With a few caveats, the best source of iodine is sea vegetables.
Avoiding Iodine Deficiency
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Why does this 15-year-old look so unhappy? Maybe it’s because of the iodine deficiency in her diet that gave her this goiter. Everyone needs iodine, but this is especially important for people who want to eat well, since many healthy plant foods like flax, soy, and broccoli have what are called goitrogenic compounds, which can interfere with thyroid function in people with marginal iodine intake. So does that mean we shouldn’t eat broccoli? Of course not. We just need to get enough iodine in our diets. It’s actually really simple to do. Rather than using natural sea salt, use iodized salt, and you’ll probably get all the iodine you need.
But if, for good reason, we don’t add salt to our food, we just need to get our iodine somewhere. Cow milk drinkers get it because iodine-containing disinfectants are used to disinfect the milk tanks, and so the iodine sort of leaches into the milk. The best source is sea vegetables, or you can get it in a multivitamin.
But I do encourage people to develop a taste for seaweed. It’s a wonderful food—dark green leafies of the sea. It may even prevent cancer. Seaweed inhibits human cancer cell growth, and this new study suggests it may even have a therapeutic potential for people battling liver cancer. Sea vegetables have lots of B vitamins and minerals—particularly the trace minerals, like iodine.
The problem with seaweed is that we can actually get too much iodine. The recommended daily intake is 160 micrograms a day, but the World Health Organization places the safe upper limit at 1,000 micrograms a day. So that’s not a huge amount of wiggle room. And it’s less for kids—300 micrograms or so may be too much for a five-year-old. This much laver or nori—a two-ounce bag—has enough iodine to last an adult a week. This much dulse; a month. This much wakame; two months. And one little bag of kelp; five years. A quarter gram a day of kelp is too much. And it would be hard to spread that little amount of kelp over five years, so I recommend going with one of these other sources.
Do not, however, eat hiziki. The reason sea vegetables are so wonderful is that they are packed with trace minerals; they just soak them up right out of the seawater. Hiziki, though, may also absorb bad minerals like arsenic. One seaweed species in particular, hiziki, sucks up so much arsenic that governments around the world are now warning consumers not to eat it. From the US EPA, to the British government, to New Zealand, to Canada—even the Chinese government. Here’s what it looks like. Note the two different spellings. No longer should anyone eat this—at least not on a regular basis. Lots of other wonderful types of seaweed out there without this problem, so we can get the anti-cancer benefits without the arsenic.
To see any graphs, charts, graphics, images, and quotes to which Dr. Greger may be referring, watch the above video. This is just an approximation of the audio contributed by veganmontreal.
Please consider volunteering to help out on the site.
- M. Gordon, C. Hall, and R. Amin. A rare cause of thyroid goitre in a UK adolescent. Acta Paediatr., 95(8) 1016, 2006.
- S. J. Bae and Y. H. Choi. Methanol extract of the seaweed gloiopeltis furcata induces g2/m arrest and inhibits cyclooxygenase-2 activity in human hepatocarcinoma hepg2 cells.Phytother Res, 21(1):52-57, 2007.
- M. Rose, J. Lewis, N. Langford, M. Baxter, S. Origgi, M. Barber, H. MacBain, and K. Thomas. Arsenic in seaweed: forms, concentration and dietary exposure. Food Chem.Toxicol., 45(7):1263-1267, 2007.
Why does this 15-year-old look so unhappy? Maybe it’s because of the iodine deficiency in her diet that gave her this goiter. Everyone needs iodine, but this is especially important for people who want to eat well, since many healthy plant foods like flax, soy, and broccoli have what are called goitrogenic compounds, which can interfere with thyroid function in people with marginal iodine intake. So does that mean we shouldn’t eat broccoli? Of course not. We just need to get enough iodine in our diets. It’s actually really simple to do. Rather than using natural sea salt, use iodized salt, and you’ll probably get all the iodine you need.
But if, for good reason, we don’t add salt to our food, we just need to get our iodine somewhere. Cow milk drinkers get it because iodine-containing disinfectants are used to disinfect the milk tanks, and so the iodine sort of leaches into the milk. The best source is sea vegetables, or you can get it in a multivitamin.
But I do encourage people to develop a taste for seaweed. It’s a wonderful food—dark green leafies of the sea. It may even prevent cancer. Seaweed inhibits human cancer cell growth, and this new study suggests it may even have a therapeutic potential for people battling liver cancer. Sea vegetables have lots of B vitamins and minerals—particularly the trace minerals, like iodine.
The problem with seaweed is that we can actually get too much iodine. The recommended daily intake is 160 micrograms a day, but the World Health Organization places the safe upper limit at 1,000 micrograms a day. So that’s not a huge amount of wiggle room. And it’s less for kids—300 micrograms or so may be too much for a five-year-old. This much laver or nori—a two-ounce bag—has enough iodine to last an adult a week. This much dulse; a month. This much wakame; two months. And one little bag of kelp; five years. A quarter gram a day of kelp is too much. And it would be hard to spread that little amount of kelp over five years, so I recommend going with one of these other sources.
Do not, however, eat hiziki. The reason sea vegetables are so wonderful is that they are packed with trace minerals; they just soak them up right out of the seawater. Hiziki, though, may also absorb bad minerals like arsenic. One seaweed species in particular, hiziki, sucks up so much arsenic that governments around the world are now warning consumers not to eat it. From the US EPA, to the British government, to New Zealand, to Canada—even the Chinese government. Here’s what it looks like. Note the two different spellings. No longer should anyone eat this—at least not on a regular basis. Lots of other wonderful types of seaweed out there without this problem, so we can get the anti-cancer benefits without the arsenic.
To see any graphs, charts, graphics, images, and quotes to which Dr. Greger may be referring, watch the above video. This is just an approximation of the audio contributed by veganmontreal.
Please consider volunteering to help out on the site.
- M. Gordon, C. Hall, and R. Amin. A rare cause of thyroid goitre in a UK adolescent. Acta Paediatr., 95(8) 1016, 2006.
- S. J. Bae and Y. H. Choi. Methanol extract of the seaweed gloiopeltis furcata induces g2/m arrest and inhibits cyclooxygenase-2 activity in human hepatocarcinoma hepg2 cells.Phytother Res, 21(1):52-57, 2007.
- M. Rose, J. Lewis, N. Langford, M. Baxter, S. Origgi, M. Barber, H. MacBain, and K. Thomas. Arsenic in seaweed: forms, concentration and dietary exposure. Food Chem.Toxicol., 45(7):1263-1267, 2007.
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Title
Avoiding Iodine Deficiency
LicenseCreative Commons Attribution-NonCommercial 4.0 International (CC BY-NC 4.0)
Content URLDoctor's Note
Other videos on iodine include:
For more on the health benefits of seaweed, see Which Seaweed is Most Protective Against Breast Cancer?
For further context, check out my associated blog posts: Do Eden Beans Have Too Much Iodine? and Nutmeg Toxicity.
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