Thyroid disease affects the body's metabolism and usually is controlled through medication. Certain foods can affect the way thyroid medication is absorbed, and should be restricted or eliminated from your diet in order to ensure healthy thyroid function.
Soy can affect your body's ability to absorb thyroid medication. You don't need to cut soy out of your diet completely, but doctors suggest waiting at least four hours after taking thyroid medicine before eating any soy products.
Limit or eliminate caffeine and alcohol consumption, and avoid the herbs ashwagandha and bladderwrak if you have hyperthyroidism. Also avoid caffeinated green tea and ginseng because of their stimulant properties.
Because calcium interferes with the absorption of thyroid medicine, don't drink calcium-fortified juices such as orange juice and apple juice until two to four hours after taking your medication. This same rule applies to antacids such as Tums or Mylanta.
Goitrogenic foods such as Brussels sprouts, cabbage, kale, cauliflower, turnips, rutabaga, millet, cassava and broccoli can disable thyroid function. There is some evidence that cooking these foods can minimize this effect, but they still should be eaten in moderation.
People with thyroid disease should avoid refined pastas, breads and sugar. Eat red meat and trans-fatty acids (which are found in processed foods such as cookies, french fries and margarine) only in moderation.