PHILADELPHIA -- Chemical relaxers used to straighten hair are not associated with an increased risk of developing breast cancer among African-American women, say researchers who followed 48,167 Black Womens Health Study participants.
In the May issue of Cancer Epidemiology, Biomarkers & Prevention, researchers from Boston University and Howard University Cancer Center found no increase in breast cancer risk due to the type of hair relaxer used or the frequency and duration of use. Women who used relaxers seven or more times a year over a 20 year span or longer had the same risk as women who used the chemicals for less than a year, researchers say.
This is good news, said the studys lead investigator, Lynn Rosenberg, Sc.D., professor of epidemiology at Boston University School of Public Health. The present study is definitive that hair relaxers dont cause breast cancer, as much as an epidemiologic study can be.
Previous research shows that breast cancer incidence is higher among African-American women age 40 or younger than among Caucasian women of the same age, and this increased risk is not fully explained by known risk factors, such as race and family history. At all ages, African-American women are more likely to die of breast cancer than are Caucasian women. To shed light on these findings and to study potential causes of breast cancer and other serious illnesses that affect black women, the Black Womens Health Study was launched across the United States in 1995. More than 59,000 women completed an initial questionnaire and more than 80 percent have answered follow-up questions every two years since, including questions about use of hair relaxers.
Hair relaxers can enter the body through cuts or lesions in the scalp. These products are not fully monitored by the Food and Drug Administration, and thus could contain potentially harmful compounds, Rosenberg said. Manufacturers of hair relaxers and hair dyes are not requ
Contact: Greg Lester
American Association for Cancer Research