Chemical hair straighteners linked to higher risk of uterine cancer

Credit – Sisters Study Facebook page

CANCER DIGEST – Oct. 22, 2022 – The risk of cancer of the uterus was found to be double among women who use chemical hair straightening products compared to women who did not use such products, a new study shows.

The study conducted by the National Institute of Environmental Health Sciences, part of the NIH, tracked 33,497 women between the ages of 35-74 over a period of 11 years. During that time 378 uterine cancers were diagnosed.

When the researchers looked at risk factors among those women and those who did not develop uterine cancer, they found that only 1.64 percent of women who never used hair straighteners would develop uterine cancer by age 70 compared to 4.05 percent of the women who frequently used hair straighteners.

"This doubling rate is concerning," said Alexandra White, PhD, in a press release. She is head of the NIEHS Environment and Cancer Epidemiology group, and lead author of the study. "However, it is important to put this information into context. Uterine cancer is a relatively rare type of cancer."

While it accounts for only about 3 percent of new cancer cases each year, it is the second most common cancer of the female reproductive system with an estimated 65,950 new cases diagnosed in 2022.

The study is the result of data from the Sister Study that has been following the women since 2011. Approximately 60 percent of the women who reported using hair straighteners in the previous year identified themselves as Black. While the study did not find a difference in uterine cancer cases by race, it did suggest that because Black women tend to use hair straitening products more frequently, these women may be at higher risk.

The finding meshes with earlier studies that have found such products were associated with hormone-related cancers in women, and this research team’s own previous findings linking hair dye and straighteners with increased breast and ovarian cancer.

The products often contain parabens, bisphenol A, metals, and formaldehyde, which are chemicals that have been linked to cancer.


Source: National Institute of Environmental Health Sciences press release