Hair dyes not linked to multiple myeloma risk

Women who’ve used hair dyes, even for decades, do not seem to have an elevated risk of multiple myeloma, a cancer in which malignant plasma cells accumulate in the bone marrow, a new US study suggests.

In recent years, some studies have linked the use of hair dyes – in particular, older formulations used before the 1980s – to an elevated risk of certain cancers, including lymphoma, (lymph cell cancer) and leukaemia (blood cell cancer).

A few risk factors for multiple myeloma have been established, such as older age and African-American background, but some studies have suggested that hairdressers and cosmetologists may also have a higher-than-normal risk.

That raises the possibility that on-the-job chemical exposures are involved. Hair dyes used prior to 1980, for example, are known to have contained potentially cancer-causing substances.

For the new study, researchers at the US National Cancer Institute looked at whether women’s use of hair dyes was related to their risk of developing multiple myeloma.

In interviews with 175 women with the cancer and 679 without the disease, the researchers found no evidence that hair dye use presented a risk.

Overall, women who said they’d ever used hair dyes were no more likely to develop multiple myeloma than those who’d never coloured their hair.

There was also no increased risk among women who’d started using the products before 1980 or those who’d used them for 28 years or more.

In addition, the study found no evidence that permanent dyes carried a different risk from semi-permanent versions.

So far, few risk factors for multiple myeloma have been pinned down, note Dr Stella Koutros and her colleagues, and the current findings suggest that hair-colouring is not one of them.

However, the investigators add, given the conflicting studies on the subject, further research should continue to look at the relationship between hair dyes and multiple myeloma, as well as other cancers.

Reuters

Source: Occupational and Environmental Medicine, January 2009