A new study in the American Journal of Epidemiology definitely adds a point to the #TeamNatural tally with a published paper from researchers at Boston University linking hair relaxers to uterine fibroid tumors in women and early puberty in young girls.

Led by 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 two- to three-times higher rate of fibroids among black women may be linked to chemical exposure through scalp lesions and burns resulting from relaxers.

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 black girls are using, according to a separate study published in the Annals of Epidemiology last summer. Three hundred African American, African Caribbean, Hispanic, and White women in New York City were studied. 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 other 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.

These studies go way beyond the damaging effects chemical relaxers may have on one’s hair, women and girls may be damaging their reproductive systems with some of the hair products they use, making it even more critical to know exactly what you’re putting in your hair and in your body.

How do you research the hair products you use and make sure their safe?

Brande Victorian is a blogger and culture writer in New York City. Follower her on Twitter at @be_vic.