Moderate, Heavy Use of Chemical Hair Relaxer Linked to Uterine Cancer

THURSDAY, Nov. 2, 2023 (HealthDay News) — Among postmenopausal Black women, moderate and heavy use of chemical hair relaxers is associated with an increased risk for uterine cancer, according to a study published online in the upcoming Dec. 15 issue of Environmental Research.

Kimberly A. Bertrand, Sc.D., M.P.H., from Slone Epidemiology Center at Boston University, and colleagues followed 44,798 women with an intact uterus who self-identified as Black from 1997 (when use of chemical hair relaxers was queried) until 2019. A total of 347 incident uterine cancers were diagnosed during follow-up.

The researchers found that the hazard ratio (HR) for uterine cancer associated with heavy use (≥15 years and at least five times/year) compared with never use or infrequent use (less than four years and no more than one to two times/year) was 1.18 (95 percent confidence interval [CI], 0.81 to 1.71). Among postmenopausal women, the HRs for moderate and heavy use compared with never/light use were 1.60 (95 percent CI, 1.01 to 2.53) and 1.64 (95 percent CI, 1.01 to 2.64), respectively. Regardless of frequency, the HR for ≥20 years of use was 1.71 (95 percent CI, 1.08 to 2.72).

“If the present results are confirmed, efforts to reduce exposure to these potentially harmful products — such as by identifying safer alternatives to straightening hair, stricter regulation of cosmetic products, and policies prohibiting discrimination against natural hair (e.g., the CROWN Act) — could represent important steps toward reducing racial disparities in this cancer type,” the authors write.

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