From New Orleans, at a meeting of the American Heart Association
Previous studies have suggested that people who drink several glasses of black tea each day are less likely to develop heart disease than are people who don't drink tea. Joseph A. Vita of the Boston University School of Medicine reports that he may have found a mechanism for tea's apparent protective effect.
In a study, Vita found that drinking black tea increases the ability of the blood vessels in a person's arm to dilate. Blood vessel dilation is hampered in people with atherosclerosis—or stiff and clogged arteries—and this condition can trigger heart attacks and strokes.
Vita used a blood pressure cuff to constrict and then release blood flow in 50 middle-age men and women with atherosclerosis. He found that when the volunteers drank two 8-ounce cups of black tea, their blood vessels immediately improved their ability to respond to changes in blood flow.