Researchers at the National Institute of Environmental Health Sciences (NIEHS), an organization that’s part of NIH, conducted a study using data responses from 46,709 women.
In the study, researchers found that women who had regularly used permanent hair dyes within the last year were 9 percent more likely to develop breast cancer than women who did not use these products.
The researchers did not find any significant increases in risks of developing breast cancer for women who used temporary or semi-permanent dyes.
The study revealed that women who have their hair done in salons are at lower risks.
This hair dye and breast cancer link primarily affect women who regularly use store-bought permanent hair dye.
NIEHS Study Finds Links Between Using Chemical Hair Straighteners and Increased Risks of Breast Cancer and Uterine Cancer
Researchers found that women who used chemical hair straighteners at least every five to eight weeks were nearly 30 percent more likely to develop breast cancer. The study also found that women who used chemical hair straighteners were also at more than double the risk for developing uterine cancer.
Links between hair straightener use and breast cancer development were generally consistent between both African American women and white women.
However, the study revealed that straightener use was more prevalent among African American women. Black women use hair straighteners at higher rates than white women, and begin use of chemical hair straighteners at a young age.
These hair straighteners and breast cancer links only apply to chemical products.
Large-Scale Study, Diverse Sample Group
The possible link between permanent hair products and increased risks of breast cancer has been hypothesized for a long time, but research has generally proved inconsistent with research done in small sample groups.
The NIEHS study was able to provide data from a large sample size with a diverse group of women. Of the 46,709 women enrolled, all were between the ages of 35 and 74 and came from all 50 states and Puerto Rico.
None of the women had a personal breast cancer history, but they all had a sister diagnosed. The average follow-up window was 8.3 years.