Tips for Eating and Cooking While on a Low Iodine Diet

In This Article

A low iodine diet is prescribed before diagnostic radioactive iodine (RAI) scans and before radioactive iodine treatments. These tests and therapies are often part of the management of thyroid disease and thyroid cancer.

The low iodine diet is a special diet that limits the amount of iodine you can consume through foods and beverages. Most people feel that a low iodine diet can be tough to adjust to. This is because iodized salt is prevalent in most foods. A number of other foods, including dairy, seafood, and soy also contain iodine even when they are not seasoned.

Overview

The thyroid gland uses dietary iodine to produce thyroid hormones that regulate metabolism. Thyroid cells are unique because they are the only cells in the body that absorb iodine.

As preparation for an RAI scan or treatment, you will need to go on a low-iodine diet, essentially starving your body of iodine. When you receive your RAI (usually in capsule form), your iodine-starved thyroid cells readily take in the RAI. This RAI uptake into the thyroid cells allows them to be visualized on a diagnostic scan or destroys them when this therapy is used as a treatment for thyroid cancer.

Recommendations

The low iodine diet may sound simple because you only need to eliminate one mineral from your diet—iodine. But it requires some planning. If you eat a lot of pre-packaged or frozen foods, or if you eat out a lot, you will need to make some major adjustments while on the diet. 

The biggest rule of the diet is to eat foods that are low in iodine. Since most salt is iodized (meaning it has iodine added to it), you need to avoid iodized salt and foods that contain iodized salt. Instead, you can use non-iodized and kosher salt, because they do not contain iodine.

Among the challenges of following a low iodine diet is that you may find conflicting information about which foods are allowed and prohibited on the diet. One source may say that you should only avoid potato skins, while another may suggest that you cannot eat potatoes at all.

Confusing information can add to the challenge of this already restrictive diet. Don't hesitate to ask your doctor for a referral to a nutritionist if you want personalized advice and guidance.

The Thyroid Cancer Survivors Association provides recommendations regarding which foods are permitted and prohibited when following a low iodine diet, and this organization is considered a trustworthy and knowledgeable source of information.

Prohibited Foods

Avoid these foods on a low-iodine diet:

  • Dairy (milk, yogurt, cheese, butter, ice cream, sour cream)
  • Egg yolks
  • Seafood (anything from the ocean should be avoided, including fish, shellfish, and kelp)
  • Processed foods (pre-packaged 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 the label)
  • Red dye #3 (check the label or call the manufacturer)
  • Beans (avoid red kidney beans, navy beans, lima beans, pinto beans, and cowpeas)

Foods Allowed 

Don't be disheartened by the list of foods you cannot eat! There are plenty of foods 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)
  • Vegetable oils
  • Sodas (as long as they don't contain red dye #3; check the label or call the manufacturer)
  • Unsalted peanut butter and nuts
  • Coffee and tea (non-dairy creamer is allowed)
  • Matzo
  • Homemade bread (without 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 the 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 following a 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.

Recipes and Cookbooks

When you season your food and cook at home, be sure to use non-iodized salt or kosher salt instead of iodized salt. You can prepare a variety of foods as long as the ingredients fit the criteria above.

Cooking can be challenging, even if you are already a good cook because it is hard to learn a new way of preparing food. The Thyroid Cancer Survivors Association offers a low-iodine cookbook that can be downloaded for free. It boasts over 300 low-iodine recipes and is a favorite among low-iodine dieters. 

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Article Sources

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  1. National Institutes of Health, Office of Dietary Supplements. Iodine: Fact Sheet for Health Professionals. Updated July 9, 2019.

  2. Ju DL, Park YJ, Paik HY, Song Y. The impact of low adherence to the low-iodine diet on the efficacy of the radioactive iodine ablation therapy. Clin Nutr Res. 2015;4(4):267-71. doi:10.7762/cnr.2015.4.4.267