In the U.S., breast cancer is the second most common cancer in women. Each year, about 230,000 new cases are diagnosed in this country. It’s a huge issue around the world as well, with 1.7 million women worldwide receiving breast cancer diagnoses in 2012 alone.
Hair dyes have long been rumored to possibly cause various forms of cancer, including breast. Even so, prohibited substances, such as aromatic amines, can still be found in many hair dyes. And remnants of these chemicals can be detected in breast cells of hair dye users.
In the current study, researchers administered questionnaires to 6,567 breast cancer patients diagnosed between 2000-2007. They also recruited 21,598 controls.
They determined that the odds of breast cancer increased by 23 percent among women who used hair dyes, as compared to those who did not. And women born before the year 1950 had 28 percent higher risk. They also determined that risk is cumulative—meaning it “adds up” over time.
The researchers wrote, “Our results suggest that use of hair dyes is associated with breast cancer incidence. The impact on public health may be substantial due to vast popularity of hair coloring in modern societies.” They further stated that the “lack of external safety assessment within the cosmetics industry is of major concern.”
Heikkinen S, et al. PLoS One. 2015 Aug 11;10(8):e0135190.