Women who use certain hair dyes or relaxers may be at an increased risk of developing breast cancer, a new study suggests.
According to researchers at Rutgers University in New Jersey, carcinogens present in the hair products may be what’s contributing to the increased risk – a risk that researchers found affects black and white women differently.
Researchers looked at 4,285 women taking part in the Women’s Circle Health Study between the ages of 20 and 75, 2,280 of whom had breast cancer (1,508 black and 772 white), and 2.005 of which did not (1,290 black and 715 white).
The data also included information about social and economic backgrounds, as well as other factors that may impact the risk of breast cancer like family history, exposure before birth, use of hormones, reproductive history, physical activity, alcohol and smoking habits, vitamin use and the use of hair products.
After focusing on hair products in particular, researchers found the link between certain hair dyes and relaxers and an increased risk of breast cancer.
“We found that use of dark shade hair dyes was associated with a 51 per cent increase overall risk in developing breast cancer among African American women, and a 72 per cent increased risk of estrogen receptor-positive breast cancer among African Americans,” researchers told the Women’s Circle Health Study. “We also found that use of chemical relaxers or straighteners was associated with a 74 per cent increased risk among Caucasians, with some differences in breast cancer risk observed by estrogen receptor status.”
While researchers say these finds support the relationship between the use of some hair products and breast cancer risk, they also believe further research is needed as exposure to these products may contribute to the development of breast cancer, as well as find ways to reduce the possible associated risks.
The article was published in the journal Carcinogenesis.
This isn’t the first study to link hair products to the possibility of increased health risks.
In 2010, a study was published in BMJ which linked hair dye and smoking to progressive liver disease.
Another study by researchers at the University of Helsinki also concluded this past March that hair dyes were associated with an increased risk of breast cancer.
In this study of 8,000 breast cancer patients and 20,000 controls from Finland, researchers observed a 23 per cent increase in the risk of breast cancer among women who dyed their hair.
But according to the American Cancer Society, hair dyes and other chemical-heavy hair products have yet to be directly linked to increased cancer risks.
In Canada, breast cancer is the third most common cancer. It accounts for 13 per cent of all cancers and 26 per cent of cancers among women, the Canadian Cancer Society reports.