Hair dye and chemical straightener use were associated with an increased risk of breast cancer, according to the findings of a recent study. The results also showed this risk disproportionately affected black women.
“Many hair products contain endocrine‐disrupting compounds and carcinogens potentially relevant to breast cancer,” the researchers said. Products used predominately by black women may contain more hormonally‐active compounds, they added.
Using data from the Sister Study, the researchers examined associations between hair dye, chemical relaxer, and straightener use and risk of breast cancer among 46,709 women aged 35 to 74 years. Participants completed a questionnaire that asked about their hair product use within the past 12 months.
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During the mean 8.3 years of follow up, the researchers identified 2794 cases of breast cancer. Among participants, 55% reported permanent dye use. Permanent dye use was associated with a 45% increased risk for breast cancer among black women (hazard ratio [HR] 1.45; 95% CI, 1.10-1.90), the researchers said, and a 7% increased risk among white women (HR 1.07; 95% CI, 0.99-1.16). Additionally, personal straightener use was associated with breast cancer risk (HR 1.18; 95% CI 0.99-1.41), they added, noting that increased frequency was associated with a higher risk.
Nonprofessional application of semipermanent dye (HR 1.28; 95% CI, 1.05–1.56) and straighteners (HR 1.27; 95% CI, 0.99–1.62) to others was also associated with breast cancer risk, they added.
“We observed a higher breast cancer risk associated with any straightener use and personal use of permanent dye, especially among black women,” the researchers concluded. “These results suggest that chemicals in hair products may play a role in breast carcinogenesis.”
Eberle CE, Sandler DP, Taylor KW, White AJ. Hair dye and chemical straightener use and breast cancer risk in a large US population of black and white women [published online December 3, 2019]. Int J Cancer. doi:10.1002/ijc.32738