A new study reveals that the age of girls reaching their puberty is going further down as compared to the last decade. This has been seen particularly in white and Hispanic girls in America.

Researcher Frank M. Biro, MD, director of the division of adolescent medicine at Cincinnati Children’s Hospital Medical Center, Cincinnati, says that ethnicity plays a vital role in earlier puberty along with the body composition of every individual.

Biro told WebMD, “We found that girls who are African-American matured before whites, and that's been shown in several studies. White girls are maturing earlier than they had before, compared to 20 years earlier.”

He conducted a study on 1,239 girls and found that 10 percent of whites, 23 percent of African-Americans and 15 percent of Hispanic girls had breast development at age 7, which indicated the onset of puberty.

The study was carried out within the Breast Cancer and the Environment Research Centers (BCERC), established in late 2003 as a partnership with the National Institute of Environmental Health Science and National Cancer Institute.