Frequent and long-term use of lye-based hair straightening products, or relaxers, may increase the risk of breast cancer among Black women, compared with more moderate use. Boston University’s Black Women’s Health Study followed 59,000 self-identified African American women for over 25 years, sending questionnaires every two years on new diagnoses and factors that might influence their health.
Black women who used hair products containing lye at least seven times a year for 15 or more years had an approximately 30% increased risk of estrogen receptor positive breast cancer compared with more infrequent users.
The minimal association between hair relaxers (with or without lye) and breast cancer risk for moderate users is generally reassuring. But the elevated risk for the heaviest users of lye-based hair products – which included about 20% of study participants – is concerning.
- See “25-year-long study of Black women links frequent use of lye-based hair relaxers to a higher risk of breast cancer” by Kimberly Bertrand on The Conversation website (July 13, 2021)
- See the abstract of the scientific paper “Hair product use and breast cancer incidence in the Black Women’s Health Study” by Patricia F Coogan et al.