Permanent hair dyes and relaxers associated with breast cancer risk
If you relax and dye your hair regularly, you may be at risk for developing cancer.
A study from the International Journal of Cancer, published on December 3, has found that there may be a link between harmful chemicals in those products and breast cancer.
The scientists said they observed a higher breast cancer risk associated with any straightener use and personal use of permanent dye, especially among black women.
The study found that products used predominately by black women may contain more hormonally‐active compounds.
The study was funded by the National Institutes of Health (NIH) and the National Institute of Environmental Health Sciences.
The study tracked 46,700 American women enrolled in a Sister Study, which recruited breast-cancer-free women whose sisters had been diagnosed with the disease.
The women ranged in age from 35 to 74 and were questioned about their lifestyle, health and demographics.
They provided researchers with updates over a follow-up period of approximately eight years.
At the end of the study, 55 percent of participants reported using permanent dye at enrollment.
Overall, using permanent dye was associated with a nine percent higher risk of developing breast cancer, compared to non-use.
Black women who used permanent dye had a 45 percent higher risk of breast cancer, compared to non-users, and those who used these products every eight weeks or more often had a 60 percent higher risk.
Black women were also far more likely to report using chemical straighteners with 74 percent compared to three percent of white women.
Alexandra White, a National Institute of Environmental Health Sciences epidemiologist and one of the study authors, told Time Magazine that this may be due to differences in the formulations of the dyes and straighteners used by women identifying as black compared to those identifying as white. Her co-author Dale Sandler adds that coarser, thicker hair may also absorb more dye.
White noted that the study tracked a relatively small group of women who actually developed cancer, and the disease is almost never caused by one thing alone.