No Evidence That Wearing Bras Increases Breast Cancer Risk
There is no scientific evidence supporting a link between bra wearing and increased breast cancer risk. A high-quality population-based case-control study specifically examining this question found no association between any aspect of bra wearing and breast cancer risk 1.
Scientific Evidence on Bra Wearing and Breast Cancer
The 2014 Seattle-Puget Sound metropolitan area study compared 1,044 breast cancer cases with 469 control women and found:
- No association between breast cancer risk and:
- Bra cup size
- Hours per day wearing a bra
- Age when first began regularly wearing a bra
- Wearing underwire bras
- Any other bra-wearing habits 1
This study specifically addressed the concerns raised in lay media about potential links between bras and breast cancer, providing reliable scientific evidence against such claims.
Established Breast Cancer Risk Factors
According to multiple guidelines, the established risk factors for breast cancer include:
Non-modifiable risk factors:
- Age (increasing risk with age) 2
- Family history of breast cancer 2
- Genetic mutations (BRCA1/2, TP53, PTEN, etc.) 3
- Early menarche (before age 11) 2
- Late menopause (after age 55) 2
- Personal history of certain benign breast conditions 2
Modifiable risk factors:
- Obesity and weight gain in adulthood (for postmenopausal women) 3
- Alcohol consumption 3, 2
- Physical inactivity 3, 2
- Hormone replacement therapy 2
Myths vs. Facts
An older 1991 study suggested that premenopausal women who didn't wear bras had half the risk of breast cancer compared to bra users 4. However, the authors themselves noted this was likely because non-bra users were thinner with smaller breasts - factors independently associated with lower breast cancer risk.
A more comprehensive 1996 study examining brassiere size as an indicator of breast size found no appreciable association between breast size and breast cancer risk after adjusting for established risk factors 5.
Evidence-Based Breast Cancer Prevention
The American Cancer Society and National Comprehensive Cancer Network recommend these evidence-based strategies for breast cancer risk reduction:
- Maintain a healthy body weight, particularly after menopause 3, 2
- Engage in regular physical activity (45-60 minutes of moderate to vigorous activity 5+ days/week) 3, 2
- Limit alcohol consumption (no more than one drink per day for women) 3, 2
- Consider risk-reducing medications for eligible high-risk women 3
- Consider risk-reducing surgery for women with genetic mutations like BRCA1/2 3
Conclusion
The scientific evidence clearly shows that wearing a bra does not increase breast cancer risk. Women should focus on established risk reduction strategies and follow appropriate screening guidelines based on their individual risk factors.