Girls are starting puberty earlier, studies show, and some researchers speculate that rising obesity rates might be a factor. A new study finds there may be a link between early puberty and girls living in higher-income households without a biological father.
The study, published this week in the Journal of Adolescent Health, looked at data on 444 ethnically diverse girls age 6 to 8, 80 of whom had no biological father living at home at the time of the study. Researchers noted the girls' onset of puberty (breast and pubic hair development), body mass index, ethnicity and income. Among the 80 participants, 21% had other men living at home, including stepfathers.
Not having a biological father at home was associated with earlier breast development, but only for girls who lived in families with incomes over $50,000. Not having a father at home was linked with earlier development of pubic hair among African American girls living in higher income homes. Factoring in BMI did not change the results.
The study offered some reasons for the link: higher-income families may have weaker support systems than lower-income families; mothers working outside of the home may put extra stress on family life and relationships; and having fathers leave while kids are young may indicate early familiarity with marital discord; and children living in higher-income households may have more exposure to environmental toxins that may have an effect on puberty.
"The hunt for an explanation to this trend is significant since girls who enter puberty earlier than their peers are not only at greater risk for reproductive cancers, they are also more likely to develop asthma and engage in higher risk sexual behaviors and substance abuse, so these studies have broader relevance to women's health," said senior author Dr. Robert Hiatt, professor and co-chair of epidemiology and biostatistics at UC San Francisco, in a news release.