In my last post I discussed a study that concluded that losing weight after menopause decreases risk of breast cancer, even if you only lose a little bit. This post is also about breast cancer risk, but it has to do with an increased risk—from permanent hair dye.
That’s right, research conducted by scientists at the National Institutes of Health (NIH) discovered a link between use of permanent hair dye, as well as chemical hair straighteners, and an increased risk of breast cancer. And the level of risk reportedly corresponds to the amount of these products you use.
The study, titled “Hair dye and chemical straightener use and breast cancer risk in a large US population of black and white women,” was published in the International Journal of Cancer. More than 46,000 women participated in the research.
Women who used permanent hair dye on a regular basis in the year before the study began were found to be 9 percent more likely to be diagnosed with breast cancer than women who didn’t use hair dye at all. The risk appears to be far greater for black women: while white women who regularly used permanent hair dye (at least once every five to eight weeks) had an 8 percent increase, black women who used the same amount were found to have an increased risk of 60 percent.
“Researchers have been studying the possible link between hair dye and cancer for a long time, but results have been inconsistent,” said corresponding author Alexandra White, Ph.D., head of the NIEHS Environment and Cancer Epidemiology Group, according to a summary on the NIH website. “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.”
As for chemical hair straighteners, women who used them with the same frequency cited above were approximately 30 percent more likely to get breast cancer. While the risk is similar between races, the study notes that chemical straighteners are more popular among black women.
Use of semi-permanent or temporary dye, on the other hand, was not found to have a significant effect on breast cancer risk.