Black Tea Helps Arteries Expand

Studies have shown that people who drink at least one cup of black tea per day have a lower risk of heart disease and stroke, but until recently no one understood why. A small study at the Boston University School of Medicine indicates that tea may work directly on blood vessels that have lost elasticity by restoring the vessels' ability to expand when the pulse rate increases.

In an eight-week study, a small group of heart patients drank four cups of either tea or water each day. Researchers inflated and deflated a blood pressure cuff to increase blood flow in each volunteer's arm, then used ultrasound to measure the dimensions of blood vessels. Tea drinkers showed improved artery function. The Boston group speculates that the flavonoids, natural compounds that give tea its flavor, act as antioxidants to protect the lining of the blood vessels.