Chemicals Used to Straighten Hair Linked to Increased Risk of Uterine Cancer.
Researchers are learning more about the link between certain hair straightening products, such as chemical relaxers and pressing products, and an increased risk of cancer in women.
Hair straightening chemicals have previously been linked to an increased risk of certain hormone-related cancers, including breast and ovarian cancers, and now a new study links hair straightening products to an increased risk of uterine cancer.
According to the researchers, black women may be more affected because they use the products more frequently.
According to the study, which was published Monday in the Journal of the National Cancer Institute, 1.6% of women who did not use hair-straightening chemical products in the previous 12 months developed uterine cancer by the age of 70, while about 4% of women who frequently used such hair-straightening products developed uterine cancer by the age of 70.
This discovery “also communicates that uterine cancer is indeed uncommon.” The study’s author and researcher at the National Institute of Environmental Health Sciences, Chandra Jackson, expressed concern about the doubling of risk.
“In this study, women with frequent use in the past year had an over two-fold higher risk of uterine cancer,” she said. Frequent use was defined as more than four times in the previous year.
Black women had the highest cancer risk.
The new study includes information from nearly 34,000 women in the United States, ages 35 to 74, who answered questionnaires about their use of various hair products such as perms, dyes, relaxers, and straighteners. The National Institutes of Health researchers also tracked the number of cancer diagnoses within the study group.
The researchers discovered a strong link between hair straightening products and uterine cancer cases, but not with the use of other hair products such as dyes, perms, or body waves.
The study data also revealed that the link between hair straightening products and uterine cancer cases was strongest among Black women, who made up only 7.4% of study participants but 59.9% of those who reported ever using straighteners.
Several factors, including Eurocentric beauty standards, social pressures placed on Black and Latina women in workplace settings related to microaggressions and the threat of discrimination, as well as desired versatility in changing hairstyles and self-expression, are likely to play a role in the frequent use of hair straightening products.
“The bottom line is that the exposure burden appears higher among Black women,” Jackson said.
“Based off of the body of the literature in this area, we know that hair products marketed directly to Black children and women have been shown to contain multiple chemicals associated with disrupting hormones, and these products marketed to Black women have also been shown to have harsher chemical formulations,” she said.
“On top of that, we know that Black women tend to use multiple products simultaneously, which could contribute to Black women on average having higher concentrations of these hormone-disrupting chemicals in their system.”
The researchers did not collect information on the brands or ingredients of the women’s hair products, but they wrote in the paper that several chemicals identified in straighteners could contribute to the increased incidence of uterine cancer observed in their study.
This is the first epidemiologic study that examined the relationship between straightener use and uterine cancer according to Alexandra White, head of the National Institute of Environmental Health Sciences Environment and Cancer Epidemiology group and lead author on the study.
He said 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 ancers in women.
‘A new and growing area of research’
Some ingredients in hair-straightening products, particularly those most popular with and marketed to Black and Latina women, are hormone disruptors, according to Tamarra James-Todd, an epidemiologist at Harvard T.H. Chan School of Public Health who was not involved in the new study but has led some of the earliest research finding links between hair products and cancer.
“They interfere with our bodies’ normal hormonal processes.”
“It makes sense to look at cancers that are hormonally mediated,” she said, adding that hormone-disrupting chemicals may also have an impact on other parts of the body.
The impact of these chemicals may not be limited to hormonal processes, but may also have an impact on other systems, such as immune and vascular systems.
Understanding how these chemicals function outside of the hormonal system is still a new and developing field of study, according to James-Todd.
She explained that it’s possible that these chemicals are operating by altering not only hormonal responses but also immune or even vascular responses. “Cancer is linked to all of these processes.”
Dr. Otis Brawley, professor at the Johns Hopkins University Bloomberg School of Public Health and former chief medical officer of the American Cancer Society, said in an email to CNN that while the new study is “well done” and shows an association between hair-straightening chemical products and increased uterine cancer risk, it is unable to determine that the products directly cause the cancer.
Brawley, who was not involved in the new study, said it is unable to demonstrate cause; it could be a pure association.
“However, the question of how we resolve this is difficult.” “The scientific ideal is a randomized trial of 40,000 or so people; 20,000 with regular hair straightener use and 20,000 never using it and never having used it and following them for 20 years,” he said, adding that “it’s impossible for science to answer better than” the recent study at this point.
Yet “the question how do we settle this is difficult. The scientific ideal is a randomized trial of 40,000 or so; 20,000 with regular hair straightener use and 20,000 never using it and never having used it and follow them for 20 years,” he said, adding that at this point, “it’s impossible for science to answer better than” the recent study.
