How Does Your Diet Affect Warfarin?
How Diet Affects WarfarinWarfarin is an anticoagulant (blood thinner) medication used to prevent blood clots. It works by interfering with the body's ability to form clots.
Warfarin is a potent medication with a narrow therapeutic index, which means there is a small window between effective and toxic levels. The dose of warfarin required to achieve the desired effect can vary significantly from person to person. This is due to a number of factors, including age, weight, diet, and other medications.
Diet can affect the effectiveness of warfarin by altering the absorption, metabolism, and excretion of the drug.
Foods that can increase the effects of warfarin:
- Green leafy vegetables: These vegetables contain high levels of vitamin K, which is an essential nutrient for blood clotting. Eating large amounts of vitamin K can reduce the effectiveness of warfarin.
- Other foods high in vitamin K: kale, spinach, broccoli, Brussels sprouts, asparagus, collard greens, mustard greens, turnip greens, parsley, soybeans,納豆(natto)
Foods that can decrease the effects of warfarin:
- Foods high in vitamin C: These foods can increase the breakdown of warfarin, reducing its effectiveness. Grapefruit juice is especially potent and can significantly increase the risk of bleeding in people taking warfarin, this effect lasts up to 7 days after consumption.
- Garlic/Garlic Supplements: Garlic can significantly increase the effects of warfarin and increase your risk of bleeding. This effect lasts up to 7 days after consumption.
- Cranberry juice: This juice can increase the breakdown of warfarin, reducing its effectiveness.
Other factors that can affect warfarin levels:
- Other medications: A number of medications can interact with warfarin, including aspirin, ibuprofen, naproxen, celecoxib, and phenytoin.
- Alcohol: Alcohol can increase the effects of warfarin, increasing the risk of bleeding. If you are taking warfarin, limit alcohol intake to two drinks per day.
It is important to talk to your doctor or pharmacist about how your diet and other medications may affect your warfarin levels.