Girls growing up in higher-income homes without a biological father are likely to reach puberty earlier than others, new research finds.
“In higher-income families, father absence predicted earlier puberty, but it did not in lower-income, father-absent [households],” said study leader Julianna Deardorff.
“Girls in upper-income households without a father were at least twice as likely to experience early onset of puberty, as demonstrated by breast development,” she said. The researchers defined higher income as $50,000 or more a year.
Early maturation in girls is linked with emotional and substance use problems and earlier sexual activity. These girls also face a higher risk for breast cancer and other reproductive cancers later in life.
Previous research has linked absent-father households and earlier puberty, but this study adds more information, said Deardorff, an assistant professor of public health at the University of California, Berkeley.
For their study, published Sept. 17 in the Journal of Adolescent Health, Deardorff and her colleagues followed 444 girls, aged 6 to 8 at the start, and their mothers. They gathered extensive data on factors such as weight, height, stage of breast and pubic hair development, father’s presence and income. Eighty percent of the girls said their fathers did not live with them.
After two years of follow-up, the researchers saw earlier breast development in higher-income girls in absentee-dad homes across the board, but noted earlier pubic hair growth only in black girls from richer families. Having another male, such as a stepfather, in the home didn’t change the findings.
Several reasons for the findings have been suggested that include unstable family environment, exposure to pheromones of unrelated males and exposure to more artificial light from computers and other technologies – findings also found in animal studies. It might be possible that African-American girls reach puberty early from exposure to estrogen stimulating beauty products.
“It’s possible girls in those homes are exposed to different environmental exposures, for example, toxins,” Deardorff said. They may be exposed more to cosmetics and other personal care products, for instance, and some experts have expressed concerns about what they see as hormone-disrupting chemicals in those products.