Hair Dyes Linked to Cancer Risk
New Research Finds Use of Permanent, Dark Dyes Especially Risky
January 30th, 2004
By Louis Wittig : eCureMe Staff Writer
January 29th, 2004 : Physician Reviewed
A new study, published in the January 15th issue of the American Journal of
Epidemiology, suggests that women who regularly dye their hair over long
periods may be increasing their risk of contracting Non-Hodgkin’s
Conducted among 1300 women with and without NHL in Connecticut, researchers
found that women who had been regularly dying their hair since before 1980 were
40% more likely to contract the disease. Women who had been dying their hair for
over 25 years with permanent, dark colored dyes - such as browns, reds and
blacks - doubled their risk.
NHL is a cancer of the lymph glands. Found in throughout the body, lymph glands
help protect against infection. According to the American Cancer Society, a typical
person has a 1 in 50 chance of contracting NHL over the course of a lifetime and
a 1 in 100 chance of dying of it. Over 53,000 cases are expected to be diagnosed
this year. Cases of the disease have almost doubled since the 1970s, though
scientists aren’t completely sure why.
In response to the study, dye manufacturers have denied that their products increase
consumers’ cancer risks. The Cosmetic, Toiletry and Fragrance Association
(CFTA) claims that "Hair dyes are among the most thoroughly studied consumer
products on the marketˇ¦the safety of hair dyes is supported by the overwhelming
wealth of scientific research." It points to a review of 78 studies related to
hair dye conducted in the 1990s that found no proven link between hair dyes and
The truth may lie somewhere between the researchers’ findings and the
industry’s claims. In 1979, the industry changed the chemical make-up of
its dyes to remove known cancer causing agents. The researchers found that women
who had begun treating their hair after 1980 showed no increased risk of developing
NHL. Whether this means that today’s dyes are safe, or that they simply
haven’t been used long enough to precipitate the risk, is an open question
for the study’s authors.
Similarly open is the question of how exactly dyes may be related to NHL risk.
A report published last year found a known carcinogen in eight of eleven commercial
dyes. The chemical, known as 4-ABP, wasn’t a regular ingredient of the
dyes. Instead, some researchers concluded that it was likely a byproduct of the
manufacturing process - and perhaps the cause of the current findings.
Tongzhang Zheng, Yale University researcher and author of the current study,
isn’t so sure. He suspects that it’s not so much a carcinogen that’s
in hair dye, but how non-harmful ingredients react once they’ve been
applied. "The issue is that permanent hair dyes all use an oxidizing process
that will create new chemicals that are not in the original dye. The oxidizing
process will create compounds that cause cancer," Zheng told reporters.
Until further research determines what’s behind the risk, and how to reduce
it, millions of Americans will likely be weighing the cost of vibrant, colorful
E-mail Louis Wittig at louis@eCureMe.com
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