A new study from the National Institutes of Health found that women who used chemical hair straightening products had a greater risk of uterine cancer than women who did not disclose using these products. Other hair products, such as hair colors, bleach, highlights, or perms, that the women reported using were not linked to uterine cancer, according to the study.
The study data includes 33,497 American women between the ages of 35 and 74 who took part in the Sister Study, an investigation into the causes of breast cancer and other illnesses led by the National Institute of Environmental Health Sciences (NIEHS), a division of the National Institutes of Health (NIH). During the nearly 11 years that the women were watched, there were 378 new cases of uterine cancer.
Women who used hair straightening products more than four times in the previous year were more than twice as likely to get uterine cancer as women who didn’t use these products.
The risk of uterine cancer by the age of 70 was estimated to be 1.64% in women who had never used hair straighteners, but it increased to 4.05% in those who used them frequently, according to lead author Alexandra White, Ph.D., who also serves as the director of the NIEHS Environment and Cancer Epidemiology group. “This rate of doubling is alarming. Nonetheless, it is critical to put this information into context because uterine cancer is a rare form of the disease.
With 65,950 expected new cases in 2022, uterine cancer is the most prevalent cancer of the female reproductive system and accounts for nearly 3% of all new cancer cases. According to studies, uterine cancer incidence rates have been rising in the US, especially among black women.
According to a study published in the Journal of the National Cancer Institute, self-identified black women made up almost 60% of the participants who admitted to using straighteners in the previous year. Despite the fact that the study did not identify a difference in uterine cancer incidence according to race, the negative health impacts may be more severe for black women due to a higher prevalence of usage.
These results may be even more pertinent for black women, according to Che-Jung Chang, Ph.D., a research fellow in the NIEHS Epidemiology Branch and one of the study’s authors. “Black women use hair straightening or relaxer products more frequently and tend to start using them at younger ages than other races and ethnicities,” Chang said.
The results are in line with earlier research that suggested women’s use of hair straighteners may raise their chance of developing malignancies linked to hormones.
The brands or contents of the hair products the women used were not gathered by the researchers. The authors of the paper do, however, mention that a number of substances that have been linked to uterine cancer risk (including parabens, bisphenol A, metals, and formaldehyde) have been discovered in straighteners. Chemical exposure from using hair products, especially straighteners, may be more concerning than chemical exposure from using other personal care items. This is because chemical exposure from using hair products, especially straighteners, can increase scalp absorption, which can be made worse by burns and sores caused by using them.
According to White, this is the first epidemiological study to look at the connection between using a straightener and uterine cancer. “More research is needed to confirm these results in different groups, to find out if hair products contribute to health differences in uterine cancer, and to find out which chemicals may be making women more likely to get cancer,” the authors write.
According to research done by this team in the past, permanent hair color and straighteners may raise the risk of breast and ovarian cancer.
