Do you drink green tea?

Hi, everyone. I have a question about green tea. Ever since getting breast cancer a number of years ago, I have been drinking green tea in hopes that there might be positive benefits in doing so. When a-fib came in Jan 2016 I stopped drinking it at the advice of my pharmacist. Does anyone on this forum drink green tea and if so, how often? I suppose consistency is the important thing. The below article suggests that HOW it is brewed, makes a difference as to how much vitamin K you might consume. Thanks for your thoughts...

Here's part of the article:

Interactions with Warfarin?

There is little to no evidence of an interaction between green tea and warfarin. Green tea does contain caffeine as well as moderate quantities of vitamin K; which may lead to a decrease in INR (International Normalized Ratio). But, brewed green tea contains low amounts of vitamin K, approximately 0.03 micrograms (ug) of vitamin K per 100 gm of brewed tea.8 The actual concentration of vitamin K in brewed tea will depend on the amount of leaves brewed and the dilution of the tea leaves.9

If you plan on drinking green tea for any of the above benefits, consuming a consistent amount of vitamin K per day will help your INR to remain in range. As always, talk to your doctor about any changes to your diet, medication or supplements.

Here's the whole page if interested in reading further:

24 Replies

  • I don't drink green tea because of its caffeine content.

  • Hiya, I have just done a post on reducing the amount of caffeine in your tea and coffee, so won't put all the info here.

    CDreamer pointed out in a reply that the Japanese throw away the first brew of the tea, (which is what I do to keep down the caffeine and diuretic effect).

    So you could do that, i.e. brew for 2 minutes, throw the water away, brew again. I do that with 'normal' tea and it really works and still tastes good.

  • Thanks for your reply, boombiddy, and you suggestion is a good one.

    I should have specified decaffeinated green tea in my post. I never drink the caffeine version. It's my understanding that the decaff has about the same benefits as that with caffeine.

  • I didn't know decaff was available!

  • Yup! Decaffeinated green tea has been my first choice of teas for quite a while. Here's a link of decaf teas:

  • Thanks

  • Hiya, I should've said, if you brew off the other things, you might also be getting rid of a significant amount of Vitamin K.

    Thinking about it, I wonder if the factory's decaffeination process also gets rid of some/all of the vitamin but I suppose there's no way of knowing...

    I was also wondering, it's such a tiny amount of leaves, so surely it can't be like eating a portion of cabbage/spinach/etc.?

    Green tea as far as I know will take several brewings, unlike 'normal' tea, so not using fresh leaves each time could also help keep down the K.

  • I agree, that drinking green tea can't be like eating cabbage, etc., if this is correct: Brewed green tea contains low amounts of vitamin K, approximately 0.03 micrograms (ug) of vitamin K per 100 gm of brewed tea.

    I think I'm going back to drinking green tea again! Yay!

  • Yay indeed, thrilled for you, a little bit of normality regained.

    By the way, where did you get your figures on the Vit K content of green tea? I really thought nobody would have done the research to establish this. Very impressed!

  • Check the link attached to my original post which will take you to the figures for vitamin K in tea.

    Tea has become a very popular choice of beverage. I've read where it is second to water but sure can't verify that! :-)

  • Thanks for the resource!

    In fact I am going away right now to toast your very good health, in tea!

  • Have you considered a NOAC instread of warfarin?? Then no worries re vitamin k.

  • Would love to switch from warfarin to an NOACwhere we wouldn't have to be concerned with amounts of vitamin K we consume. So many vitamin K foods are an excellent choice of nutrition!!

    But because there is still not an effective method for stopping the bleeding for folks who are on an NOAC, I am sticking with warfarin.

  • Of course this is your choice. I personally believe it's a red herring as most bleeds can be stopped. Lots of stuff on here about this.

    My EP in favour and I have switched.

  • I recently visited with a surgical nurse who spoke of how difficult it is to stop bleeding in people who are on NOAC's vs those on Coumadin. (She was speaking of emergencies such as car accidents, falls, etc. ) According to her, stopping a bleed in people on warfarin is easy, versus those taking an NOAC.

  • I actually feel much much safer on Rivaroxaban than I did on Warfarin.

  • I, too, have an uneasy feeling between INR testing. 3 weeks is the most I will go; this last time, I asked for a 2 week interval and that is what I got. 2 weeks is long enough; too much at stake to go longer. The INR testing is one of the "negatives" for those who use is the vitamin K issue. :-(

    If the bleeding issue is resolved for the NOAC's, I will head that direction in a flash! The next time I visit with my EP cardiologist, I will definitely ask about bleeding/ NOAC's.

  • Sorry I edited out the bit about INR testing as I felt I'd said too much! I did find Warfarin unsettling as I could be sent off for weeks with an INR near the top of the therapeutic range. I once went 56 days - and had an INR of 3.7 at the end of it. Where else had it been all that time? I feel constantly protected on Rivaroxaban.

  • I used to drink green tea all the time until my GP told me to avoid it because it makes the heart race. I didn't know you could buy decaffeinated green tea either.

  • I also started drinking green tea after breast cancer diagnosis, and felt it was a healthy thing to do. Immediately after second mastectomy surgery I went into first episode of AF, and my heart has been irritable ever since and with regular AF episodes I've had to go on to the Decaff variety. Fortunately I'm on Apixaban and so have no interaction with Vit K, but thanks for the information, good luck x

  • Now that it's winter, I'm back on Breakfast (black) tea. In the warmer months I have green tea - Twinings with orange and lotus flower - and earlier in the year I had ceremonial grade Matcha. I wasn't taking any anticoagulant up until August but now I'm on dabigatran (Pradaxa). I do have decaf coffee at around 6 p.m. but normal tea during the day.

  • I managed to buy some Hawthorn tea. (Hawthorn is supposed to be good for AF) It is very weak, but does seem to calm my heart. Worth a try?

  • Sure, might be worth a try! I googled it and found this.... (I Google frequently but TRY to be careful to use (what I think to be) reputable sites.)

    Hawthorn, also known as may flower, is a dense, thorny bush related to the rose family that grows in areas with moist climates throughout the world. Hawthorn tea is most widely known for its medicinal uses and primarily for its cardiovascular applications. The active compounds are derived from the leaves, flower and fruits, which have an unpleasant odor and a slightly bitter taste. Many cultures throughout history have recognized hawthorn's heart-healing properties, including the ancient Greeks and Native Americans, according to Prior to using hawthorn tea medicinally, you should consult a physician.


    Decaffeinated Hawthorn:

  • Green or black may cut dementia risk

    . AARP, March 22, 2017

    I was re-reading what we had said about drinking tea/afib. This article was in my email today, and I thought it would add to our (old) discussion of tea consumption. Here's another good reason to drink tea!

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