Scientists from Tongji Hospital and other institutions have found that drinking green tea may strongly reduce blood pressure.
The study, led by Renfan Xu and colleagues, was published in Medicine (Baltimore).
High blood pressure, or hypertension, occurs when blood flows through the arteries at higher-than-normal pressure. Blood pressure is measured using two numbers: systolic and diastolic.
- Systolic pressure is the force exerted on artery walls when the heart pumps blood out.
- Diastolic pressure is the pressure between heartbeats, when the heart relaxes and fills with blood.
For most adults, normal blood pressure is below 120/80 mm Hg. Hypertension is diagnosed when systolic pressure consistently reaches 130 mm Hg or higher, or when diastolic pressure is 80 mm Hg or higher.
Green tea is widely consumed as a beverage and is also available as a dietary supplement.
It is often promoted for benefits such as improved mental alertness, relief of digestive discomfort and headaches, and support for weight loss. Green tea and its key compounds—particularly epigallocatechin-3-gallate (EGCG)—have also been studied for their potential protective effects against heart disease and cancer.
Previous research has suggested that green tea may help lower blood pressure. In this new review study, researchers assessed the overall impact of green tea supplementation on blood pressure control. They analyzed findings from 24 clinical studies involving nearly 1,700 participants.
The results showed that green tea intake produced significant reductions in both systolic and diastolic blood pressure. The researchers also found no strong evidence of publication bias, suggesting the results are reliable.
Overall, the team concluded that green tea strongly reduced systolic and diastolic blood pressure over short-term intervention periods. However, they note that larger and longer-duration studies are needed to confirm these findings and understand the long-term effects of green tea supplementation on blood pressure.
