Diet and Warfarin (Coumadin®)

If you are taking warfarin (Coumadin®), you have probably been cautioned not to eat certain things, but what are they? What can and can't you eat? The most sensible advice is to keep your diet consistent. The swings of intake, whether it is from vitamin K foods or other dietary items, can upset your gastrointestinal system, causing stomach upset and diarrhea, which may upset the balance of the warfarin concentration in your blood. You should avoid supplements and vitamins (most contain vitamin K, which decreases the action of warfarin). If you feel you must take these items, make sure you clear it with your health care provider first. Whether you decide to change your diet, become a vegetarian or lose weight, talk to your doctor first. Many things may affect the way warfarin works.

You should avoid alcohol while on warfarin. If your doctor approves a certain amount of alcohol, stick to that amount daily so that the levels of warfarin in your blood will remain consistent. Do not drink grapefruit juice or eat grapefruit. You should avoid cranberry juice and green tea as well as any ginkgo supplements.

There are certain vegetables that are rich in vitamin K, which may decrease the action of warfarin. They include: broccoli, Brussel sprouts, cabbage, green onions, asparagus, cauliflower, peas, dark leafy lettuce, spinach, greens (turnip, collard and mustard), parsley, kale, leeks, bean sprouts, okra, watercress and endive. Fruits which are high in vitamin K include: blueberries, kiwi, blackberries, and canned pumpkin. Some meats to avoid are beef, liver and pork liver. Other foods to avoid include: cashews, mayonnaise, canola oil, soybean oil, fresh cilantro, garlic and dried thyme.

This is not to say don't ever eat these things. But if you eat them, eat them consistently so that your blood level of warfarin stays the same. Make sure your doctor is aware of your diet. If you travel, try to stick to your home diet so that your blood level of warfarin isn't affected after your trip.