Black tea helps in blood circulation

A recent study shows that a cup of black tea may give a quick boost to blood flow to the heart. Numerous studies have suggested that tea drinking may do a heart good, with effects on cholesterol, blood clotting and blood vessel function being among the proposed mechanisms. Researchers from the Osaka City University, Japan, in an experiment with 10 healthy men, found that blood-flow in the coronary arteries improved two hours after the men drank black tea. The same was not true of a caffeinated drink used for comparison. The study suggests a more immediate beneficial effect. The authors believe that black tea improved the widening of the blood vessels of the heart, allowing better blood flow. Tea is rich in antioxidant compounds called flavonoids, and these may be the key to the potential heart benefits of tea. For the study, the researchers used a special ultrasound method to gauge coronary flow velocity reserve (CFVR). This reflects how much blood-flow can speed up when demands are put on the heart, and shows the healthiness of the coronary circulation. The researching team measured the CFVR of each men after they drank either black tea or a caffeinated beverage, and found that it increased significantly after the black tea. The results of this study suggest that black tea consumption has a beneficial effect on coronary circulation. The researchers speculate that the flavonoids in black tea improve the functioning of the lining of the blood vessels, increasing the widening of the vessels in response to demand.