Investigators at the National Institutes of Health recently discovered that women who use permanent hair dye and chemical straighteners are at a higher risk for developing breast cancer compared to those who don't use these products.
"Researchers have been studying the possible link between hair dye and cancer for a long time, but results have been inconsistent," commented one of the study authors, Alexandra White, PhD, and head of the National Institute of Environmental Health Sciences (NIEHS) Environment and Cancer Epidemiology Group. "In our study, we see a higher breast cancer risk associated with hair dye use, and the effect is stronger in black women, particularly those who are frequent users."
Data obtained from the research, deemed the Sister Study, was taken from 46,709 women aged 35-74 who had a sister with breast cancer but did not have breast cancer themselves. Each participant filled out questionnaires regarding their hair product use in the past 12 months.
After a follow-up of 8.3 years, there were reports of 2,794 breast cancer cases in the study population. Over half (55%) of women reported using permanent dye at enrollment. The researchers found that permanent hair dye use was linked to a 45% increase in breast cancer risk in black women and a 7% increase in white women. In addition, personal chemical straightener use was linked to a higher breast cancer risk that continued to escalate as frequency increased. Nonprofessional application of semipermanent dye and straighteners to others was also linked to increased breast cancer risk.
In response to whether women should stop dyeing or straightening their hair, one of the researchers, Dale P. Sandler, PhD, and Chief of the Epidemiology Branch of the NIEHS, replied, "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. 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."
For More Information
Eberie CE, Sandler DP, Taylor KW & White AJ (2019). Hair dye and chemical straightener use and breast cancer risk in a large US population of black and white women. Int J Cancer. [Epub ahead of print] DOI:10.1002/ijc.32738
Image Courtesy of National Institute of Environmental Health Sciences