Papillary thyroid cancer is one of the two most common types of thyroid cancer. The other is follicular thyroid cancer. These two cancers can usually be treated with radioactive iodine. Prior to the treatment, for the treatment to be effective there is usually a requirement to become “hypo” raising the thyroid stimulating hormone level. For approximately two weeks before the treatment there is a need to follow a low iodine diet.
What is the purpose of the mineral iodine?
To be able to understand the use of radioactive iodine, it is important to understand the purpose of iodine in the human body. The thyroid gland is the body’s main storage of the mineral. All the cells in the body depend on iodine with concentrations found in the glandular system. High concentrations are also found in the ovaries, breast, brain and prostrate.
Iodine’s principle job is for proper metabolism and proper function of the thyroid gland. The mineral is also necessary for a healthy immune system and has antibacterial, antiviral and anticancer properties.
Why does the treatment require a low iodine diet?
Following a total thyroidectomy they may be some thyroid tissue remaining that may not of been removed. Radioactive iodine is administered to destroy these cells and will treat thyroid cancer that may of spread to the lymph nodes or other areas of the body.
With the thyroid gland being the major iodine absorbing area, for the remaining thyroid cell to absorb the radioactive iodine depletion of the mineral is necessary. Hence the low iodine diet.
By following a low iodine diet for ten to fourteen days before the treatment and for about two days after the remaining thyroid cells will be starving for the mineral and will “suck” up the radioactive iodine and be destroyed.
Basic Principles of a low iodine diet
- This is a low iodine diet not an iodine free diet. The American Thyroid Association recommends that the diet contain no more than 50 mcg of iodine daily. You may eat foods that have up to 5 mcg per serving but avoid foods with over 20 mcg per serving.
- Sodium is allowed on the diet. Non iodized salt is permitted on the diet, as long as it is not sea salt.
- Any products that come from the sea, such as sea salt, seaweed, fish, shellfish, are not permitted because of their natural high content of iodine.
- Because of the iodine content in the feed given to the cattle and the iodine found in the cleaners used for the teats and the equipment, dairy products have to be eliminated from the diet. Therefore, no cheeses, milk, cream, ice cream or yogurt. Be aware that nondairy creamers may also contain iodine.
- Egg whites are acceptable rather than the whole egg as the yolk contains most of the iodine. Avoid commercially baked products for the duration of the diet. Iodine/iodate is a dough conditioner used in most bakeries. This products have to be avoided because of the milk and eggs in them. With the uncertainty of the salt content and other ingredients of foods eating in restaurants may have to be avoided.
- Eating freshly prepared foods rather than manufactured or processed is the best way of making sure of the iodine content of the food. Cooking from scratch is the way to go.
- Any food containing red dye #3 have to be eliminated from your menu planning because of the iodine content. The red food dye #40 is acceptable. Because foods pills and capsules containing ted, red-orange, and brown food dyes are not well labelled avoiding them for the two week period is advisable.
- Consult with your doctor making sure that the medications, vitamins and food supplements are permitted while on the low iodine diet. Check the labels because most vitamins and minerals do contain iodine.
Some doctors have different ideas and protocols for the low iodine diet. They will advise you of any differences they may have from the standard diet put out by the thyroid cancer associations.