You still decide whether you want to follow the go gray trend and be au naturel?
We're not sure if the following eases your ambivalence to graying out.
Last year, the National Institute for Environmental Health Sciences reported the results of the sister study, in which 46,709 women participated. After reviewing the data, the researchers found that women who reported using permanent hair dye and chemical hair straighteners were at higher risk of developing breast cancer than women who did not. Women who used permanent hair dye regularly in the year prior to enrollment in the study were 9% more likely to develop breast cancer than women who did not use hair dye. In African American women, using permanent dyes every 5 to 8 weeks or more increased this risk to 60% and in white women to 8%.
When the women reported using semi-permanent or temporary dyes, the researchers found that the risk of breast cancer was little or no increase.
In a report released in early September, researchers at Brigham and Women’s Hospital and Harvard Medical School in Boston examined data from 117,200 women who participated in the Nurses' Health Study. "[Long-term] users were not at increased risk for most specific cancers [including] … estrogen receptor positive breast cancer, progesterone receptor positive breast cancer, hormone receptor positive breast cancer …"
What these researchers found was an increased risk of basal cell carcinoma in long-term users, if only slightly, and this was only the case for women with naturally fair hair; Your overall risk of breast cancer was also higher.
However, as the doses increased, so too did the risk of estrogen-negative breast cancer, progesterone-receptor negative breast cancer, hormone-receptor negative breast cancer, and ovarian cancer. These so-called triple negative breast cancers are more common in African American women than their white counterparts.
And then there were the differences between those with naturally dark and naturally light hair.
In the former, those who used permanent hair dyes had an increased risk of Hodgkin lymphoma but a lower risk of lung cancer compared to those who did not dye their hair. The researchers did not find these compounds in women with naturally fair hair. As mentioned earlier, the researchers found that these women were at increased or possibly increased risk of basal cell carcinoma and breast cancer overall.
"Researchers have long studied the possible link between hair dye and cancer, but the results have been inconsistent," said author Alexandra White, Ph.D., director of the NIEHS group on environmental and cancer epidemiology. "In our study, we see a higher risk of breast cancer associated with hair dye use, and the effect is stronger in African American women, especially women who use it frequently."