Can Estrogen and Prolactin Be The Main Triggers of Graves’ Disease and Hashimoto’s Thyroiditis?
Published April 7 2014
There are numerous factors which can trigger an autoimmune response, thus leading to a condition such as Graves’ Disease or Hashimoto’s Thyroiditis. Some of these factors include stress, a leaky gut, pathogens, and even blood sugar imbalances. However, after you read this article you might be convinced that the hormones estrogen and prolactin are the main culprits when it comes to autoimmunity.
Most people reading this know that I was diagnosed with Graves’ Disease, and restored my health back to normal through natural treatment methods. However, most of the people who have autoimmune thyroid conditions are women. In fact, just about all autoimmune disorders are more prevalent in women. At least 85% of thyroiditis, systemic sclerosis, systemic lupus erythematosus, and Sjögren disease patients are female (1). But why is this the case? Although earlier I briefly mentioned numerous factors which can lead to autoimmunity, the biggest differentiating factor between men and women are the sex hormones. Women of course have higher levels of the hormones estrogen and progesterone, while men have higher levels of androgens, such as testosterone.
Prolactin is also a hormone secreted in higher amounts by women. Although prolactin is secreted in both men and women, prolactin levels increase during pregnancy, which causes the breasts to enlarge and eventually stimulates the production of milk from the mammary glands. What actually happens during pregnancy is that high circulating concentrations of estrogen increase prolactin levels, while at the same time inhibit the stimulatory effects of prolactin on milk production. After the birth of the baby the estrogen and progesterone levels fall, which allows the elevated prolactin to induce lactation. Other factors can also lead to elevated prolactin levels, such as hypothyroidism, hypothalamic disease, kidney disease, a pituitary tumor, and certain medications (2). And as I’ll discuss later in this article, elevated prolactin levels are associated with autoimmunity.
Keep in mind that there might be other reasons why women are more likely to develop an autoimmune condition than men. So while one needs to consider the impact of these hormones, genetics definitely can be a factor, as women carry two X chromosomes (men carry an X and Y chromosome), and there is a possibility that this can play a role in immunity.
The immune system also differs to some extent between men and women. For example, females have stronger humoral and cellular immunity than men (3). This is manifested by higher levels of circulating antibodies, higher numbers of circulating CD4 T cells, enhanced cytokine production in response to infection, and rapid rejection of allografts (4). These differences in immunity can also make a woman more susceptible to developing an autoimmune condition. However, this can also relate to the sex hormones, as there is evidence that the sex hormones can affect the function of the immune cells directly via binding to the steroid receptors (4). So perhaps it’s the combination of high estrogen or prolactin levels and these differences in immunity which lead to a greater likelihood of a woman developing an autoimmune condition.
Correcting Estrogen Dominance Can Be A Key Factor In Restoring One’s Health Back To Normal
I have written numerous articles and blog posts about estrogen dominance. This is a common problem, and what’s important to understand is that estrogen dominance can not only be caused by an excess of estrogen, but can also be caused by a progesterone deficiency. In other words, one also wants to pay attention to the ratio between estrogen and progesterone. If someone has a progesterone deficiency with normal estrogen levels then this is considered to be a form of estrogen dominance.
Some of the common symptoms associated with estrogen dominance include weight gain, mood swings, irritability, hot flashes, depression, and fatigue. But many of these symptoms are common in other conditions as well (i.e. hypothyroidism), and so testing is the best method to determine if someone has an imbalance between estrogen and progesterone. This is easy enough in postmenopausal women, as a one sample test is usually sufficient to determine this. In cycling women it is more challenging, as while most medical doctors just choose a day and see what the levels should be on that specific day, the most accurate test to determine the levels in a cycling woman is through a cycling female hormone panel. In perimenopause I usually recommend testing the hormone levels two weeks apart.
The Role Of Xenoestrogens In Triggering An Autoimmune Response
Xenoestrogens can also potentially trigger an autoimmune response. I discussed this in another article I wrote entitled “Endocrine Disruptors and Thyroid Health: Part 2“. In this article I discussed some of the common sources of xenoestrogens, and I focused on four specific xenoestrogens which can have a negative impact on the endocrine system. This of course is a problem with both men and women, as while it’s more common for estrogen dominance to be associated with women, it is also possible for men to have estrogen dominance. And exposure to xenoestrogens is one of the reasons why there is a high prevalence of estrogen dominance in both men and women.
Can High Prolactin Levels Lead To Autoimmunity?
Prolactin is a hormone secreted from the pituitary gland, as well as other organs, and there is evidence that it is a big factor in promoting autoimmunity (5). Hyperprolactinemia has been described in the active phase of certain autoimmune conditions such as systemic lupus erythematosus, rheumatoid arthritis, Celiac disease, type 1 diabetes mellitus, Addison’s disease, and autoimmune thyroid conditions (6). In these conditions prolactin increases the synthesis of Interferon gamma (IFNgamma) and Interleukin 2 (IL-2) by Th1 lymphocytes, and activates Th2 lymphocytes with autoantibody production (6). Both IFNgamma and IL-2 are cytokines, and while they both play an important role in immunity, the abnormal expression of these cytokines can be a factor in autoimmunity. And so prolactin causes an increase in these two cytokines, which in turn can lead to the development of an autoimmune condition.
This could explain why there is a correlation between postpartum and autoimmunity. While there are numerous theories as to why some women develop postpartum autoimmune thyroiditis, high prolactin levels might be a big factor. Prolactin is in fact the only anterior pituitary hormone that increases progressively during pregnancy (7). Postpartum autoimmune thyroiditis is a common endocrine disorder that uniquely manifests itself within one year after delivery (7). The prevalence of 8% in the general population increases to 20% in women with type 1 diabetes or a family history of thyroid disease, and to 42% in women with a history of prior postpartum autoimmune thyroiditis (8).
How Can One Correct Estrogen Dominance and Hyperprolactinemia?
In a previous article entitled “Estrogen Dominance and Natural Treatment Solutions” I not only discussed some of the more common causes of estrogen dominance, but I also explained how to correct this problem. And so I would recommend reading the article for more information on this. As for how to correct hyperprolactinemia, conventional medical treatment usually involves the patient taking dopamine agonists. The reason for this is because dopamine can inhibit the secretion of prolactin by the anterior pituitary cells. As for a natural approach, the herb chaste tree can successfully lower high prolactin levels in many women.
Of course if someone is pregnant or has just given birth then it’s normal for these levels to be high, and if a woman is breastfeeding, then giving a dopamine agonist will affect the production of breast milk. And there are other factors which can cause elevated of prolactin levels, such as a tumor (referred to as a prolactinoma). Taking a dopamine antagonist (which are used to treat schizophrenia) will also cause hyperprolactinemia.
Plus, keep in mind that even if the high prolactin levels trigger an autoimmune response, using medication or an herb such as chaste tree to lower the prolactin levels won’t necessarily suppress the autoimmune response. In other words, removing the trigger is important, but other actions probably will be necessary to suppress the autoimmune component of the conditions. In order to understand this better, when something triggers an autoimmune condition you have the chronic activation of something called nuclear factor kappa B (NF-kappaB), along with the release of proinflammatory cytokines, and when the autoimmune trigger is removed these cytokines will still be present, and NF-kappaB needs to be inhibited. I discussed this more in my blog post entitled “The Role of Cytokines in Autoimmune Thyroid Conditions“.
In summary, estrogen dominance and hyperprolactinemia both can be triggers for autoimmune thyroid conditions such as Graves’ Disease and Hashimoto’s Thyroiditis. These factors can explain why women are more likely to develop autoimmune conditions than men. However, the immune system also differs between men and women, and so this can be a factor as well. With regards to estrogen dominance and elevated levels of prolactin, while correcting these hormone imbalances is important to restore someone’s health back to normal, this usually won’t be sufficient to suppress the autoimmune component. One needs to balance the hormones, but also needs to inhibit NF-kappaB, which I have discussed in other articles and blog posts.