Of all the hormone-related topics that I have tried to understand, estrogen dominance has been one of the most confusing. The misconception for me was that if you have “estrogen dominance” then your ovaries must be producing too much estrogen. This is very rarely the case. The term estrogen dominance does not mean producing too much estrogen but rather that there is too much estrogen in relation to progesterone. It is entirely possible and in fact very common to have low estrogen but have estrogen dominance at the same time.
Women who do not ovulate regularly (eg. PCOS) or at all are by default estrogen dominant. This is not because they produce too much estrogen. In actual fact, women who do not ovulate have low ovarian estrogen output. A certain level of estrogen is needed to be released for a period of time to trigger ovulation. If there is no ovulation, there is no progesterone production by the ovary. Progesterone is only produced after ovulation. The aim for women who do not ovulate is to establish ovulation and produce progesterone.
For women who do ovulate regularly and have regular periods, estrogen dominance is rarely an issue of overproduction of estrogen from the ovaries but rather an issue with how much estrogen is retained in the body. In order to understand this, it is important to understand the pathway of estrogen throughout the body:
The pituitary gland in the brain sends a signal to the ovary to produce estrogen. Once estrogen is released it is sent out to affect its target tissue (eg. the uterus, the brain, the bones and the heart). Once estrogen has done its work it is then sent to the liver to be metabolised. The liver will then send the estrogen to the gall bladder and is then sent to the intestines/gut for excretion out of the body. Estrogen also gets excreted in the urine. If there is compromised or inadequate function in the liver, gall bladder or gut this often leads to an inability of the body to successfully breakdown and eliminate estrogen and therefore estrogen can recirculate or re-enter the system leading to symptoms of estrogen excess. There are different metabolites of estrogen (the liver converts estrodiol into different forms) that can affect the body, some more harmful than others. Common symptoms of estrogen dominance are tender breasts, heavy and painful periods and PMS symptoms. Over time estrogen dominance can lead to issues like ovarian cysts, fibrocystic breasts, uterine fibroids and estrogenic cancers.
The liver: the liver’s job is to process estrogen and render it inactive in the body. It does this through phase I and phases II liver detoxification pathways. There are two main reasons the liver would fail to process estrogen correctly: 1. the liver is overburdened with toxins or 2. nutrient deficiencies (or both). Regular exposure to toxins in our food and environment can overburden the liver. Alcohol, medications and recreational drugs are highly toxic to the body. Estrogen is seen as less of a threat and so is not prioritised by the liver. Other environmental toxins that can burden the liver include chemical food additives, herbicides & pesticides, cosmetics, plastics and cleaning products.
It is still possible for the liver to not be functioning optionally even if external toxins are kept low. This is due to nutrient deficiencies. The liver needs an extensive amount of nutrients including protein, fat-soluble vitamins A D E and K, magnesium, zinc, selenium and B vitamins in order to function optimally. For women, this may be caused by inadequate diet but often it is also caused by nutrient depletion following hormonal contraception (which is known to cause nutrient deficiencies and interfere with both liver and gut function). Medications can deplete nutrients as well as periods of intense nutrient demand such as pregnancy, breastfeeding or active lifestyles that require intense physical exercise. Refined sugars and grains, as well as stress, also impede liver function by depleting the liver of essential nutrients.
The solution to improving estrogen dominance by optimising liver function is to reduce external toxin exposure and correct any nutritional deficiencies.
Gall bladder: The main role of the gall bladder is to process fat. The exact role of the gall bladder in processing estrogen is not well understood however it comes down to the relationship between estrogen and fat. We know that periods of high estrogen exposure such as in pregnancy, using synthetic estrogens in hormonal birth control as well as hormone replacement therapy (HRT) increases cholesterol production in the liver which can burden the gall bladder and lead to gall stones. At the same time, high-fat diets have been shown in studies to increase estrogen in the body. High fat leads to high estrogen and high estrogen leads to high cholesterol. Studies show fat greatly increases the reabsorption of estrogen from bile secretions leading to estrogen dominance. Conversely, removal of the gall bladder leads to a sharp increase in estrogen dominance symptoms shortly after surgery. Gall bladder issues that relate to estrogen dominance are more likely to occur in the perimenopause period when estrogen levels are fluctuating and varying changes in metabolism occur.
Improving gall bladder function is first dependant on improving liver function, and taking care not to overeat or consume overly fatty or greasy foods and avoiding exposure to external estrogens from hormonal birth control and HRT. Improving gall bladder function may improve both liver and gut function which can help minimise symptoms of estrogen dominance.
Intestines/Gut: The role of the gut is to safely remove metabolised estrogens from the body. Generally speaking, constipation will lead to the reabsorption of estrogen in the body. Regular bowel movements 1-3 times a day are needed for adequate excretion of estrogen from the body. A good microbiome is also needed to help move estrogen out of the body. Gut dysbiosis is a known cause of estrogen dominance. Some less friendly bacterial strands have been shown to excrete an enzyme called beta-glucuronidase that can reactivate the inactive forms of estrogen which will then re-enter the bloodstream and recirculate in the body.
Improving gut function can be complex but eating fibre found in whole plant foods helps to trap estrogen in the stool while also building the gut microbiome and healing “leaky gut” or gut permeability. Women consuming high fibre diets showed significantly increased excretion of estrogen in the stool.
External estrogen sources: Estrogen dominance is usually caused by a reduced capacity of the above organ systems to remove used up endogenous estrogen, however, estrogen can also be obtained through external sources which further burdens the organ systems and makes it more challenging for them to do their job. Toxic chemicals found in everyday cosmetics, cleaning products, as well as herbicides and pesticides, contain chemicals known as “xenoestrogens” which can mimic the action of estrogen in the body and further increase the load of estrogen in the body.
Animal products are known to lead to estrogen dominance. Meat and dairy contain real estrogens produced in the body of the animals, even if the animals are not treated with added hormones. All animals still produce their own estrogen which is then consumed increasing the load of estrogen on the body. Animal products are also high in saturated fat. Environmental toxins such as pesticides are stored and concentrated within animal fat. This toxicity and high fat intake will simultaneously “clog” up liver cells and burden the gall bladder. Animal-based saturated fat is also shown to negatively impact the microbiome in the gut.
Body Fat: One final aspect of estrogen dominance is excess body fat. There is a strong relationship between fat and estrogen. Too little body fat can lower estrogen produced by the ovary leading to a lack of ovulation and loss of period (this is partially why many women with eating disorders lose their periods). Conversely, having too much body fat can lead to estrogen dominance. This is because fat cells create estrogen and the more fat cells there are the more estrogen is produced. Excess body fat can lead to estrogen dominance symptoms as mentioned above.
To conclude, estorgen dominance is a complex topic and it takes a little discression and investigation to determine which body symptoms need help in processing estrogen. In my case, I was very low estrogen (though not low enough to not ovulate) for many years but I was also estrogen dominant and would get PMS, heavy and somewhat painful periods (not too bad in my case), water retention and sore breasts. In my case it was mostly an issue with my liver caused by nutrient deficiencies. At the beginning of my health journey I have no doubt that my gut was also mildly compromised but my gut fixed up relatively quickly after turning plant-based and adding a variety of plant foods into my diet. However my history of hormonal birth control use as well as antidpressant use (which both deplete nutrients heavily) coupled with having a very minimal and fussy diet most of my life and then suffering through years of low appetite and nausea following antidpressant use meant that my nutrient stores were very low. Additionally my anxiety disorder further burdened my liver on a daily basis causing more nutrient deficiencies that were very hard to get on top of (especially as I lose my appetite when anxious). I tried to remove as many toxins from my lifestyle early on but this alone could not compensate for the nutrient deficiencies I had for so many years. I think this is an important message to share as many women are incredibly depleted for various reasons but are told they are too toxic and must detox and restrict to help their liver. Although removing toxins from the diet and environment is important for most women, its not always enough.