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This complete study came out just last Thursday, August 8, 2013, in the Reproductive Biology and Endocrinology journal and it’s certainly not good news on top of what thyroid patients already know has been a failure in so many ways.

The Italian authors said the correlation between lung cancer and T4-only treatment was “significant“!

In other words, as hypothyroid patients raise their T4-only levothyroxine medication to chase continuing symptoms of hypothyroidism, it can lead to medication-induced hyperthyroid state, which in turns leads to an overproduction of oxidative stress, says the study from Italy. The latter oxidative stress is a known cause of cancer and other chronic diseases. But with T4-use, it’s specifically problematic for lung cancer.

Oxidative stress can be defined as a that which results in “significant decrease in the effectiveness of your inherant antioxidant defenses, such as glutathione” (Wikipedia). And there are two main consequences: your body doesn’t detoxify itself well, nor does it repair any damage well because of free radicals.
Forskningen ligger her http://www.rbej.com/content/pdf/1477-7827-11-75.pdf

Mary Shomon: Thyroid Patient Advocate, Author
Does Levothyroxine Increase the Risk for Lung Cancer?

Many people have been asking me about the GreenMedInfo article at http://www.greenmedinfo.com/blog/stu...dd3c1-86829085 titled: "Study: Millions Treated for Hypothyroidism At Risk for Lung Cancer."

I've looked at the Italian study and what it seems to be suggesting is that levothyroxine increases oxidative stress -- impairing the body's ability to detoxify and repair damage. Oxidative stress is a factor in disease, and in this case, they found a small increased risk of lung cancer that could be -- but is not demonstrated to be -- due to oxidative stress from levothyroxine.

The lungs require thyroid hormone to function properly. Hypothyroidism is associated with a variety of dysfunctions in organs, glands and tissues. The researchers stated in their conclusions that they can not exclude the idea that the hypothyroidism itself may be a contributing factor to the lung cancer, and not the levothyroxine used to treat it.

I've asked some doctors to review the study and share their thoughts with me. But in the meantime, I don't believe this is cause for alarm. Especially as the study is not definitive.

All thyroid patients, but perhaps especially those who are taking levothyroxine, should make sure they are eating an antioxidant rich diet. http://www.webmd.com/food-recipes/an...mal-healthThat means lots of vitamin-rich fruits and vegetables for the most part, which are definitely linked to a lowered risk of cancers, including lung cancer, and are known to fight oxidative stress from all causes.

As for the GreenMedInfo article, I have some concerns about the article, which seems to draw conclusions that the researchers didn't even reach.

Sayer Ji of GreenMedInfo writes:

"The reality is that most cases of hypothyroidism today are diagnosed in populations who are experiencing a combination of basic nutritional deficiencies and chemical exposures, or who are simply going through a temporary down-cycle in thyroid function following a natural change, such as the natural postpartum drop that occurs in women after giving birth. Even acute bouts of stress and subclinical adrenal insufficiency can cause cyclical downshifts in thyroid function."

Hashimoto's disease -- which is the primary cause of hypothyroidism in the Western world -- is a disease that has multiple triggers and causes, including heredity. It can not be explained away as simply due to "nutritional deficiencies and chemical exposures."

Ji also asks: "Why call a mineral deficiency-induced decrease in T4 a monolithic disease entity such as "hypothyroidism"? Why not simply call it selenium deficiency? Or, if fluoride, mercury, or any number of xenobiotic chemicals in the environment requiring selenium-dependent glutathione-mediated detoxification is causing the "low thyroid," why call chemical poisoning "hypothyroidism"? "

Thyroid patients and practitioners know that adding selenium, which may help lower antibodies in some patients, is not a thyroid cure-all. Hypothyroidism is not "selenium-deficiency disease." As for the toxins, while there is some evidence that toxins may trigger an autoimmune thyroid disease in a subset of patients, removing the toxins is rarely a "cure" or "treatment" for the resulting hypothyroidism.

I agree with Ji that the medical world is not doing due diligence in researching the role of nutritional deficiencies and toxic exposures in autoimmunity and in particular hypothyroidism, as well as the potential that levothyroxine may cause oxidative stress. But I think it's premature to start worrying that "levothyroxine causes lung cancer" -- when the researchers themselves admit that the opposite could be true.

Source: Cornelli, Umberto et. al. "Levothyroxine and lung cancer in females: the importance of oxidative stress," Reproductive Biology and Endocrinology, 2013, 11:75 doi:10.1186/1477-7827-11-75
Online, PDF format: http://www.rbej.com/content/pdf/1477-7827-11-75.pdf