Chemical hair relaxers carry an increased risk of uterine cancer. Do I need to worry?

Long-term use of chemical hair relaxers by postmenopausal Black women is associated with an increased risk of uterine cancer, according to new research that’s part of Boston University’s Black Women’s Health Study. Given that up to 95% of adult Black women in the U.S. report ever using hair relaxers, this news impacts a lot of people.

The Food and Drug Administration now plans to propose a ban on formaldehyde (FA) and other FA-releasing chemicals, such as methylene glycol, as an ingredient in hair smoothing and hair straightening products marketed in the United States. Black and Latina women all over the world likely have questions about what this means for their health and their hair. Yahoo Life reached out to medical experts to get some answers.

What’s happening?

Many Black and Latina women have suspected for years that there’s a link between using chemical hair relaxers and developing gynecologic cancers, such as breast, ovarian and uterine cancer. This latest study — which asked 45,000 women without a prior history of cancer and with an intact uterus about their past use of chemical hair relaxers and then followed them for up to 22 years — shows those concerns may be justified.

“Results from our analysis in the Black Women’s Health Study showed that postmenopausal women who reported using hair relaxers more than twice a year or for more than five years had a greater than 50% increased risk of uterine cancer compared to women who never or rarely used hair relaxers,” Kimberly Bertrand, co-author of the study and associate professor of medicine at Boston University’s Slone Epidemiology Center, tells Yahoo Life. Postmenopausal Black women who used hair relaxers for 20 or more years had about a 70% increased risk of uterine cancer compared to never or light users.

Do I need to worry?

The specific formulations of hair relaxers are proprietary, so it is difficult to know what specific ingredients may be associated with health risks. “We did not have information on specific brands of hair relaxers used by women in our study,” says Bertrand. “However, we did ask about the usual use of lye vs. no-lye formulations. Positive associations were apparent for both lye and no-lye formulations.”

These products are known to contain potentially harmful toxicants and carcinogens, such as formaldehyde and heavy metals, along with phthalates, parabens and other endocrine-disrupting chemicals. Bertrand says that prior studies have linked endocrine disruptors to a wide range of women’s reproductive health issues, including infertility. Identifying these ingredients isn’t necessarily easy either, since parabens and phthalates are often only listed on labels as “preservatives” and “fragrance.”

What can I do about it?

There are products that are being marketed as safer alternatives to relaxers. However, the scientific evidence to substantiate this is lacking. “This speaks to the need to support ongoing research not just to determine the harm from substances in chemical relaxers, but innovation to support alternatives for women who wish to style their hair curly, straight or in whatever ways we choose,” Dr. Monique Gary, breast surgeon and medical director of the Grand View Health/Penn Cancer Network cancer program, tells Yahoo Life.

Keratin treatments, for example, may be touted as more natural, but beware of formaldehyde that can be a hidden ingredient in some of these products. Read the labels and have a discussion with your hair care professional to determine the best course of action for you.

Gary suggests choosing your products wisely. “As an oncologist, I am seeing increasing data attempting to closely associate these chemicals with breast cancer as well,” she says. “With a staggering mortality rate [for Black women], it’s important that we are mindful of what we put on and in our bodies.”

The conversation regarding using chemical hair relaxers is complex, as societal pressures about appropriate hairstyles for Black women, especially in professional settings, impact their hair care choices. New federal laws like the CROWN Act help with hair discrimination in the workplace, but more needs to be done to help Black girls and women accept their natural hair and see it as beautiful in its natural state.

“I recommend women be as conscientious about diet and lifestyle as we are about our hair, and know that there are proven lifestyle changes to reduce the risk for the development of gynecologic cancers and we should lean into this as well,” says Gary. Additionally, experts advise that women consider longer intervals between chemical hair relaxing treatments.

The main takeaway

It’s worth noting that not everyone who uses chemical hair relaxers will develop gynecologic cancers, and the study found the greatest risk with moderate to heavy use. An important limitation of the study is that the researchers did not update exposure information over time. So it’s not known whether these results are generally applicable to chemical hair relaxers on the market today (the women in the study were followed from 1997 — “when chemical hair relaxer use was queried,” per the study — to 2019) or to contemporary patterns of use.

However, more recent studies have documented the presence of parabens and phthalates, as well as formaldehyde, a known carcinogen, in modern-day formulations of some hair products, including chemical relaxers and even shampoo.

Bertrand also points out that the study did not find evidence of an association between hair relaxers and risk of uterine cancer among premenopausal women. “But there is a caveat to that result,” she says. “There may have been too few women in that group to observe an association.”

It’s possible that exposure could have occurred during the premenopausal years, and likely did for the majority of women, which is associated with a future risk. However, it’s also important to point out that postmenopausal women — those between the ages of 50 and 70 — are already at a higher risk of developing uterine cancer.

Bertrand hopes the study will raise awareness about the potential harm chemical hair relaxers may cause, and calls for stricter regulations of cosmetic products like these — something the FDA is currently proposing with the possible ban on formaldehyde — along with the need for safer alternatives.