There’s more to breast health than mammograms. Let’s talk about the everyday habits and emerging science shaping our understanding of breast cancer risk.

When October rolls around and the pink ribbons come out, it feels like the whole world finally agrees on something: Breast cancer sucks.

And even if breast cancer hasn’t walked into your life yet, you still have a stake in it. Because the women who are living it need a world that cares before it has to.

So today I want to talk about prevention, but I want to be careful about what I mean by it.

Risk is something we can lower over time. It can never be erased, and a lot of it sits outside our hands. At the same time, I don’t want that to overshadow the things we do have some say in.

Most of our breast health conversations revolve around screenings like mammograms. Don’t get me wrong, those are very important! But there’s a much bigger side to breast cancer prevention that I wish got more airtime. There are things we can do to support our long-term health, small enough to fold into an ordinary day.

I think every woman deserves to hear what the research says. So let’s get into it.

What do we actually know about lowering breast cancer risk?

For all the things we still don’t understand about breast cancer, there’s actually quite a bit of research looking at how our everyday habits and overall health may influence our risk.

Some of it goes back decades. Other research is beginning to uncover connections between breast cancer and things we don’t often associate with it, like insulin resistance, gut health, and the metabolic changes that happen as we move through our 40s and 50s.

We’re still figuring out what some of these findings mean, and I want to be careful about drawing conclusions before the science is there. But I also think these questions deserve more attention, especially when they could shape how we think about breast cancer prevention.

I want to start with the connections we have the strongest evidence for, then work our way into the newer research.

Alcohol: Drinking less can help lower breast cancer risk

If you enjoy a glass of wine at the end of the day, this one is probably for you. Alcohol increases the risk of breast cancer.

A 2026 meta-analysis looked at 37 studies involving more than 2.5 million women.¹ Researchers found that women who consumed alcohol had a 17% higher relative risk of developing breast cancer compared with women who didn’t drink. 

And the risk increased with the amount of alcohol consumed.

Now, I want to explain what relative risk actually means, because 17% sounds like a lot.

Imagine following 100 women who don’t drink, and 10 of them develop breast cancer. A 17% increase in relative risk would mean that among 100 otherwise comparable women who drink, we’d expect roughly 12 to develop breast cancer.

I’m using hypothetical numbers here, but you get the idea. The research found a difference in risk between groups of women with different drinking habits. It doesn’t mean that 17% of women who drink will develop breast cancer.

So what do we do with this information?

I think we start by being a little more intentional about alcohol. Maybe that means saving wine for occasions when you really want it, instead of pouring a glass out of habit every evening. Or drinking less often than you do now.

And please, I don’t want women feeling bad about every glass of wine they’ve ever enjoyed. Science gives us a good reason to drink less. How we work that into our lives is a personal decision.

Exercise: Staying active is associated with lower breast cancer risk

A 2024 study followed more than 187,000 women, some for nearly three decades, and found that women who exercised regularly had a lower risk of developing certain types of breast cancer.² (These women said their exercise habits were equivalent to at least nine hours of moderate-paced walking per week.) Compared with less active women, their risk was about 17% lower before menopause and 14% lower after menopause. 

Movement is a big part of my life, so I love seeing numbers like these. If that’s already your routine, keep it up. If it isn’t, you’re in good company, and this next study is for you.

Researchers found that women who became more active after menopause had a lower risk of breast cancer, even if they hadn’t been particularly active in the years earlier. Women who reported activity equivalent to about four hours of walking per week had roughly a 10% lower risk.³ 

Think about that for a second. If you’re in your 40s or 50s and haven’t made exercise a priority, there’s still good reason to start. 

And we’re talking about all kinds of movement here: walking, cycling, swimming, and other types of activities.

If walking is your thing, start there. Find a little time in your week and build on it. You don’t need to know exactly how many miles you’ll be walking six months from now to take your first one today.

Body composition: Excess body fat is linked to higher breast cancer risk after menopause

Our bodies change a lot through adulthood. Hormones shift, and muscle gets harder to hold onto. And as if that weren’t enough, weight starts settling in new places around menopause. Much of this is simply what aging does to most women.

Researchers have been studying how those changes relate to breast cancer risk for a long time, and weight gain during adulthood is one of the most heavily researched pieces. 

Study after study has found that women who gained the most weight over the years tend to have a higher risk of breast cancer after menopause than women who gained the least.⁴ That’s a comparison between the two ends of the range, though, and it describes groups, not what will happen to any one woman. 

I also want to mention that weight is a blunt tool. Most of these studies tracked the number on the scale, which can’t tell us how much of that weight is muscle and how much is fat. And biologically, those are two very (VERY!) different things. It’s one reason I wish we’d spend more time talking about body composition rather than obsessing over the number on the scale.

What we’re still learning about breast cancer risk

Here’s the question researchers are asking next: Is it the weight itself that matters, or what’s happening underneath it? 

Nobody has a full answer yet. 

Weight is simple to measure, so it’s what most studies tracked. But it doesn’t tell us much about what’s happening metabolically, like how our bodies handle blood sugar or the inflammatory signals coming from fat tissue. 

That’s where the newer research is headed, and a lot of it hasn’t made its way into everyday breast health conversations yet.

Could metabolic health influence breast cancer risk?

If you’ve been following the conversation around metabolic health, you’ve probably heard plenty about insulin resistance. Usually, we’re talking about it in relation to blood sugar or weight. But there’s another reason researchers are interested in it: breast cancer.

When your cells become resistant to insulin, your pancreas compensates by producing more of it. Besides managing blood sugar, insulin also helps regulate cell growth, which has researchers wondering whether chronically elevated insulin could encourage the development of certain cancers.

This is where the weight question comes back in. Two women can weigh about the same and have very different body composition and metabolic health. 

So what happens when researchers compare women at similar weights? 

A 2025 study of more than 52,000 postmenopausal women with a normal BMI found that those with higher body fat percentages had a 19% higher relative risk of breast cancer than women with lower body fat percentages.⁵ Same BMI, different body fat percentages, and different breast cancer rates.

Other research has looked at metabolic health more directly. A 2020 analysis of 25 studies involving nearly 400,000 women found that women with metabolic syndrome, a combination of metabolic problems that often includes insulin resistance, had a higher risk of developing breast cancer, particularly after menopause.⁶

What about chronic inflammation?

Fat tissue sends out inflammatory signals, and sometimes those signals get more active than usual, especially when metabolic health is off. Researchers are now investigating whether this ongoing, low-grade inflammation may influence breast cancer risk.

Inflammation may help explain some of the relationship between body composition and breast cancer risk. Whether lowering inflammation can actually change that risk is another question, and one researchers are still trying to answer.

Gut health is earning a place in the breast cancer conversation

Now we’re getting into some of the newest research, and it’s still very early.

Small studies have found differences in the gut bacteria of women with and without breast cancer, although the results vary quite a bit.^{7 8} We don’t know whether those differences are meaningful or contribute to breast cancer risk, and there’s no evidence yet that changing your gut bacteria can prevent it.

But there’s a biological connection researchers are exploring.

Your gut is home to trillions of bacteria, and some of them produce enzymes that can reactivate estrogen after your liver has processed it for elimination. This allows some estrogen to be reabsorbed instead of leaving the body. Researchers call the collection of microbial genes involved in estrogen metabolism the estrobolome.

We’re still figuring out what this means for breast cancer risk.

Does the way we metabolize estrogen matter?

This is another area where I want to be careful with the language. Estrogen is essential to women’s health. Certain breast cancers respond to estrogen, but that doesn’t mean estrogen itself is the cause of breast cancer.

Researchers have found that some patterns of estrogen metabolism are associated with lower breast cancer risk than others. A 2017 study involving more than 2,800 postmenopausal women found that greater activity along one estrogen metabolism pathway was associated with a lower risk of breast cancer.⁹

We’re still a long way from understanding whether the gut microbiome influences those patterns enough to change breast cancer risk. And we certainly don’t have evidence that manipulating estrogen metabolism through supplements or gut health interventions prevents cancer.

But I’m hopeful. I think we’re beginning to ask some worthwhile questions about how gut health and hormone metabolism fit into the bigger picture of breast cancer prevention. And I’d love to see where this research takes us.

A whole-body approach to breast cancer prevention

After digging into all this research, I keep thinking that we have more influence over our long-term health than we sometimes realize. Of course, there are no guarantees. But I still find this encouraging.

From a functional medicine perspective, I want us to pay attention to how well our bodies are working day to day: how we eat, how much we move, how we sleep, and what’s happening with our blood sugar and metabolic health.

For me, that means eating plenty of fiber-rich whole foods, keeping up with strength training and movement, being mindful of alcohol, and making time for sleep and recovery. It also means noticing when something feels off and talking with my doctor about it.

Some of these habits have stronger evidence behind them than others when it comes to breast cancer risk. And none of them replaces recommended screenings or knowing your personal and family history.

Women who take beautiful care of themselves still get breast cancer. I never want this conversation to become another reason for women to blame themselves or feel like they haven’t done enough.

There’s still so much we need to learn. In the meantime, small choices made day after day can support our health, and we can stay curious about what the next decade of research uncovers.

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Disclaimer: This article is for educational and informational purposes only and isn’t intended to diagnose, treat, cure, or prevent any medical condition or replace individualized medical advice. Always talk with your healthcare provider before starting or changing medications, supplements, hormones, or other treatments.

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