What Estrogen Dominance Really Is — and How It Can Put You At Risk for Breast Cancer

What Estrogen Dominance Really Is — and How It Can Put You At Risk for Breast Cancer

During our initial consultation, my 34-year-old patient Jennifer brought up a host of health issues that were making her feel less-than-optimal on a daily basis. “The post-lunch bloating, pulsing afternoon headaches, and feeling tired all the time are the worst,” she told me, exhaling with frustration.

Over the past year, Jennifer had gained about 20 pounds and began suffering from irregular periods, frequent mood swings, and almost constant sugar cravings. Her frustration was palpable and she felt her gut health was to blame.

Fatigued Woman Suffering with Headache - Happy Gut Life

All of the symptoms she described pointed to something that I’m seeing more and more often among premenopausal women: estrogen dominance. Her lab tests on day 21 of her cycle confirmed my suspicion: Jennifer had high estrogen levels.

Estrogen Dominance 101: What it Means for Your Health

Estrogen dominance occurs when there is too much estrogen circulating in the body over the course of the monthly cycle. And while estrogen is technically a beneficial hormone and plays a huge role in a woman’s health from puberty all the way through menopause — helping to maintain healthy skin, strong bones and muscle, heart health, brain and mental health, and reproductive health — like all hormones, estrogen needs to stay in balance. When it doesn’t, it becomes that noisy patron at a bar who talks loudly over everyone else, leading to internal chaos.

Estrogen dominance is probably the most common issue with estrogen that I see in my office. It usually impacts perimenopausal women in their 40s but I have seen this condition in women in their 30’s and 50s.

Many of these women didn’t know they were estrogen dominant. What they did know was that they had symptoms of excess estrogen exposure , like:

  • Breast tenderness and swelling starting up to one week before menstruation
  • Extended PMS starting two weeks before menstruation
  • Heavy periods
  • Mood swings
  • Sugar cravings
  • An inability to lose those stubborn pounds
  • Feeling puffy and water retention

These symptoms are miserable on their own. But over time, they can contribute to other problems, including increasing your risk of :

  • Certain cancers, including breast, ovarian, and endometrial cancers
  • Blood clots and stroke
  • Thyroid dysfunction, creating further problems such as fatigue and weight changes

In my last blog , I talked about the connection between breast cancer and the gut microbiome. Well, guess what? Maintaining healthy levels of estrogen is often the factor that connects the two. How? Like I explained in my Gut Detox Masterclass, an unhappy gut can lead to higher estrogen levels, which causes estrogen dominance and eventually can increase your risk of breast cancer .

As I explained to Jennifer during our first consultation, getting estrogen levels under control is critical to managing weight and eliminating symptoms like mood swings and fatigue, but also for preventing bigger-picture issues like breast cancer.

Progesterone — Your Missing Female Superpower in Estrogen Dominance

Progesterone is another important female sex hormone — it basically helps keep the effects of estrogen on your body in balance. Think of progesterone and estrogen as the yin-yang of the female body.

The Balance Between Estrogen and Progesterone

Estrogen would be the activating yang element, while progesterone is the calming yin element. Without progesterone, estrogen becomes a runaway train car. The problem women with estrogen dominance face is inadequate progesterone production.
And you need a healthy menstrual cycle in order to produce adequate amounts of progesterone. You see, your ovaries produce most of the body’s progesterone, which plays a critical role in the menstrual cycle after ovulation.

The effects of progesterone in the body include:

  • Preventing fluid retention
  • Improving sleep
  • Promoting calm
  • Boosting mood stability
  • Supporting bone health
  • Assisting with a healthy libido
Estrogen Molecular Structure
Progesterone Molecular Structure

When estrogen and progesterone are in balance, you feel like a rock star. Life feels good! You maintain a healthy weight, have great energy, and your sex drive stays stellar. When progesterone levels drop, however, estrogen can dominate the scene. Headaches, migraines, mood disorders such as anxiety and depression, and an irregular, shortened menstrual cycle are all signs of low progesterone .

When there’s estrogen dominance, progesterone deficiency is usually part of the problem. That said, rarely does one factor alone fuel estrogen dominance. Environmental exposures also fuel excess estrogen in the body by adding to the toxin load with EDC’s (endocrine-disrupting chemicals), which you can read more about from my blogpost, Avoid Obnoxious Toxins to Build Your Immuno-Resiliance .

Ultimately, a near-constant onslaught of low-nutrient, high-calorie foods (like sugar, refined carbohydrates, and packaged foods) and hormone-disrupting lifestyle factors are what knock estrogen levels out of balance in the first place. The key factors that often drive estrogen dominance include:

The Sneaky Causes of Estrogen Dominance

Gut Dysbiosis - Illustration - Happy Gut Life

Gut Dysbiosis

Probably the most important underlying cause of estrogen dominance is a gut microbiome imbalance, which can allow bound, metabolized estrogen to be released and recirculate throughout the body. We’ll do a deep dive into this relationship later on in the article but for now, know that gut dysbiosis often translates to more estrogen in the body.

Endocrine Disruptors - Happy Gut Life

Environmental Toxins

Everything from the air we breathe to the water we drink bombards our body with toxins, which can disrupt hormone balance . Many pesticides and other toxins can bind to and potentially activate estrogen receptors. We call these toxins endocrine disruptors because they disrupt the balance of hormones. Some act as xenoestrogens, “foreign” estrogens that bind to estrogen receptors and mimic its effects .

An Overwhelmed Liver - Happy Gut Life

An Overwhelmed Liver

Toxins can impair the body’s detoxification process, including its ability to detox excess hormones. This toxic overload can also increase the body’s demand for important antioxidants such as glutathione, which help the body detoxify excess estrogen levels leading to even higher estrogen. Talk about a lose-lose situation! If you want to learn more, I explain more about the liver and detoxification process in my Gut DETOX Masterclass.

Pre-Packaged Farm-Raised Meat - Happy Gut Life

Too Much Farm-Raised Meat

I like to say, “You are what you eat.” The inflammatory foods, hormones, and antibiotics that conventionally-raised animals receive can end up in your food. This happens a lot with red meat, but the same problem exists in factory-farmed chicken and even fish. Sugar, refined carbohydrates, alcohol, dairy, and caffeine are other culprits that in my experience, can exacerbate estrogen dominance.

Stress - Happy Gut Life


Constantly feeling stressed out can damage the immune system , gut microbiome, and more. Stress can also disrupt hormones, leading to lower progesterone levels and menstrual cycle disruptions. I talk about how to manage stress here .

Subpar Sleep - Happy Gut Life

Subpar Sleep

When you don’t sleep well, critical hormones like insulin can get out of whack, leading to insulin resistance . In my practice, I see how when insulin is disrupted, other hormones, including testosterone and estrogen are quick to follow. Too much estrogen and not enough progesterone can also impair the production of melatonin , which regulates your circadian rhythm. To learn more about the many ways melatonin and gut health are connected, check out my blog about magnifying your melatonin production .

Medications - Happy Gut Life


Many over-the-counter and prescription drugs can disrupt hormonal balance. A frequent estrogen-dominance offender is birth control pills. Many of the newer pills introduce synthetic progesterone (called progestin ) into the body, inhibiting the body from making natural progesterone to balance estrogen levels.

Constipation - Happy Gut Life


If you aren’t having regular bowel movements, hormones such as estrogen can go back into circulation instead of being eliminated from the body. Eventually, this can lead to estrogen dominance, which ironically, can cause more constipation . The goal is to have at least one bowel movement daily. Gradually increasing dietary fiber will support the gut’s detoxification abilities and promote regularity.

Clearly, there’s more than one sneaky underlying cause of estrogen imbalance. But as I mentioned, the most important one is dysbiosis, which is why now, I’ll be diving into the details of how the gut microbiome and estrogen metabolism are linked.

The Gut, Dysbiosis and Estrogen Metabolism

Jennifer was absolutely correct when she told me she suspected that her gut health was contributing to many of her symptoms. And that’s because a healthy gut is critical to keeping hormones like estrogen in balance.

In fact, hormone management is such an important part of gut health that we have coined a subset of the gut microbe environment called the estrobolome. The estrobolome contains bacteria that:

  • Metabolize estrogen
  • Regulate the circulation of estrogen
  • Determine how well estrogen metabolites are excreted from the body

Here’s one example of how this works in real life: Gut bacteria make beta-glucuronidase , an enzyme that reactivates metabolized estrogen, releasing it so that it can then re-enter the body and bind to estrogen receptors. When the gut falls into a state of dysbiosis, the amount of beta-glucuronidase-producing bacteria increases , leading to estrogen imbalances.

To maintain hormone harmony, you need the right amount of estrogen-metabolizing bacteria in your gut. When there’s an imbalance between favorable and unfavorable microorganisms in the gut, harmful levels of bacteria can proliferate and lead to excess estrogen , which then build up and go on to circulate throughout the body. This creates estrogen dominance and increases the risk of breast-related problems, including breast cancer.

The gut is a critical and often-overlooked organ for detoxification. To learn more, we’re providing FREE Access to my Gut DETOX Masterclass this month in honor of Breast Cancer Awareness.

Estrogen Dominance, The Gut, and Weight Gain

Weight loss resistance and weight gain are two of the major symptoms of estrogen dominance, as Jennifer discovered when we started working together. Many times, environmental toxins contribute to this type of estrogen overload. The word “ obesogens ” has even been coined to describe the xenoestrogens that can increase the size of fat cells.

When a female patient carries excess weight, especially in the hips and thighs, I will always check estrogen levels. I also suspect estrogen dominance when a woman tells me she “has tried every diet” but can’t seem to lose weight.

I find that the key to fixing this type of estrogen dominance and finally losing that pesky weight is almost always tending to the gut. That’s because not only does a healthy gut help maintain healthy estrogen levels; estrogen and the gut work together. Besides leading to excess estrogen circulating in the body, an unhealthy gut can create chronic inflammation, a major player in weight loss resistance and obesity. In my practice, I see how dysbiosis can develop into leaky gut, small intestinal bacterial overgrowth (SIBO), and other gut problems. Conversely, a healthy balance of gut microbes can help maintain a healthy weight and reduce your risk of metabolic diseases. I talk more about how specific gut bacteria can help you lose weight in this blog .

Over time, the relationship between estrogen metabolism and your gut health can either increase or reduce your risk of developing obesity, type 2 diabetes, and even cancer, depending on how healthy the relationship actually is. And what influences the health of that connection more than anything is — you guessed it! — your lifestyle choices.

How to Combat Estrogen Dominance

Eating a Happy Gut® diet dramatically helped Jennifer rebalance her estrogen levels. We nixed the sugary foods and refined carbohydrates and brought in a lot of gut-healing plant foods, including more fermented foods and root vegetables like sweet potato to support progesterone production in the second half of the cycle. To manage gut inflammation, we brought in omega-3 fatty acid-rich foods such as wild-caught salmon and flax and chia seeds.

I also had her incorporate five key lifestyle factors that are critical to balancing estrogen levels. Along with her upgraded diet, Jennifer saw a big improvement in her estrogen:progesterone balance within two months. I’ve seen these same strategies work wonderfully with other patients who have struggled with estrogen dominance for years.

5 Ways To Fend Off Estrogen Dominance

Skin Care Products Containing EDCs - Happy Gut Life

1. Avoid Endocrine-Disrupting Chemicals (EDCs) in Topical Products.

Women use an average of 16 skincare and cosmetic products daily. And in America, there are about 12,500 chemical ingredients that could be hiding in these products. That’s a lot of potential estrogen-disrupting chemicals that you’re adding to your body every day! Sunscreen products are especially notorious for containing estrogen-mimicking ingredients such as oxybenzone and octinoxate. The Environmental Working Group’s (EWG’s) Skin Deep Guide allows you to search specific ingredients, brands, and products to determine whether your skincare products are safe.

Plastic Water Bottles and Food Containers (EDC) - Happy Gut Life

2. Avoid EDCs from the Environment.

We just talked about hormone-disrupting chemicals in skincare products, but these chemicals are nearly everywhere. One of the biggest offenders is bisphenol-A (BPA), which is found in water bottles, food storage containers, and even sales receipts. This endocrine disruptor derived from petroleum mimics estrogen in the body and can cause hormonal abnormalities that are not easily detectable through laboratory tests. BPA can leach into your foods and drinks, especially if you leave plastic food containers or water bottles in the heat or direct sunlight.

Progesterone Enhancing Foods - Happy Gut Life

3. Enhance Progesterone Levels.

Progesterone is the leading hormone during the second half of your menstrual cycle. And as we learned earlier, when progesterone stays balanced, estrogen is more likely to stay balanced, too. With optimal progesterone levels, many women find that symptoms like mood swings are less of a problem during their monthly moon cycle. One way to naturally restore progesterone levels is by eating foods rich in nutrients including vitamin C, magnesium, vitamin B6, and zinc, which you can get from foods like wild-caught fish, grass-fed beef, sweet potatoes, cassava, and spinach.

Seed Cycling - Pumpkin, Sesame, Flax and Sunflower Seeds - Happy Gut Life

4. Try Seed Cycling.

Many women find seed cycling to be very effective for balancing hormones, improving fertility, and reducing menopausal symptoms. One study even showed that adding flaxseeds alone, for instance, could improve the regularity of your menstrual cycle. Seed cycling involves rotating flax seeds with pumpkin, sesame, and sunflower seeds at different times of the month. These seeds are high in lignans, powerful antioxidants, and polyphenols that can help the body manage estrogen levels. One specific lignan, called enterolactone, can help manage the populations of estrogen-metabolizing bacteria, which can potentially lower the risk of breast cancer over time. Here’s how seed cycling works:

  • During the first 13 to 14 days of your menstrual cycle (the follicular phase), eat one tablespoon of freshly ground flaxseeds and pumpkin seeds daily.
  • During the second half of your cycle (the luteal phase — this is when progesterone is key), eat one tablespoon of ground sunflower and sesame seeds daily until menstruation.
Quick Fact - Happy Gut Life

Quick Fact : The luteal phase of your menstrual cycle is always 14 days long; so, if you have a short menstrual cycle, it’s very likely you have progesterone deficiency due to a weak luteal phase.


5. Show Your Liver Some Love.

When the liver is backed up, detoxification can come to a standstill. As a result, hormones like estrogen can go back into circulation rather than being properly excreted. For women with estrogen dominance, a critical step to restoring balance is ensuring that the liver is properly detoxifying. Wondering where to start? I formulated my HAPPY GUT® RESET: 7-Day Detox to get amazing detox results in just one week. That means you can heal your gut, help your liver more effectively detoxify, balance your hormones, and drop those unwanted pounds — STAT.

I’ve used this results-driven program with Jennifer and many other patients, and I’m excited to say that it is now available to the public. The response to the HAPPY GUT® RESET: 7-Day Detox has been overwhelming, and I want to help you get those same results if you think estrogen dominance might be a problem for you. When you reset the gut and detox the liver, you balance hormones, find your happy weight, and prevent breast cancer and other serious health conditions down the line.

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