iThei mdcdaelcinfd o c elllllrlllll tiThcl elThhlThscd mmshblkdho c dhpIn normal thyroid cells, the antioxidant glutathione peroxidase neutral-
izes the hydrogen peroxide, preventing thyroid cell damage. This anti-
oxidant is made from glutathione and selenium. Depletions of various
substances, especially selenium and glutathione, have been recognized as
triggers for Hashimoto’s.
The following mechanism explains why supplementing with iodide can
cause an immune system flare-up:
Iodide gets in the blood.
Iodide gets oxidized to iodine by TPO.
Oxygen-free radicals are formed during oxidation.
In the absence of selenium, free radicals cause damage to the
thyroid cells instead of being neutralized.
Lymphocytes (white blood cells) infiltrate the thyroid tissue to
repair the damage and produce inflammation of the thyroid.
Inflammation causes further destruction of thyroid tissues.
More white blood cells infiltrate the thyroid.
Figure 2: Iodine as a TriggerOur immune system evolved to protect us from harmful foreign invad-
ers. As TPO expression results in oxidative damage, our immune system
starts recognizing it as an enemy. Whenever the immune system identifies
a foreign invader, it forms antibodies against the invader. In the case of
Hashimoto’s, the target is the thyroid peroxidase enzyme (TPO).