Girls in U.S. Hitting Puberty Early; Study Finds

Girls are hitting puberty earlier now than they did 20 years back, a new study has found. Researchers believe that rising obesity rates might be behind early maturity.

For the study, researchers looked at data from multi-ethnic longitudinal study to assess the approximate timing of breast development in girls of similar ages.

"The impact of earlier maturation in girls has important clinical implications involving psychosocial and biologic outcomes," said Frank Biro, MD, lead investigator and a physician in the Division of Adolescent Medicine at Cincinnati Children's Hospital Medical Center, according to a news release. "The current study suggests clinicians may need to redefine the ages for both early and late maturation in girls."

A study published in 2010 had shown that girls in the U.S. are maturing earlier now than few decades back. Previous research had shown that early menarche in girls is associated with heart diseases, cancer, adult onset of diabetes and depression. It can also affect lung function and result in adult asthma.

In the present study, researchers at San Francisco Bay Area, Cincinnati and New York City analyzed records of 1,239 girls who were enrolled in a long-term study that was conducted between 2004 and 2011.

African American girls in the study had early breast development- at eight years and ten months, on an average. Hispanic girls developed breasts at around nine years and four months while it was nine years, eight months for white and Asian girls, Reuters reported.

Researchers are still trying to find why girls in the U.S are reaching puberty earlier than before. However, they said that there is evidence to support the idea that rising obesity among girls is linked with early maturation.

"It may not just be as simple as calories in and calories out," said Janice Barlow, executive director of Zero Breast Cancer, reported SF gate.com. "There may be other factors in environment that may be fueling the obesity epidemic."

The study was published in the journal Pediatrics.