Childhood hair product use and earlier age at menarche in a racially diverse study population: a pilot study.

PURPOSE Previous studies suggest that hair products containing endocrine disrupting chemicals could alter puberty. We evaluated the association between childhood hair product use and age at menarche in a racially diverse study population. METHODS We recruited 300 African-American, African-Caribbean, Hispanic, and white women from the New York City metropolitan area who were between 18-77 years of age. Data were collected retrospectively on hair oil, lotion, leave-in conditioner, perm, and other types of hair products used before age 13. Recalled age at menarche ranged from 8 to 19 years. We used multivariable binomial regression to evaluate the association between hair product use and age at menarche (<12 vs. ≥12), adjusting for potential confounders. RESULTS African-Americans were more likely to use hair products and reached menarche earlier than other racial/ethnic groups. Women reporting childhood hair oil use had a risk ratio of 1.4 (95% confidence interval [CI]: 1.1-1.9) for earlier menarche, adjusting for race/ethnicity and year of birth. Hair perm users had an increased risk for earlier menarche (adjusted risk ratio = 1.4, 95% CI: 1.1-1.8). Other types of hair products assessed in this study were not associated with earlier menarche. CONCLUSIONS Childhood hair oil and perm use were associated with earlier menarche. If replicated, these results suggest that hair product use may be important to measure in evaluating earlier age at menarche.