Dr. Tim Says...

From My Inbox (on Coumadin) …

April 24, 20006

I receive a great deal of email from readers who take Coumadin® (warfarin). For those of you who aren't aware of it, warfarin is prescription medication taken orally. Its purpose is to reduce the clotting ability of the blood. People who have had blood clots form in their legs (known as Deep Vein Thrombosis or DVT) take Coumadin. Sometimes the DVT will break loose and the clot will travel to the lungs (this is known as a Pulmonary Embolus or PE).

There are a number of other conditions that we use warfarin for, including irregular heart beats like Atrial Fibrillation, and some doctors use this in cases of stroke.

Diet can have an effect on how well Coumadin works in the body. The issue has to do with the amount of Vitamin K in the diet of those taking the medication. Vitamin K changes how well blood clots and the result is that it decreases the effectiveness of warfarin.

We need Vitamin K in our diets, however. Most foods have some Vitamin K, but there are a few that have a lot of it. Canola and soybean oils are higher in Vitamin K, for instance, but one would have to use a whopping 2/3 cup for it to be a problem. To be on the safe side, however, using olive oil or grapeseed oil are great alternatives.

Patients ask about coffee and tea all the time and in low doses both of these are safe.

When asked about foods that contain Vitamin K, the quick answer is “green leafy vegetables.” Unfortunately, these are the foods that are so good for us and the ones that we have been told to eat all our lives. The best way to deal with this is to eat about the same amount of these each day. Here's a list:

Bibb lettuce
Broccoli
Brussels sprouts
Collard greens
Endive
Green onion
Green pepper
Kale
Mustard greens
Parsley
Red leaf lettuce
Spinach
Swiss chard
Turnip greens
Watercress
White cabbage

The herbs chives and cilantro (coriander) have a lot of Vitamin K but they shouldn't be an issue unless you are going to eat a lot of either. Used as garnish they don't contain much Vitamin K.

There are other foods to consider. Mayonnaise can be an issue because it is usually made with corn or soybean oil. On most lists mayo is in the “medium” category but the measurement is for 2/3 cup (as with the soybean and canola oil). A tablespoon or occasionally two shouldn't be a problem. There are some on the market made with corn oil, but they can be harder to find.

Many stick margarines are made with soybean or canola oil but it's easier to find spreads that are made with other oils (and stick margarine is something to avoid anyway because of the trans-fats). Look for spreads made with corn oil.

Green apple peel has Vitamin K as well (eat red apples). Asparagus, celery, iceberg lettuce and okra have a moderate amount.

By eating a consistent amount of these, or the other veggies listed above, the intake of Vitamin K is stable and won't have as much of an effect on how well Coumadin works.

Eat well, eat healthy, enjoy life!

Dr. Gourmet

Last updated: 04/17/06