Bras and Breast Sagging

A Carnivore Influencer, 7,500 Likes, and a Community Note

In March 2026, wellness influencer "Carnivore Aurelius" posted an image to X with the caption: "Been tellin ya'll. Give the girls gravity."¹ The image referenced a famous French study claiming that bra-wearing causes breast sagging — that going braless actually keeps breasts firmer. The post racked up over 7,500 likes and 450 shares within hours. It also got something else: a community note from X's fact-checking system, pointing out that the study was never published, never peer-reviewed, and the researcher himself said his findings applied only to young athletic women aged 18–35.¹

This is not the first time this claim has gone viral. It has been circulating since 2013, when a French radio interview was picked up by international media and alchemized into headlines proclaiming that science had proven bras cause sagging. The claim resurfaces every few months, usually boosted by wellness accounts, "natural living" influencers, or — in this case — a carnivore diet personality who apparently also has opinions about lingerie biomechanics.

I took this one because the pattern is textbook: a real researcher with preliminary data, media amplification that stripped away every caveat, and a decade of social media repetition that has calcified a preliminary observation into settled "fact." The actual evidence says something very different.

15 Years of Data That Were Never Published

The study in question was conducted by Jean-Denis Rouillon, a sports science professor at the Université de Franche-Comté in Besançon, France. According to Rouillon's own statements, he spent 15 years measuring breast position in women using hand-held calipers and rulers. His preliminary finding: among the women he studied, those who went braless showed an average nipple elevation of 7 millimeters per year compared to bra-wearers.²

That sounds dramatic. Here's what the viral posts never mention.

The study was never published in a peer-reviewed journal. Not in 2013 when the radio interview aired. Not in the 13 years since. No formal methodology paper exists. No statistical analysis has been submitted for review. The sample size — reported variably as 130 to 330 women depending on which media outlet you read — consisted entirely of young, athletic university women between 18 and 35 years old.^2,3 There was no mention of a control group. The measurement tools were calipers and a ruler — not the kind of rigorous anthropometric methodology you'd expect for a claim this sweeping.

Most importantly, Rouillon himself warned against generalizing his findings. In interviews following the media firestorm, he explicitly stated that his results applied only to young athletic women, that the sample was too small for population-level conclusions, and that a proper study would require approximately 300,000 participants.³ He never followed up with a published paper. The scientific community never had the opportunity to scrutinize his methodology, because he never submitted it for scrutiny.

What we're dealing with is not bad science. It's the absence of science — preliminary observations from a single researcher that entered the media ecosystem before they entered the scientific one, and never made it to the second stop. Every time someone posts "a 15-year French study proved bras cause sagging," they are citing a study that does not exist in any form that science can evaluate.

Cooper's Ligaments Don't Care About Your Bra

To understand why the "bras cause sagging" claim doesn't hold up anatomically, you need to understand what actually holds breasts in place. The primary support structure is a network of Cooper's ligaments — fibrocollagenous connective tissue bands that run from the clavicle and deep chest fascia through the breast tissue to the skin, named after surgeon Sir Astley Cooper, who described them in 1840.⁴

Cooper's ligaments are passive connective tissue structures. They provide shape and structural support, but they are not muscles. They don't strengthen with exercise. They don't atrophy from disuse. The idea that wearing a bra would somehow "weaken" these ligaments — the way immobilizing a limb weakens muscle — fundamentally misunderstands what kind of tissue they are.^4,5

Even bra manufacturers acknowledge this reality. Industry literature consistently states that bras affect breast shape only while being worn — they cannot permanently strengthen or weaken Cooper's ligaments, alter their composition, or change their elasticity over time.⁵ A bra is a garment, not a medical device. Taking it off at the end of the day doesn't reverse some therapeutic effect, because there was no therapeutic effect to begin with.

What does degrade Cooper's ligaments over time is the same thing that degrades collagen and elastin everywhere in the body: aging, hormonal changes, gravity (acting over decades, not hours), and external insults like smoking and UV exposure. These are systemic biological processes. Whether you're wearing a bra while they happen is irrelevant.

What Actually Causes Breast Ptosis

While the internet debates bras, the peer-reviewed literature has been quietly identifying the actual risk factors for breast ptosis — and not one of them involves underwire. A study of 141 patients published in the Archives of Breast Cancer identified the following significant predictors of ptosis (p < 0.05): smoking history, higher BMI, number of pregnancies, larger breast size, age, and significant weight loss (defined as greater than 50 pounds).⁶

The NCBI StatPearls reference — the medical profession's standard clinical summary — lists the established causes of breast ptosis as aging (particularly post-40 when collagen production declines), macromastia (large breast tissue creating downward mechanical force), significant weight loss, pregnancy, hormonal changes, smoking, and genetics.⁷ Bra-wearing does not appear in any authoritative clinical reference as a risk factor, because no evidence supports it.

One finding from the risk factor literature deserves special attention, because it counters another persistent myth: breastfeeding does not cause breast sagging.⁸ Multiple studies have specifically tested whether lactation history, duration of breastfeeding, or number of children breastfed correlate with ptosis. They don't. The sagging associated with pregnancy comes from the pregnancy itself — the hormonal changes, the tissue expansion, the volume shifts — not from nursing. Women should not avoid breastfeeding out of concern for breast shape. That fear is not supported by data.

The One Scenario Where Support Actually Matters

There is one context where breast support has genuine biomechanical relevance, and it has nothing to do with daily bra-wearing: high-impact exercise. During activities like running, jumping rope, and high-knee movements, breasts experience substantial acceleration forces — up to 4.18g in the superior-inferior direction during high-knee skipping, with significant medial-lateral and anterior-posterior motion as well.¹⁰

Sports bras have been shown to reduce breast acceleration by 36–74% compared to conventional bras, depending on design factors like encapsulation style, padding, and underband construction.^10,11 A meta-analysis published in the Journal of Women's Sports Medicine found that sports bras are associated with significantly less breast pain during physical activity compared to standard bras or no bra at all.¹²

The mechanism here is protective, not formative. Repeated high-impact forces can cause cumulative mechanical trauma to Cooper's ligaments over time — not because the ligaments "weaken from disuse" (they don't), but because they can be stretched and damaged by repetitive acceleration forces that exceed their elastic capacity.⁵ A sports bra during a run protects ligaments from acute and cumulative trauma. This is entirely different from the claim that wearing a bra during daily life prevents sagging.

This distinction matters because the "bras cause sagging" narrative often gets weaponized against sports bras too, discouraging women from wearing proper support during exercise. The evidence is clear: during high-impact activity, breast support reduces pain and protects connective tissue. During daily life, bra choice has no demonstrated effect on long-term breast shape.

The Other Bra Conspiracy, Briefly

The "bras cause sagging" claim doesn't circulate in isolation. It exists in an ecosystem of bra-related health misinformation, the most egregious of which is the thoroughly debunked claim that bras cause breast cancer. This theory, popularized by Sydney Ross Singer's 1995 book Dressed to Kill, hypothesized that bras restrict lymphatic drainage, leading to toxin accumulation and cancer.¹³

The theory was never published in a peer-reviewed journal. The methodology was fatally flawed. And it has been directly contradicted by large-scale studies. A detailed study from the Fred Hutchinson Cancer Research Center, involving over 1,000 women, found zero association between bra use, cup size, underwire, age at which bra-wearing started, and breast cancer risk.¹³ The National Cancer Institute, the American Cancer Society, and every major oncological body have stated unequivocally that bras do not increase breast cancer risk.¹³

I mention this not to relitigate a settled question, but to note a pattern: bras are a uniquely fertile target for health misinformation. They're worn by billions of women, they involve a body part that already carries cultural anxiety, and the claims — whether about sagging or cancer — are difficult for individuals to verify through personal experience. This makes bra myths particularly sticky and particularly worth correcting.

Modifiable Risk Factors (None of Them Are Your Bra)

If you're genuinely concerned about breast ptosis, the peer-reviewed literature points to a short list of factors that actually matter — and several of them are modifiable.

Notice what's missing from that grid: bra-wearing. Not because we're ignoring it — because the evidence doesn't support including it. The Cleveland Clinic's clinical guidance on going braless is straightforward: there are no health risks associated with either wearing or not wearing a bra, and the choice should be based on personal comfort.¹⁴ McGill University's Office for Science and Society reached the same conclusion in their evidence review: breast size and age are the primary determinants of ptosis, and bra-wearing has no established causal role.¹⁵

What bras can cause, when ill-fitting, is musculoskeletal discomfort — shoulder pain, back pain, neck strain, and skin irritation from friction, trapped moisture, or material allergies.¹⁶ These are real issues that affect comfort and quality of life, and they're solved by proper fitting, breathable materials, and regular replacement — not by going braless in pursuit of a nonexistent anti-sagging benefit.

Comfort Is a Reason. Preventing Sagging Isn't.