Dark hair dyes and relaxers increase breast cancer risks for both African American (AA) and White Women.
Hair Product Use and Breast Cancer Risk Among African American and White Women
Authors: Llanos AAM, Rabkin A, et al.
Source: AAM et. al. Carcinogenesis, 2017, 1-10.
Data suggests that certain hair care products – specifically, hair dye – are associated with breast cancer. This information is derived from animal studies and small numbers of human subjects. This group attempted to test the theory on a larger number of participants. Given the higher breast cancer mortality rates among AA women, the group made a pointed effort to include many of these women in the study.
AA and White women with breast cancer were matched to women of the same ages and ethnicity. Each person was interviewed in detail about her use of hair dyes, chemical relaxers and cholesterol- or placenta-containing deep conditioning creams.
Comparing AA women with and without breast cancer, there was a greater risk of disease among women who used dark hair dye shades with salon applications. There was no difference in risk with use of relaxers. Comparing White women with and without cancer, there was no difference in risk with use of hair dye. However, White women who used home relaxers or used relaxers and hair dye were at increased breast cancer risk (the investigators noted that the number of White women who reported using relaxers was very small, so the results may differ in a larger study).
There was no difference in breast cancer risk with the use of deep conditioners.
Regarding specific breast cancer types, the risk of estrogen receptor (ER) positive disease was greater among AA women who received regular salon applications of dark hair dye. White women who used both relaxers and hair dye had a greater risk of ER positive disease. Although the numbers were low, data suggested that use of lye-containing relaxers increased risk of ER negative disease among AA women and triple negative (TN) disease among White women. More study is needed for those observations.
These interesting results add to the general theories that certain hair care products increase breast cancer risk. The specific ingredients of these products need to be evaluated in order to determine a more direct cause and effect, if one exists.