Estrogen dominance and breast cancer prevention: A Functional Nutrition approach

As Functional Nutrition practitioners, we play a vital role in guiding our clients toward understanding how estrogen dominance impacts their health, especially when it comes to hormone-driven cancers like estrogen receptor-positive (ER-positive) breast cancer. In this article, we’ll explore key insights and practical strategies to help you support your clients in balancing hormones, reducing cancer risk, and optimizing their health outcomes.

Introduction to estrogen dominance (ED) and breast cancer

Estrogen receptor-positive (ER-positive) breast cancers account for 70-80% of all breast cancers. These cancers thrive in the presence of excess estrogen, making estrogen dominance a critical factor to address in breast cancer prevention and management.

But as practitioners, it’s important to clarify to our clients that estrogen is not the enemy—it’s a vital hormone responsible for many essential bodily functions. The goal is to help clients understand that it’s the imbalance—too much estrogen relative to other hormones like progesterone, or poor estrogen metabolism—that contributes to health issues, including cancer risk.

Our role is to guide clients toward hormone balance using Functional Nutrition strategies that empower them to take charge of their health in a proactive and personalized way.

What is estrogen?

Estrogen is a class of hormones that influence everything from reproductive health to brain function. The three most well-known types of estrogen are estrone (E1), estradiol (E2), and estriol (E3). Estradiol, or E2, is the most potent and active form in premenopausal women, impacting myriad functions in the body.

Estrogen is produced primarily in the ovaries but it’s also made by the adrenal glands, fat cells, and the testes (in those who have them). After menopause, fat cells and adrenal glands become the primary sources of estrogen production.

Helping your clients understand the broad roles estrogen plays in the body, from cardiovascular to cognitive health, lays the foundation for deeper conversations about why its balance is so essential.

Receptors: The key players in hormone-related breast cancer growth

Estrogen exerts its effects by binding to receptors on cells—like a lock and key. The two primary estrogen receptors, ERα and ERβ, are found in various tissues throughout the body. ERα is more prevalent in the breast and uterus, while ERβ is dominant in the brain, bones, and cardiovascular system.

In ER-positive breast cancer, the cancer cells develop an overabundance of these estrogen receptors, making them highly responsive to circulating estrogen. When estrogen binds to these receptors, it fuels the growth and proliferation of those cancerous cells.

As practitioners, it’s important to explain this process clearly to clients, helping them understand that supporting estrogen balance and metabolism can reduce the fuel available to these cancer cells. The fuel in this case is excess circulating estrogen. 

Understanding estrogen dominance

Estrogen dominance occurs when there is too much estrogen relative to other hormones, particularly progesterone. This imbalance can arise for a variety of reasons, and as Functional Nutrition Counselors, it’s important to address these underlying causes:

1. Hormonal imbalances As clients age, especially as they approach menopause, progesterone levels drop more rapidly than estrogen, setting the stage for estrogen dominance. Chronic stress can exacerbate this imbalance, as the body prioritizes cortisol production over progesterone, a process often referred to as the “cortisol steal.” 

Functional Nutrition Nugget: Help your clients understand the importance of managing stress and cultivating resilience as a key component of hormone balance.

2. Xenoestrogens and environmental toxins Xenoestrogens are synthetic compounds found in everyday products like plastics, pesticides, and cosmetics that mimic estrogen in the body. They can bind to estrogen receptors, disrupt hormonal balance, and contribute to estrogen dominance. Educating your clients about reducing their exposure to these toxins and opting for more natural alternatives is an essential step in supporting hormone health.

Functional Nutrition Nugget: Manage what’s possible with xenoestrogen exposure instead of aiming for some state of perfection (which will only create more stress.)

3. Estrogen from fat cells Fat cells naturally produce estrogen, particularly estrone. This is one reason why individuals with more body fat may experience higher circulating levels of estrogen, which can influence hormone balance. Rather than focusing on weight as the primary issue, it’s important to emphasize overall well-being. Supporting clients in nurturing their bodies through balanced nutrition, joyful movement, and lifestyle practices that respect their unique needs and circumstances is key. Our goal as practitioners is to help clients feel empowered and healthy in their own bodies, rather than focusing solely on weight as a marker of health.

Functional Nutrition Nugget: Inflammation, one of our 3 Roots of any chronic issue, plays a key role in hormone balance and weight management. Chronic inflammation can drive fat storage and disrupt hormone function. Helping clients reduce inflammation—through anti-inflammatory foods, stress management, and gut health support—can naturally support balanced hormone levels and body composition without focusing solely on weight loss.

Strategies for balancing estrogen and progesterone

As Functional Nutrition practitioners, we’re uniquely positioned to offer clients a comprehensive approach to hormone balance that works in tandem with or instead of hormone replacement therapy, depending on the case. Here’s your game plan:

1. Support progesterone levels Progesterone counteracts the effects of estrogen, helping to maintain balance. When clients have low levels of progesterone—which happens naturally as we age or when we’re under chronic stress—they’re at a higher risk for estrogen dominance, even if their estrogen levels are not elevated. Supporting progesterone production through stress management, adequate sleep, and specific nutrients such as healthy fats, high-quality protein and fiber-rich foods can help balance hormone levels.

2. Focus on detoxification and metabolism The liver is responsible for metabolizing estrogen and preparing it for elimination. The gut also plays a crucial role in ensuring that excess estrogen is excreted from the body. Encourage your clients to focus on liver and gut health through nutrient-dense, fiber-rich foods, hydration, and regular bowel movements. Proper detoxification can help prevent estrogen from being reabsorbed and recirculated in the body. At the Functional Nutrition Alliance, proper detoxification starts with sleep, poop, and blood sugar balance (our Non-Negotiable Trifecta.)

3. Minimize xenoestrogen exposure Reducing exposure to environmental toxins can help minimize estrogen-like compounds in the body. Encourage your clients to opt for organic, non-toxic products when possible and avoid common sources of xenoestrogens like plastics, processed foods, and conventional personal care products. Note: It’s important to meet clients where they are. Encourage them to start by focusing on one area at a time—whether it’s switching to non-toxic skincare or reducing plastic use—and build from there. Small, consistent changes can create a meaningful shift without overwhelming them and adding to their stress load. Progress is about taking the current state to version 2.0, step by step, rather than aiming for perfection all at once.

4. Manage stress We know! This is easier said than done. Chronic stress increases cortisol production, which can lead to a depletion of progesterone, contributing to that state of estrogen dominance. Help your clients develop stress resilience through practices like mindfulness, meditation, and regular physical activity. These strategies not only support hormone balance but also contribute to overall well-being. And remember, our Non-Negotiable Trifecta (sleep, poop, blood sugar balance) are also key ways to support the physiological impacts of stress. 

5. Nourish the microbiome A healthy gut microbiome is critical for estrogen metabolism. The estrobolome, a subset of gut bacteria, helps break down estrogen and prepare it for elimination. By supporting gut health with prebiotic and probiotic-rich foods, you can help your clients optimize estrogen elimination and reduce the risk of estrogen dominance. We love everything digestion and microbial support at the Functional Nutrition Alliance!

Breast cancer prevention through Functional Nutrition

Estrogen dominance is not a diagnosis. It’s a lens through which we can better understand the increasing rates of hormone imbalance and its corresponding signs, symptoms and diagnoses. Addressing these imbalances is key to breast cancer prevention and overall health. Here are the core components of a prevention strategy through Functional Nutrition:

1. Reduce chronic inflammation Chronic inflammation disrupts hormonal balance and can increase the risk of breast cancer. By helping clients incorporate anti-inflammatory foods and lifestyle practices, you can support hormone balance and reduce cancer risk.

2. Support detoxification pathways Encourage clients to support their liver and gut health to ensure the proper metabolization and elimination of estrogen. Without efficient detoxification, excess estrogen can accumulate and contribute to hormone-driven cancers. Detoxification starts with elimination. 

3. Tailor your approach Remember, every client is unique, and one-size-fits-all solutions don’t work when it comes to hormone health. Work with clients to develop a personalized plan that takes into account their hormonal status, stress levels, environmental exposures, and individual health history, socioeconomic status, support mechanisms and more.

Education is empowerment

As practitioners, our role is to educate and empower clients to take control of their hormone health. Estrogen is a powerful hormone, and when it’s out of balance, it can lead to significant health challenges, including an increased risk for breast cancer. By applying Functional Nutrition principles—supporting detoxification, managing stress, minimizing toxin exposure, and fostering gut health—we can guide our clients toward more balanced hormones and reduced cancer risk.

Remember, estrogen is not the enemy. But its balance is essential. Through personalized nutrition and lifestyle strategies, we can support our clients in ways that might otherwise be missing from their medical team.

At the Functional Nutrition Alliance, we believe in the power of education and empowerment. By incorporating these principles into your practice, you’re not only helping your clients lead healthier, more balanced lives, but you’re also contributing to a larger movement that prioritizes whole-person care and sustainable health solutions.

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