Permanent hair dye, straighteners may increase breast cancer risk

December 06, 2019
Hair color

SCIENTISTS at the National Institutes of Health (NIH) found that women who use permanent hair dye and chemical hair straighteners have a higher risk of developing breast cancer than women who don’t use these products.

The study published online in the International Journal of Cancer  suggested that breast cancer risk increased with more frequent use of these chemical hair products.

Using data from 46,709 women in the Sister Study, researchers at the National Institute of Environmental Health Sciences (NIEHS), part of NIH, found that women who regularly used permanent hair dye in the year prior to enrolling in the study were nine percent more likely than women who didn’t use hair dye to develop breast cancer.

Among African American women, using permanent dyes every five to eight weeks or more was associated with a 60 percent increased risk of breast cancer as compared with an eight percent increased risk for white women. The research team found little to no increase in breast cancer risk for semi-permanent or temporary dye use.

Corresponding author Alexandra White, Ph.D., head of the NIEHS Environment and Cancer Epidemiology Group said they found a higher breast cancer risk associated with hair dye use, and the effect is stronger to frequent users.

An intriguing finding was the association between the use of chemical hair straighteners and breast cancer. Dr. White and colleagues found that women who used hair straighteners at least every five to eight weeks were about 30 percent more likely to develop breast cancer.

Should women stop dyeing or straightening their hair? Co-author Dale Sandler, Ph.D., chief of the NIEHS Epidemiology Branch, said women were exposed to many things that could potentially contribute to breast cancer, and it is unlikely that any single factor explains a woman’s risk and avoiding these chemicals might be one more thing women can do to reduce their risk of breast cancer.