Iodine (part 2)
No mention of iodine is complete without emphasizing its fundamental role in the thyroid gland. Our body’s largest store of iodine is, of course, in the thyroid, where it holds up to about 80% of our total iodine. This makes sense since the thyroid is the most iodine-hungry organ; it literally snatches four iodine atoms whenever the brain sends the 'go' signal. These atoms are used to create thyroxine (T4), where two of the atoms are placed on the inner ring of the hormone, while the other two are on the outer ring. And make no mistake, our body produces quite a bit of this, as T4 acts more like a storage hormone rather than the one that will directly affect your function.
Our body can only efficiently use the thyroid hormone once the outer ring is thinned a little bit of its iodine—that is, one iodine atom instead of two. That’s because when the hormone has three iodine atoms (T3), one of the iodines is uncoupled and therefore more readily reactive to the cells that need it. This process of ripping an iodine atom from the T4 hormone is called deiodination, and consequently, the enzyme that performs this gets the name deiodinase.
We have deiodinases (DIOs) everywhere in the body. This is a protein we call a selenoprotein, meaning selenium is at its core structure. So now you know why selenium is important for a healthy thyroid status. There are three types of DIOs, numbered 1 to 3. DIO1 and DIO2 primarily turn T4 into T3. However, DIO3, which is found in the brain, skin, and reproductive sites, actually rips one of the inner ring iodine atoms from the thyroxine hormone rather than the outer one. This still turns T4 into T3, but due to the different, less stable location, it is called reverse T3 (rT3). Guess what? We can’t use rT3 for normal thyroid function. It is a program our bodies have to put a brake on too much T3 being produced from T4—or a shunt, if you like that concept better.
Can you guess why the brain might need this brake function? Well, you can't sleep if you have too much T3 in the brain at night. The same is true for the skin, uterus, and placenta—the brake stops too much T3 in these vulnerable areas. Because we have DIOs everywhere in the body, we also see iodine everywhere in the body every time it is cleaved off thyroxine. Some people think these are waste iodine atoms, but I think the brighter ones are humble enough to acknowledge that there is always a plan for everything, whether we have grasped it or not. It turns out that we can use these 'waste' atoms to turn hydrogen peroxide (H2O2) into hypoiodite and water, as otherwise hydrogen peroxide can easily be turned into a hydroxyl radical—something we don’t really want inside us. So you can think of it like an antioxidant. We know water is useful, but what about hypoiodite? Well, it is our body’s natural bleach to keep pathogenic bacteria and fungus at bay. This is all the more important when we are sick, as we make a lot more hydrogen peroxide as part of our metabolic stress. If we then use some of the excess hydrogen peroxide to turn into water (hydration is important, especially during sickness) and hypoiodite, we have increased our options for fighting the invading illness.
Talking about bleach, or what is chemically called hypochlorous acid (HOCl), this is exactly what iodine also does inside our neutrophils, one of the key players in our immune system. It activates the myeloperoxidase enzyme in these neutrophils to make more HOCl, therefore having a more potent action against invading pathogens.
The article is getting too long, and I haven’t even finished listing iodine’s role in promoting a healthy body. My main hope is to get everyone to agree that we need this element in many different ways, and I think I might have just achieved that without having to write a whole book on it.
Next up is what I have found since opening up my holistic practice in Bundaberg. In the future we’ll talk about treatment too, and ways to keep your iodine levels healthy—yes, you guessed right, it does not include screens!