Study: Hair Relaxers Not Linked to Breast Cancer

Study: Hair Relaxers Not Linked to Breast Cancer
Likely Not a Factor in Black-White Breast Cancer Gap
Article patientINFORM

Summary: Using hair relaxers, even over a period of many years, does not appear to raise a woman's risk of breast cancer, according to a large study of African-American women. Researchers were looking at the possibility that exposure to chemicals in these widely used hair-straightening products might explain why young black women have higher rates of breast cancer than young white women do.

Why it's important: When looking at all age groups, breast cancer is more common in white women than in blacks. But African-American women are more likely to develop the disease at a young age (under 40) and are more likely to die from it. Researchers are trying to understand what is behind this difference.

What's already known: Social and economic factors play a role in some of the differences. For instance, African Americans tend to have lower incomes and less health insurance than whites and may therefore be less likely to get regular mammogram screenings that can catch cancer early when it is most treatable. Scientists are searching for more clues to these differences so they can try to lessen their impact.

How this study was done: Because use of hair relaxers is very common among African-American women, especially younger ones, but not common at all among white women, researchers from Boston University and Howard University decided to investigate the possible relation of these products to breast cancer risk specifically in black women. They used data from the Black Women's Health Study, a large, ongoing study of lifestyle and disease involving tens of thousands of African-American women in the US. Since 1995, participants have answered periodic questionnaires about their health and habits like smoking, exercise, and diet.

What was found: The research team had information on the use of hair relaxers for more than 48,000 women in the study. Between 1997 and 2003, 574 of these women developed breast cancer. But the researchers did not find any link to hair relaxer use. Basically, women who had never used hair relaxers were found to have the same risk for breast cancer as those who had used the products for many years (even 20 or more), those who used them multiple times each year (even 7 times or more), those who began using them at a young age (under age 10), or those who had been burned by the products multiple times when using them. The type of product (with lye or without lye) also had no effect on breast cancer risk. The findings are published in the journal Cancer Epidemiology Biomarkers & Prevention.

The bottom line: Because the study was so large, the findings offer strong evidence that hair relaxers are probably not contributing to the breast cancer gap between African-American women and white women, and they are not likely to be a cause for concern among the women who use them.