Several recent studies on people suggest that one way black tea may help reduce risk of heart disease is by helping to maintain healthy function of the endothelium, the inner lining of all blood vessels, such as arteries and veins. When endothelial function is impaired the capability of blood vessels to expand and contract is decreased. A decrease in the ability of the blood vessels to expand and contract contributes to development of cardiovascular disease and is associated with higher rates of acute medical events in heart disease patients. A recent study published in the medical journal Circulation, of 60 patients with coronary heart disease who drank 4 cups of black tea daily for four weeks showed significant improvement in impaired endothelial function. This effect was seen as early as two hours after drinking 2 cups of black tea as well as was sustained after drinking 4 cups of tea per day for four weeks (44). These results show that tea had both an immediate benefit as well as a longer term benefit on blood vessel function. This beneficial effect also has been seen in two other studies in healthy volunteers. One of these studies with healthy volunteers found that drinking 4 cups of black tea each day for 4 weeks improved endothelial function by 41% (45). A second study found that drinking a cup of black tea enhanced the ability of arteries in the heart to expand and increase blood flow by 15% (46). Taken together, these clinical trials suggest that regularly tea drinking as part of healthy diet may help maintain cardiovascular health by improving endothelial function.

*While tea is a naturally rich source of antioxidants, it is not a substitute for fruits or vegetables which provide a wide range of antioxidants and essential vitamins and minerals. Please consult your doctor regarding a diet/nutritional plan that is right for you.