Low-Iodine Eating: Day 7 (Effects of a Low-Iodine Diet)

This is the seventh in a 21-day series showing how I kept a low-iodine diet in preparation for radioactive iodine treatment.

A Little (Innocent) Mistake...

This post is going to be a little different, and I'll tell you why...

I accidentally started the low-iodine diet a week early.

The amount of time you're on a low-iodine diet varies, but is usually 2-3 weeks. From what I've read, most people are on it about 2 weeks, but a lot depends on your lab work in between. You have enough thyroid hormone in your system to keep you going for about a month after your surgery, so your doctor will monitor your natural hormone levels, as she begins your replacement hormone therapy. Also, there are different replacement therapies, some fast-acting (like Cytomel), and some slow-acting (like Sythroid). If you are going to have tests that require weaning off your medication temporarily, your doctor is likely to prescribe Cytomel, so you later go off it to prepare for tests. All these reasons mean that a lot of your doctor's choices will depend on how your own body responds to various procedures and treatments.

Sooooo.... my bloodwork showed the doctor that ...

1. I had almost no TSH (thyroid stimulating hormone) = 0.0135
2. I had low Tg (thyroglobulin) = 3
3. I had no anti-Tg (thyroglobulin antibodies) = 0

The Tg tells us that there is no thyroid to produce Tg, and the TSH tells us that the brain is not detecting the need to stimulate the thyroid (because hormones are being provided artificially).

Because I officially was to begin my low-iodine diet the next week, I gave myself a day off, went to the Big E, and ate fairground food.

With some thought, you can eat a good, tasty diet, even when on a low-iodine regimen.

The Goal of the Treatment...

Over the next week, my doctor wants to prepare my body to make the most of the radiation treatment (scheduled for the end of the month). Here are the things that she is trying to do:

1. Decrease my body's iodine levels. We are doing this by cutting down on iodine in my diet. Iodine is required by the thyroid in order to produce thyroid hormone. By removing dietary iodine, it ensures that the only source of iodine available to any cancer cells is the radioactive iodine that I will ingest later this month.
2. Decrease any thyroid hormone in my body. We will do this by cutting my Cytomel (synthetic thyroid hormone) from two pills per day to one pill per day. This will cause my pituitary gland (in my brain) to detect low thyroid hormones, and cause it to produce thyroid stimulating hormone (TSH).
3. Increase thyroid stimulating hormone (TSH) in my body. We will do this by cutting out any artificial source of thyroid hormone. This will cause any scraps of thyroid cells to fire up, to try to make up the difference.
4. Any increase in Tg in the blood will be a sign that there are thyroid cells (and potential tumors) remaining in the body -- it is a good tumor marker.
5. Ablate (wipe out) any remaining thyroid cells (cancerous and normal). We will do this by providing the iodine that these cells are now craving (in their efforts to provide the body with thyroid hormone) -- but instead of dietary iodine, we will be tricking them into "eating" radioactive iodine -- a toxin to them.

 Steps 1-4 will occur this week, leading up to Step 5 (the next week).

Effects of the Treatment on the Body

Effects of Low Iodine on the Body

In a person with a thyroid, low iodine effects are really the effects that having reduced iodine has on thyroid function: hypothyroid (low thyroid function), goiter, etc. We'll talk about those next. But there are some other effects of going on a low-iodine diet, as well.

• Weight loss.  Cutting out dairy, seafood (for the iodine), processed foods (for the salt), and processed baked goods (for the dough conditioners) cuts out a lot of calories and food choices for most of us. I have found that I have lost 6 lbs after one week of low-iodine diet (and I was very conscientious about my diet).
• Calcium deficiency. Since you are cutting out one of the primary sources of calcium in your diet, dairy, you will often be put on a calcium supplement while you are on a low-iodine diet. But you likely will be already on this, as your parathyroids sometimes shock after your surgery, and they control your body's calcium levels.

You will become an expert at reading food labels during your treatment.

Effects of Low Thyroid Hormone on the Body

While you are on the low-iodine diet, you will also likely be decreasing your thyroid medication, which will cause you to have low thyroid hormones, and symptoms of hypothyroid. Here are the ones listed at the Mayo Clinic website:

• Fatigue
• Sluggishness
• Increased sensitivity to cold
• Constipation
• Pale, dry skin
• A puffy face
• Hoarse voice
• An elevated blood cholesterol level
• Unexplained weight gain
• Muscle aches, tenderness and stiffness
• Pain, stiffness or swelling in your joints
• Muscle weakness
• Heavier than normal menstrual periods
• Brittle fingernails and hair
• Depression

Some of these will happen quickly, and others may develop over time, or not at all -- everyone is different. The one that most people comment about, and report as the most problematic, is the first one: fatigue. My doctor pointed out that the fatigue can often be enough to make driving hazardous.

My doctor also said that my bone health and heart health can be impacted by all the treatments, and will be closely monitored.

Getting others to help in household tasks will help you when you are fatigued.

Knowledge is Power

If you are fortunate, your endocrinologist will keep you very informed with your blood test results, treatment plan, any symptoms and side effects, and sources of information for help during your course of treatment. Here are some websites that I have found helpful:

ThyCA: The Thyroid Cancer Survivor's Association, Inc.  Takes you from your first symptoms, through your initial diagnosis, through various treatments, and aftercare. This is the site of the Low-Iodine Cookbook, a free .pdf file you can download and print out. The recipes were developed by other thyroid cancer survivors. 

LIVESTRONG, a website and organization developed by Lance Armstrong, world class cyclist and cancer survivor, has a separate section just about thyroid cancer. The site has lots of information about healthy living before, during and after cancer treatment.

The National Cancer Institute has a very thorough web page that is very useful for helping you understand the medical terms, types of cancers, tests and procedures. It also has a collection of links to other resources (such as the ones above) for all the questions you might have.

You will likely come across lots of chats and other online communities of thyroid cancer patients. These are helpful for showing you what most people go through. Remember to always consult with your doctor before trying anything, as the folks on the chat line are not medical professionals.

Do your research, and prepare yourself for your treatment.

Next Week:

1. Decrease Cytomel to one pill per day.
2. Continue low-iodine diet.
3. Continue taking Vitamin D and calcium supplements.
4. Prepare low-iodine meals for the second week of the diet (when I'll be hypothyroid, and too tired to prepare meals)
5. Purchase food items that other members of my family can prepare (see #3).
6. Think about where I have to drive the following week, and (perhaps) make alternative travel arrangements (see #3).