Women who used chemical hair straightening products were at higher risk for uterine cancer compared to women who did not report using these products, according to a new study from the National Institutes of Health. The researchers found no associations with uterine cancer for other hair products that the women reported using, including hair dyes, bleach, highlights, or perms.
The study data includes 33,497 U.S. women ages 35-74 participating in the Sister Study, a study led by the National Institute of Environmental Health Sciences (NIEHS), part of NIH, that seeks to identify risk factors for breast cancer and other health conditions. The women were followed for almost 11 years and during that time 378 uterine cancer cases were diagnosed.
a research fellow in the NIEHS Epidemiology Branch.
The researchers did not collect information on brands or ingredients in the hair products the women used. However, in the paper they note that several chemicals that have been found in straighteners (such as parabens, bisphenol A, metals, and formaldehyde) could be contributing to the increased uterine cancer risk observed. Chemical exposure from hair product use, especially straighteners, could be more concerning than other personal care products due to increased absorption through the scalp which may be exacerbated by burns and lesions caused by straighteners.
“To our knowledge this is the first epidemiologic study that examined the relationship between straightener use and uterine cancer,” said White. “More research is needed to confirm these findings in different populations, to determine if hair products contribute to health disparities in uterine cancer, and to identify the specific chemicals that may be increasing the risk of cancers in women.”
This team previously found that permanent hair dye and straighteners may increase breast and ovarian cancer risk.