Soy and Hypothyroidism

I've heard and read that soy may have a detrimental effect on the thyroid gland (elevates T4 without modifying T3, leading to weight gain).  I am borderline hypothyroid, and a new vegetarian.  I'm finding soy hard to avoid, it's in everything!  I've also heard that dairy (specifically the protein casein) and some vegetables and nuts (cabbage, broccoli, rutabega, cauliflower, kale, brussels sprouts, watercress, peanuts, almonds, walnuts, pine nuts, millet, turnips, turnip greens, cassava root, spinach, peach, pear, grape, mango and peas!  Whew, long list!) have a similar effect, though not as strong.  I don't know the mechanism behind this, other than some of them are supposed to have something called goitrogens, which inhibit thyroid hormones.  Apparently the goitrogens are destroyed when the foods are thoroughly cooked, though.

 Does anyone know if there is any truth to the claim that soy, and perhaps all of those other foods, are bad for the thyroid?  Don't tell me this is all wrong without explaining why, please!     

And also, are there any foods that may improve the function of the thyroid?  Not for weight loss, just to balance out my hormones!  I'm tired all of the time no matter how much I eat (and I eat a lot + daily exercise)!

From the internets:

America's leading alternative doctor, Dr. Andrew Weil, has said about soy, at his Ask Dr. Weil website

"…you're unlikely to get too many isoflavones as a result of adding soy foods to your diet -- but you probably will take in too much if you take soy supplements in pill form. At this point, I can only recommend that you avoid soy supplements entirely." 

I for one think there is too much emphasis on soy.  Consider soy as just another legume.  You wouldn't eat peanuts or peanut products at every meal, so don't do that with soy.  Over-consumption of any one thing (including soy) is bound to be bad for you is my point I guess.  Soy products that use the whole bean have been shown to have positive health effects in study after study so there's no reason to remove them from your diet completely.  Just don't sit there and drink a glass full of soy milk, don't eat soy products for every meal, and avoid soy isolates (fake meats and stuff). Make leafy green veggies the focus of your diet, add in lots and lots of other veggies and fruits, get some grains, beans, nuts, and seeds to round it out and you'll be fine.

Hope that helps.

I don't know much about it, but it makes you think. It seems harder for me to lose weight now, and I've been trying hard. Also, I pack on the pounds a lot quicker. I've cut back on the soy a lot, so I guess I'll just have to wait and see if it's that or something else.

There's so much conflicting info on this issue it will make your head spin.  I've been diagnosed with hypothyroidism, and still enjoy fermented soy products in moderation (at most a few times a month).  I read labels and avoid products containing unfermented soy products or hydrolyzed vegetable protein.  I will indulge in fermented soy products every once in a while, and it's usually opposite the time I take my medication - usually at dinner since I take my pill at 6AM. 

I highly recommend Living Well with Hypothyroidsim, by Mary Shomon.  She recommends avoiding unfermented soy products such as fresh soybeans, soy nuts, soy sprouts, soy milk, and tofu.  Fermented products such as tempeh and soy sauce don't seem to be problematic if consumed in moderate amounts. Unfortunately there doesn't seem to be enough research re: hypothyroid patients and soy consumption, so I try to keep my intake to a minimum.  As for the other foods you listed, Shomon recommends avoiding them in raw form.  Thorough cooking will minimize or eliminate the goitrogenic effects of these foods.  She also goes into much detail re: being hypothyroid and losing weight, and discusses other sympoms of hypothyroidism such as fatigue and sluggishness.

Thanks for the recommendation, I'll try to find time to read it.  Sounds like it will be helpful.  I'm glad that someone else at least knows what I'm talking about!  Take care!

I am going to talk to my doctor about this when i see her this week and get my levels tested out. I hope this isnt true cause if all those foods have soy in them then I eat soy a lot. I have a glass of soy milk at least one or 2 times a day. this worries me.

 

Well, there isn't actually soy in all of those foods, they just contain a compound that may (or may not) affect the function of the thyroid.  Soy is supposed to have the most detrimental effect of all of them.  I honestly don't know if any of these theories are true, I only wanted to know if anyone else had heard about it and if it helped their thyroid to stop eating soy.  

I actually just got my most recent blood test results back today and everything was normal!  Including normal thyroid levels!  Yay!  But whether the change was a result of cutting soy from my diet, or not, I don't know.  You could try it, couldn't hurt!  Just read food labels because it's literally in almost every processed food.  And definitely ask your doctor about it, I'd be interested to hear what he or she has to say.