In a previous article I showed why, when used alone, thyroid hormone replacement often fails. In this post I’ll explain why optimizing your iodine intake is so crucial, and why both too little and too much iodine can be harmful.
Iodine deficiency is the most common cause of hypothyroidism worldwide. Once researchers realized this, health authorities around the world began adding iodine to table salt.
This strategy was effective in correcting iodine deficiency. But it had an unanticipated—and undesired—effect. In countries where iodine has been added to table salt, the rates of autoimmune thyroid disease have risen. The following is just a sample of studies around the world demonstrating this effect:
Why does this happen? Because increased iodine intake, especially in supplement form, can increase the autoimmune attack on the thyroid. Iodine reduces the activity of an enzyme called thyroid peroxidase (TPO). TPO is required for proper thyroid hormone production.
On the other hand, restricting intake of iodine can reverse hypothyroidism. In one study, 78% of patients with Hashimoto’s regained normal thyroid function with iodine restriction alone.