Study: Permanent hair dyes linked to breast cancer

Results published in International Journal of Cancer

Two common beauty products, permanent hair dyes and chemical straighteners, may be associated with an elevated risk for breast cancer, a new study said.

The study, published in the International Journal of Cancer, tracked more than 46,000 women over several years.

Overall, women using permanent dye had a 9% higher risk of developing breast cancer.

Black women who used permanent dye had a 45% higher risk of breast cancer compared to non-users, and those who used the products every for eight weeks or more often had a 60% higher risk.

The study was funded by NIH and recruited breast cancer-free women whose sisters had been diagnosed with the disease.

Women in the study ranged in age from 35 to 74.

The study says more research is needed.