Does Hair Dye Cause Cancer?

Problem: I had a nurse tell me not to use any dark brown or black hair coloring because it might cause cancer. I read your book on hair care about this particular subject explaining there is nothing to worry about, but it seems to still be an issue in the medical world. Is dark hair color safe, or isn't it?

Solution: Unfortunately, few of the 75 million women who color their hair on a regular basis even know that an issue about hair dye and its association with certain types of cancers exists. However, although the issue is real, what it means isn't settled or conclusive in any regard. The best I can do is to provide the information and research that is available so that you can make a final decision for yourself.

Much of this controversy began when a study conducted by the American Cancer Society found that women who used black hair dye for more than 20 years had a slightly increased risk of dying from non-Hodgkin's lymphoma and multiple myeloma (a bone-marrow tumor that is usually malignant). Researchers surveyed 573,369 women who completed questionnaires about their use of permanent hair dye. However, this same study concluded that women who dyed their hair showed a slightly reduced risk overall of dying of cancer than women who never used dyes. (Sources: Journal of the National Cancer Institute, February 2, 1994, pages 210–215; Environmental Health Perspectives, June-July 1994, volume 102, number 6–7.)

Subsequent studies found no correlation and did not support risk of any kind. An article in FDA Consumer magazine, January-February 2001, explained that in a "...study, published in the October 5, 1994, issue of the Journal of the National Cancer Institute, researchers from Brigham and Women's Hospital in Boston followed 99,000 women and found no greater risk of cancers of the blood or lymph systems among women who had ever used permanent hair dyes. Then in 1998, scientists at the University of California at San Francisco questioned 2,544 people about their use of hair-color products. After integrating the results of this study with those of animal and other epidemiological studies, they concluded that there was little convincing evidence linking non-Hodgkin's lymphoma with normal use of hair-color products in humans. The study was published in the December 1998 issue of the American Journal of Public Health."

There have also been other subsequent studies showing hair dye to have no association with cancer or other diseases. One noted that: "The lack of an association between exclusive use of a single type of hair coloring application and breast cancer risk argues that hair coloring application does not influence breast cancer risk among reproductive-age women. Thus, the results of the present study, as well as negative ones from most (but not all) prior studies, are most consistent with the conclusion that neither hair coloring application nor hair spray application influences breast cancer risk" (Source: Cancer Causes and Control, December 1999, pages 551–559). Another stated: "We found no evidence that permanent hair dye use, age at first use, frequency of use, or duration of use is associated with the development of systemic lupus" (Source: Arthritis and Rheumatism, April 1996, pages 657-662).

Then in February 2001 this issue was given new life when researchers from the University of Southern California reported a link between the use of permanent hair coloring and bladder cancer. "They analyzed questionnaires from 897 patients with bladder cancer and compared them to questionnaires from 897 similar individuals without bladder cancer. They found that individuals with bladder cancer were three times as likely to have used permanent hair dyes at least once a month for 15 years or more. In addition, subjects who worked for 10 or more years as hairdressers or barbers were five times more likely to have bladder cancer than people who were not exposed to permanent hair dye" (Source: www.sciencedaily.com).

It is important to point out that this study was an epidemiological investigation looking at behavior and the possible relationships between products and their effect on health. Epidemiological studies are not definitive in any way. For example, it isn't clear from this study what percentage of this group smoked, what kind of diet they had, or whether or not they had other mitigating illnesses. It also doesn't say that hair dye causes cancer, just that it has a casual relationship (meaning there is no definite or conclusive evidence).

As you can tell, the jury is still out on this issue. There is not enough information or research to assert that you should avoid dark-colored hair dyes.

If you want to be extra cautious you can choose to avoid dark permanent or intermediate hair dyes. In view of the University of Southern California study showing that women who dye their hair 12 times or more each year for a period of 15 years were at a higher risk, you may want to consider dying your hair less frequently, no more than say 6 or 8 times a year. It is also important to keep in mind that although hair dyes may increase the risk of getting bladder cancer, such a risk would represent a relatively small number of cases, since women account for only about 15,000 of the 40,000 new cases of bladder cancer diagnosed each year. (Source: www.webmd.com.)