Goitrogens and Fatigue / Worsening Symptoms - Thyroid UK

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Goitrogens and Fatigue / Worsening Symptoms

canyouhearmeaya profile image

Currently waiting on my medicheck thyroid bloods back, as suspect hypothyroid for many reasons.

One interesting observation I made lately that after certain meals I was getting SUPER fatigued and brain fogged, I would eat and then within 5-10 minutes I'd be totally exhausted. I played around with different foods to see if there was something that seemed to be causing it, carbs, no carbs, meat, no meat etc...

Turned out to be brocolli and kale.. After doing some research, I found that these foods are goitrogens and if you have impaired thyroid function, they can cause worsening of this.

Has anyone experienced this? As soon as I removed them from meals, the fatigue and brain after eating stopped - it was like night and day. I did wonder if it was placebo effect, but the difference was so profoundly different it seems incomprehensible.

Can goitrogens really cause that much of an effect, and that quickly? (5-10 minutes after consumption.)

16 Replies

Yes. But my problem foods weren't broccoli and kale, I could eat them ok. For me it was strawberries, walnuts, corn and soy. Even in tiny weeny quantities. So, yes, goitrogens can cause that much of a problem, and pretty rapidly, too. Once you start thyroid hormone replacement, and no-longer rely on your thyroid for your main supply of hormone, you should be able to eat them again. :)

It's crazy isn't it. Almonds too, used to eat a LOT of them at some stages in my life.

For one period, I ate them 3x a day (with each meal) 7 days a week, for about 6-7 weeks.

One day, I was at work and I suddenly felt FLAT, just all my emotion gone, and my hands were FREEZING cold. To this day I've never understood what happened, on that day, and the symptoms seemingly passed... I wonder if my thyroid effectively 'crashed', because of continous consumption of almonds?!

It wouldn't have crashed, but it could have run out of iodine, and therefore been unable to make more hormone. And, the symptoms will certainly pass unless you continue eating large quantities day in day out.

Goitrogens impede the uptake of iodine by the thyroid gland. If this goes on for long enough, you can develop a goitre, as the thyroid expands to try and absorb more iodine. But, things go back to normal when the goitrogen consumption ceases. And, this doesn't just happen to hypos. I can happen to anyone who consumes inordinate amounts of goitrogenic food.

Interesting. I have a tendency to eat repetetive meals.. so recently I'd be eating kale and brocolli 2-4x a day, for weeks on end. Never thought eating brocolli and kale like that could have been a problem - lol!!

Well, maybe it was a blessing in disguise, as it's helped me to *hopefully* diagnose this condition, which has been plagueing me for so many years of my life.

When goitrogenic foods have this effect it indicates an iodine deficiency. This is likely to be exaggerated when commencing levothyroxine as a result of being hypothyroid, as this speeds up the metabolism and the body needs more iodine and more thyroid hormone. Oxidised fat has a similar effect and ground almonds are very much worse than whole almonds for this reason. It is worth getting ones iodine levels tested to see if supplementation is necessary. If supplementation is necessary then start with a very low dose 150ug initially. If this is the problem and iodine levels are increased the problem with goitrogens will be reduced/eliminated.

So is it possible for 10+ years I've just had a defiency? Could there be an underlying reason?

Seems odd to have that when I eat a lot of meat, vegetables etc?

Are there underlying conditions that can cause the body not to retain iodine properly ?

Also, if I were to use t3 temporarily, does that also deplete iodine?

My t4 leaves are mid range so seem to be likely a conversion issue / low t3 (waiting for bloods to confirm)

Iodine is no longer in salt or bread so even with a good diet it is possible to be deficient.

If there has been a history of bowel issues or the requirement for excessive use of laxatives this can also deplete mineral levels. If you have ever taken the antibiotic ciprofloxacin this too will deplete iodine and magnesium levels. Anaesthetics can cause depletion also as can antidepressants.

It would be worth getting you levels checked. Bio labs uk provide this test. Or just to see if it helps try 150 ug per day for a few days and see if you notice a change, then read up everything you can about this subject.

Other symptoms of iodine deficiency will show up eg the feeling of being hung over If: prescribed a high dose fluoride tooth paste from the dentist, eating any processed foods which contain poor quality oxidised fats, or preservatives, consuming raw brassicas or using rapeseed or soy oils etc

If your thyroid levels are low then treatment with thyroid hormones is required.

If the cause of thyroid issues is iodine it may possibly correct itself however this will take time , a long time, and your thyroid hormone levels will need to be maintained meanwhile. However, the ability to eatbrassicas should be restotred fairly quickly probably within a week or two.

helvella profile image
helvellaAdministrator in reply to Jeanrwhaley

Iodine is no longer in salt or bread so even with a good diet it is possible to be deficient.

Was iodine (or iodine compounds) ever used as a conditioner in UK and/or EU bread?

Iodised salt has never been common in the UK. It is still available.

Maybe it hasn't, I've never seen it, I did look in the shop the other day and couldn't see any mention of it on any brand of salt.

helvella profile image
helvellaAdministrator in reply to canyouhearmeaya

Cerebos Extra Fine Iodised Table Salt (400g)

Ocado 95p 23.8p / 100g

Sainsbury's 95p

Waitrose 95p


Other makes have been available elsewhere.

Ah okay, I only looked in Tesco. Certainly isn't commonplace here!

What are the usual culprits of a long term iodine defiency? Are some people just genetically prone to it?

helvella profile image
helvellaAdministrator in reply to canyouhearmeaya

The most common reason seems to be inadequate iodine in diet!

We actually get quite a bit of our iodine from dairy. It used to be common to use an iodophore teat disinfectant when milking - and some of that would enter the milk supply. On top of the iodine already present in milk. There has been a widespread change to other teat disinfectants - I was told by a goat farmer that it is gentler! And consumption of milk has fallen.

Somehow we have managed to also eat less sea-fish... another significant source.

Put it altogether, we have lower iodine intake than we used to - in the UK.

On the other side, a significant number of products in Aldi and Lidl are manufactured using iodised salt - indeed some other German and Polish manufacturers do as well.

Interesting. I have cut my dairy intake over the last year to virtually nil, so maybe that factors in.

Although I must admit, even when I used to consume dairy daily, the problem was still present.

I need to wait for my results, but I'm confident that for one reason or another, my conversion from T4 to T3 is the problem.. And my next job will be to figure out why. (My TSH is 1.1 and T4 is 15 (10-22 range) which I understand is an okay reading. Waiting on full panel results.

But having looked back at my life, and things that are associated with reducing T4 to T3 conversion, it's pretty evident now as to why during those periods my symptoms got worse..

When you say iodine deficiency is the main cause... I thought Hashimotos was the main cause for most people? Or can hashimotos CAUSE the iodine deficiency?

I've ordered some T3, my results won't be back for another week or so but I'm tempted to give the T3 a go at 25mcg ED when it arrives Wednesday or Thursday. I'm almost certain that i'm going to be one of those people that suddenly feels drastically better after taking it.

My hope then if that is the case, was to continue using T3 and do further testing to try and figure out what the underlying cause is in the first place e.g. iodine defiency, MHTFR mutation etc.

Using T4 doesn't seem logical if my TSH and T4 are in range, as it suggests the problem is likely to be a conversion issue, is my logic correct there? Especially if the issue has been going on 10+ years and my T4 and TSH are still coming back good?

helvella profile image
helvellaAdministrator in reply to canyouhearmeaya

What are the usual culprits of a long term iodine defiency?

I read that as asking what are the causes of long term iodine deficiency. :-)

Yes - autoimmune issues are the cause of most hypothyroidism in the UK and USA.

Giving up smoking is often thought to be behind thyroid issues being identified. There are several ideas - whether smoking masks the issue, or causes it, is not entirely clear.

Yes - your FT4 is in range. But the range is wide and exactly where in range you as an individual need to be is not clear.

Smoking definitely correlates for me. Funnily enough, at the end of last year I was in Peru and smoked a lot of Mapacho, which is pervuain Tobacco. Nicotina Rustica. It contains 10-20x the amount of Nicotine of the tobacco over here.

And funnily enough, during that period my symptoms especially with mood and energy did improve, I brought some back with me but ran out. When I went back to UK tobacco, I declined a bit, and then I quit smoking I got much worse.

So it would seem that nicotine plays some role in this. The fact that my symptoms go back beyond smoking, to me would suggest that the tobacco may not be casual, but rather something hypothyroid patients may do (without realising) to self-medicate. But maybe it can also be causal too, paradoxically - not sure the research has been done.

My B12 and Vitamin D came back at top end of the range, don't know about other minerals yet until the full tests come back.

Are there many scenarios where taking T3 is 'risky'? As I'm feeling so run down/exhausted lately, that even waiting 10 days for my results to come back seems too much! I really am tempted to just give the T3 a go when it arrives this week prior to my results - but my only apprehension is if there may be scenarios where that could be a bad move?

helvella profile image
helvellaAdministrator in reply to canyouhearmeaya

Your comment about self-medicating by nicotine is, in my view, a distinct possibility. Why do some people find it so easy to get addicted to nicotine and so difficult to quit?

If you look through deaths caused by medicines - thyroid hormones - T4 and T3 - scarcely get a look in. Not that that cannot be dangerous - but most of the time the excess taken is modest, and the patient will stop taking them if they feel bad.

We do see the odd person who is massively over-dosed, but unaware. There is some difficulty in that some symptoms (e.g. palpitations) occur in both under- and over-dosed states.

Having said that, going from nothing to 25 micrograms of liothyronine because you have convinced yourself that it will work seems a touch, umm, foolhardy. May I suggest splitting the tablets to start with? Take it slowly. Very slowly.

You might consider taking B3 in one form or another. Nicotinamide. Does it help in post-quitting situations? Maybe, maybe not.

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