Hair dyes have chemicals that cause cancer. This isn't necessarily something to get all upset aboutthere are a whole lot of chemicals that can cause cancer, and they're all around. But some studies have suggested a link between using hair dye and getting cancer. A group of epidemiologists at the University of Illinois and the National Institute of Environmental Health Sciences looked for a link between hair dyes and leukemia.
What the researchers wanted to know: What part do hair dyes play in the risk of leukemia?
What they did: When adults were diagnosed with leukemia, they were invited to take part in studies of the disease. Between 1986 and 1989, 811 patients enrolled, and either they or their next of kin were interviewed about risk factors and medical history. The patients were matched to controlspeople without leukemia who were contacted by random phone dialing and also completed an interview. Among many other questionseach interview took about 45 minutesthe subjects were asked about use of permanent and temporary hair dyes.
What they found: People who'd ever used permanent hair dye had a 50 percent higher risk of leukemia. Risk increased if they'd started using hair dye before 1980earlier dyes may have been more carcinogenic (or it could just be that people who started dying their hair more recently hadn't gotten enough exposure yet to increase their cancer risk). Using the dye for a long time increased the risk. There was no relationship between temporary hair dyes and leukemia risk.
What the study means to you: It is possible that using permanent hair dye increases your risk of leukemia. If your risk is tiny to start with, a 50 percent increase isn't a very big deal1.5 in a million is not much bigger than 1 in a million.
Caveats: People probably weren't totally accurate in recalling their hair dye usage from decades before. There's no reason that should bias the results in one direction or another, but it would tend to muddy the conclusions.
Find out more: Learn about the major risk factors for leukemia, from the National Cancer Institute.
Read the article: Rauscher, G.H., Shore, D. and D.P. Sandler. "Hair Dye Use and Risk of Adult Acute Leukemia." American Journal of Epidemiology. July 1, 2004, Vol. 160, No. 1, pp. 19-25.
Free abstract online: http://aje.oupjournals.org/