Deanna Denham Hughes was stunned when she was diagnosed with ovarian cancer in 2022. She was only 32. She had no family history of cancer, and tests found no genetic link. Ms. Hughes wondered why she, an otherwise healthy Black mother of two, would develop a malignancy known as a “silent killer.”
After emergency surgery to remove the mass, along with her ovaries, uterus, fallopian tubes, and appendix, Ms. Hughes said, she saw an Instagram post in which a woman with uterine cancer linked her condition to chemical hair straighteners.
“I almost fell over,” she said from her home in Smyrna, Ga.
When Ms. Hughes was about 4, her mother began applying a chemical straightener, or relaxer, to her hair every 6-8 weeks. “It burned, and it smelled awful,” Ms. Hughes recalled. “But it was just part of our routine to ‘deal with my hair.’ ”
The routine continued until she went to college and met other Black women who wore their hair naturally. Soon, Ms. Hughes quit relaxers.
Social and economic pressures have long compelled Black girls and women to straighten their hair to conform to Eurocentric beauty standards. But chemical straighteners are stinky and costly and sometimes cause painful scalp burns. Mounting evidence now shows they could be a health hazard.
Relaxers can contain carcinogens, such as formaldehyde-releasing agents, phthalates, and other endocrine-disrupting compounds, according to National Institutes of Health studies. The compounds can mimic the body’s hormones and have been linked to breast, uterine, and ovarian cancers, studies show.
African American women’s often frequent and lifelong application of chemical relaxers to their hair and scalp might explain why hormone-related cancers kill disproportionately more Black than White women, say researchers and cancer doctors.
“What’s in these products is harmful,” said Tamarra James-Todd, PhD, an epidemiology professor at Harvard T.H. Chan School of Public Health, Boston, who has studied straightening products for the past 20 years.
She believes manufacturers, policymakers, and physicians should warn consumers that relaxers might cause cancer and other health problems.
But regulators have been slow to act, physicians have been reluctant to take up the cause, and racism continues to dictate fashion standards that make it tough for women to quit relaxers, products so addictive they’re known as “creamy crack.”
Michelle Obama straightened her hair when Barack Obama served as president because she believed Americans were “not ready” to see her in braids, the former first lady said after leaving the White House. The U.S. military still prohibited popular Black hairstyles such as dreadlocks and twists while the nation’s first Black president was in office.
California in 2019 became the first of nearly two dozen states to ban race-based hair discrimination. Last year, the U.S. House of Representatives passed similar legislation, known as the CROWN Act, for Creating a Respectful and Open World for Natural Hair. But the bill failed in the Senate.
The need for legislation underscores the challenges Black girls and women face at school and in the workplace.
“You have to pick your struggles,” said Atlanta-based surgical oncologist Ryland J. Gore, MD. She informs her breast cancer patients about the increased cancer risk from relaxers. Despite her knowledge, however, Dr. Gore continues to use chemical straighteners on her own hair, as she has since she was about 7 years old.
“Your hair tells a story,” she said.
In conversations with patients, Dr. Gore sometimes talks about how African American women once wove messages into their braids about the route to take on the Underground Railroad as they sought freedom from slavery.
“It’s just a deep discussion,” one that touches on culture, history, and research into current hairstyling practices, she said. “The data is out there. So patients should be warned, and then they can make a decision.”
The first hint of a connection between hair products and health issues surfaced in the 1990s. Doctors began seeing signs of sexual maturation in Black babies and young girls who developed breasts and pubic hair after using shampoo containing estrogen or placental extract. When the girls stopped using the shampoo, the hair and breast development receded, according to a study published in the journal Clinical Pediatrics in 1998.
Since then, Dr. James-Todd and other researchers have linked chemicals in hair products to a variety of health issues more prevalent among Black women – from early puberty to preterm birth, obesity, and diabetes.
In recent years, researchers have focused on a possible connection between ingredients in chemical relaxers and hormone-related cancers, like the one Ms. Hughes developed, which tend to be more aggressive and deadly in Black women.
A 2017 study found White women who used chemical relaxers were nearly twice as likely to develop breast cancer as those who did not use them. Because the vast majority of the Black study participants used relaxers, researchers could not effectively test the association in Black women, said lead author Adana Llanos, PhD, associate professor of epidemiology at Columbia University’s Mailman School of Public Health, New York.
Researchers did test it in 2020.
The so-called Sister Study, a landmark National Institute of Environmental Health Sciences investigation into the causes of breast cancer and related diseases, followed 50,000 U.S. women whose sisters had been diagnosed with breast cancer and who were cancer-free when they enrolled. Regardless of race, women who reported using relaxers in the prior year were 18% more likely to be diagnosed with breast cancer. Those who used relaxers at least every 5-8 weeks had a 31% higher breast cancer risk.
Nearly 75% of the Black sisters used relaxers in the prior year, compared with 3% of the non-Hispanic White sisters. Three-quarters of Black women self-reported using the straighteners as adolescents, and frequent use of chemical straighteners during adolescence raised the risk of premenopausal breast cancer, a 2021 NIH-funded study in the International Journal of Cancer found.
Another 2021 analysis of the Sister Study data showed sisters who self-reported that they frequently used relaxers or pressing products doubled their ovarian cancer risk. In 2022, another study found frequent use more than doubled uterine cancer risk.
After researchers discovered the link with uterine cancer, some called for policy changes and other measures to reduce exposure to chemical relaxers.
“It is time to intervene,” Dr. Llanos and her colleagues wrote in a Journal of the National Cancer Institute editorial accompanying the uterine cancer analysis. While acknowledging the need for more research, they issued a “call for action.”
No one can say that using permanent hair straighteners will give you cancer, Dr. Llanos said in an interview. “That’s not how cancer works,” she said, noting that some smokers never develop lung cancer, despite tobacco use being a known risk factor.
The body of research linking hair straighteners and cancer is more limited, said Dr. Llanos, who quit using chemical relaxers 15 years ago. But, she asked rhetorically, “Do we need to do the research for 50 more years to know that chemical relaxers are harmful?”
Charlotte R. Gamble, MD, a gynecological oncologist whose Washington, D.C., practice includes Black women with uterine and ovarian cancer, said she and her colleagues see the uterine cancer study findings as worthy of further exploration – but not yet worthy of discussion with patients.
“The jury’s out for me personally,” she said. “There’s so much more data that’s needed.”
Meanwhile, Dr. James-Todd and other researchers believe they have built a solid body of evidence.