Warfarin diet: what food affect my INR?
There are a number of natural supplements and food products, which may affect the level of warfarin in different ways. For example, research has shown that the popular herbal product with ginseng may decrease the effects of warfarin, Ginkgo biloba may increase its effects. Both of these changes represent a health risk, since the effect of warfarin on the blood clotting must remain stable in the blood system to be safe and effective.
Vitamin K and warfarin
Vitamin K is known to have reducing effects on the level of warfarin and food with a high content of vitamin K are e.g. liver, broccoli, Brussels sprouts, and green leafy vegetables (such as spinach, chard, coriander, kale and cabbage). If you are taking warfarin, you should avoid abrupt changes in the daily intake of these foods.
There have also been reports from the UK about the possible interaction between warfarin and cranberry, so patients taking warfarin were advised to limit or avoid drinking cranberry juice.
Over time, scientists will undoubtedly discover new information about products, which can affect warfarin. To date, there is evidence that these herbal, vitamin and mineral products may change levels of warfarin in the bloodstream or may directly affect blood clotting themselves:
- Chondroitin and glucosamine
- Coenzyme Q10 – also known as ubiquinone, ubidecarenone
- Devil’s claw (Harpagophytum procumbence)
- Dong quai – also known as Danggui, Chinese Angelica (Angelica sinensis);
- Supplements with fish oil containing eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA)
- Ginkgo biloba
- Ginseng (Panax ginseng)
- Green tea (Camellia sinensis)
- Buckeye (Aesculus hippocastanum)
- Lycium barbarum – also known as Chinese berries, Di Gu Pi, goji berry, Gou Qi Zi
- Papaya extract (containing papain)
- St. John’s Wort (Hypericum perforatum)
- Vitamin A
- Vitamin K
- Wintergreen (applied to skin) – also known as methyl salicylate.
These foods are also proven, that may affect warfarin levels:
- Cranberry juice
- Flax seeds (linseed)
- Seaweed (sushi)
- Soy protein products (including soy milk and tofu)
What is warfarin diet?
In the past doctors and pharmacists warned that when taking warfarin, you need to adhere to the diet, which involved restriction to exclusion of vegetables containing higher amounts of vitamin K – so called Warfarin diet. Today modern medicine says that the recommended daily intake of vegetables should not adversely affect the interaction between the two substances. Additionally, absorbency and utility of vitamin K in the body of vegetables is not large and therefore not reflect tabular data on the content of vitamin K in various kinds of vegetables. It should be emphasized the fact that the vegetables contain essential vitamins and minerals and many other nutritionally important factors that are important in the prevention of cardiovascular disease or cancer. Warfarin diet means finding a balance in daily eating vegetables without major fluctuations in amount.
Lege artis practice is getting regularly tested on your INR, adjust the current dose of warfarin and thus simultaneously ensuring the effectiveness and safety of treatment, without having to reduce the intake of vegetables. The only advice is to avoid a sudden, extreme changes in the amount of vegetables eaten. Alcohol should conversely be minimized because it may increase the effect of the drug, leading to increased risk of bleeding.
What is the average alcohol content in alcoholic beverages?
• Beer has an average of from 3.5 to 5.5% of alcohol,
• Dark beer 3.5%
• Champagne 12%
• White wine 12%
• Red wine 10-15%
• Port wine 20%
• Gin 38%
• Baileys 18%
• Whisky 40%
• Vodka 30% and more
• Plum 40%
• Homemade plum brandy 52%
This means that the least risky alcohol is a beer. Alcohol consumption up to about 12% in a day should be relatively safe, i.e. 0.5 litres of beer or 2 dcl wine. But that’s only if you know your current INR, your INR results are stable and you consult it with your doctor.
Hard alcohol should be avoided in any case. Bleeding complications with warfarin are dangerous and very real, so do not underestimate this risk. Risk of bleeding is increased also by other factors – here you can try to calculate your risk (calculator). Avoiding alcohol generally, contribute to the security of your treatment. Your doctor knows your individual condition, therefore first of all always consult everything with your doctor.