Recently, I received this email question:
“Dr. Brownstein stated something in his June, 2014 Natural Way To Health newsletter (http://brownsteinhealth.com/) that caused quite a stir. He said, “Studies have shown that women who take thyroid hormone for more than 15 years have a higher risk of breast cancer than those who have not taken thyroid hormone.”
My question is this: Is the thyroid hormone you are referring to I this statement synthetic hormone or is both synthetic and natural, desiccated thyroid hormone that is causing the cancer?
Thank you for clarifying this. There are a lot of people across many Facebook and Curzone thyroid groups who are quite concerned and we would all like a clarification on this statement, please.
Than you,
Karen D
Karen,
Unfortunately, it is true: there is an association between long-term thyroid hormone use and breast cancer. (1) However, I have a typo in the original article, which I apologize for (no excuses for this one—I looked at the wrong graph). However, the typo does not detract from my explanation of why women who take thyroid hormone have an increased risk of breast cancer.
The study found a 200% (not a 50%) increase risk of breast cancer in women who took thyroid hormone for at least 15 years as compared to women who did not take thyroid hormone. You read that correctly: a 200% increase risk of breast cancer in women who took thyroid hormone as compared to women who did not take thyroid hormone.
How could that be? The answer is simple: The increased breast risk in thyroid supplemented women is due to iodine deficiency. If the majority of the women were deficient in iodine, then taking thyroid hormone would be the wrong treatment. Thyroid supplementation increases the body’s metabolic needs and therefore increases the body’s need for iodine. If someone is iodine deficient and is prescribed thyroid hormone, thyroid supplementation will worsen the iodine-deficiency problem. As I have stated in my newsletters and books, I believe that iodine deficiency could be responsible for why one in seven U.S. women are suffering with breast cancer.
What is the solution? If you are prescribed thyroid hormone to have your iodine levels checked. If you are low in iodine, it is best to either correct iodine deficiency first or at least take iodine concurrently with thyroid hormone. Iodine is needed by the breast tissue to maintain a normal breast architecture free of cysts, nodules and cancer.
What if you are already taking thyroid hormone and you are not supplementing with iodine? It is ne er too late to have your iodine levels tested. Keep in mind that the thyroid gland often improves its’ function when iodine deficiency is rectified. Therefore, if you are already taking thyroid hormone, starting iodine supplementation may require you to lower your dose of thyroid hormone. An iodine-knowledgeable health care provider can help you with this.
Folks, iodine deficiency is occurring at epidemic rates. I (along with my partners) have tested over 6,000 patients for their iodine status. I can unequivocally state that iodine deficiency is alive and well in the 21st Century as over 96% of my patients have tested for iodine deficiency—the vast majority significantly deficient.
The original JAMA article did not distinguish between which brands of thyroid hormone were taken. I do not feel it would matter which thyroid hormone prescription was taken as all supplemental thyroid hormones—both natural and synthetic forms—increase the body’s metabolic needs for more iodine.
More information about this can be found in the latest edition (5th) my book, Iodine: Why You Need It, Why You Can’t Live Without It.
JAMA. 9.6.1976. Vol. 236, N. 10. 1124
Dr. B.
I know you are not saying for us thyroid hormone dependents to go off of our meds but how do we wean safely with the
threat of breast cancer?
And is this necessary?
I just did a urine loading test with your accomplice Dr. Flechas and have started 50 mg iodoral.
I currently have 2 sisters with breast cancer. They are not known thyroid patients.
Again: would you recommend I find a way to get off the t4/t3 that I am on?
Please advise.
Thank you. Read your everything!
S
Sally,
Good question. My point was that it is important to maintain optimal iodine levels when one is taking thyroid hormone (or even if someone is not taking thyroid hormone). It is the iodine that is crucial for breast health.
DrB
Dearest Dr B,
Would it be too dramatic to say you saved my life and brought the joy back to me with your info on iodine? I started 50 idoral a day and followed your protocol in Jan. 2014. At the time I had a cluster of cyst on my left thyroid for at least 2 years. Almost right away, I began feeling an ache on the left side of my neck. This continued for about 5 months. In July, 6 months after starting Idoral I had a new ultra sound. Not a trace of the cyst on the left side, the calcification on the right side greatly improved! I also started 5000 vit d3 a day in April. I think the ache I was getting was actually the area with cysts healing! I felt a peace about the discomfort is the only way I can describe it. I have Hashimoto, adrenal fatigue and celiac, but feel more wonderful than I have in 15 years in spite of it. I would like to say though I began to feel better right away, it wasn’t until the end of April, 4 months into it, that the joy in the center of my being returned. I would suggest folks think of this as a process that takes many months, hang in there, don’t give up! I tried dropping to 25 mg a day of idoral for financial reasons but found I wasn’t feeling as well so will stay on 50 for a while.
I tell absolutely everyone I can about your web site and about iodine. I love seeing you on Dr Becker’s show as well ~ May God bless you and keep you in His tender care. Love , Terri
Terri,
I am not sure what to say, but thank you for sharing your story. You made my day,
DrB
So you are saying that the iodine contained in thyroxine (t4) is only used in the thyroid and doesn’t make it’s way into the rest of the cells in the body?
I have Hashimotos and Graves Disease (hyperthyroidism). Both are auto-immune diseases of the thyroid. I am on the Iodine Yahoo group through which I learned about Dr. Brownsteins book Iodine:Why You Need It, Why You Can’t Live Without it. I bought it I read it and UPPED my Iodine via Iodoral 50mgs tablets.. The “iodine” you need is Iodoral (tablets) or Lugol’s Solution ( liquid).. Be aware that Potassium Iodide is NOT Iodine.. Iodoral and Lugols are a COMBO of Elemental Iodine and Potassium Iodide.. be SURE you are taking the correct type.
Anyway I read the book upped my iodine to 300 mgs a day and got RID of my Hashimoto’s antibodies. Unfortunately, I ignorantly let the accursed Endocrinologist give me a RADIOACTIVE iodine pill to cure my hyperthyroidism. This was before I got informed about Iodine. The Thyroid runs on iodine. The thyroid pills contain very LITTLE iodine.. IF you were low in iodine before getting your thyroid pills you are STILL low.. so this is why I supplement with Iodine. and if you read read read you will find many more good reasons to use that iodine. Thank you Dr. B for writing that book. It has helped me immeasurably.
I’m confused. I thought thyroid meds were iodine? T4 – 4 molecules of iodine? Why would we need to take extra iodine, isn’t the t4 replacing the iodine that we can’t make ourselves? I guess I must be wrong so it would help immensely if you could explain whether or not thyroxine contains iodine and if it does, why we might need to take extra. Surely if a patient is optimalised on meds all of their iodine needs are taken care of?
Dany,
You are right, T4 contains 4 atoms of iodine. However, other tissues of the body need iodine–like the breast, ovary, uterus, etc. We need extra iodine for the other cells of the body which also require iodine.
DrB
Dr. Brownstein, I realize that this is addressing the use of thryoid hormone, but my question, Is it the chicken or the egg when it comes to interventions with the hormones? I feel that supplementation is beneficial for many thyroid patients and I hope that other physicians in the medical arena would beneficially use Armour, but there are few and far between those who will consider it. Also would these women still have the same risk for breast cancer without treatment ?? I see that you suggest that Iodine supplementation also as key also but I am questioning whether there is a link between thyroid function and diabetes (glucose intolerance ) and the longterm effects it has on the function or lack of function at the cellular level reflected by the function or dysfunction of the thyroid. In order to properly use iodine or any hormone in the body, basic funciton at cellular level has to be recognized with basic nutrtition needs and understanding diet in relation to the endocrine system. I believe that calcium has been totally neglected and misunderstood in it’s relationship to disease. My second question is why do you think Iodine deficiency is occurring at record rates and what factors do you feel may be the cause ? I have yet to find a reasonable and knowledgeable endocrinologist in the Pittsburgh area.
Dear doctor.
The following study found quite the opposite. I am really confused by your conclusion as correlation is not proof of causation.
Thyroid patients are forced to take the required hormones and this is scaring a lot of patients. While information should be given I feel this is quite alarming. Also I cannot see where in the research it stated that taking iodine would protect from it. Yes if people are low then take it but hypothyroid patients are low in lots of things quite often. Some people myself included feel quite bad when taking supplemental iodine, needle like pains in the thyroid, swinging from hyper to hypo symptoms. I have AI thyroid disease. I have always eaten plenty of sea food as I don’t react to the iodine in that.
Here is the conclusion of the 2005 study ”CONCLUSIONS:
Primary HYPT was associated with a reduced risk for PBC and a more indolent invasive disease. These data suggest a possible biologic role for thyroid hormone in the etiology of breast carcinoma and indicate areas of research for the prevention and treatment of breast carcinoma” They thought it could be used as a treatment for breast cancer! There was a great number of individuals too. Here is the link http://www.ncbi.nlm.nih.gov/pubmed/15712375
I would be interested in your comments doctor.
Dawn,
The research article did not state anything about taking iodine. I did. It was my interpretation of the research coupled with my clinical experience.
The research correlating low iodine with breast disease is pretty clear. It would make common sense as well as biochemical sense that taking thyroid hormones when someone is deficient in iodine is the wrong course. This study would lend credence to that theory.
Finally, the number one cause of hypothyroidism (at least in my practice) is low iodine. Therefore, having hypothyroidism (from low iodine) and taking thyroid hormone to treat hypothyroidism may cause the same untoward issues: an increase in breast diseases.
DrB
DrB
I am a 54 year old woman fortunate to be energetic and healthy. The 24 hours urine loading test from Hakala Labs showed I was not iodine deficient, 98%. I have Hashimoto’s Thyroiditis, am slightly hypothyroid, have thyroid nodules, TPO antibodies tested at 36. I also have extreme fibrocystic breasts and strong family history, (mother and 3 sisters) with breast cancer. I have researched a good bit on natural health methods. I have read your books and participated in Thyroid Summit and Thyroid Sessions webinars. Having symptoms of iodine deficiency yet testing sufficient, puzzles me. I find very little info on possible defective sodium iodine symporter.
I am now taking 12.5 Lugals tablets, but have no iodine proficient doctor in the Baton Rouge, La. area. How much iodine should I take although I am not deficient? My endocrinolgist doesn’t have a natural view, and it haven’t found any endocrinologist that share my natural inclination in treatment. Thank you for sharing your suggestions. Jody Kaiser
Jody,
You have a classic story of someone who may have a symporter problem.
As for the fibrocystic breast component–the number one cause of fibrocystic breast disease (which affects over 70% of U.S. women) is iodine deficiency.
How can you find a health care practitioner knowledgeable about iodine? It is not easy. Look for a chiropractor, naturopathic doctor or a nurse practitioner who is knowledgeable about iodine. The search may be difficult, but, in the end, will be worth it. Try contacting a local compounding pharmacy and find out who is using natural items in your area.
DrB
I do not know if I missed it or you have not commented onRT3.
What are the consequences of high RT3
What is the best way to correct high RT3.
A possible blog topic in the future???????
What about men? In your practice…are men being effected by long term use of thyroid too?
Susan,
Good question. There are no studies that I am aware of looking at this. However, breast cancer in men has increased dramatically over the last 20 years. This may be related to iodine deficiency as well.
DrB
This blog post is based on selective publication of outdated science. The link between thyroid hormone treatment and breast cancer was not confirmed in a larger, later published studies. This is also seen in a meta-analysis of 2012 that included the mentioned JAMA study from 1976. It is misleading to not mention this in your article.
http://www.ncbi.nlm.nih.gov/pubmed/22023791
Dear B,
I also did not mention the two other studies that found an association between taking thyroid hormone and an increased risk of breast cancer.
DrB
Had my thyroid removed 36 years ago and must take synthroid supplement daily in order to live. Does this apply to me as well?
Please advise.
Thanks.
Arlene
Arlene,
It applies to all of us. It is best to have your iodine levels checked. If low, begin supplementation to optimize iodine stores.
DrB
Hi Dr Brownstein.I follow your blog regularly and I live in Melbourne . I’m 32 years old and I have never been tested for iodine levels.Does it do any harm to take iodine supplements via an oral spray or not? I don’t have a thyroid problem but not sure of my iodine levels.Just wandering if i can still take iodine as a daily supplement and does it cause any harm or it causes more good then harm.Your response will be very helpful.Thanks a lot.
Nina,
G’day, mate!
It is best to work with a health care practitioner knowledgeable about iodine. In Australia, the Lucy Rose Clinic may be an option for you (thelucyroseclinic.com.au).
DrB
Dr B: I have several of your books and subscribe to your newsletter. You state that autoimmune thyroid illnesses (like Hashmioto’s) is caused by iodine deficiency.
Isn’t it true that the trigger for automimmune thyroid illnessess varies according to the individual? For some people, the trigger could be an infection, for others gluten sensitivity, and for others gut dysbiosis. I have Hashimotos and have yet to find the cause, but I suspect it may be a virus such as EBV.
John
John,
I agree with your ideas. It may take some detective work, but finding the underlying cause of an autoimmune disorders can help optimize a treatment plan.
DrB
Dr Brownstein, thank you very much for your answer regarding the 200% number!!! And many thanks for helping us, even non-US citizens around the world.
All the best,
Marcus
Thank you for all the information that you provide! I did have the urinary iodine test by ordering through Life Extension. I was deficient at 65% rather than the 90% recommended as normal. I have had such varying opinions on how much iodoral to take as I am beginning thyroid supplementation. What is your recommendation for dosage? Thank you!
Belinda,
Everyone’s iodine needs are different. Having said that, most patients seem to do well when taking 12-25mg/day. It is best to work with an iodine-knowledgeable health care practitioner who can guide you as well as test your iodine levels.
DrB
How does this affect those with Hashimotos, and have also had their thyroid removed?
Amanda,
The study only looked at women taking/not taking thyroid hormones. The important take home point is to ensure that you have sufficient iodine intake.
DrB
Dr Brownstein,
Are you sure you linked the correct article ?
This is what the Abstract of JAMA. 9.6.1976. Vol. 236, N. 10. 1124 (http://www.ncbi.nlm.nih.gov/pubmed/988872) says :
Abstract
This study was undertaken to determine the relationship between thyroid supplements and breast cancer. The incidence of breast cancer among the patients who received thyroid supplements was 12.13%, while in the control group it was 6.2%. The incidence rate of breast cancer was 10%, 9.42%, and 19.48% among patients who received thyroid supplements for one to five, 5 to 15, and for more than 15 years, respectively. The incidence of breast cancer among nulliparous women who received thyroid supplements was 33%, while in the nulliparous women without thyroid supplements the incidence was only 9.25%. Even in a specific age group, the incidence rate of breast cancer was higher among patients receiving thyroid supplements, when compared to the control patients in the same age group.
Where do you get the 200% number from ?
Thanks!
Best Regards,
Marc
Marc,
For women who took thyroid hormone for more than 15 years, the incidence of cancer was 33%, for those without thyroid hormone, it was 9.25%. 33/9.25 is 3.56 or 256% increased (I rounded the number down).
DrB
Thank you for this informative article! Dr Nusbaum has me on Nature-throid. I am currently taking a few drops of an iodine that I believe is derived from a seaweed or bladderwrack. I stopped taking Iodoral because another dr. told me it is not bioavailable. What tests should I ask Dr. Nusbaum to order to test my iodine levels?
Thank you!
Dr. Brownstein, can you provide a range of optimum levels for iodine in the blood?
Is the best iodine test a blood test or a urine test?
Belinda,
Urinary iodine testing provides the most information.
DrB
I’m so confused. I was supplementing my daily 75mcg of Armor Thyroid with eating seaweed and I was told to stop because it would exacerbate my Hashimotos. So is iodine supplementation a good idea in cases of autoimmunity?
Elizabeth,
As I explain in my book, Iodine: Why You Need It, Why You Can’t Live Without It, autoimmune thyroid illnesses (like Hashmioto’s) is caused by iodine deficiency.
DrB