The ingredients in the tea are believed to weaken the effects of caffeine and may even lower blood pressure. The researchers decided to test this. They gave the volunteers black and green tea and took their blood pressure after half an hour and an hour later. In addition, 13 high blood pressure patients were given five cups of tea a day for a week. In some cases, this beverage has been replaced with a dose of caffeinated water.
Both types of tea appeared to increase blood pressure 30 minutes after drinking more than caffeine.
Source: Ferra
