Changing your hair color with the seasons may give you split ends, but it probably won't make you sick. A new large-scale analysis has found that people who dye their hair do not have a greater risk for most cancers.
Previous studies examining the link between hair dye and cancer have had conflicting results, making the issue a confusing one for the estimated 40% of women and 5% of men who dye their hair.
"In spite of existing alarm on the topic, we did not find any marked increase in risk of cancer among hair dye users," says lead researcher Bahi Takkouche, an epidemiologist at the University of Santiago de Compostela in Spain.
Takkouche and colleagues analyzed data from 79 studies in 11 countries to assess the link between personal use of hair dyes and relative risk of cancer. This type of analysis expands the sample size of the study, making the results more reliable than smaller studies, he says.
Overall they found no strong evidence that using hair dye increased risk for breast or bladder cancer. The researchers did find a small increase in risk for blood and lymph cancers, but Takkouche says this finding may not hold up to further scrutiny.
More research is needed, he says, to determine cancer risk among hairstylists who have frequent contact with the chemicals in hair dye and to clarify risk for blood and lymph cancers or bladder cancer in people with a genetic risk.
The research was published in the May 25 issue of the Journal of the American Medical Assn.