Bahi Takkouche, MD, PhD, and colleagues analyzed 79 studies from 11 countries, focusing only on personal use of hair dye, not occupational exposure. "Our results indicate that, globally, there is no effect of personal hair dye use on the risk of breast and bladder cancer," they write.
Their findings are reported in the May 25 issue of The Journal of the American Medical Association.
'Borderline Effect' for Blood-Related Cancers
The researchers found a leukemia and multiple myeloma, but "the evidence of a causal effect is too weak to represent a major public health concern." They add that this effect, as well as two studies showing a borderline increase in the risk of brain tumors and ovarian cancer, warrant further investigation.such as
"About one-third of women in Europe and North America, along with 10% of men older than 40 years, use some type of hair dye," the researchers note, making any relationship between hair dye and cancer "an important public health concern."
The FDA makes the following safety precautions for people who use hair dyes:
- Don't leave the dye on your head any longer than necessary.
- Rinse your scalp thoroughly with water after use.
- Wear gloves when applying hair dye.
- Carefully follow the directions in the hair dye package.
- Never mix different hair dye products because you could induce potentially harmful reactions (if not an unappealing hair color).
The researchers recommend future studies focusing on people who are exposed to hair dye on the job. "Efforts should be targeted toward the assessment of the risk of cancer in occupational settings where exposure to hair dyes is more prolonged and has a higher concentration and frequency than personal exposure."