Let’s start with a relatively harmless, yet very persisting, myth: bras can cause breast
cancer. I call this harmless, because if you believe it, you just don’t wear a bra. No harm done. However, it can still cause misinformation and anxiety over wearing a bra. So let’s find out the science behind this!
I dug into the literature and internet and found the source of this myth: a book written in 1995. Yes, a book. Many health bloggers and bra-haters referred to it as a research study, but it is not. They do not even present data in the book. The book is entitled “Dressed to Kill: The Link Between Breast Cancer and Bras” and is written by the dynamic duo (and married couple) Soma Grismaijer and Syndney Ross Singer. They are often referred to as doctors or researchers, but after some digging, I found out that they never finished med school! Sydney even enrolled 3 Ph.D. programs and did only finish with a master’s degree, not a Ph.D. I wonder why…
Anyways, they have postulated a theory, that, I have to be honest here, has some face validity. They describe how a tight bra, especially those with an underwire, can block the lymphatic system from circulating properly. As a result, your breast can get swollen and “toxins” will accumulate in the tissue which, in turn, will cause breast cancer. I understand why this sounds reasonable to some people. However, they provide NO prove for this theory and it is complete nonsense! Health gurus online have thankfully copied this theory and presented it as a known and evidence-based fact.
Some bra-haters did some extra work and also provide references that should prove that bras in fact do cause breast cancer. The most frequently copied reference (also cited in the bra-of-dead book) is a study from researchers at Harvard. It’s Harvard – sounds legit, right! Also, the study was published in a decent scientific journal, the European Journal of Cancer and Clinical Oncology (Hsieh & Trichopoulos, 1991). After reading the study, I have to admit it is a solid paper with good methodology. The problem? The study does not say that bras cause cancer, but that larger breasts are a risk factor:
“Premenopausal women who do not wear bras had half the risk of breast cancer compared with bra users (P about 0.09), possibly because they are thinner and likely to have smaller breasts. Among bra users, larger cup size was associated with an increased risk of breast cancer (P about 0.026), although the association was found only among postmenopausal women and was accounted for, in part, by obesity. These data suggest that bra cup size (and conceivably mammary gland size) may be a risk factor for breast cancer.”
The critical reader may think “they do mention wearing a bra versus not wearing a bra and breast cancer”, but the authors conclude that this is because breast size, not because wearing a bra. There goes the argument “You can’t argue with Harvard scientist!” No, you probably can’t, but you can still misread their conclusions.
So enjoy wearing your bra, folks, or don’t – it doesn’t really matter ^_^
Conclusion: NO EVIDENCE
The lethal bra book: https://www.amazon.com/Dressed-Kill-Between-Breast-Cancer/dp/0895296640
The Harvard study: http://www.sciencedirect.com/science/article/pii/027753799190469T