intervals (95% CIs). Results Out of 1624 records, 10 studies that enrolled 563 participants were included. GCBE consumption significantly decreased SBP (WMD: -2.95 mmHg; 95% CI: -4.27 to -1.62; p < 0.001) and DBP (WMD: -2.15 mmHg; 95% CI: -2.59 to -1.72; p < 0.001). However, there was no significant effect on HR (WMD: -1.20 bpm; CI: -2.93 to 0.51; p = 0.170). Subgroup analysis showed that GCBE consumption had a more significant effect on SBP and DBP in participants with high SBP and DBP and had no effect on blood pressure in females. Linear and non-linear dose-response analyses were conducted to find the optimum GCBE dosage and duration of intervention. However, no significant associations were observed for SBP, DBP, and HR in linear meta-regression and non-linear dose-response based on the dose and duration of the intervention. Conclusion GCBE has the potential as a hypertension-reducing supplement in hypertensive patients. However, GCBE did not significantly change HR.