The positive association between the use of hair dyes and breast cancer risk does not represent evidence of a cause effect relationship. - Kefah Mokbrl
Women's Health

Does Hair Dye Really Increase Breast Cancer Risk?

Earlier this week, one of the UK’s best known authorities on breast cancer suggested that there could be a link between hair dye and breast cancer. That doctor, breast surgeon Kefah Mokbel, has since clarified his comments, sort of, by explaining–to use his words–“The positive association between the use of hair dyes and breast cancer risk does not represent evidence of a cause effect relationship.”

The Background On The Hair Dye & Cancer Story

Late last week Mokbel created something of a sensation when he made a simple Facebook post:

The post Kefah Mokbel made on Facebook about dye and cancer.
Kefah Mokbel’s Facebook post on the possible link between hair dye and breast cancer.

Over the weekend a London newspaper ran a story without linking to Mokbel’s work or even mentioning where it had been published–if, in fact it ever actually was. The newspaper simply quoted him as saying things like, “Although further work is required to confirm our results, our findings suggest that exposure to hair dyes may contribute to breast cancer risk.”

Even though other news media have since picked up the story, Mokbel has still not published his findings. Nor has he publicly responded to any of the numerous questions posed to him on social media by clearly worried women. He did, however, make a single one-sentence follow-up post a few days later, clarifying that an apparent link does not prove a cause/effect relationship.

How Worried Should Women Who Dye Their Hair Be?

Regardless of whether or not Mokbel ever decides to publish the results of his review, other scientists have published theirs. A 2017 study from Iran, for example, looked at workers’ occupational exposure to certain chemicals and found hair dye to be a “main predictor” when it came to bladder cancer risk.

And a 2017 American study published in the journal Carcinogenesis this summer looked at dyes, relaxers and other chemical haircare products and found that “dark shades” of hair dye, especially, appeared to be associated with an increased breast cancer risk both in women of color and those of Caucasian ancestry.

These studies do not prove that hair dyes cause cancer in women who occasionally dye their hair. The Iranian study, of course, looked at people who use hair dyes as part of their jobs and the American study could be explained, in part, if it is discovered that women who regularly dye their hair are also more likely to be heavier users of a wider variety of beauty products.

###