A study from researchers at the National Institutes of Health linked a higher risk of breast cancer for women using permanent hair dye and chemical hair straightener. The risk is more than six times higher for black women.
The study in the International Journal of Cancer, followed 46,709 women and found that, overall, women who said they used permanent hair dye in the year before enrolling in the study were 9% more likely to develop breast cancer when compared with women who did not.
Permanent hair dye was associated with a 45% higher risk of breast cancer in black women and 7% higher in white women.
Black women who dyed their hair every five to eight weeks had a 60% higher risk for breast cancer.
Using a straightening product at least once every couple of months made it 30 percent more likely that a participant would develop breast cancer, regardless of whether they were white, African American, or Hispanic.
Hair products contain more than 5,000 chemicals, the authors write, and most of the dyes and straighteners did not “reliably document” ingredients on the label.
Hair products are amongst the many sources of potential endocrine disruptors and carcinogens in our environment.
The study doesn’t pinpoint which of the chemicals caused the damage, but makes some suggestions: Some aromatic amines, chemicals also found in tobacco smoke and industrial byproducts, disrupt the endocrine system, and some dyes have been found to induce tumors in rats’ mammary glands.
“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,” says researcher Dale Sandler, chief of the NIEHS Epidemiology Branch.
So, if you are concerned about your personal breast cancer risk, it’s always best to just talk to your doctor about it, and not worry too much about scary headlines.
This research was published in the International Journal of Cancer.