New Research Reveals A Concerning Link Between Forever Chemicals & Breast Cancer
By now, most of us are familiar with forever chemicals. We've heard about them in our drinking water, food packaging, cookware, and even our clothing. And while avoiding them entirely is nearly impossible, there's good reason to pay attention to how these chemicals might affect our long-term health.
Over the past several years, researchers have been investigating the potential health consequences of PFAS exposure, from hormone disruption to certain cancers. But when it comes to breast cancer, the research hasn't always been consistent.
Part of the challenge is that breast cancer isn't a single disease. Different types of tumors have different characteristics, risk factors, and treatment options, which means environmental exposures may not affect them all in the same way.
Now, a new study from the National Institutes of Health (NIH) is offering a closer look at how two common forever chemicals may relate to a particularly aggressive form of breast cancer.
Forever chemicals & breast cancer risk
In this new study published in the Journal of Clinical Oncology, researchers investigated whether exposure to certain forever chemicals was associated with breast cancer risk.
Forever chemicals, formally known as per- and polyfluoroalkyl substances (PFAS), are a large group of synthetic chemicals used in products ranging from stain-resistant fabrics to certain food packaging materials. They're called forever chemicals because they break down extremely slowly in the environment, and some can remain in our bodies for years.
Researchers analyzed blood samples from ~1,600 women who developed breast cancer and a comparison group of ~2,300 women enrolled in the NIH's Sister Study.
Importantly, the researchers collected these samples years before participants received a cancer diagnosis, allowing them to examine whether earlier chemical exposure was associated with future disease.
They measured 17 different PFAS and looked at breast cancer risk overall, as well as specific tumor types.
Two forever chemicals were linked to higher rates
The most notable finding involved two chemicals: PFOA and PFOS. Compared with women who had the lowest blood concentrations:
- Women with the highest PFOA levels had a 67% higher rate of estrogen receptor-negative (ER-negative) breast cancer.
- Women with the highest PFOS levels had a 93% higher rate of ER-negative breast cancer.
These percentages represent relative differences between exposure groups, not an individual's likelihood of developing cancer.
ER-negative breast cancer lacks the estrogen receptors that allow certain tumors to respond to hormone-based treatments. These cancers tend to be more aggressive, and researchers know less about their specific risk factors.
Interestingly, neither PFOA nor PFOS showed a clear association with breast cancer risk overall. Instead, the relationship was concentrated among women who developed ER-negative tumors, suggesting that environmental exposures may be associated with some breast cancer subtypes more than others.
Scientists suspect that changes in immune function or gene regulation might help explain the association, although this study didn't investigate those mechanisms directly. And because the research was observational, it cannot establish that PFAS exposure causes breast cancer.
How to reduce your exposure to forever chemicals
PFAS are pretty much everywhere, so avoiding them completely isn't realistic. But there are a few simple swaps and habits that can help you cut back on everyday exposure.
- Invest in a good water filter. Look for one certified to reduce PFAS. Certain activated carbon and reverse-osmosis filters can help, but not all filters remove the same chemicals.
- Rethink your takeout containers. Grease-resistant food wrappers and packaging can contain PFAS, so try transferring takeout to your own plates or glass containers rather than storing or reheating food in the original packaging.
- Skip the stain-resistant treatments. Shopping for a new couch, rug, or jacket? Look for options made without added PFAS or stain-repellent chemical treatments.
- Check your nonstick cookware. Some nonstick pans use PFAS-based coatings. If you're replacing an older pan, stainless steel, cast iron, or uncoated ceramic are alternatives worth considering.
- Take a closer look at your beauty products. Some long-wear and waterproof cosmetics contain PFAS. Check ingredient lists for names containing "perfluoro" or "polyfluoro," and consider PFAS-free options when possible.
- Up your fiber intake. Eating more fiber may help your body eliminate certain PFAS through your digestive system, potentially reducing how much accumulates over time.
RELATED READ: Follow This Guide To Get 30+ Grams Of Fiber Daily
The takeaway
We've known for some time that forever chemicals can have consequences for human health, but researchers are still working to understand which exposures pose the greatest risks and who may be most vulnerable.
This study adds to that picture by identifying a potential connection between two widely encountered chemicals and a breast cancer subtype with relatively few established risk factors.
There's still plenty we don't know, particularly about newer PFAS chemicals that have replaced PFOA and PFOS in many products. But the findings offer another reason to take environmental exposures seriously, both in the choices we make individually and in the broader efforts to reduce these chemicals in our water, food, and everyday environments.