Iodine Consumption and Breast Health

In October, we will be awash in a sea of pink ribbons to commemorate Breast Cancer Awareness Month and raise further awareness of the disease and its early detection. American Cancer Society statistics show the multi-year education effort is paying off: Nearly 70 percent of women get mammograms and, as a result, more than 203,000 cancer deaths have been averted since 1991.1

In fact, every month is a great time to begin thinking about Breast Health, and one way to do so is by taking a safe, over-the-counter iodine supplement that’s repeatedly been shown to improve the health of breasts and other organs.

Indeed, iodine supplements simply restore balance to the body. The fundamental problem is that the world suffers from a global iodine deficiency. The World Health Organization estimates that more than 2 billion people may be iodine deficient and as many as 50 million may be suffering from serious symptoms of iodine deficiency, such as brain damage. 2

Even in the United States efforts to cut salt intake have resulted in the reduction of iodine consumption – through iodized salt – by more than half over two decades. 3,4

Why Iodine Matters to Breast Health
Iodine deficiency impacts the brain, thyroid and other organs, but it can also affect breast health. Significant evidence suggests that it results in breast tissue being more sensitive to estrogen. And studies have found molecular iodine supplementation can reduce breast density.2.7

Breast density compares fat to other tissue in a woman’s breast. Dense breasts tend to contain more fibrous and glandular tissue than fatty tissue. This fibrocystic or fibroglandular tissue is extremely common in women, and often increases as premenstrual women get older.8

Originally, concerns about this condition arose because dense tissue appears white on a non-digital mammogram, looking exactly like a cancerous lesion. 9 This can make it difficult to accurately detect cancer. However, newer studies show that dense breasts actually are linked to a higher risk of cancer.10,11

SEE ALSO: Breast Cancer Awareness Month 2015

While medicine has not definitively determined what causes dense breast tissue to develop in humans, animal studies show that depriving breast tissue of iodine results in the growth of fibrocystic breast tissue. 12,13

Growing Awareness Leads to Greater Concern
Women are aware of the connection between breast density and cancer. A new survey of American women shows that 55 percent understand there is a link between breast density and cancer. What’s troubling, however, is that the same survey found that 61 percent of women 25 and over believe nothing can be done to reduce breast density.

From my own patient experience, I can say there is growing awareness that fibrocystic breast changes are common, painful and can lead to dense breasts.

Medicine has long been aware of the lower incidence of fibrocystic breast condition in cultures that consume significant quantities of seaweed, which is rich in iodine. But research dating back to 1993 also shows that using molecular iodine supplements reduces fibrocystic breast tissue in the West. 15

How iodine works continues to be the subject of scientific study, but the evidence points to molecular iodine supplementation as a way to potentially prevent fibrocystic breast condition and promote breast health.16 And in 2005, a study demonstrated what may be the strongest evidence so far. It concluded, in part, that “continuous I2 (molecular iodine) treatment has a potent antineoplastic effect on the progression of mammary cancer.”17

So, if all this is correct, why aren’t we all taking molecular iodine supplements?

The Fear of Iodine
In 1948, two University of California researchers, Drs. Jan Wolff and Israel Lyon Chaikoff, concluded that the public should avoid inorganic, non-radioactive iodine.18 Their study on rats found that iodine injections almost completely inhibited the organification of iodine in the thyroid gland. This launched an American panic that resulted in a significant amount of iodine being removed from the nation’s food supply.

It led to an all-out assault on the chemical element. Iodine, long used in commercial breads, was replaced with bromine. The increased use of bromine, chlorine and fluorine – the latter two to improve the quality of public water supplies and promote dental health – competed with iodine to be absorbed by the body. Then the medical profession encouraged reduced consumption of salt, and iodized salt is the primary source of iodine supplementation since the element is rarely found in land-based foods.

As a result, iodine consumption by American consumers was halved by the late 20th Century.

Follow-up research has since found that the deleterious effects on the thyroid gland tend to be temporary and that the thyroid returns to normal function, typically within 24 hours.19 This study also suggests that exceeding the recommended daily allowances of iodine tends to be well tolerated by most individuals.

Safe Levels and Sources of Iodine
There is significant disagreement about what comprises an adequate dietary allowance of iodine. The U.S. recommends 150 mcg per day for an adult, rising to 220 mcg for pregnant women and 290 mcg for lactating women. 20 However, studies17 have found the Japanese routinely ingest between 1,000 and 3,000 mcg (1 mg to 3 mg) of iodine each day.17,21

A 2011 study23 published in Thyroid Research found that “The Japanese are considered one of the world’s longest living people, with an extraordinarily low rate of certain types of cancer. A major dietary difference that sets Japan apart from other countries is high iodine intake, with seaweeds the most common source.” It cited the fact that Japan has lower rates of breast and prostate cancer, heart disease and infant death. 17

Seaweed, therefore, is one of the best natural sources of iodine. Other sources are seafood, dairy products, grain products and eggs.22 Unfortunately, iodine levels can vary significantly even among foods high in iodine content.

So the most reliable way to increase iodine consumption is likely to be through the use of supplements. Several – ranging from kelp tablets to various forms of iodine in tablet and liquid form – are readily available. In general, there are two primary forms of iodine for human consumption: iodide (I-) and molecular iodine (I2). It is believed by many that the thyroid absorbs the former more readily than the latter, and that molecular iodine is probably the safer option, but it tends to be harder to come by.

A simple option has recently become available in the form of Violet brand iodine, a tablet form of iodine manufactured by BioPharmX. It contains 3,000 mcg of iodine (84 percent potassium iodide and 16 percent potassium iodate) and 55 mcg of selenium. Once ingested, the iodide-iodate combination forms molecular iodine in the stomach, the safer iodine supplement.

While scientific studies must continue, research completed to date offers compelling reason to encourage patients to take iodine supplements. The new supplements are safe when taken as directed. And they give women a new weapon to more proactively protect their breast health than to simply perform frequent breast exams and undergo annual mammograms.

1. Text Alternative for Breast Cancer: Mammography Statistics (2015), American Cancer Society.
2. Dr Oleg Chestnov. Sustaining the elimination of iodine deficiency disorders (IDD). Noncommunicable Diseases and Mental Health World Health Organization.
3. Hoption Cann SA. Hypothesis: dietary iodine intake in the etiology of cardiovascular disease. J Am Coll Nutr. 2006 Feb;25(1):1-11.
4. Caldwell KL, Jones R, Hollowell JG. Urinary iodine concentration: United States National Health And Nutrition Examination Survey 2001-2002. Thyroid. 2005 Jul;15(7):692-9.
5. Cann, Stephen A.; van Netten, Johannes P.; van Netten, Christiaan (2000). “Hypothesis: iodine, selenium and the development of breast cancer”. Cancer Causes and Control (review)11 (2): 121-127. doi:10.1023/A:1008925301459. ISSN 0957-5243. PMID 10710195
6. Joseph E. Pizzorno; Michael T. Murray (14 September 2012).Textbook of Natural Medicine. Elsevier Health Sciences. p. 1371.ISBN 1-4377-2333-0.
7. Patrick L (2008). “Iodine: deficiency and therapeutic considerations”. Altern Med Rev 13 (2): 116-27. PMID 18590348
8. Breast density becoming an important predictor of breast cancer risk,
9. Boyd NF, Guo H, Martin LJ, et al. Mammographic density and the risk and detection of breast cancer. N Engl J Med. 356(3):227-36, 2007.
10. Yaghjyan L, Colditz GA, Collins LC, et al. Mammographic breast density and subsequent risk of breast cancer in postmenopausal women according to tumor characteristics. J Natl Cancer Inst. 103(15):1179-89, 2011.
11. Lynn C. Hartmann, M.D., Thomas A. Sellers, Ph.D., Marlene H. Frost, Ph.D., Wilma L. Lingle, Ph.D., Amy C. Degnim, M.D., Karthik Ghosh, M.D., Robert A. Vierkant, M.A.S., Shaun D. Maloney, B.A., V. Shane Pankratz, Ph.D., David W. Hillman, M.S., Vera J. Suman, Ph.D., Jo Johnson, R.N., Cassann Blake, M.D., Thea Tlsty, Ph.D., Celine M. Vachon, Ph.D., L. Joseph Melton, III, M.D., and Daniel W. Visscher, M.D.Benign Breast Disease and the Risk of Breast Cancer. N Engl J Med 2005; 353:229-237July 21, 2005DOI: 10.1056/NEJMoa044383.
12. Eskin BA. Iodine and mammary cancer. Adv Exp Med Biol. 1977;91:293-304.
13. Krouse TB, Eskin BA, Mobini J. Age-related changes resembling fibrocystic disease in iodine-blocked rat breasts. Arch Pathol Lab Med. 1979 Nov;103(12):631-4.
14. Harris Survey of 985 U.S. women, ages 25 and older, conducted online within the United States by Harris Poll on behalf of BioPharmX from July 31 to Aug. 5. This online survey is not based on a probability sample and therefore no estimate of theoretical sampling error can be calculated.
15. Ghent WR, Eskin BA, Low DA, Hill LP. Iodine replacement in fibrocystic disease of the breast. Can J Surg. 1993 Oct;36(5):453-60.
16. Stoddard F, Brooks A, Eskin B, Johannes G. Iodine Alters Gene Expression in the MCF7 Breast Cancer Cell Line: Evidence for an Anti-Estrogen Effect of Iodine. Int J Med Sci. 2008; 5(4): 189-196.
17. Garcia-Solis P, Alfaro Y, Anguiano B, Delgado G, Guzman RC, Nandi S, Diaz-Munoz M, Vazquez-Martinez O, Aceves C. Inhibition of N-methyl-N-nitrosourea-induced mammary carcinogenesis by molecular iodine (I2) but not by iodide (I-) treatment Evidence that I2 prevents cancer promotion. Molecular and Cellular Endocrinology 236 (2005) 49-57.
18. Wolff J, Chaikoff IL. Plasma inorganic iodide as a homeostatic regulator of thyroid function. J Biol Chem.1948;174:555-564. [PubMed]
19. Leung A, Braverman L. Consequences of excess iodine. Nat Rev Endocrinol, 2014 Mar: (10)3: 136-142.
20. Institute of Medicine, Food and Nutrition Board. Dietary Reference Intakes for Vitamin A, Vitamin K, Arsenic, Boron, Chromium, Copper, Iodine, Iron, Manganese, Molybdenum, Nickel, Silicon, Vanadium, and Zinc. Washington, DC: National Academy Press, 2001.
21/ Nagataki S. The average of dietary iodine intake due to the ingestion of seaweeds is 1.2 mg/day in Japan. Thyroid. 2008;18:667-668. doi: 10.1089/thy.2007.0379. [PubMed] [Cross Ref].
22. Murray CW, Egan SK, Kim H, Beru N, Bolger PM. US Food and Drug Administration’s Total Diet Study: dietary intake of perchlorate and iodine. J Expo Sci Environ Epidemiol. 2008 Nov;18(6):571-580. [PubMed abstract].

23.Zava, T, Zava, D. Assessment of Japanese iodine intake based on seaweed consumption in Japan: A literature-based analysis.Thyroid Research (2011).

Lee Shulman heads the Division of Clinical Genetics in the Department of Obstetrics and Gynecology at the Feinberg School of Medicine at Northwestern University. He is a diplomat of the American Board of Obstetrics and Gynecology and the American Board of Medical Genetics, a Fellow of the American College of Obstetricians and Gynecologists and a Founding Fellow of the American College of Medical Genetics. He also serves as an Adjunct Professor in the Department of Medicinal Chemistry and Pharmacognosy at the College of Pharmacy of the University of Illinois at Chicago.

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