14/09/2025
🚨 A study has linked permanent hair dye to increased breast cancer risk.
Women who frequently use permanent hair dye or chemical hair straighteners may face a higher risk of developing breast cancer, according to a major study from the National Institutes of Health.
Using data from over 46,000 participants in the long-running Sister Study, researchers at the National Institute of Environmental Health Sciences (NIEHS) found that regular users of permanent hair dye were 9% more likely to develop breast cancer than non-users.
The risk was especially pronounced for African American women, who saw a 60% increase in breast cancer risk when using permanent dye every five to eight weeks, compared to an 8% increase for white women.
The study also revealed a strong link between chemical hair straighteners and breast cancer. Women who used straighteners at least every five to eight weeks were about 30% more likely to develop the disease, regardless of race. While the findings do not prove causation, they add to mounting evidence that chemical exposures from beauty products may influence cancer risk. Scientists emphasize that more research is needed to confirm these associations, but suggest limiting exposure could be one step women take toward reducing risk.
Source: Eberle, C. E., Sandler, D. P., Taylor, K. W., & White, A. J. (2019). Hair dye and chemical straightener use and breast cancer risk in a large US population of black and white women. International Journal of Cancer.
