Hair Products May Increase Breast Cancer Risk

Study points to permanent hair dye and straighteners

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, according to researchers at the National Institute of Environmental Health Sciences (NIEHS).

Using data from 46,709 women in the Sister Study, the researchers found that women who regularly used permanent hair dye in the year prior to enrolling in the study were 9% 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% increased risk of breast cancer as compared with an 8% increased risk for white women. The research team found little to no increase in breast cancer risk for semi-permanent or temporary dye use.

Alexandra White, PhD, head of the NIEHS Environment and Cancer Epidemiology Group, and colleagues also found that women who used hair straighteners at least every five to eight weeks were about 30% more likely to develop breast cancer. While the association between straightener use and breast cancer was similar in African American and white women, straightener use was much more common among African American women.

When asked if women should stop dyeing or straightening their hair, co-author Dale Sandler, PhD, chief of the NIEHS Epidemiology Branch, said, "We are exposed to many things that could potentially contribute to breast cancer, and it is unlikely that any single factor explains a woman’s risk. While it is too early to make a firm recommendation, avoiding these chemicals might be one more thing women can do to reduce their risk of breast cancer."

Source: NIH, December 4, 2019