I wish more women would take iodine. Not for thyroid—but to prevent breast cancer.
Iodine for immune and breast health
Did you know that 80 percent of the body’s iodine is not in the thyroid gland? Instead, it’s in the immune system, eyes, stomach, salivary glands, brain, ovaries, and breasts. It’s there to stabilize the fatty acids of the cell membrane and protect cells from oxidative damage. Iodine also directly supports immune cells — to the point that immune cells have been known to actively break apart thyroid hormone to harvest the iodine.
In the breasts, iodine down-regulates estrogen-responsive genes and up-regulates the genes required for estrogen detoxification. Having enough iodine can prevent breast tissue from becoming hyper-sensitive to estrogen.
Interestingly, progesterone enhances iodine uptake, which may be one way that progesterone protects against breast cancer.
Researcher Carmen Aceves has recently trialed iodine as an adjuvant therapy for breast cancer.
Safe use of iodine
Be careful with iodine supplementation because iodine overdose can trigger autoimmune thyroid disease and hypothyroidism. Fortunately, that is less likely to occur when there is adequate selenium to stabilize thyroid tissue.
How can you get enough iodine for breasts without injuring the thyroid?
Before I prescribe iodine, I test for thyroid autoimmunity or “thyroid antibodies.” If there is autoimmune thyroid disease, then I stay below 500 mcg (0.5 mg) of iodine or avoid it altogether. If there is not autoimmune thyroid disease, then I typically prescribe between 250 mcg (0.25 mg) and 3000 mcg (3 mg) in the form of either potassium iodide (KI) or molecular iodine (I2). Molecular iodine is safer than potassium iodide because it’s absorbed more slowly into the thyroid and more quickly into breast tissue.
👉🏽 Tip: Breast tenderness can be a sign of iodine deficiency. I personally find it more useful than tesing for urinary iodine.
A high dose of iodine in the range of 30,000 – 50,000 mcg (30-50 mg) is not safe. Read your supplement label. There is a 1000x difference between mcg and mg.
Please also read: Why I Prescribe Iodine for Breast Pain, Ovarian Cysts, and PMS