Hair relaxers not associated with increased risk of breast cancer in black women

May 18 2007

According to researchers at Boston University's Slone Epidemiology Center, hair relaxers are not associated with increased risk of breast cancer in black women.

The findings will be published in the May issue of Cancer Epidemiology Biomarkers & Prevention.

Hair dye use has been associated with an increased risk of various cancers in some studies, but these results have generally not been confirmed. The present study is the first to assess hair relaxers in relation to a cancer.

Since millions of women have used hair relaxers, and because the carcinogenic potential of hair relaxers is unknown, Lynn Rosenberg, ScD, associate director of Boston University's Slone Epidemiology Center, and colleagues examined the association of hair relaxer use with breast cancer incidence in the Black Women's Health Study.

The Black Women's Health Study is a follow-up study of 59,000 African American women from across the United States conducted by investigators at Boston University's Slone Epidemiology Center and Howard University Cancer Center. While tracking data from 1997 to 2003, researchers combed through more than 266,000 person-years of follow up data to determine that there is no increase in breast cancer incidence associated with hair relaxer use.

"In the present study of African American women, increases in breast cancer risk were not associated with any categories of duration of hair relaxer use, frequency of use, age at first use, number of burns experienced during use, or type of relaxer used," stated Rosenberg. "Of particular interest, null associations were observed among younger women, who used relaxers at earlier ages and more frequently than older women. Thus, the findings provide empirical evidence that hair relaxers are not carcinogenic to the breast and do not contribute to the higher incidence of breast cancer in young African-American women than in young white women."