We know coffee affects absorption of levothyroxine doi.org/10.1089/thy.2007.0222 but there have been no studies showing a similar effect of tea. This new study doi.org/10.3389/fendo.2022.... shows that tea had a similar effect to coffee.
They identified 37 out of 2,000 patients for the trial. This suggests only 2% of patients need worry about tea or coffee affecting their levothyroxine medication. The authors feel the problem lies with tea and coffee affecting the dissolution of the tablets.
I usually take my levothyroxine and liothyronine with orange juice and no tea / coffee. When on holiday I often have a coffee a few minutes or so after taking my tablets and have not noticed a problem. It may be that I don't notice a fall in levothyroxine absorption because I take liothyronine. It could be that the acidity in the orange juice is sufficient to overcome the effects of coffee - I'm waiting for a combined orange juice / coffee study! (We all know combination therapy is better, including breakfast drinks).
I would urge people not to worry about this unless they have absorption problems.
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jimh111
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Do we have any clarity yet on what it is in the tea and coffee that affects thyroid medication? I know people have assumed it's the caffeine, and/or the addition of milk etc. But all teas and coffees are not created equal!
I usually take my T4 and T3 with black decaff coffee and do not seem to have a problem. if away i take with water but may have breakfast and coffee within 30 mins.
However, it looks like those in the study drank tea without milk.
The difference between a light far eastern type of tea, without milk, and "builders' tea" with loads of milk might well be greater, even much greater, that the difference between water and far eastern tea.
If I have tea the tea bag is dipped into the cup of boiling water for about 1 maybe 2 seconds . So I guess it can’t really be called tea🙃. I love the outcome anyway . 🙂
Same reaction when I was pregnant . Hormones again !
I believe it is the Tannin in tea that affects absorption and not just of levo but of Vitamins too. I never have anything to eat or drink for a whole hour after taking my Levo. I am not so fussy with my final 5mcgm lio in the evening!
You may be right about tannin. That would make tea a worse drink to consume (for medication absorption) than coffee, as apparently tea has a lot more tannin than coffee.
RedApple, I thought it was common knowledge. maybe showing my age but seem to recall it was advised not to drink tea with a meal but wait for a while after to ensure good absorption of vits etc.
That's not something I've ever been told (as far as I remember!). But I only drink tea with cake anyway which probably doesn't count when it comes to vitamins! 🤣
For levothyroxine at least the study shows tea and coffee have very similar effects.
Many people in China (and in UK in my youth) drink tea throughout the day so it doesn't seem to affect nutrition in general but it might affect medicines as they are not natural in the sense tablets are designed to be difficult to break down so the drug remains stable.
IMO (which might not align with anyone else's) studies like this are bricks in the "it can't possibly be your thyroid" patient-blaming wall. I take my thyroid meds when I take them and adjust according to how I feel and results. Day to day deviations (again, IMO) tend to even out over time.
It is less likely that people will adjust if they do not appreciate that they need to. If they get, say, a single 100 microgram tablet to take every day, so cannot readily make smaller changes. And if they do not feel the differences relatively quickly if they do make any changes.
If you are very aware, can get sufficient of whatever thyroid hormone in appropriate dosages, and notice quickly, it is far more achievable.
It's useful for patients whose fT4 fails to rise even though they are on an adequate dose of levothyroxine. Often in these cases the patient is blamed as in this recent study healthunlocked.com/thyroidu... .
This tea study is another example of how absorption can be affected by a common beverage. This is further evidence that in most cases the patient is innocent and unusual results as not due to noncompliance.
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