August 14, 2023

Experts urge caution with chemical hair straighteners following study's findings

A hairdresser using chemicals to straighten a client's hair

Experts urge caution and moderation on the use of chemical hair straighteners after a study from the National Institutes of Health showed a possible link between frequent use of those styling products and higher uterine cancer risk.

“It’s good to be proactive,” said Dr. Janelle Sobecki, assistant professor of gynecologic oncology in the UW Department of Obstetrics and Gynecology. “This is newer information, there hasn’t been a lot of research done in this area, and we’re probably going to see more information coming out in the future.”

The findings, published in Journal of the National Cancer Institute, came from a comparison of hair straightener use among more than 30,000 study participants. The researchers found that those who reported having chemical hair straightening more than four times within a year had 2.5 times higher risk of developing uterine cancer than those who didn’t straighten their hair.

Dr. Che-Jung Chang, a postdoctoral research fellow in the Epidemiology Branch at the National Institute of Environmental Health Sciences, was lead author of the report. She said that Black women used chemical hair straightener more often than women of other races and ethnicities in their study, with about 60% of women who reported having their hair straightened in the previous 12 months being Black.

“Although the risks (of uterine cancer) are similar when you show the association by race, the fact that more Black women are using these products, they are being impacted more,” Chang said.

American Cancer Society data shows non-Hispanic Black women have the highest death rate from uterine cancer compared to other racial groups.

Chang said additional research is needed on the specific ingredients within these products that could influence cancer risk. One hypothesis is the products could be exposing women to chemicals such as endocrine disruptors, which can mimic, block or interfere with the body’s natural hormones and cause adverse health effects.

“We want to know the specific chemicals that drive this elevated risk,” Chang said.

Uterine cancer is the most common gynecologic cancer and is most often diagnosed in post-menopausal women. Most uterine cancers develop in the endometrium, or uterine lining, which is called endometrial cancer. New vaginal bleeding after menopause can be an early indication of uterine cancer, and Sobecki urged women to tell their doctor if that occurs.

“Any bleeding after menopause, after your period has stopped for 12 months, is never normal,” she said. “One of the most effective ways to detect endometrial cancer early is to notify your healthcare provider right away if you experience any vaginal bleeding after menopause. This can lead to early detection and hopefully, excellent treatment outcomes.”

Diagnosed in its earliest stage, uterine cancer has a high cure rate. The most common treatment is surgery to remove the uterus, as well as fallopian tubes and ovaries. Chemotherapy and radiation could also be necessary.