Researchers from the National Institute of Environmental Health Sciences (NIEHS) discovered that permanent hair dye and straighteners could increase consumers’ risk of developing breast cancer.
“Researchers have been studying the possible link between hair dye and cancer for a long time, but results have been inconsistent,” said researcher Alexandra White, PhD. “In our study, we see a higher breast cancer risk associated with hair dye use, and the effect is stronger in African American women, particularly those who are frequent users.”
Identifying the risk factor
To understand the risks associated with hair treatments, the researchers analyzed over 46,000 responses to the NIEHS’ Sister Study. The sample was unique in that the women who took the survey were cancer-free, but they had sisters who had been diagnosed with breast cancer.
Participants reported on how often they dyed their hair, the frequency with which they have their hair permanently dyed, and other questions that assessed the hair products they used and treatments they received.
The survey revealed that the more frequently women used permanent hair dye or received permanent straightening treatments, the more likely they were to develop breast cancer.
As Dr. White explained, the risk for breast cancer was stronger for black women when it came to using hair dye products. Using permanent hair dye every eight weeks was associated with an eight percent increased risk of the disease for white women but a 60 percent increased risk for women of color.
This demographic difference didn’t extend to permanent straightening treatments, as all of the women involved in the study were approximately 30 percent more likely to develop breast cancer when they received such treatments every eight weeks.
While the study also revealed that temporary or semi-permanent dyes didn’t pose as great a risk for breast cancer, the researchers don’t want to be prescriptive when it comes to avoiding certain hair care options. However, they do want consumers to be aware of the potential risks associated with such treatments.
“We are exposed to many things that could potentially contribute to breast cancer, and it is unlikely that any single factor explains a woman’s risk,” said researcher Dale Sandler, PhD. “While it is too early to make a firm recommendation, avoiding these chemicals might be one more thing women can do to reduce their risk of breast cancer.”