Some Women May Be At Greater Risk From Hair Dye By Paula Moyer NEW YORK, Apr 10, 2002 (Reuters Health) Some research has suggested that women who regularly use permanent hair dye might be at greater risk for bladder cancer. Now new study findings indicate that the risk may be more pronounced among women with a specific genetic variation, according to a California researcher who presented the results at the American Association of Cancer Research meeting in San Francisco, California. "Our findings provide further evidence supporting a causal link between hair dye use and bladder cancer risk," Dr. Manuela Gago-Dominguez told Reuters Health. "In earlier research, we found that permanent dye was a significant, independent risk factor for bladder cancer. Now we have found a genetic connection. Women who eliminated the carcinogen more slowly are more at risk." Typically, the US Food and Drug Administration requires safety testing of all coloring agents used in cosmetics and food. However, hair dyes have historically been exempt from this requirement, Gago-Dominguez told Reuters Health. The current research identified several genes that influence the rate of clearance of arylamines, an ingredient in permanent hair dye, said Gago-Dominguez, a researcher in preventive medicine at the Keck School of Medicine and Norris Comprehensive Cancer Center at the University of Southern California in Los Angeles. Past research has suggested that people who have a "slow version" of an enzyme known as N-acetyltransferase-2 (NAT2) take longer to clear arylamines from the body. Subtle variations in other enzymes have been implicated, as well, including enzymes known as NAT1, GSTM1/T1/P1, and CYP1A2. In the study, Gago-Dominguez and colleagues compared 228 women with bladder cancer to 131 healthy women the same age, specifically looking for variations in such enzymes. Among the overall population, the researchers did not find variations in these enzymes that seemed to be associated with permanent hair dye and bladder cancer. However, they did find that women who were nonsmokers who had a "slow acetylator" version of the NAT1 enzyme did seem to be at greater risk of bladder cancer if they used permanent hair dye. "Among nonsmoking women, NAT1 slow acetylators demonstrated a much stronger permanent hair dye-bladder cancer association," the investigators reported. Those with NAT1-influenced slow metabolism of arylamines were 6.8 times more likely to develop bladder cancer than those with NAT1-influenced rapid metabolism. The overall risk of bladder cancer is still relatively low. About 6% of new cancer cases in men and 2% of cases in women arise in the bladder. Irene Malbin, vice president of public affairs at The Cosmetic, Toiletry, and Fragrance Association, a group that represents hair dye manufacturers, says that the safety of hair dyes is well-documented. "Hair dyes are one of the most thoroughly studied consumer products on the market today," she said. "The research shows that they are safe and consumers can have great confidence in these products." The research "does not present new data that would prove any connection between hair dyes and bladder cancer," according to Malbin. She notes that two large studies have found that women who use hair dye are no more likely to die of blood or immune system cancers, such as non-Hodgkin's lymphoma, than women who don't use such dyes. Annie Berthold Bond, Care2.com Euro J of Cancer, 7/02 AACR Abstract # R1560, 2003 Smoking/Drinking & Hair Dye: Adult Leukemia AACR Abstract #1563, 2003 Am J Epidemiology, 7/04 Remember we are NOT Doctors and have NO medical training. This site is like an Encylopedia - there are many pages, many links on many topics. Support our work with any size DONATION - see left side of any page - for how to donate. You can help raise awareness of CAM.