Could thyroid medication be the reason why more women are getting breast cancer?

The link between thyroid medication and breast cancer incidence was first established in the 1970s when researchers from the Ferdinand-Sauerbruch Hospital in Wuppertal, Germany found that women who took these drugs for more than 15 years were 20 percent more likely to develop the disease. Since then, several more studies have confirmed that the continual use of thyroid medicine increases a woman’s risk of breast cancer. Yet pharmaceutical drug companies still insist that their products are safe — citing that their medicines are “identical” to the natural thyroid hormone it is meant to supplement. If that were the case, then how could it be patented?

Most thyroid medicines mimic thyroxine (T4), a hormone that is naturally produced in the body. People diagnosed with hypothyroidism are typically prescribed these medicines to alleviate the symptoms associated with the condition, such as thinning hair and fatigue. Studies do suggest that thyroid medicines help stabilize a severe thyroid imbalance, but prolonged use of these drugs is associated with various health risks.

Unfortunately, thyroid medication may create immediate effects that cause a woman to need them even when her hypothyroidism is no longer there. Synthetically produced T4 may block the body’s natural use of thyroxine. In fact, synthetic versions can compete with natural T4 hormones for cellular receptor sites. This may be a reason why those who were prescribed thyroid medicine may be on them for life.

Additionally, thyroid medicines only replace T4 hormones. Thyroxine is inactive and needs to be converted to its active form called triiodothyronine (T3) so that it can be used by various organs such as the liver and kidneys. Data show that the body is unable to, or has difficulties with, converting the synthetically produced T4 hormone to T3.

This works well for Big Pharma though: Difficulties with the T4-to-T3 conversion means that it is extremely challenging to find the right dose for the drug. To offset this, more of the drug is given.

Thyroid health AND breast tissue linked to iodine levels

There is a clear link between the thyroid and breast tissue, and both are associated with the levels of iodine found in the body. An article written by Dr. Veronique Desaulniers on NaturalHealth365 discussed the importance of iodine in maintaining the health of both. Mammary glands have a “trapping system” for iodine, much in the same way as the thyroid gland. Glands found in the breast compete with the thyroid gland for needed iodine.

The body needs iodine for hormone distribution, yet around 90 percent of the world’s population is iodine deficient. An iodine deficiency in pregnant women can permanently damage the fetus by causing stunted growth, intellectual disability, and delayed sexual development.

Emerging evidence suggests that hypothyroidism can be a consequence of iodine deficiency. Instead of a band-aid solution of adding synthetic hormones to the body, naturopaths suggest treating the root cause of the disease, which may be supplementing with iodine instead.

Which brings us back to why synthetically derived thyroid hormones may be contributing to an increased risk for breast cancer. These drugs do not address the main cause of the problem. As the thyroid gland and mammary glands compete for iodine, the thyroid is unable to properly produce hormones, which may cause breast cells to abnormally develop and cause cancer. (Related: Taking Thyroid Hormones like Synthroid Causes Breast Cancer (The Reason Why May Surprise You).)

A study published in the European Journal of Clinical Investigation set out to determine if iodine supplementation worked just as well as a thyroid drug in treating an enlarged goiter. While both treatments significantly reduced goiter size, patients treated with iodine still had normal-sized thyroid glands even four months after they had stopped supplementing with iodine. Those who were prescribed the thyroid medicine saw their goiters return to pre-treatment levels almost immediately after they stopped taking the drug. This suggests that iodine can be a safe (and more effective) alternative treatment for hypothyroidism.

Sources include:

NaturalHealth365.com

CancerActive.com

NCBI.NLM.NIH.gov 1

NCBI.NLM.NIH.gov 2

NCBI.NLM.NIH.gov 3

YourHormones.info

ODS.OD.NIH.gov