Girls in fatherless families may enter puberty early

Girls living in homes without their biological fathers are more likely to enter puberty at an earlier age, a study published in the Sept 17 2010 issue of the Journal of Adolescent Health suggests.

The study, led by Julianna Deardorff at the University of California Berkeley's School of Public Health, found that the absence of a biologically related father in the home was associated with earlier breast and pubic hair development among girls from higher income households.

According to a press release by UC Berkeley, one study of 1200 girls released last month found that approximately 15 percent of the participating girls started developing their breasts at age 7. The study, which was also reported by foodconsumer.org, was led by researchers at Cincinnati Children's Hospital Medical Center.

Early puberty has been linked to a number of health problems, including reduced self-esteem, eating disorders, depression, early sexual activity, and later menopause, which is linked to an elevated risk of breast cancer and other female reproductive cancers.

Earlier puberty in girls may have something to do with their diet. Previous research suggests that consuming soy products in childhood may help delay puberty; conversely, environmental toxins such as estrogenic chemicals, childhood obesity and high intake of sugar and animal protein can push girls to enter puberty early.

"While overweight and obesity alter the timing of girls' puberty, those factors don't explain all of the variance in pubertal timing. The results from our study suggest that familial and contextual factors – independent of body mass index – have an important effect on girls' pubertal timing," Deardorff said.

What Dr. Deardorff essentially said is that supportive family environment is important for girls.  

Jay Belsky, of Birkbeck University in London published a study last month in Psychological Science which reported that an insecure infant-mother attachment bond was linked with increased risk of early puberty.

Bruce J. Ellis at the University of Arizona and Marilyn J. Essex at the University of  Wisconsin Madison reported in 2007 in the journal Child Development that girls who grew up with supportive parents who themselves had a strong relationship. were more likely to delay the onset of puberty.

In the current study, Dr. Deardorff and colleagues followed 444 girls aged 6 to 8 through Kaiser Permanente  Northern California, annually. Their analysis was based on data collected during the first two years of follow-up.

They found the absence of a biologically related father was associated with earlier breast development in girls in families having annual household incomes of $50,000 or higher. Paternal absence predicted earlier onset of pubic hair, but not breast development in high income African American families.

The researchers offered a few explanations. One of which is that girls in fatherless families were more likely to receive less care from their single mothers because of their long hours on the job. Specifically, this disallowed them from providing all of the care their girls needed.  This speculation is supported by earlier studies suggesting that the mother-girl bond is important.

A health observer suggested that because single mothers normally don't have enough time to prepare meals for their girls, they are left with an overabundance of  processed foods, which can contain high animal protein, high fat, and high sugar. A diet full of such foods has also been linked with early puberty.

By David Liu and editing by Rachel Stockton