The ﬁndings are the ﬁrst epidemiologic evidence of an association between the use of hair products and uterine cancer

The use of chemical hair straightening products leads to an increased risk of uterine cancer, reveals the latest research published in the Journal of the National Cancer Institute.

The ﬁndings are the ﬁrst epidemiologic evidence of an association between the use of hair straightening products and uterine cancer.

“We examined associations between hair product use and incident uterine cancer among 33947 participants aged 35-74 years who had a uterus at enrollment (2003-2009),” the researchers wrote. “In baseline questionnaires, participants in this large, racially and ethnically diverse prospective cohort self-reported their use of hair products in the prior 12 months, including hair dyes; straighteners, relaxers, or pressing products; and permanents or body waves.”

Over an average of 10.9 years of follow-up, 378 uterine cancer cases were identiﬁed, the study found.

Uterine cancer is one of the most common gynecologic cancers. With more than 65950 new cases and 12550 fatalities anticipated in 2022, the incidence and mortality rates in the United States have generally increased during the past 20 years.

Hair product use has been associated with hormone-sensitive cancers including breast and ovarian cancer in previous epidemiologic studies.

The ingredients in hair products, such as formaldehyde and formaldehyde-releasing chemicals in some straighteners, oxidised para-phenylenediamine, and 4-aminobiphenyl in hair dyes, may also contribute to the development of cancer.

Hair product use is common among women in the United States and Europe with more than 50 percent reporting using permanent hair dyes.

The researchers have previously observed a higher breast cancer incidence associated with adolescent and adult use of hair products and a higher ovarian cancer incidence associated with adult use of straighteners.

They have also observed an 80 percent higher risk of uterine cancer among study participants who had used straightening products, and that risk increased with more frequent use.

“Previous studies have found hair product use to be associated with a higher risk of hormone-sensitive cancers including breast and ovarian cancer; however, no previous study has investigated the relationship with uterine cancer,” the study pointed out.

Limitations of this study include self-reported product use, potential variation in product use over time, and no collection of information on brands or ingredients of hair products.