A study published yesterday in the Journal of Cancer tracked 46,709 women ages 35-74 over eight years. The results are particularly harrowing for black women: those who used permanent dyes at least every 5-8 weeks had a 60% higher risk of developing breast cancer than those who did not; white women were 8% more likely to develop breast cancer.

Chemical straighteners also proved problematic: Women who used straighteners every 5-8 weeks were 30% more likely to develop breast cancer. Straighteners are much more commonly used among black women. (In the study, 74% of black women had, versus 3% of white women.)