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Low Iodine Diet

Eating Well on the Low Iodine Diet


Updated May 20, 2014

Written or reviewed by a board-certified physician. See About.com's Medical Review Board.

A low iodine diet is prescribed before radioactive iodine (RAI) scans and radioactive iodine treatments. It is a special diet that limits the amount of iodine that is consumed through foods and beverages. As RAI scans and therapy are standard methods of treating thyroid cancer*, the diet is common and can easily be adhered to with a few modifications.

* Please note that RAI treatment are not exclusive to thyroid cancer. Other thyroid diseases like hyperthyroidism utilize RAI for treatment. This article focuses on those who have thyroid cancer, however.

What Does Iodine have to Do With Thyroid Cancer?

The thyroid gland uses iodine from our water and food intake to produce essential hormones that regulate our metabolism. Thyroid cells are unique because they are the only cells in the body that absorb iodine. Before undergoing RAI scans and treatment, patients go on a low-iodine diet, starving the body of iodine. When a patient is given radioactive iodine (usually in capsule form), the iodine starved thyroid cells uptake the RAI, allowing the cells to be detected for scans or to be destroyed for treatment (ablation).

Details About the Low Iodine Diet

The low iodine diet is simple, but requires some planning. Those who eat a lot of foods that are pre-packaged or frozen may find the diet to be a challenge. The same goes for those who frequent fast-food restaurants and eat a lot of take-out meals.

The basis of the diet is to eat foods that are low in iodine. One of the biggest rules of the iodine diet is to avoid eating salt. Iodized salt is enriched with iodine, therefore not allowed. Non-iodized and kosher salt are allowed because they do not contain iodine. When reading labels and packages, remember that salt is not the same as sodium.

Eating on the Low Iodine Diet

The Internet is a great source for information about the low iodine diet, but you may come across some conflicting information about the foods allowed and prohibited on the diet. One source may say only potato skins should be avoided when eating potatoes, while another claims you cannot eat potatoes at all! Who should you believe?

When you read conflicting information, the best source you can go to is your doctor. A quick phone call to your doctor can clear up any questions you have about a certain food. Conflicting information exists based on nutritional studies about iodine in foods. Fellow researchers and physicians may feel that a certain study may have merit, while another may feel differently. This list of foods below is based on the low iodine diets recommended by The National Institutes of Health and the Thyroid Cancer Survivors Association.

Prohibited Foods

  • dairy (egg yolks, milk, yogurt, cheese, butter, ice cream, sour cream)
  • seafood (anything from the ocean should be avoided, including fish, shellfish, and kelp)
  • processed foods (prepackaged foods, frozen dinners, deli meats, hot dogs, bacon, sausage, foods at restaurants and fast food eateries)
  • commercial baked goods (commercially baked breads and confections)
  • soy (includes soybeans, soy sauce, tofu, and any other food with soy)
  • maraschino cherries
  • chocolate (milk chocolate contains dairy; some dark chocolates may be allowed - check label) red dye #3 (check label or call manufacturer)
  • beans (avoid red kidney beans, navy beans, lima beans, pinto beans, and cowpeas)

    Foods Allowed on the Low-Iodine Diet

    Don't be disheartened by the list of foods you cannot eat! There are plenty of foods that you can eat. Here are foods that are allowed on the low-iodine diet:
    • fresh meats (no more than 5-6 ounces a day)
    • fresh fruits and vegetables (no potato skins)
    • frozen vegetables, without added salt (no rhubarb) unsalted nuts
    • vegetable oils
    • sodas(as long as they don't contain red dye #3 - check the label or call manufacturer)
    • unsalted peanut butter
    • coffee and tea (non-dairy creamer is allowed)
    • Matzo
    • homemade breads (no egg yolks, dairy, or iodized salt in the ingredients)
    • fresh and dried herbs and spices, including pepper
    • beer, wine, and distilled alcohols (wine coolers and flavored liquors may contain red dye #3, check label)
    • canned peaches, pineapple, and pears
    • honey
    • maple syrup
    • jams and jelly (without red dye #3)
  • Dining Out

    Eating out is almost nearly impossible while undergoing the low-iodine diet. You can't guarantee what type of salt a restaurant uses in their recipes. Foods served in fast food restaurants are mostly processed and contain salt, so they should be avoided as well. If do not cook, you may want to become more kitchen savvy or think about hiring a personal chef for the time you are on a diet.

    Low-Iodine Recipes and Cookbooks

    The Thyroid Cancer Survivors Association offers an excellent low-iodine cookbook online that can be downloaded for free. It boasts over 300 low iodine recipes and is a favorite among low-iodine dieters. ThyCa Low Iodine Cookbook

    You can also follow your favorite recipes as long as the ingredients fit the criteria above. Use non-iodized salt or kosher salt instead of iodized salt in recipes.

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    5. Thyroid Cancer
    6. How to Eat Well on a Low Iodine Diet

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