Blood-Thinners and Leafy Greens
Brand names: Coumadin and Jantoven. Generic name: warfarin
People who have had heart attacks or at a high risk of developing blood clots are sometimes put on warfarin, a drug that thins the blood so it can circulate more easily. Vitamin K, found mostly in leafy greens, can block the effects of warfarin, putting you at risk of developing a blood clot. That’s why experts recommend limiting leafy greens to a single serving a day—and eating the same amounts every day. Garlic and ginger, which can increase warfarin’s blood-thinning abilities, may be off the menu, too, along with cranberries (and cranberry juice), but check with your doctor or pharmacist to see how much is too much.
What you need to know: Greens that are particularly high in vitamin K are kale, spinach, collard, parsley, and Swiss chard. Green tea also contains this nutrient, so talk to your doctor if you drink it regularly.