Do Bras Cause Breast Cancer or Make Your Breasts Sag? (No, and No)

Fantastic questions, and two of the most persistent myths I hear: Do bras cause breast cancer? And do they make your breasts sag more? The short answer to both is no. But these rumors are everywhere, so let's talk about where they came from and what the evidence actually says.

This one circulates constantly in the wellness community, underwire bras especially. You'll hear all sorts of wild reasoning, like the bra "blocks your lymphatic drainage" and traps toxins. It's just not true.

Here's the actual data. About 10 years ago, a population-based case-control study looked at this exact question, and found that none of the following were associated with breast cancer:

• Wearing a bra or not
• Underwire vs. no underwire
• The age you started wearing bras
• How many hours a day you wear a bra

None of it. The bra is simply not the culprit.

There are two real, related risk factors that can create a misleading association:

1. Higher BMI is an independent risk factor for developing breast cancer.
2. Breast size itself (separate from BMI) appears to be a risk factor as well.

Here's the key: women with larger breasts are more likely to wear bras (and to wear underwire). So if you don't account for breast size and BMI, you might think you see a link between bras and cancer, when really the breast size and BMI are doing the work. It's not the bra.

This is the other big one, and it has a specific and kind of fascinating origin story.

Years ago, a researcher in France followed a group of women for about 15 years, took breast measurements over time, and claimed that wearing a bra was associated with more drooping. He released the data to the New York Times and other outlets, it was all over the news, and that's where this rumor was born.

But here's the catch that almost never gets mentioned: the research was never actually published. It never underwent peer review. No one in the scientific community really got to see or scrutinize it. It was essentially a press release that got the researcher a lot of attention, and there is no evidence that the claim is true.

So no, bras do not cause your breasts to sag.

Drooping (the medical term is ptosis) is real, it's just not caused by your bra. The things genuinely associated with more drooping are:

• Age
• BMI
• Weight loss
• Number of pregnancies
• Smoking
• Breast size

Those are the real drivers. Notice the bra isn't on the list. (And if you've ever wondered why natural breasts tend to droop more than implants of the same size, it comes back to these same tissue factors, not to whether or how you wear a bra.)

Bras do not cause breast cancer, and bras do not make your breasts sag.

• The "bras cause cancer" myth fails when you look at the actual case-control data, no link to bras, underwire, age started, or hours worn. The real risk factors are higher BMI and breast size, which just happen to correlate with bra-wearing.
• The "bras cause sagging" myth traces back to a never-published, never-peer-reviewed French press release, not real evidence. Drooping is driven by age, BMI, weight loss, pregnancies, smoking, and breast size, not your bra.

When you see a scary health claim in the wellness space, it's always worth asking the same questions I do: What does the actual published, peer-reviewed evidence say? In this case, it says wear whatever bra you like, it's not causing either problem. This is the same pattern I keep running into with health misinformation that spreads faster than the facts, and the same fix applies: go back to the data.