hair dye causing cancer?
Findings from a new French study are further evidence that individuals
in regular contact with hair dyes formulated before 1980 – particularly
hair care professionals – have a higher risk of developing
Professor Paolo Boffetta presented the results of the study – by
the International Agency for Research on Cancer – in Switzerland
this week, at the International Conference on Malignant Melanoma.
Some results, first reported by the BBC and confirmed by Boffetta,
found that women who regularly dyed their hair before 1980 had
a 20 percent increased risk of developing lymphoma compared to
women who had never dyed their hair during the same period.
Although the study, which included 5,000 women, found that the
most dangerous chemicals had been removed from most hair dyes
during the 1970s, it stresses that many people who were in regular
contact with such chemicals before this time were at an increased
risk of developing lymphoma.
During his presentation, Boffetta said, “It is reassuring
to notice that dyes used in the last 25 years do not seem to carry
an increased risk.” He did indicate that it might be premature
to conclude that newer hair dye formulas are safer, but noted
mounting evidence to support that statement.
Another study, published in the May 25 issue of the Journal of
the American Medical Association, revealed similar findings. A
team at Spain’s University Dantiago de Compostela found
that a meta-analysis of the scientific evidence associating cancer
with hair dye found no strong indication of an increased risk.
“Our results indicate that, globally, there is no effect
of personal hair dye use on the risk of breast cancer and bladder
cancer,” the authors reported. “There is a borderline
effect for hematopoietic cancers (for example, leukemia and multiple
myeloma.) However, the evidence of a causal effect is too weak
to represent a major health concern.”
Researchers concluded that further study in this area should
concentrate on the effects of hair dyes on individuals who use
such products on a daily basis, emphasizing that the average consumer,
who comes into contact with hair dye formulas once every one or
two months, was under no significant risk of developing cancer
as a result.
With an estimated one third of women in the US and Europe and
ten percent of men over age 40 using some sort of hair coloring,
the need for further research is pressing. To date, medical literature
searches identify 79 studies from 11 countries that have examined
the association between hair dye use and the relative risk of