What do fluoride, chlorine and brominated sodas have to do with Hashimoto’s?

And why should you care?

If you cast your memory back to High School Chemistry class, you might vaguely remember the Periodic Table of the Elements.  You know the one, Hydrogen, Helium, Lithium, Beryllium and so forth.  So what does this have to do with Hashimoto’s?

Well, if you look at the second to last column, you’ll see a group of elements known as the Halogens.  They are interesting to Chemists because they are highly reactive and are “the only group that contains elements in all three states of matter at room temperature and pressure.  Fluorine and chlorine are gases, bromine is a liquid and iodine is a solid.” (Royal Society of Chemistry)

Aha!  I hear you say!  I know some of those!

Fluoride is in my toothpaste, chlorine is in my drinking water and iodine is in my salt.

This is where it gets really interesting.

Not only are they all highly reactive, but because they all have the same number of electrons in their outer shell, they can easily swap places with each other in all sorts of situations – especially in your body!

Iodine is essential for good thyroid function.  In fact, it is one of the essential “ingredients” your body needs to make thyroid hormones.  You can read more about Iodine and what it does to the thyroid here.

Many people who have been diagnosed with Hypothyroidism – both autoimmune (Hashimoto’s) and non-autoimmune, are deficient in Iodine.  This can be caused by a myriad of things, most commonly believed to be low dietary iodine intake.  What is often overlooked however, is the role that the other halogens play.

When you brush your teeth, have a glass of water, or drink some softdrinks (sodas), you are ingesting halides.

Fluoride is used not only in toothpaste, but also dental gels and even flosses.  Tap water contains both chlorine and fluoride in many places, and brominated oils are a common ingredients in some fizzy drinks (especially Mountain Dew).

This becomes a problem due to their chemical nature.  Because they all have the same number of electrons in their outer shell, they can take the place of each other in many receptor cells.  One classic example of this is iodine receptors within the thyroid.  Chlorine, fluorine and bromine can all attach to, and thereby block iodine receptors.  This means that when you do ingest iodine, it isn’t able to bind to its receptors in your thyroid cells because they have already been blocked by the other halides.

The good news is

that increasing your intake of iodine under the careful supervision of an appropriately qualified healthcare professional such as a Nutritional Medicine Practitioner, Naturopath or Integrative Doctor can displace the misplaced halogens in your body.

Of course, prevention is always better than cure,

so when you have low thyroid function, it is always best to use fluoride-free toothpastes and dental products, avoid brominated softdrinks, and if you must drink tap water, ensure that it has been passed through a filter that can remove both chlorine and fluoride.


Royal Society of Chemistry. (2016). Periodic Table.  Retrieved from: http://www.rsc.org/periodic-table/?gclid=CjwKEAjwu6a5BRC53sW0w9677RcSJABoFn4s5P3Ga3_bcuLk5_x4sQDd4HYkBFJEV3-twbgUnw1dhxoCKGTw_wcB