August 2024 | George M. Pikler, M.D., Ph.D., FACP, Lead Oncology Advocate N1X10
Emerging data show that frequent use of permanent hair dyes, chemical relaxers, and straightening products marketed largely to Black women in the United States might contribute to increased risk of hormone-related cancers, including breast, ovarian and uterine cancer. These women are disproportionately diagnosed with aggressive types of uterine and endometrial cancers (eg, non-endometroid carcinoma), breast cancer (eg, triple-negative, inflammatory) with a death rate 28% higher than that for white women, and aggressive ovarian tumors (eg, high-grade serous carcinoma), all have lower 5-year survival rates and higher mortality rates for these cancers relative to White women. Scientific evidence has now shown that these hair products marketed to Black girls have been linked to endocrine-disrupting substances associated with the early onset of menstruation and many of the reproductive-health issues that follow, from uterine fibroids, preterm birth and infertility as well as the malignancies listed above.
In October 2022, the Sister Study, which was led by the National Institute of Environmental Health Sciences followed a cohort of nearly 34,000 women, found that those who frequently used chemical hair-straightening products, a majority of whom were Black women, were two and a half times as likely to develop uterine cancer as those who did not use the products. Over the past year and a half, this research has prompted lawsuits involving nearly 9,000 plaintiffs across the country and at least the promise of new action from the federal government.
The products most often used by Black women remain vastly underregulated and, until recently, insufficiently studied. Many of the substances they contain are prohibited in other countries. The European Union regulates more than 1,300 ingredients for use in cosmetics; the F.D.A. prohibits or restricts only nine ingredients that have been proved harmful to human health. In fact, hair relaxers marketed to children in the United States have been found to contain the highest levels of five of the chemicals prohibited in the European Union.
This means that even as the evidence is increasingly harder to ignore or deny, consumers remain shockingly unprotected, leading to an entirely preventable continuing public-health crisis. Most of the studies have been published in science journals that never reach the general public. Many Black people have quietly wondered for years whether hair relaxers were safe but burning scalps and even hair loss have been normalized as the price of desirably straight hair.
