dyed their hair frequently, every one or two months.
“The association was notably higher among black women,” says epidemiologist Alexandra White, study author and an investigator with the National Institute of Environmental Health Sciences, who studies environmental risk factors for breast cancer.
Researchers don’t know which ingredients in the products might be of concern. The study did not look at the specific ingredients in the products women were using, only at whether they had used the product and whether they developed breast cancer.
All women in the Sister Study were already at high risk for breast cancer since they had a sister who had breast cancer.
Researchers note that in the United States, breast cancer incidence remains high for all women and appears to be increasing for non-Hispanic black women, who also are more likely to be diagnosed with