Quercetin on foods are bad for hypothyroidism?

Hi everyone:

Recently i was diagnosed with hypothyroydism now i´m on levothyroxin 50 mcg, i´ve been reading about foods good and bad for hypothyroidism, i was reading that quercetin interfere with thyroid function, this compoud is present on onions, apples(i love apples and daily with my eggs i chop 1/4 of onion and some tomato), also much other vegetals and fruits contain it. I would know which is your experience with this foods being hypo?


24 Replies

  • where were you reading that? I take quercatin to stop trembling in excess Substance P

  • OMG that is scary, I shant be taking anymore and I am getting fed up with keep on logging in every time I come on here it is driving me BATTY!!!!!

  • Me too Pettals I have to log on everytime I want to read a post it is driving me mad.

  • I would question how much of these particular foods containing this compound you have to consume to actually have any effect?

  • Well it did say "...excessive intake..."

    If I tried to eat a bucket full of apples, I am sure I would be as sick as a dog.

  • This summary of quercetin doesn't mention thyroid:


    Quercetin is generally considered safe. Side effects may include headache and upset stomach. Preliminary evidence suggests that a byproduct of quercetin can lead to a loss of protein function. Very high doses of quercetin may damage the kidneys. You should take periodic breaks from taking quercetin.

    Pregnant women, breastfeeding women, and people with kidney disease should avoid quercetin.

    At doses greater than 1 g per day, there have been reports of damage to the kidneys.


    It does, however, reference this paper:

    Giuliani C, Noguchi Y, Harii N, Napolitano G, Tatone D, Bucci I, Piantelli M, Monaco F, Kohn LD. The flavonoid quercetin regulates growth and gene expression in rat FRTL-5 thyroid cells. Endocrinology. 2008;149(1):84-92.

    Whatever that says!

  • This is really interesting. I take Quercitin for my sinus problems and find it really helpful but didn't know much about it! Thank you 😊

  • ncbi.nlm.nih.gov/pubmed/244...

    I don't really understand this. Perhaps you could translate?

  • Basically flavonoids interfere with the process of t4 and t3, so disrupt thyroid function

  • What process are we talking about?

  • Neither of the PubMed.gov articles mention T3, just T4.

    Maybe that's another study that supports the prescribing of T3 rather than just T4......

  • I don't think either of them were talking about thyroid hormone replacement, but the effect of Quercitin on the thyroid gland itself.

  • I haven't a clue but as you are newly diagnosed (and welcome to the forum) there is a load of good advice on the Thyroid Uk site you may find interesting and things not to do so any think you are not sure of would take well away from your thyroid meds. I've not heard that before but so thank you for posting.

  • I would be VERY wary of this information. Quercetin is a mast cell inhibitor. Research over the last few years has found that many patients suffering from hypothyroidism have mast cell disorders that cause inflammation resulting in thyroid dysfunction amongst other things. Quercetin can be of assistance to many of these patients in reducing this inflammation. Mast cell disorders can become a problem following infections. This has been the case with my daughter and she is now being helped with natural remedies and medication. She eats lots of quercetin rich foods. To learn more you should read about the work of Dr. Lawrence Afrin who is the pioneer in mast cell disorders. He has a book called Never Bet Against Occam. Jane x

  • Thanks janeb15. You always have something informative to gift us and it's highly appreciated x

  • Thank you. x

  • This is really useful thank you janeb15. I think quercetin is great for most allergy sufferers, sinus issues and those of us with food intolerances (due to histamine intolerance). I'm going to seek out this book. I started eating a lot of ramen as a way of utilising some homemade broth at the beginning of this year using ginger, garlic, left over roast chicken, spring onions and watercress and some rice noodles (with a little bit of gluten free sweet chilli rather than soy sauce).

  • That sounds delicious! I always make lentil soup from leftover roast chicken with lots of onions, celery and carrots, but will try your suggestion. Ginger and garlic are a great favourite in my house. x

  • I eat lots of vegetables & fruit, & have noticed no difference in how I feel from eating goitrogens, aside from unfermented soya. Almonds, apples, onions, brassicas, etc, are part of my daily diet.

  • I don't have any adverse effects from eating onions or apples thatI can see or feel.

  • Not another substance to avoid. There are so many different health issues that many of us suffer from and each one has a list of foods to avoid, I really cannot keep up with it all, one says such and such are good for you and in another situation you should not eat/take them. I give up.

  • It seems to me that every other day, a new food is added to the list of foods that are said to be bad for the thyroid. If I avoided them all, I`d starve!

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