Across 4 studies, 3 reported beneficial effects on diastolic blood pressure, with effect sizes predominantly small. The most robust study, a meta-analysis of 821 participants, showed a moderate reduction (MD -3.42 mmHg), while another meta-analysis found a small significant reduction (WMD -1.09 mmHg); one meta-analysis reported a neutral effect. Median study duration was 90 days, and evidence applies to healthy adults or those at high risk of cardiovascular disease.
Caveats: One 2025 meta-analysis found no significant effect (SMD -0.24, p=0.53), and the two significant meta-analyses showed considerable heterogeneity (I²=74%). The clinical significance of the observed small reductions is uncertain. Doses varied widely and no specific form was assessed across studies.
Adverse events were measured in five trials and included a diagnosis of prostate cancer, hospitalisation for influenza, appendicitis and retinal detachment but these are unlikely to be directly attributable to the intervention.
from: Green and black tea for the primary prevention of cardiovascular disease.Adverse events were measured in five trials and included a diagnosis of prostate cancer, hospitalisation for influenza, appendicitis and retinal detachment but these are unlikely to be directly attributable to the intervention.
from: Green and black tea for the primary prevention of cardiovascular disease.Adverse events were measured in five trials and included a diagnosis of prostate cancer, hospitalisation for influenza, appendicitis and retinal detachment but these are unlikely to be directly attributable to the intervention.
from: Green and black tea for the primary prevention of cardiovascular disease.Adverse events were measured in five trials and included a diagnosis of prostate cancer, hospitalisation for influenza, appendicitis and retinal detachment but these are unlikely to be directly attributable to the intervention.
from: Green and black tea for the primary prevention of cardiovascular disease.DBP: MD -3.42, 95% CI -4.54 to -2.30
Green tea reduced DBP (WMD: -1.09 mmHg; 95% CI: -1.67, -0.50; I² = 74.0%)
diastolic blood pressure (SMD: -0.24; 95%; P = 0.53)
green tea consumption was observed to have a beneficial impact on lowering both diastolic and systolic blood pressure