foods with iodine

Eating For A Healthy Thyroid: All About Iodine, Soy, and Salt

foods with iodine
how to use diet to improve your thyroid

From the comments in my review of Dr. Schulze’s Superfood:

 Hi there I have underactive thyroid not on any medication. My TSH level is 6.84. Does anyone know if DR Schulze’s superfood plus will help. Any advice appreciated. I would like to avoid medication thyroxine. I am a vegetarian any supplement advise appreciated.

I’ll answer her specific question, and then comment on the issue of using diet to improve thyroid functioning in general.

To kick things off though, I’ll start with a disclaimer:

I’m not a doctor and nothing I say in this piece constitutes medical advice.  I’m only giving my own opinion.  I don’t represent any other organization besides Health Kismet with my writings. 

Anyways, on to the show….

As for taking a superfood supplement to improve thyroid function, my overall synopsis is that it probably couldn’t hurt although the most reported health benefits of green foods tend to lie in areas that lie outside the thyroid.

But diet is definitely important.

Of course I don’t know your background or what you’ve been told already, but I think there’s plenty of reason to think that good nutrition is a potent tool in any thyroid treatment.  I honestly don’t know enough about thyroid related drugs to say one thing or another about them.  (Although my personal opinion is that good nutrition should be the basis for any healing plan).

If you want a stronger opinion than mine on this issue then read this lady’s story.

Hypothyroidism: When The Organ Doesn’t Produce Enough Hormone

Just so we’re clear, hypothyroidism is the condition when your thyroid does not produce enough thyroid hormone, most commonly thyroxine and triiodothyronine.  There’s also hyperthyroidism, which is when your body makes too much.

I’ve never had the condition, nor known anyone who’s had it, so I’m merely writing from my own personal research, which includes medical journals, research papers, and personal stories and the blogosphere.

Eating to Improve Thyroid Function

In as few as words as possible, here’s my practical advice for increasing thyroid activity with diet:

  • make a point to add iodized table salt to home cooked meals (salt used in commercial restaurants is NOT iodized)
  • cut down processed soy intake
  • cook green foods and raw soy products (tofu, tempeh, soy beans) before eating them
  • consume wild farmed seafood
  • consume kelp or other sea vegetables if you’re a vegetarian or vegan
  • take a thyroid supplement if necessary

Iodine: The Key Nutrient

When it comes to foods that increase thyroid function, all roads lead down one path: iodine.

Iodine deficiency is the cause of a variety of thyroid related malfunctions such as goiter, and in most cases the root cause for an inactive thyroid.  Getting enough iodine is really important.

But it’s not the only thing.

foods with iodine
iodine is key for a healthy thyroid

Foods That Slow Down Your Thyroid

Some foods have substances called “goitrogens”, which depress the activity of your thyroid hormones.  This is especially true when your iodine levels are already lacking.

Goitrogens are usually found in two different types of foods:

  1. soy and soy based products
  2. cruciferous vegetables

At first this list might seem like a bit of a head scratcher since the latter two foods are always associated with positive health benefits.  They’re what you start eating when you want to stop disease, not start them up.  So what gives?

The story has a bit of nuance.  I’ve written about cruciferous vegetables and your thyroid before, and my overall advice would be to not let having thyroid problems stop you from eating green foods.  The effect of goitrogenic compounds in green foods is *very* mild, and the other health benefits they provide are simply too great to pass up, especially when you consider improved health supports all bodily functions, including your thyroid.

The deal with soy is a little bit more complex.  Soy contains a type of compound called an isoflavone which has been shown to depress thyroid activity in some capacity, although it’s not clear on what margin.  The effect of soy in your diet and thyroid health is complicated because soy is put into everything.

Soy, its concentrates, protein isolates, extracts and hydrolysates are used in all stages of the food production process, and is one of the most omnipresent ingredients in the western diet, even if you don’t eat much of it directly.

This is perhaps one of the reason why people who “go green” with their diet report improved thyroid conditions.  Your “hidden” soy intake goes way down.

The overall message is that it’s a good idea to cut down on your processed soy intake if you have an underactive thyroid.  Soy, like many other ingredients, can cease to be nutritious if desecrated enough.

Junk Food…..the Answer?

Underactive thyroids might be that rare case when certain processed foods (except for soy) offer an advantage over natural alternatives.  Table salt in the US is iodized and for most people this is sufficient to prevent major thyroid problems.   Lots of commercial bread products also have some iodine containing components in their dough.

This is not advice to eat crap, but buying some iodized table salt and adding it to your cooking or meals is a good idea.  For most people 1/2 tsp per day is enough.  If you have an underactive thyroid then perhaps a little more is necessary.

Food Sources of Iodine

The amount of iodine in food varies greatly because it’s usually dependent on  the conditions of the soil the food was grown in.  That said, aquatic organisms seem to be the most potent source.  Here’s a useful table that compares the iodine content in different foods in Greece:

foods with iodine
Seafood and aquatic greens are the best sources of iodine, particularly kelp.

If you’re a vegetarian or vegan then sea vegetables are your best bet.  Think about it…..where do fish get their nutrients from? Kelp is particularly potent and is the food most commonly used to treat a dysfunctional thyroid.

Certain nuts and beans can also provide some iodine, but not reliably.  So if you’re looking for your iodine from vegetables it’s seaweed all the way baby.

Healthy Recipes For Getting Lots of Iodine

Here are some nutritious recipes which will give you ample supply of iodine:

Healthy seafood gumbo

Seaweed stir fry

seaweed salad

Supplements and Other Products

In addition to eating more sea vegetables, taking an iodine capsule might not be a bad idea.  When it comes to iodine supplements you have a few options.  You can take condensed iodine, an iodine complex (iodine plus other stuff), kelp capsules (kelp is a great source of iodine), or a few handy seaweed based food products that are easy to add to other foods.

Here are some of your choices for the following categories:

Iodine complex supplement: NOW Foods Thyroid Energy Complex, $11.99 

Kelp Capsules: Nature’s Way (a good brand), 180 capsules for $6.99

and my favorite option……


iodine seasoning
seasoned dulse flakes: yummm!

Maine Coast Kelp and dulse flakes.  They’re mildly salted and you can add them to food!  This is a very easy (and delicious!) way to enjoy sea vegetables.  It also comes with iodized salt as well, a nice touch.

Getting one of these products, in conjunction with good diet will more than likely improve your underactive thyroid.


World’s Healthiest Foods.  “What Are Goitrogens and In What Foods Are They Found?”


Doerge, Daniel, et. al. “Inactivation of thyroid peroxidase by soy isoflavones, in vitro and in vivo”


Forsythe, William. “Soy Protein, Thyroid Regulation and Cholesterol Metabolism”


Doerge, Daniel, et. al. “Goitrogenic and Estrogenic Activity of Soy Isoflavones”


Koutras, D. A., et. al. “Dietary Sources of Iodine in Areas with and without Iodine-Deficiency Goiter”


Pearce, Elizabeth, et. al. “Sources of Dietary Iodine: Bread, Cows’ Milk, and Infant Formula in the Boston Area”


Vought, R. L. “Dietary Sources of Iodine”


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