A recent study conducted by Clairol reports that 75% of American women habitually use hair dye. Eighty-percent of these occasioned doing so to boost their self-esteem but could it come at a major health risk? New research provides insight into the association between hair dye and cancer.
In the time since that analysis was published, between 50% and 80% of women and roughly 10% of men over the age of 40 have been studied regularly use hair dyes and hair straighteners in the US and Europe.
Literature published on the subject indicates a cancer risk associated with chemicals found in common hair dye–epically with respect to breast cancer.
The World Health Organization’s International Agency for Research on Cancer even identifies hair dye as a carcinogen.
“Concern about cancer risk is largely limited to the semi-permanent and permanent dyes. Because darker dyes have more of some chemicals that may cause cancer, these products are of greatest potential concern,” the American Cancer Society reports.
Personal use of permanent hair dye not associated with greater risk of most cancers or cancer death
A new study published in the BMJ journal repudiates these findings.
“117,200 women enrolled in the Nurses’ Health Study, an ongoing prospective cohort study of female nurses in the US. The women were free of cancer at baseline, reported information on personal use of permanent hair dyes, and were followed for 36 years,” the authors wrote of their study’s setting. “Users of permanent hair dyes had no significant increases in risk of solid cancers or hematopoietic cancers overall compared with non-users. Additionally, ever users did not have an increased risk of most specific cancers or cancer-related death.”
The follow-up conducted 36 years after the initial study revealed that hair dye did not increase cancer risk for cancers of the bladder, brain, colon, kidney, lung, blood, and immune system, or cancers of the skin including cutaneous squamous cell carcinoma and melanoma.
Although the researchers did observe a significant cancer risk increase with respect to permanent hair dye and cancer, they did report a slight increase in risk for ovarian cancer as well as breast and skin cancers. A comparable outcome was demonstrated for natural hair color.
The depth of cancer risk was impacted by several different actors. Basal cell carcinoma of the skin risk increase was more prominent among women with lighter hair while Hodgkin lymphoma risk increases were only exhibited in women with dark hair.
Similarly prolonged exposure to darker hair dyes yielded slightly higher cancer risk increases compared to dyes of lighter shades.
“Possible explanations could be that shades of permanent hair dyes are associated with the concentration of ingredients, with darker colors having higher concentrations,” the authors concluded. “No positive association was found between personal use of permanent hair dye and risk of most cancers and cancer-related mortality. The increased risk of basal cell carcinoma, breast cancer (estrogen receptor-negative, progesterone receptor-negative, hormone receptor-negative) and ovarian cancer, and the mixed findings in analyses stratified by natural hair color warrant further investigation.”