I am now on the low iodine diet. My last regular meal was supposed to be a pepperoni, mushroom and black olive pizza. I was looking forward to it. Well, no pepperoni--they forgot.
Why the low iodine diet?
1. Iodine is used by thyroid cells to create the hormone thyroxin.
2. My thyroid was removed--but there are probably some remnant thyroid cells, with cancer or without still in my neck. The thyroid doesn't just float there--it is attached to the walls of my neck and to other muscles. The doctor did not know at the time that I had cancer, so he might not have scrapped off every millimeter of thyroid tissue.
3. If the cancer has spread, it would be thyroid cells which have broken off and spread to other parts of my body. Even if it is in my brain or my leg bone, it is thyroid cancer--growing there.
4. The goal is to deplete the body of iodine. This makes any remaining thyroid cells "hungry" for iodine. They are trying to make thyroxine and they need iodine to do so. The thyroid cells are the ONLY cells in the body that use iodine.
So, if you starve your body of iodine, then, when you put radioactive iodine (the poison!) in your body, these remaining thyroid cells will really gobble it up.
What is the low iodine diet?
There is iodine in a lot of food.
It is picked up in the soil by plants growing.
It is used to clean our milk drums and butter making equipment (remember putting iodine on a cut?)--so all dairy products have it.
It is in meats and poultry.
It is in the sea.
It is put in table salt (iodized salt) as a necessary nutrient, just like they put flouride in water.
So, a low iodine diet is cutting back on these foods during the time that you are getting ready for the thyroid scan (read the next post), and for the therapeutic dose to kill the remaining cells.
You can find a good diet http://www.cc.nih.gov/ccc/patient_education/pepubs/lowio.pdf
This is the National Institute for Health's diet. There are others, and they vary slightly, but this one looks reasonable.
For me, it means no more than 6 ounces of meat per day, no more than 1/2 cup cooked pasta, no more than one slice of bread, nothing with eggs, no milk, butter or cheese or any products that contain these things. It means eating a lot of vegetables, and none of that stuff that adds the weight--cookies, ice cream, or snack food. Plus no sea food. The sea if full of iodine, and so are the fish and the sea salt that comes from the sea. Lastly, anything I eat can't have iodized salt. I can eat salt, but not iodized salt. Iodine has nothing to do with salt. Salt has nothing to do with sodium. I can eat salt. I can eat sodium. Under federal law, manufacturers must list the ingredient as "iodized salt" or just "salt". If it is just "salt", it is fine. The rule is--pick a national brand. The smaller guys probably don't read the "federal laws".
How long for the diet?
This question receives different answers from different doctors. How about a month? The longer the better, right? Most sources say two weeks. Two weeks until you receive the scan which tells you how big a dose of radioactive iodine you will receive. The more cancer--the bigger the dose.