WASHINGTON (Reuters) - Dark chocolate can not only soothe your soul but can lower blood pressure too, researchers reported Monday. The study, published by the American Heart Association, joins a growing body of research that show compounds found in chocolate called flavonoids can help the blood vessels work more smoothly, perhaps reducing the risk of heart disease. "Previous studies suggest flavonoid-rich foods, including fruits, vegetables, tea, red wine and chocolate, might offer cardiovascular benefits, but this is one of the first clinical trials to look specifically at dark chocolate's effect on lowering blood pressure among people with hypertension," said Jeffrey...