Seaweed and iodine content

[moribundman]

I want to incorporate more seaweed in my diet, but I'm unsure about iodine content. Since we should consume no more than 150 mcg iodine per day, it is pretty much unclear to me how much of which type seaweed we can safely consume. I know that nori contains relatively little iodine, but I can't find any concrete numbers, and I'm totally in the dark when it comes to kombu and wakame. Does anybody know the iodine content of the various types of algae or a reliable source of information?

 

[Pablo]

Why the concern about iodine?

I think neither kombu or wakame has substatially more than nori. They are all well rinsed and processed - and the uptake is about the same.

 

[moribundman]

Well, some sources say that consuming more than 100g (dry) seaweed per year may result in a serious iodine overdose. Nori seems to contain so little iodine that several sheets can be consumed safely on a daily basis. One sheet weighs about 2.6 g.

Iodine intake is critical to the thyroid and metabolism. I don't want to mess something up.

 

[Shaman]

I can't make any promises, but I can ask my japanese english teacher if I can find out.

 

[Pablo]

100g per year of seaweed = I overdose?

I don't believe that.

I agree that too much I is not a good thing, but I think the threshold is fairly high.

 

[MarkC]

The Japanese eat tons of seaweed, and I haven't heard of them having any problems. In fact, as you may know, they are the second-most long-lived group of people on the planet, behind the Okinawans.

 

[moribundman]

I found this:

Excessive intake of iodine from high-iodine-content macroalgae can upset thyroid function. Such toxicity, however, is rare. The maximum tolerated dose of iodine is 1000 mcg per day. In a recent study of 12 different species of macroalgae, their iodine content ranged from 16 mcg/g in nori (Porphyra tenera) to over 8,165 mcg/g in kelp granules made from Laminaria digitata. Relatively low-iodine-containing species include undaria and sargassum.

16 mcg/g of iodine in nori is a lot less than 8,156 mcg/g in kelp granules. That's like, what? about 510 times as much iodine in kelp compared to nori, Pablo!

Shaman, I already asked my Japanese girlfriend to look for information.

 

[moribundman]

Mark, hypothyroidism, not to mention high blood pressure due to high salt intake, are common health issues in Japan. I know they get old, but they might get even older!

Please read:

http://jcem.endojournals.org/cgi/content/abstract/78/2/393
http://thyroid.about.com/b/a/025606.htm

 

[Pablo]

Kelp granules?? Please expand.

 

[moribundman]

kelp granules

Someone might eat that stuff like candy.

As I said, I'd like to know the actual amount of iodine contained in the various types of seeweed. I'm a cautious fellow.

 

[Pablo]

I don't think I would power eat those granules. But even those treated as a "salt" topping, won't kill you.

You could stop the iodized salt, which you probably have

Your original question is a good one.

 

[moribundman]

Well, I use barely any salt anyway and I do switch from iodized to plain salt when my diet contains larger than normal quantities of iodine. However, consider that most multi-vitamins already contain about 75 mcg iodine. Taking one of those, using iodized salt and eating seaweed could easily push you far beyond the recommended 150 mcg per day.

I just realized this thread should probably be in the Foods/Cooking/Beverages forum. Then again, it may get bigger exposure here.

 

[MarkC]

What, you wanna live forever?

 

[moribundman]

I only want to outlive my enemies.

 

[sprintman]

A young man sitting at our table at the big night out Saturday at Fins the seafood cafe said he could no longer eat seafood. His mother butted in and said he'd had an 'Iodine test'. She opined if you love seafood/shellfish don't have an 'Iodine test'. No idea why but apparently no more seafood after something to do with this 'iodine Test;. If you can't eat seafood may as well commit Sepuku!

 

[moribundman]

If you suffer from hyperthyroidism, additional iodine may kill you.

I grew up in an area, far away from any ocean, where soil and produce are naturally deficient in iodine. For most part of the last century, the local populace was supplemented with iodine from various sources. The occurrance of goiters, which is connected to both, hypo and hyperthyroidism, is relatively high in European inland areas. Many people, although they grew up with supplemented food, have a predisposition to thyroid disorders. I have slightly hyperactive thyroid, which is reflected in my temper and my rather fast metabolism. You wouldn't want to see me on too much iodine.

 

[oilyriser]

Maybe some populations are genetically adapted to a low iodine diet, and can be harmed by too much in the diet.

 

[Al]

I started taking food suplements 35 years ago. Over the years I have come to see that 90% of that stuff is a waste of time. The whole culture is marked indirectly/directly by health magazines and advitisers of supplements for propagating their own culture ($$$$$$$$) I have seen suplement after suplement get tested independently and results hafe mostly shown that suplements are wothless at best-harmful at worst.

Take a multiple vitamin/mineral and you have all you need. Better yet, objectively look at the claims. The latest busts are SawPalmetto, Vitamin E, Calcium, Condroiton, Chromium, Echinacea. Thats just recently.

My wife is still in the supplement camp..she believes that any huckster who writes a book touting the junk makes it G0D-Like.

I do admit that I take garlic and Fishoil.

 

[Pablo]

quote:

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I do admit that I take garlic and Fishoil.

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[moribundman]

quote:

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Maybe some populations are genetically adapted to a low iodine diet, and can be harmed by too much in the diet.

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That's not the case. Wherever people suffer from iodine definciency, goiters and cretinism are rampant. Where people eat at least some seafood, hypothroidism is much more rarely seen.

Hey Al, while I do take vitamin and mineral supplements, I believe that ideally we should get all those things from out diet. Not being a super-careful eater, this is difficult to do today, especially with (over)processed foods. For example, I would not want to get most of my calcium from dairy product due to all the chemicals and hormones that may have been added or simply gotten in the food chain. Fish oil is another good example. While high quality fish oil is purified, eating fish may also increase your heavy metal intake beyond what's acceptable.

The thing about seaweed is that it is a true super-food. Its mineral content (weight-to-mineral content) is higher than in any other food. I also happen to like its taste.