The results of a new study in the American Journal of Epidemiology have some black women thinking about going “au natural” when it comes to their hair. A published paper from researchers at Boston University linked hair relaxers to uterine fibroid tumors in women and early puberty in young girls.
Led by Dr. Lauren Wise of Boston University’s Slone Epidemiology Center, scientists followed more than 23,000 pre-menopausal black American women from 1997 to 2009 and found that the increased rate of fibroid growth among black women may be linked to chemical exposure through scalp lesions and burns resulting from relaxers.
In the study, among African-American women who had reported being diagnosed with uterine fibroids, a majority of them also admitted to having had chemical relaxer treatments at some time. According to researchers, such hair products may contain hormonally active chemicals, like parabens and phthalates that have been known to cause negative effects on cell models and animals and are not regulated by the US Food and Drug Administration. The article proposes that these chemicals can be absorbed into the skin via lesions from chemical burns.
According to the study, women who got their first menstrual period before the age of 10 were also more likely to have uterine fibroids, and early menstruation may result from hair products that these young, black girls are using. This is reportedly at an earlier age than other racial groups including African Caribbean, Hispanic, and White women in New York City. The women’s first menstrual period (menarche) varied anywhere from age 8 to age 19, but African Americans, who were more likely to use straightening and relaxers hair oils, also reached menarche earlier than these racial/ethnic groups.
While so far, there is only an association rather than a cause and effect relationship between relaxers, menarche, and fibroid tumors, as Tamika Fletcher, co-owner of Natural Resources salon in Houston, pointed out in a Fox Report, the hair care industry isn’t regulated by the FDA so there’s no telling what black women are putting in their hair and how harmful those products may be.
Medical Journal of Epidemiology
“Hair relaxers are used by millions of black women, possibly exposing them to various chemicals through scalp lesions and burns. In the Black Women’s Health Study, the authors assessed hair relaxer use in relation to uterine leiomyomata incidence. In 1997, participants reported on hair relaxer use (age at first use, frequency, duration, number of burns, and type of formulation). From 1997 to 2009, 23,580 premenopausal women were followed for incident uterine leiomyomata. Multivariable Cox regression was used to estimate incidence rate ratios and 95% confidence intervals. During 199,991 person-years, 7,146 cases of uterine leiomyomata were reported as confirmed by ultrasound (n = 4,630) or surgery (n = 2,516). The incidence rate ratio comparing ever with never use of relaxers was 1.17 (95% confidence interval (CI): 1.06, 1.30). Positive trends were observed for frequency of use (Ptrend < 0.001), duration of use (Ptrend = 0.015), and number of burns (Ptrend < 0.001). Among long-term users (≥10 years), the incidence rate ratios for frequency of use categories 3–4, 5–6, and ≥7 versus 1–2 times/year were 1.04 (95% CI: 0.92, 1.19), 1.12 (95% CI: 0.99, 1.27), and 1.15 (95% CI: 1.01, 1.31), respectively (Ptrend = 0.002). Risk was unrelated to age at first use or type of formulation. These findings raise the hypothesis that hair relaxer use increases uterine leiomyomata risk”
Correspondence to Dr. Lauren A. Wise, Slone Epidemiology Center, Boston University, 1010 Commonwealth Avenue, Boston, MA 02215 (e-mail:).
- Received June 15, 2011.
- Accepted September 9, 2011.