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A new study looks at hair color and risk of cancer. Getty Images
  • Anywhere from 50 to 80 percent of women and 10 percent of men over age 40 use hair color in the U.S. and Europe.
  • A new study finds hair dye likely doesn’t increase the risk for most cancers.
  • However, researchers did see a slight increase for certain cancers including ovarian and some breast and skin cancers.

People who use permanent hair dye aren’t at a higher risk for most cancers, or dying from them, according to a new study.

The authors linked permanent hair color with a slight increase in the risk of ovarian cancers, as well as some breast and skin cancers. The research was published by The BMJ.

Anywhere from 50 to 80 percent of women and 10 percent of men over age 40 use hair color in the United States and Europe, the authors stated.

Permanent dyes are the most aggressive and make up about 80 percent of all dyes used in the United States and Europe — and even more in Asia.

Hair dye is considered a probable carcinogen for beauticians and others who administer it regularly, the World Health Organization says. But they haven’t issued a warning about personal use due to inconclusive evidence.

Researchers examined data from 117,200 women over a 36-year span. At the start of the study, none of the women had cancer.

Of those who reported using permanent hair dye, there was no increased risk for developing most cancers, or of cancer-related death.

Specifically, hair dye didn’t increase the risk for bladder, brain, colon, kidney, lung, blood, and immune system cancers.

Women who used it were also not at a higher risk for most skin cancers, including cutaneous squamous cell carcinoma and melanoma. Additionally, women using hair dye weren’t at a higher risk for estrogen receptor (ER) positive, progesterone receptor (PR) positive, or hormone receptor-positive breast cancer.

Permanent hair dye was linked to a slightly increased risk for basal cell carcinoma of the skin, and this risk was higher in women with naturally light hair.

It was also associated with a higher risk for ER-negative, PR-negative, and hormone receptor-negative breast cancers, as well as ovarian cancer.

Women with naturally dark hair also had a higher risk for Hodgkin’s lymphoma. This could be because darker colored hair dye has higher concentrations of harmful chemicals, the authors stated.

Dr. Yin Zhang, an author and research fellow in medicine at Brigham and Women’s Hospital, told Healthline the results were consistent with those from a widely publicized 2019 study linking dye and straighteners to certain forms of cancer.

The 2019 study detected potential differences in ER status, in a sense that the risk associated with permanent hair dye appeared to be specifically elevated for ER-negative breast cancer compared to those with ER-positive breast cancer.

“Our study observed similar findings for ER-negative breast cancers,” Zhang said. “In addition, ours is the first study to be able to perform stratification analyses according to PR status, and risk was similarly increased for PR-negative and ER-negative/PR-negative breast cancer.”

A 2018 analysis showed an increased risk for certain cancers from hair dyes, as have other published reports.

Alexandra J. White, PhD, an investigator with the National Institute of Environmental Health Sciences, said the results are consistent with findings from her 2019 study.

“Hair products such as hair dyes contain many different chemicals that may act as carcinogens or endocrine disruptors,” White told Healthline.

Endocrine disruptors — compounds that can bind to the estrogen receptor and impact estrogen levels in the body — may be particularly important for cancers such as breast and ovarian cancer which are influenced by hormonal pathways.

Chemicals in hair dye could be absorbed through the skin or inhaled, she said.

A previous study demonstrated that chemicals found in hair dye have been measured in the breast tissue, White added.

White plans to further study hair dye as it relates to cancer risk across a larger span of time to give a more complete understanding about how risk may vary with timing of exposure, duration of use, and frequency.

The BMJ research cites White’s 2019 report that found considerably higher breast cancer risk in Black women and a borderline increased risk among white women who used permanent hair dyes. That’s largely consistent with other findings among American women with predominantly European ancestry.

Black women were found to have the most increased breast cancer risks in the 2019 research, but the population in the BMJ article didn’t include many Black women.

“Nevertheless, both studies found that hair dye use is associated with increased breast cancer risks,” noted Veena Singla, PhD, a senior scientist with the Natural Resources Defense Council.

“Women should consider their use of hair products in light of the fact that the chemicals in hair dye may influence their risk of developing breast cancer,” White said.

“However, the overall risk observed in both studies is not large, and chemical hair products are just one of many factors including alcohol intake, body size, and physical activity that may influence a woman’s chances of getting breast cancer,” White added.

The study also shows that using permanent hair dyes may not be strongly related to other cancer types.

“In the Sister Study [another database that includes women who had a sister with breast cancer], we found no higher risk of breast cancer for use of semi-permanent dyes,” White noted. “Women might consider switching from permanent to semi-permanent products if those products would work for them.”

The study is observational. That is, it doesn’t say that hair dye causes cancer.

“It would be unethical to do a randomized trial — usually the gold standard for human research — so we have to rely on these types of observational studies,” said Dr. Anne McTiernan, a professor of epidemiology at the Fred Hutchinson Cancer Research Center in Seattle.

The majority of women in it were white Americans with European ancestry. Other products used may have affected results.

White called for more research to identify the specific ingredients in permanent dyes and straighteners that may be contributing to a higher cancer risk.

Before more conclusive evidence is found, people should take precautions if they choose to use hair dye. Rinsing the chemicals out well and wearing gloves may offer some protection, Zhang added.