Dark color hair dyes and relaxer linked to breast cancer.

courtesy: http://ataxe.com

New research suggests that women of color who use the dark brown or black hair dyes are at increased risk of cancer while use of straighteners and conditioners increase the odds in white women.

The study was published online 09 June 2017 in journal Carcinogenesis.

The safety of hair colors has been debated for years, but no studies have demonstrated conclusively, that using hair dye leads to increased risks of cancer or other diseases.

Some observational and epidemiological studies have found increased incidence of bladder cancer in hairdressers and barbers.

It is estimated that nearly 66%- 70% of women in US use some kind of hair color.

Nearly 5000 different chemical compounds are used to make the dyes. Permanent hair dyes occupy 80% of market and are made with aromatic amines, which are known to be carcinogenic in animals.

The study by Rutgers University looked into data from 4,285 African-American and Caucasian women with ages between 20-75 years. Nearly 2,280 were breast cancer survivors.

Besides, looking into the patient’s demographics, lifestyle and hormone use, they also looked into family and personal history. But the study specifically looked into history of use of hair products like hair dyes, chemical relaxers and cholesterol or placenta-containing conditioners and incidence of breast cancer. 

Cholesterol is marketed as a moisture restorer, and placenta is sold as a hair repairer.

The women who were breast cancer survivors were labelled as cases (2,280) whereas, the rest 2,005 women constituted the control group.

The study found out that African American women(AAs) who used dark color hair dye where at 51 % greater risk of developing breast cancer. When use of dark shades and greater frequency of dying the hair was combined, the risk of getting ER+ cancer increased by 72%.

White women who used relaxer were at 74% increased risk of breast cancer while combined use of relaxer and hair dye increased the risk 2.5 times. Dark dyes were associated with ER+ disease and relaxer was liked to ER- disease.

"One hypothesis is that the chemical composition of hair products marketed for and used among whites may differ from the products marketed for use by African-Americans," Lead author Llanos said. "More research is needed to determine specifically which compounds and chemicals are dangerous and even which specific consumer products and brands contain those chemicals."

Among the control arm of the study, greater percentage of white women (58%) used hair dye as compared to AAs (30%), while AAs women used more relaxer and deep conditioner.

Adana Llanos cautioned, "Our findings do not suggest that simply using hair dyes, relaxers or both will cause a woman to get breast cancer. The reality is that we regularly encounter a variety of harmful exposures, which we have no control over."

However, she added, "we should limit or reduce the possibility of harmful exposures when we are able to do so."

The authors concluded in a press release, “Our findings highlight the need for further examinations of the link between the use of hair products as important exposures that may contribute to the development of breast cancer, as well as ways to reduce the associated risks.”