New research on the potential link between permanent hair-dye and breast cancer

A new study has revealed a new, surprising potential risk factor for breast cancer: the use of permanent hair dye or chemical straightening treatments. According to the researchers, hair products contain more than 5,000 chemicals, including those that can interfere with a woman’s hormone function and cause health risks.

Analyzing data from the Sister Study, researchers explored the medical records of more than 46,000 women between the ages of 35-74. Unlike early studies that focused on mostly white women, the new study included 9% African American women.

Researchers found that women who used permanent hair dye or chemical straighteners were at higher risk of developing breast cancer. The association between the use of permanent hair dye and cancer risk was much higher among African American women, but there were no racial differences when it came the risk linked to chemical straighteners. There was also no increased risk associated with semi-permanent hair dyes that wash out after a certain period of time.

The authors of the study were careful to note that the study’s findings should be considered in context. The actual risk found for use of these hair treatments is relatively low, especially when compared with other known risk factors like tobacco use, obesity, and living near environmental contaminants. A key lesson of the study? Pay attention to risk factors, get preventive screenings, and communicate with your doctor about any concerns you may have.  Read more about the study at NPR.