A new study published in the International Journal of Cancer found an alarming link between the use of hair dyes and chemical straighteners and the likelihood of developing breast cancer.
Previous studies have linked working in hair salons to a slightly increased incidence of bladder cancer in hair stylists, according to the American Cancer Society. Beyond this finding, there is little definitive evidence that hair dyes are carcinogenic.
The new results may change that.
The study of almost 47,000 women between the ages of 35 and 74, who already had a family history of breast cancer, found that black women who colored their hair frequently —every five to eight weeks — were 60% more likely to develop breast cancer than those who didn’t color their hair. Oddly enough, white women who colored their hair frequently were only 8% more likely, the Washington Post reports.
When including women who died their hair less frequently than every five to eight weeks, the numbers still reflect an increased risk, according to Guardian, with black women 45% more likely to be diagnosed with breast cancer and white women 7% more likely.
Overall, the entirety of the study population was found to have an 18% higher risk of breast cancer if they chemically straightened their hair, and a 9% higher risk if they had ever used permanent dye on their hair, according to Science Times.
Why is the risk so much higher for black women? A study done by the Silent Springs institute in 2018 found that many hair products that were more commonly used by the black community, particularly hair relaxers that had endocrine disrupting chemicals, played a role.
The Guardian reports that severe disruptions of the endocrine system have previously been linked to tumors, birth defects, neurological disorders, infertility and lack of fertility, and developmental problems.
The Washington Post faults the lack of regulation for beauty products in America for the inclusion of harmful chemicals in commonly used hair straightening and dyeing products.