**4. Tea and blood pressure**

Hypertension is a multifactorial clinical condition characterized by constant elevation of systolic blood pressure (SBP) levels ≥140 and/or diastolic blood pressure (DBP) ≥ 90 mmHg. It is often associated with metabolic disorders and functional and/or structural changes in target organs, aggravated by the presence of other risk factors, such as dyslipidemia, abdominal obesity, glucose intolerance, and T2D [34]. Hypertension is one of the leading risk factors for CVD, and it is a major cause of premature death worldwide; it affects about 1 billion people worldwide [34].

Tea flavonoids can reduce the risk of hypertension and consequently the risk of CVD [9, 35]. Catechins act as antioxidants and vasodilators and inhibit endothelial dysfunction and thrombogenesis [9, 36]. Catechins might reduce blood pressure by enhancing nitric oxide signaling [9]. The health benefits of tea for blood pressure were demonstrated in healthy subjects, diabetic subjects, and obese and/or hypertensive subjects [37]. Clinical trials showing the effect of tea on blood pressure are summarized in **Table 2**. It should be noted that several factors may influence the effect of tea consumption on blood pressure such as the duration and frequency of consumption, dosage, tea bioactive compounds, the evaluated population, and the degree of hypertension [37].
