A new study by researchers at the t Cincinnati Children's Hospital Medical Center has found that the age at which girls attain puberty is falling.
The study said that some girls were attaining puberty at the age of 7. "In 1997, people said, 'That can't be right; there must be something wrong with the study,' "said lead author Dr. Frank M. Biro. "But the average age is going down even further."
The study included 1,238 girls ages 6 to 8. Puberty was determined by two examiners who worked independently. They were tasked to report on breast development in girls.
The study found that by age 8, 27% of the girls had begun puberty. Among them 18.3% were whites, 42.9% were blacks and 30.9% were Latinas.
Researchers said that the increase in average body weight over the last 30 years is one of the main causes for the falling age of puberty in girls. The details appear in the journal Pediatrics.