Cancer, Brain Health, and Thyroid Disease: The Iodine Connection
Back in the day, we added a specific nutrient to the most frequently eaten food in the country: bread.
That nutrient helped to offset a number of conditions that arose due to its deficiency, namely goiter, depressed immune function, mental retardation, and even headaches.
So why on earth was it taken out and replaced with a different chemical that actually depletes this critical nutrient?
And for goodness sakes, why did we then take it a step further and add a second chemical to the most frequently consumed beverage—water—that also depletes this vital nutrient.
As a result, we now have a rampant, chronic deficiency of this nutrient running through the country… a deficiency that has been linked to so many of today’s diseases, namely the very things it was supposed to protect us against—thyroid health, breast cancer, and brain health.
And the name of this miraculous nutrient? Iodine.
Riches From the Sea…
Bernard Courtois discovered iodine in 1811 while he was making gunpowder out of potassium and sodium from seaweed. After accidentally adding a bit too much sulphuric acid, a strange purple vapor started rising out of his concoction. Based on this, Courtois named the strange element iodine, after the Greek word iodes, which means violet.
Iodine’s first medicinal use came several years later when Jean Francois Coindet treated goiter with iodine. It was the first time a solitary nutrient was used to treat a specific condition. As such, many people herald this occasion as the “birth of Western Medicine.”1
In 1824, Coindet’s work was supported by Jean-Baptiste Boussingault, who discovered that people who drank iodine-rich water at silver mining sites were protected from goiter. He suggested using the iodine-rich salts also found in the mines to protect the population at large.1
Of course, silver mines are not the only source of iodine. In fact, they aren’t even the best source. Iodine is found in seawater, rocks found in or near the ocean, and seaweed. Of these, seaweed is considered to be the best, most concentrated source of the mineral.
You also have naturally occurring iodine in every cell of your body, with the thyroid gland boasting the greatest concentration. Other iodine-rich areas are the salivary glands, cerebrospinal fluid, brain, ovaries, breasts, and areas of the eye.
For these reasons, iodine plays a role in many bodily functions, namely:
- Thyroid health,
- Immune function,
- Brain health,
- Fertility, and
- Breast and ovarian health.
Some researchers even claim that iodine is cancer protective. Those are some pretty big claims for a lone little nutrient. So what’s the truth?
Iodine and Thyroid Health…
One area that seems to be pretty clear-cut when it comes to iodine is the thyroid. Iodine is the most critical nutrient for proper thyroid function. It is essential for the production of the hormone thyroxin, which your thyroid uses to regulate many bodily functions, including metabolism.
If you don’t have enough iodine, your body cannot produce adequate levels of thyroxin. This leads to the symptoms commonly associated with hypothyroidism. In fact, even small iodine deficiencies can have profound effects on thyroid function.
Case in point. In the early 1920s, the Great Lakes region of Michigan had a pretty big goiter issue. In fact, of the 66,000 school children tested in a 1923-1924 survey, 40 percent had goiter.2
Goiter is an enlargement of the thyroid gland. When there is a deficiency of iodine, the raw material needed to make the thyroxin hormone, the thyroid gland has to work harder and harder in an effort to produce more of the hormone. It then becomes enlarged as a result.
A year or two later, iodized salt was being used in the area, and four years later, there was a 75 percent reduction in goiter. Fast-forward to 1951, and suddenly less than half a percent of children had goiter.2
A study from the University of Tennessee Health Science Center saw similar results when detailing the cases of three women, aged 24 to 38 years of age.3 All three lived in iodine-rich areas, yet exhibited signs of iodine-deficiency disorders. Two of the three had hypothyroidism, with goiter.
After receiving dietary iodine supplementation, all three had complete remission of iodine-deficiency disorders, including the two women with hypothyroidism. Researchers concluded, “These cases underscore the need for considering iodine deficiency in the etiologic diagnosis of goiter and hypothyroidism, even in iodine-sufficient regions.”
Put in plain English: Too little iodine leads to problems with hypothyroidism with severe deficiencies possibly leading to goiter.
Iodine and Breast Cancer…
One of the more hotly contested areas regarding iodine is in the treatment and/or prevention of cancer. While there are critics that downplay the benefits of iodine as an anti-cancer therapy, several studies show its promise.
The key to iodine’s benefits lie in its ability to promote apoptosis, or cell death.4 This is critical when it comes to fighting cancer. The greater a compound’s ability to bring about apoptosis in cancer cells, the more likely the treatment is to be effective.
For iodine, the types of cancer that seem to be the most responsive are thyroid cancer and hormone-related cancers, namely breast cancer. One of the best-studied areas of research around iodine and breast cancer is in the mineral’s ability to support the effectiveness of traditional therapies, namely Tamoxifen.
A 2008 study from the International Journal of Medical Sciences noted the use of iodine has been found to “enhance the efficacy of Tamoxifen therapy…thus preventing or slowing the development of Tamoxifen resistance.”5
In an animal study published in 2005, researchers found that in rats that were induced with breast cancer, iodine inhibited tumor formation.6 Similarly studies found that in the absence of iodine, breast tissue (from animals) is more likely to show indications of developing breast cancer,7 leading researchers to hypothesize, “Maintenance of the optimum structure and function of the breasts requires the presence of continuous and specific amounts of iodine.”8
But iodine’s benefits are not limited to the thyroid and breast. It also plays a critical role in brain health.
Iodine and the Brain…
Another large area of iodine research centers around brain health…and for good reason. First and foremost, the World Health Organization themselves, a bastion of traditionally conventional medicine, has abdicated that iodine deficiency is the world’s single largest cause of preventable mental retardation.9
Iodine deficiency has also been linked to other brain-related illnesses, namely ADHD, cretinism, and reduced mental and intellectual ability.10
In the 1960s, commercial bakers added iodine to bread as a dough conditioner. With bread one of (if not the most) commonly consumed food, a single slice provided nearly 150 mcg of iodine.
Soon thereafter, the iodine was removed from the bread and replaced with a similar compound (bromine), which competes with iodine in the body. Specifically, the more bromine you have, the less iodine you have.
That’s because bromine interferes with the absorption of iodine, contributing to iodine deficiency. And since bromine doesn’t convey the same benefits that iodine does, that’s not a good thing for your health.
But bromine isn’t alone. Other members of this halide compound gang include fluoride and chloride, both of which have the same obstructing effect on iodine.
Combine this dangerous trio together and you have an environment conspiring against adequate iodine absorption. Between the bromine in your bread, the fluoride in your toothpaste, and the one-two punch of both fluoride and chlorine in your drinking water, and it’s no wonder we have a rampant iodine deficiency in this country.
Boost Iodine, Boost Health…
While iodine has since been added to salt, it goes without saying that excess salt is a bad idea. Plus, research has shown that only about 10 percent of the iodine in salt is actually utilized by your body.11
Therefore, to ensure you are getting the iodine you need, you can start by eating more iodine-rich foods. These include:
- Baked potato, with skin,
- Cooked navy beans,
- Sardines, and
- Saltwater fish.
Next, reduce your exposure to bromide, fluoride, and chlorine. Start by reading labels and choosing fluoride-free toothpaste. You can also install a water filter for your kitchen and shower alike to reduce the amount of chlorine and fluoride you drink, as well as absorb through your skin.
You can also work with your doctor to test your thyroid levels to see if you are at risk for goiter, Hashimoto’s disease, or hypothyroid. Be sure to have them test for T3, T4, and thyroid antibodies, as well as thyroid-stimulating hormone, or TSH.
Similarly, ask to have your current levels of iodine, fluoride, chloride, and bromine checked. That will help you determine your next course of action, namely supplementation.
Should you decide to supplement with iodine, you need to be aware of the two types: iodine itself and iodide. Iodide is a reduced form of iodine, meaning it basically has one less electron than iodine, thus making iodide more water-soluble. Additionally, your thyroid uses primarily iodide versus iodine for normal functioning.
Because both forms play critical roles in overall health, the common recommendation is to choose a supplement that offers both iodine and iodide. While ideal dosages are best determined on a person-by-person basis, a good rule of thumb is between 12 and 50 mg per day of an iodine/iodide blend.
You’ll also want to be sure to take supplemental selenium with your iodine, as proper levels of this mineral are needed to metabolize iodine and regulate thyroid function. Aim for 100 to 200 mcg per day.
Finally, remember to keep an open mind to new ideas, but ALWAYS do your own homework…and combine that with common sense to figure out what’s best for YOU.
1Brownstein, D. Iodine. Why You Need It, Why You Can’t Live Without It 4th Edition. Medical Alternatives Press, 2009;25.
2Hollowell, JE et al. Iodine nutrition in the United States. Trends and public health implications: Iodine excretion data form National Health and Nutrition Examination Surveys I and III (1971-74 and 1988-94). J Clin Endocrinol Metab. 1998 Oct;83(10):3401-8.
3Nyenwe, EA and Dagogo-Jack, S. Iodine deficiency disorders in the iodine-replete environment. Am J Med Sci. 2009 Jan;337(1):37-40.
4Vitale, M et al. Iodide excess induces apoptosis in thyroid cells through a p53-independent mechanism involving oxidative stress. Endocrine. 2000 Feb;141(2):598-605.
5Stoddard, FR 2nd et al. Iodine alters gene expression in the MCF7 breast cancer cell line: evidence for an anti-estrogen effect of iodine. Int J Med Sci. 2008 Jul 8;5(4):189-96.
6Garcia-Solis, P et al. Inhibition of N-methyl-N-nitrosourea-induced mammary carcinogenesis by molecular iodine (I-) treatment: evidence that I2 prevents cancer promotion. MolCell Endo. 2005 May 31;236(102):49-57
7Krouse, TB et al. Age-related changes resembling fibrocystic disease in iodine-blocked rat breasts. Arch Pathol Lab Med. 1979 Nov;103(12):631-4
8Eskin, BA Iodine and mammary cancer. Adv Exp Med Biol. 1977;91:293-304.
9World Health Organization. Iodine deficiency. 1998 Nov 12:EB103/27.
10Foster, H. The iodine-selenium connection: Its possible roles in intelligence, cretinism, sudden infant death syndrome, breast cancer and multiple sclerosis. Med Hypoth. 1993;40:61-5.
11Abraham, G. The concept of orthoiodosuppplementaiton and its clinical implications. The Original Internist. June 2004.
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