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Personal Hair Dye Doesn't Cause Bladder Cancer

CancerWise - March 2007

In a large-scale study, researchers determined that do-it-yourself permanent hair dye does not put users at higher risk for bladder cancer.

Ingredients are controversial

In the United States, permanent dye is used by 80% of people who color their hair. This includes:

  • More than one-third of women over 18 years old
  • 10% of men over 40 years old

Most hair dye contains small amounts of aromatic amines, which are carcinogenic in animals. Dark dyes contain higher concentrations of the chemicals.

“The role of hair dye in cancer has long been a topic of debate, and a large study is needed to elucidate this association,” says Xifeng Wu, M.D., Ph.D., professor in M. D. Anderson’s Department of Epidemiology.

A number of studies have shown that occupational exposure to hair dyes by hairdressers and barbers increases bladder cancer risk.

Study pairs those who dye, those who don’t

To compare the effects of hair dye, researchers matched by age, gender and ethnicity:

  • 712 newly diagnosed bladder cancer patients who had not received treatment
  • 712 patients who did not have bladder cancer

Participants completed questionnaires about risk factors including:

  • Demographic characteristics (age, gender, ethnicity)
  • Work history
  • Tobacco use
  • Personal hair dye use (frequency, type, duration, color)

Results show negative connection

Analysis of the figures showed the use of permanent hair dye was not associated with bladder cancer risk. This result was consistent in men and women of all ages and was not affected by:

  • Duration of use
  • Frequency of use
  • Age at first use
  • Dye color

“Based on these results and the very modest increase of bladder cancer risk in hair care professionals, it seems that personal hair dye use does not cause an appreciable increase in bladder cancer risk,” Wu says.

“However, a possibility of increased risk in certain subgroups cannot be ruled out given the nonsignificant increased risk in users of dark-colored dyes. Further, the overall lack of association does not exclude genetically susceptible subpopulations.”

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© 2015 The University of Texas MD Anderson Cancer Center