Do hair dyes and straighteners cause breast cancer?

Hair dye and straigteners
A recent study shows that some chemical hair straighteners and dyes may increase the risk of breast cancer in women, especially those of African-American descent.

Recently, an important research study showed that hair dyes and chemical straighteners may significantly increase a woman’s risk of breast cancer. More than a third of American women use such hair products. Prior studies have been inconclusive, but much of that research involved only white women. This study, however, incorporated African-American women, though they made up only a small number of participants (9 percent). Published online on Dec. 3 in the International Journal of Cancer, the study conducted between 2003 and 2009 looked at 46,709 women aged 35 to 74 living in the United States and Puerto Rico. The participants had not been diagnosed with breast cancer at the beginning of study but had a family history of the disease.

Among the results of the study:

  • During the eight years the participants were followed, 2,794 developed breast cancer.
  • Women who used a permanent hair dye showed an elevated risk of breast cancer.
  • Black women had a 60 percent higher risk compared to 8 percent for white women.
  • Black women used hair dye more frequently. Seventy-four percent of black women said they used these products every five to eight weeks compared to 3 percent of white women who used them for that long.
  • Women who chemically straightened their hair had a 30 percent higher risk of breast cancer.

Permanent hair dye and chemical straighteners may contain hormone-disrupting chemicals and carcinogens that may be linked to the development of breast cancer. Hair products that are designed for African-American hair may contain even more endocrine-disrupting compounds than others. Chemicals, such as formaldehyde, which is a known carcinogen, are active ingredients in a common hair-smoothing solution. These products may contain hormone-disrupting compounds, including chemicals able to imitate estrogen, which may fuel certain types of breast cancer, and carcinogens that may be connected to the development of cancer. Hair straighteners may contain more than 5,000 chemicals and are used more often in hair products for African-American women.

This was a prospective observational study, and follow-up studies are needed, but consumers should be aware of potential risks. Talk to your physician about how using hair dyes or chemical straighteners may affect your risk of breast cancer. It’s also important to note that this study consisted of women with a family history of breast cancer and who were at increased risk of the disease to begin with.

As a board-certified endocrinologist for oncology patients, I aim to provide a unique expert perspective on health news and its impact on our patients’ health. As a black woman, this study is particularly important to me, as ever since childhood, family, friends and I have made regular visits to the hair salon. Our sisters, nieces, aunts, mothers, grandmothers and daughters are using these products. It’s important to know the risks that might exist with their use, so we can make better-informed decisions based on our individual situations.

Ironically, adhering to beliefs that resist the natural process of aging may cause consequences. For black women, hair and its straightening has had a complex history steeped in cultural pressures of conforming and political undertones rooted in race and gender debates. If you were looking for another good reason to embrace your signs of aging and your natural hair color and texture, this may just be it.

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