Iodine, the Thyroid and Breast Health

by Mike Bauerschmidt, MD

After the thyroid, the breast is the second largest user of iodine. Scientific evidence connects inadequate dietary iodine with higher instances of breast cancer. Japanese women, who consume an average of 14 mgs of elemental iodine daily, have the lowest prevalence of breast and reproductive cancers in the world.

In the US, bread was a daily source of sufficient iodine until the 1960’s because the industry used iodine as a dough conditioner in bread and baked goods. At that time, breast cancer risk in the U.S was one in 20 women. Due to bromine being cheaper and easier to come by, it has been substituted for iodine by the food processing industry. Since then, the breast cancer rate has steadily risen in the US, and statistics now show that 1 in 8 women will get invasive breast cancer in their lifetime. Early detection is secondary only to prevention.

Compounding the Problem

In addition to bromine, our exposure to fluorine and chlorine also conspire to interfere with iodine absorption and thyroid function. Iodine, bromine, fluorine and chlorine are all in the same halide family in the periodic table of elements, meaning that they all share similar chemical structures and actions. In the body, chlorine, bromine and fluorine displace iodine in the thyroid hormone and in the tissues. Your exposure is widespread and daily, from your morning shower to your computer:

These chemicals are commonly found in the following places:

• Bromine – Bread, hot tubs, nasal sprays, citrus-flavored sodas, fire retardant used in fabrics, electronics (pay attention computer users), carpets & upholstery, pesticides
• Chlorine – Drinking water, swimming pools, hot tubs
• Fluorine – Drinking water (if fluoridated), toothpaste, antidepressants

Increased consumption of and exposure to bromine, chlorine and fluorine causes complications because they all displace what little iodine you do have, further lowering tissue iodine levels. Why is this so important? Because the thyroid gland needs iodine for proper functioning, which involves producing thyroxin (thyroid hormone) to drive the body’s metabolism. Iodine also stimulates the metabolism of the more potent estrogens estradiol and estrone into weaker estriol, which increases your cancer protection. When there is sufficient iodine in your system, bromine, chlorine and fluorine are eliminated from your body.

Not Just for Women

The prostate contains thyroid hormone receptors; therefore iodine is also important for prostate health. While hypothyroidism is more common in women than in men, we are seeing more cases in men.

What Can You Do?

Remove the offending chemicals wherever possible. Use filters to remove chlorine from drinking water and showers. There are ionizers that can attach to pool filters that reduce the amount of chlorine required. We have one on our pool filter and hot tub.

Look for breads without “potassium bromate.” Substitute sprouted grain breads as they don’t contain bromine. Eat organic fruits and vegetables as much as possible, and be particularly aware of non organic strawberries as they are commonly sprayed with methyl bromide.

Before beginning an iodine supplementation program, be aware that your thyroid may become enlarged or tender. It has likely been deprived of the nutrient for so long that it may want to store extra. This symptom will usually pass with time or with a slight reduction in dosage. It is best if you work with a physician who understands thyroid physiology and can help guide you on a path to your best breast health and thyroid function.