Use of hair relaxers and hair dyes during pregnancy and breast tissue composition in mothers and adolescent daughters.
10 affiliations
- 1Department of Environmental Health Sciences, Columbia University Mailman School of Public Health, New York City, NY, USA. [email protected].
- 2Department of Epidemiology, Columbia University Mailman School of Public Health, New York City, NY, USA. [email protected].
- 3Princess Margaret Cancer Centre, University Health Network, Toronto, ON, Canada.
- 4Laser Research Centre, University of Johannesburg, Johannesburg, South Africa.
- 5Department of Epidemiology, Columbia University Mailman School of Public Health, New York City, NY, USA.
- 6Herbert Irving Comprehensive Cancer Center, Columbia University Medical Center, New York, NY, USA.
- 7Division of Clinical Immunology, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York City, NY, USA.
- 8West Harlem Environmental Action Inc, New York City, NY, USA.
- 9Department of Environmental Health Sciences, Columbia University Mailman School of Public Health, New York City, NY, USA.
- 10Silent Spring Institute, Newton, MA, USA.
Abstract
Background
Black and Hispanic women are more likely to present with advanced-stage breast cancer and have lower survival rates compared to white women. Hair products are a source of exposure to environmental chemicals (e.g., formaldehyde, phthalates) that may contribute to these persistent inequities, particularly when used during sensitive exposure windows for breast tissue development (i.e., pregnancy, gestation). In this study, we examined the association between maternal hair product use during pregnancy and breast tissue composition (BTC) later in life among mothers and their adolescent daughters.Methods
We analyzed data from a prospective cohort of self-identifying non-Hispanic Black and Hispanic mother-daughter pairs in New York City (n = 186 daughters and 180 mothers). Mothers reported on their use of hair relaxers and hair dyes during and prior to pregnancy at a visit occurring in the third trimester. One to two decades later, the BTC of mothers and daughters was measured using optical spectroscopy, which estimates BTC properties that are positively (water, collagen, and optical index [Oindex]) and negatively (lipid) correlated with mammographic breast density, an intermediate marker of breast cancer risk. Adjusted multivariable linear regressions were used to examine the associations between hair product use (categorized as "never," "before pregnancy only," and "during pregnancy") and BTC.Results
Maternal hair relaxer use during pregnancy (versus never use) was associated with several BTC measures among daughters and mothers, whereas hair dye use during pregnancy (versus never use) was only associated with Oindex among mothers (Adjusted βmother for Oindex = - 0.38; 95% CI = - 0.70, - 0.05). Consistent associations were reported between hair relaxer use and BTC among daughters and mothers. Specifically, hair relaxer use during pregnancy (versus never use) was associated with lower lipid content (Adjusted βdaughter = - 0.36, 95% confidence interval (CI) = - 0.65, - 0.07; Adjusted βmother = - 0.35, 95% CI = - 0.65, - 0.04), higher collagen content (Adjusted βdaughter = 0.33, 95% CI: 0.01, 0.64; Adjusted βmother = 0.34, 95% CI = 0.04, 0.63), and higher Oindex (Adjusted βdaughter = 0.47, 95% CI: 0.17, 0.77; Adjusted βmother = 0.50, 95% CI = 0.21, 0.79).Conclusions
Maternal hair relaxer use during pregnancy was associated with BTC later in life for both mothers and daughters. The consistency of associations across generations suggest pregnancy and gestation are potentially sensitive periods for this exposure, capturing both maternal and prenatal influences on BTC with potential implications for breast cancer risk.
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BibTeX
@article{chan2026hair,
title = {{Use of hair relaxers and hair dyes during pregnancy and breast tissue composition in mothers and adolescent daughters.}},
author = {Marissa Chan and Lothar Lilge and Jane Walter and Parisa Tehranifar and Rachel L Miller and Anhthu Hoang and Peggy Shephard and Frederica Perera and Julie B Herbstman and Mary Beth Terry and Jasmine A McDonald and Rebecca D Kehm},
journal = {Breast cancer research : BCR},
year = {2026},
month = jul,
doi = {10.1186/s13058-026-02353-1},
url = {https://europepmc.org/article/MED/42928199},
note = {CC BY-NC-ND},
}
RIS
TY - JOUR
TI - Use of hair relaxers and hair dyes during pregnancy and breast tissue composition in mothers and adolescent daughters.
AU - Marissa Chan
AU - Lothar Lilge
AU - Jane Walter
AU - Parisa Tehranifar
AU - Rachel L Miller
AU - Anhthu Hoang
AU - Peggy Shephard
AU - Frederica Perera
AU - Julie B Herbstman
AU - Mary Beth Terry
AU - Jasmine A McDonald
AU - Rebecca D Kehm
PY - 2026
DA - 2026/07/29
JO - Breast cancer research : BCR
DO - 10.1186/s13058-026-02353-1
UR - https://europepmc.org/article/MED/42928199
AB - Background Black and Hispanic women are more likely to present with advanced-stage breast cancer and have lower survival rates compared to white women. Hair products are a source of exposure to environmental chemicals (e.g., formaldehyde, phthalates) that may contribute to these persistent inequities, particularly when used during sensitive exposure windows for breast tissue development (i.e., pregnancy, gestation). In this study, we examined the association between maternal hair product use during pregnancy and breast tissue composition (BTC) later in life among mothers and their adolescent daughters.Methods We analyzed data from a prospective cohort of self-identifying non-Hispanic Black and Hispanic mother-daughter pairs in New York City (n = 186 daughters and 180 mothers). Mothers reported on their use of hair relaxers and hair dyes during and prior to pregnancy at a visit occurring in the third trimester. One to two decades later, the BTC of mothers and daughters was measured using optical spectroscopy, which estimates BTC properties that are positively (water, collagen, and optical index [Oindex]) and negatively (lipid) correlated with mammographic breast density, an intermediate marker of breast cancer risk. Adjusted multivariable linear regressions were used to examine the associations between hair product use (categorized as "never," "before pregnancy only," and "during pregnancy") and BTC.Results Maternal hair relaxer use during pregnancy (versus never use) was associated with several BTC measures among daughters and mothers, whereas hair dye use during pregnancy (versus never use) was only associated with Oindex among mothers (Adjusted βmother for Oindex = - 0.38; 95% CI = - 0.70, - 0.05). Consistent associations were reported between hair relaxer use and BTC among daughters and mothers. Specifically, hair relaxer use during pregnancy (versus never use) was associated with lower lipid content (Adjusted βdaughter = - 0.36, 95% confidence interval (CI) = - 0.65, - 0.07; Adjusted βmother = - 0.35, 95% CI = - 0.65, - 0.04), higher collagen content (Adjusted βdaughter = 0.33, 95% CI: 0.01, 0.64; Adjusted βmother = 0.34, 95% CI = 0.04, 0.63), and higher Oindex (Adjusted βdaughter = 0.47, 95% CI: 0.17, 0.77; Adjusted βmother = 0.50, 95% CI = 0.21, 0.79).Conclusions Maternal hair relaxer use during pregnancy was associated with BTC later in life for both mothers and daughters. The consistency of associations across generations suggest pregnancy and gestation are potentially sensitive periods for this exposure, capturing both maternal and prenatal influences on BTC with potential implications for breast cancer risk.
SN - 1465-5411
SN - 1465-542X
ER -