5 Breast Cancer Risk Factors You Can Influence

Today, many television series include a character facing cancer. When we see these stories repeatedly, it can feel as though we are being prepared to accept cancer as an increasingly ordinary part of life.

For a moment, you imagine someone you love sitting in that doctor’s office.

October, Breast Cancer Awareness Month, gives us a reason to pause and ask a more useful question: What can we understand - and do - before a diagnosis?

Beyond the pink ribbons, it brings us back to a personal question: What can we do for our mothers, grandmothers, aunts, daughters - and ourselves?

Many of us know a woman who ate carefully, exercised, and still developed breast cancer. A nutritious diet matters, but it cannot cancel every influence of genetics, lifelong hormonal exposure, or environmental conditions. A diagnosis does not mean someone failed to take care of herself.

There is no single formula that prevents breast cancer in every woman. The goal is to understand the factors we can influence and make informed choices over time.

A functional medicine perspective asks us to look at those connections: what the body is exposed to, how it processes hormones, and how daily habits fit into the picture.

1. Think beyond your estrogen level

Estrogen often becomes the first suspect in a conversation about breast cancer. Yet it also supports reproduction, bone maintenance, and vaginal tissue function. It belongs in a healthy female body.

What matters is the amount and duration of exposure, how tissues respond, and how the body processes the hormone. Longer lifetime estrogen exposure is associated with higher breast cancer risk, and many—but not all—breast cancers respond to estrogen signals.

An estrogen level is one piece of information. Hormone metabolism is a whole process.

As estrogen is broken down, it becomes different metabolites. Some can be converted into reactive compounds capable of damaging DNA.

This is where the COMT gene comes in. It provides instructions for making catechol-O-methyltransferase, an enzyme that helps process certain estrogen metabolites—the compounds formed as estrogen is broken down—through methylation.

Some COMT variants, often described as “slow COMT,” reduce the enzyme’s activity and may slow this part of estrogen metabolism. These metabolites matter because some can form reactive compounds that damage DNA; methylation helps limit that conversion.

That connection helps explain why estrogen metabolism interests researchers.

The useful starting point is understanding your own context: menstrual stage, symptoms, medications, family history, and any reason for a clinician to investigate further.

2. Take liver and digestive function seriously

You may think about your liver after a glass of wine, or your gallbladder after an uncomfortable meal. These organs also participate in hormone processing and elimination.

The liver changes hormones and attaches chemical groups that help the body handle and remove them. Some estrogen metabolites leave through urine. Others travel in bile to the intestine.

The liver makes bile. The gallbladder stores and releases it.

Bile helps digest fats and carries certain substances out of the liver. Once estrogen metabolites reach the intestine, some leave in stool. Others can be changed by bacterial enzymes, including beta-glucuronidase, and reabsorbed.

This recycling helps explain why digestion, gut microbes, and circulating estrogen are being studied together. Breast tissue is part of a body whose systems continually interact.

Here, detoxification refers to actual biochemical processing and elimination. Caring for those functions includes adequate nutrition, appropriate fiber and fluid intake, limiting alcohol, and getting persistent digestive symptoms or known liver and gallbladder conditions assessed.

3. Ask what is actually in your hormone prescription

Two women may both say, “I take hormones,” while using different medicines with different effects. Understanding your prescription begins with knowing the exact hormones it contains.

Estradiol, or 17β-estradiol, is an estrogen your body naturally produces. This is what bioidentical means: the hormone matches one made by the human body.

Ethinyl estradiol is an example of a chemically modified, synthetic estrogen, commonly used in combined birth control pills. Its structure differs from the estradiol your body produces. Both activate estrogen receptors, but their effects depend on the formulation, dose, and how they are used.

The hormone paired with estrogen matters, too. Micronized progesterone is bioidentical to the body’s progesterone. Medroxyprogesterone acetate, found in medicines such as Provera, is a synthetic progestin with a different molecular structure. These medicines share some functions, but their biological effects are not identical.

In the French E3N cohort study, estrogen combined with progesterone was associated with a lower breast cancer risk than estrogen combined with several other progestogens.

Before starting or renewing a prescription, ask: What are the names of my hormones? Why were these chosen for me? What benefits can I expect, what risks apply to me, and when should we review the treatment?

4. Look closely at the products you use every day

Your hormone environment extends beyond what your ovaries produce or what appears on a prescription. Chemicals in food packaging, personal-care products, and even shopping receipts can interact with the body’s hormone system.

Xenoestrogens are chemicals from outside the body that can mimic estrogen’s activity.

They belong to a broader group called endocrine-disrupting chemicals, which can interfere with hormone production, signaling, or action. BPA is one well-studied example. Other endocrine disruptors act through different pathways, so they should not all be described as “extra estrogen.”

Start with the plastic touching your food. Bisphenol A, or BPA, is used to manufacture polycarbonate plastic and epoxy resins, including coatings inside some food and beverage cans.

BPA can migrate from these materials into food and drinks, and heat can increase migration from polycarbonate containers. A practical change is to reheat food in the oven and use glass or stainless steel for hot drinks and food storage.

A “BPA-free” label tells you that BPA has been excluded; it does not identify the replacement chemical or establish its safety. Alternatives such as bisphenol S (BPS) and bisphenol F (BPF) have also shown hormone activity in laboratory studies. Choosing glass or stainless steel reduces reliance on these plastic formulations altogether.

Phthalates are another group worth recognizing. Some are added to plastics to make them flexible; others are used in personal-care products. For example, diethyl phthalate (DEP) functions as a solvent and fixative in fragrances.

Individual fragrance ingredients are not always disclosed on cosmetic labels, so “fragrance” or “parfum” may not reveal the full formulation. Choosing fragrance-free products is a concrete way to reduce this potential source of exposure.

Different phthalates have different effects; they are not interchangeable in their health risks.

Then consider the receipt handed to you at checkout. Many receipts use thermal paper, where heat creates the printed image through a chemical coating. The concern is the BPA or BPS used in that coating, rather than ordinary printer ink. These chemicals can transfer to skin during handling.

Choose a digital receipt or decline an unnecessary one, keep receipts away from food, and wash your hands before eating after handling them. Avoid giving receipts to children to play with. For someone handling receipts throughout a workday, switching to digital systems or verified phenol-free paper addresses the exposure at its source.

Your bathroom shelf deserves the same attention. Parabens—including methylparaben and propylparaben—are preservatives used in some cosmetics. Read ingredient lists if you want to reduce exposure to these specific chemicals, and review the lotions, makeup, and hair products you apply repeatedly.

5. Choose food that supports your metabolic health—and reconsider alcohol

The way you eat influences your body’s energy balance, insulin levels, and long-term health.

Consistently consuming more energy than your body uses can promote excess body fat, which is associated with a higher risk of breast cancer after menopause. Fat tissue also produces estrogen and can contribute to chronic inflammation.

Insulin does more than regulate blood sugar—it also sends growth signals. With insulin resistance, the body often produces more insulin to keep blood glucose under control.

Persistently elevated insulin and related growth-factor signaling are among the mechanisms researchers investigate to explain the connection between obesity and breast cancer. After menopause, excess body fat, higher estrogen exposure, inflammation, and insulin resistance can overlap.

Make your daily choices concrete: replace sugary drinks with water or unsweetened beverages, build meals around minimally processed foods, include vegetables and other fiber-rich foods, and choose portions that meet your energy needs.

Regular movement belongs alongside nutrition; physical activity is associated with lower breast cancer risk.

Alcohol deserves particular attention because its connection to breast cancer is established.

Risk increases with the amount consumed, and an increase is seen even at one drink per day. One standard drink means approximately 5 ounces of wine, 12 ounces of regular beer, or 1.5 ounces of spirits. A generous pour can contain more than one serving.

Alcohol can raise circulating estrogen levels. Its breakdown also produces acetaldehyde, which can damage DNA, and generates reactive molecules that contribute to oxidative stress. These mechanisms explain why alcohol’s effects extend beyond simply making the liver “work overtime.”

For reducing breast cancer risk, drinking less alcohol - or none at all - is the lower-risk choice. Red wine is not an exception.

Let awareness become everyday care

Breast cancer rarely develops from one factor alone. Age, inherited susceptibility, hormonal exposure, and lifestyle can contribute in different ways. A woman can make thoughtful choices and still develop the disease. A diagnosis is never proof that she failed to care for herself.

What we can do is act on the factors we can influence: nourish ourselves well, stay active, limit alcohol, reduce avoidable chemical exposures, and understand our hormone prescriptions.

Decisions about menopausal hormone therapy or oral contraceptives should include their specific benefits and risks for the woman taking them. Personal risk assessment and appropriate screening also deserve a place in that conversation.

For women who have already had breast cancer, healthy habits remain valuable. Physical activity is associated with better outcomes.

Every woman deserves clear information about her treatment options, expected benefits, risks, and alternatives—and the opportunity to ask questions and participate in decisions.

This October, let caring for our mothers, grandmothers, aunties, daughters, and ourselves become something practical: a conversation about family history, self-examination we have postponed, a shared walk, or a daily habit we are ready to change.

Awareness becomes meaningful when it changes how we care for one another.