At the Cosmic Cafe in Dallas, patrons enjoy a variety of healthy vegetarian dishes.
Many customers wash it down with a cup of green tea.
Green tea is rich in vitamin K. Vitamin K is important for healthy blood and clotting. But U.T. Southwestern Medical Center nutrition researcher Dr. Margo Denke says that for tens of thousands of people taking common prescription blood thinners like coumadin, the benefits of green tea turn to health risks. Blood clots often lead to strokes or heart attacks. High concentrations of vitamin K are also found in dark green vegetables like broccoli. Dr. Denke has been documenting dangerous interactions with some common foods.