By Amy Norton, Reuters News Agency
NEW YORK-- People who spent years using older permanent hair
dyes may have somewhat higher odds of developing leukemia, a new
Researchers found that among men and women surveyed in the late
1980s, those who had used permanent hair dyes prior to 1980 were
more likely to develop leukemia than adults who had never dyed
Acute leukemia is a quickly progressing form of leukemia in which
immature, non-functioning blood cells accumulate and crowd out
normal cells. Hair dyes have long been studied as a potential
risk factor for a number of cancers, but research has yielded
Older formulations contained potentially cancer-causing chemicals,
and there is evidence tying hair dyes to the risk of blood-related
cancers such as leukemia and multiple myeloma. Not all studies,
however, have come to this conclusion.
The new study compared 769 acute leukemia patients with 623
adults without the disease. It found that men and women who had
used permanent dyes one to five times per year for 15 years or
longer were more than twice as likely to develop leukemia as people
who had never dyed their hair. Temporary hair dyes that wash out
with a few shampoos and hair dye use beginning in 1980 or later
were not linked to the disease.
Together with past research, these findings suggest hair dye
use is a "potential but not an especially strong risk factor"
for leukemia and other blood-related cancers, according to lead
study author Dr. Garth H. Rauscher of the University of Illinois
in Chicago. And it does appear that long-term use and use of older
coloring products are key factors, Rauscher told Reuters Health.
He and his colleagues report the findings in the current issue
of the American Journal of Epidemiology. The findings are similar
to those of a study earlier this year that linked long-term use
of older permanent hair dyes to an increased risk of non-Hodgkin
lymphoma in women. Again, women who used hair dyes after 1980
did not have an elevated cancer risk, and the researchers speculated
that changes in product formulations made in response to cancer
concerns could be the reason.
Rauscher said evidence so far suggests that while people who
have colored their hair do not seem to face a greater risk of
most cancers, the "possible exception" is cancer of
the blood or lymph nodes-which includes leukemia and non-Hodgkin
The reason is unclear, but it may have to do with the fact that
the blood is the "first point of contact" for cancer-promoting
chemicals that are able to penetrate the scalp, Rauscher noted.
However, he also pointed out that while some studies like his
-- comparisons of leukemia or lymphoma patients with healthy adults
-- have linked hair dyes to a higher cancer risk, other studies
that have followed hair dye users over time have failed to do
SOURCE: American Journal of Epidemiology, July 1, 2004.