Permanent Hair Dyes Are Possible Links to Cancer

Tongzhang Zheng, ScD is a researcher from Yale who suspects that permanent hair dyes used over a long period of time can cause certain types of blood cancer. These dyes can expose you to chemicals that may be harmful. These chemicals are also suspected of causing Non-Hodgkin's lymphoma, an array of diseases which are rapidly becoming more common across the planet with no known cause. Zheng led a research group that studied hair dye use in 601 women with lymphoma and 717 women who didn't have cancer. An increased instance of cancer was found in women who used hair colorants before 1980 and women who had used these products for 25 years or more had twice the risk of developing Non-Hodgkin's lymphoma. They also found similar risk in women who reported using 200 or more applications of hair dye over the years. Zheng saw that there were no increased instances of lymphoma in people who used hair dyes after 1980. If this means that hair dye is safer now or if not enough people have used the newer dyes to come to an accurate conclusion about cancer risks is still a big question.

Zheng recommends using semi-permanent or temporary hair dyes such as henna to avoid any potential dangers.

The Cosmetic, Toiletry, and Fragrance Association insists that hair dyes are still safe and points to inconclusive research by large scale epidemiological studies. Zheng points out that those studies could have been hampered by methodological research that might have left the dangers underestimated.

There are also other studies that strongly link hair dyes to cancers. Mimi C. Yu, PhD is a professor at the University of Southern California's Keck School of Medicine. Her studies found that people are are at a much higher risk of bladder cancer according to how much hair dye they have used. While she thinks more research should be done on the subject, she also thinks that more scientists in the community should take notice.

The specific chemical thought to be harmful is called 4-ABP. 4-ABP is only found in commercial hair dyes that are sold on store shelves and are thought to be a byproduct of manufacturing. The various chemicals in the hair dyes can oxidize and create new chemicals like 4-ABP that were not originally intended to be a part of the dye.

Both Zheng and Yu are looking into genetic factors that might place a particular person at a higher risk. The human body is normally able to detoxify itself from harmful chemicals like those found in hair dye, but genetics might make someones ability to do this weaker.

It seems that more in-depth study is needed before strong conclusions can be made, but it can't hurt to be on the safe side and use less harsh hair dyes.

From WebMD