Do hair dyes cause cancer? No, says a study published recently in a medical journal. Yes, say researchers who presented their findings to an international conference this week.
The most dangerous dyes, both research groups agree, are those that were produced before 1980, but there's growing evidence to suggest that even those produced today may contain carcinogenic chemicals. People who regularly use dyes, as well as hairdressers who work with them, should check themselves for any abnormal lumps or bumps, a cancer specialist has warned.
It's a subject for public concern, as around one-third of all women and 10 per cent of men in North America and Europe use a dye, and permanent dyes - regarded as the most aggressive - represent 70 per cent of the entire hair dye market.
The published study, which concluded that there was no compelling evidence of an association between dyes and cancer, was based on a study of 210 articles on the subject that had been published between 1966 and last January.
This definite and categorical conclusion was a little surprising, as the papers the researchers studied included one that discovered that dyes were responsible for a five-fold increase in non-Hodgkin Lymphoma.
The point was picked up by speakers at the International Conference on Malignant Lymphoma this week, who confirmed that the dyes were most likely to cause this type of cancer than any other.
The new study, which was presented at the conference, involved 5,000 women in Europe. It concluded that women who regularly use hair dyes increased their risk of lymphoma by 20 per cent compared with women who had never dyed their hair before 1980.
Lead researcher Prof Paolo Boffetta said that it was 'reassuring' that the risk has not increased in the last 25 years, but as experts believe that the earlier hair dyes were more carcinogenic than the current generation of products, the findings wouldn't seem to be reassuring at all.
Conference chairman Prof Franco Cavalli points out that the frequency of lymphoma in the west has doubled over the last 20 years, although the increase cannot be laid solely at the door of hair dyes. Other chemicals are also responsible for the increase along with viruses, doctors believe.
Prof Gordon McVie, senior consultant at the European Institute of Oncology, says that manufacturers have removed carcinogens from hair dyes following tighter regulatory guidelines, so users 'should not be alarmed.' Then, in the next breath, he urges hairdressers and people who regularly use dyes to 'be on the alert and look out for any abnormal lumps and bumps', presumably in a non-alarmist way.
Both teams of researchers agree on one thing at least. The jury's still out, and more research needs to be done if we are to finally establish if hair dyes cause cancer. In the meantime, of course, nothing will be done. It's enough to make your hair turn white.