Does Dying Your Hair Increase Your Risk of Dying?
This article is part of our “In Medical News” series where Dr. Sara Laudani shares a recent study or article and offers some analysis and tips about the news, to help patients stay informed.
A recent study published in the International Journal of Cancer links permanent hair dye and chemical straighteners to breast cancer. Permanent dye use was associated with a 45% higher breast cancer relative risk in black women and a 7% higher relative risk in white women. Chemical hair straighteners and applying dye to someone else’s hair (as a non-professional) also showed links to cancer. However, neither the use of semi-permanent or temporary dyes on one’s own hair increased breast cancer risk.
Past studies have been inconsistent, but medical experts say this study clearly raises concerns about the safety of permanent dyes. Even adjusting for body-mass index, alcohol use, and hormone replacement therapy did not significantly change results. However, this study was done on women who all had a sister with breast cancer, so it will be important to do further research to see if similar results apply to all women. Risk levels also appeared to vary widely by ethnicity, type of product, and situation.
Additionally, "We were not able to evaluate the formulation of the hair dyes or straighteners assessed, nor are they reliably documented on labels, which is a limitation," the authors acknowledge. So, more studies will be needed to help medical professionals and patients further evaluate risks and distinguish safe usage.
Hair Dye and Straightener Risks for Different Ethnicities
More frequent use of hair dye was associated with a higher relative risk of breast cancer among black women. For those who colored their hair at least every 5 to 8 weeks, the risk of breast cancer was 60% higher compared with non-users, and this association was equally true for both dark-colored and light-colored hair dyes.
In contrast, among white women, the relative risk of breast cancer increased by only 12% with the use of light-colored hair dye. Moreover, the same risk was not seen with the use of dark-colored hair dye.
All women who used a chemical hair straightener every 5 to 8 weeks had a 31% higher relative risk of breast cancer compared with non-users. And, almost three-quarters of black women in the study reported using some form of hair straightener within 12 months of study enrollment compared with only 3% of non-Hispanic white women.
Helping a Friend, Hurting You: Risk of Non-Professional Application to Another Person’s Hair
Nonprofessional application of semi-permanent hair dye to another person's hair was associated with a 28% increased relative risk of breast cancer. A higher risk for breast cancer was also apparent for nonprofessional application of chemical straighteners to another person's hair.
- Avoid hair dyes and straighteners when possible, especially if you have an elevated/family risk of cancer. Black women, in particular, should avoid use of permanent hair dye and chemical hair straighteners.
- Use semi-permanent or temporary dyes instead of permanent dyes.
- Do not apply hair dye to friends or family members yourself/at home. Lack of proper ventilation, gloves and a mask can make this situation especially risky.
- Ask your doctor for advice based on your situation. As more studies come out, we will better be able to identify the highest-risk products and situations.
Sara Laudani, M.D., PhD., offers consultations in internal medicine and functional medicine in our Hongmei Road Clinic – Hongqiao. Click here to schedule an appointment to get an evaluation and personalized health plan.