In one study, Australian researchers examined the blood pressure of 95 male and female tea drinkers. First, all three cups were given black tea a day for four weeks. Thereafter, they were divided into two groups. Some were about 6 more months still tea, the other a caffeinated drink that tasted like tea though, but that did not include the typical for the tea ingredients such as flavonoids.
Three cups of tea a day for six months lowered their blood pressure by 2 to 3 millimeters of mercury (mmHg). That sounds like a lot at first not at first. According to scientists, but even such a small change in blood pressure has been a major influence on vascular health: How would already with a reduction in blood pressure of 3 mm Hg, the risk for cardiovascular disease decrease by 7 to 10 percent.
The experts suggest that the black tea acts primarily on the blood vessel walls. Factors are released from the vessel walls, which can relax the muscles and the blood vessels that provide far. Thereby, the decrease of blood pressure . In previous studies, the scientists showed that flavonoids from black tea, these factors have a positive effect.