Puberty in Girls Starts Earlier Than Ever

Apr 29, 2009
More girls show puberty signs earlier than it was several years ago, a new study says.

The study at Rigshospitalet in Copenhagen, Denmark found that there is an increased number of girls in Europe, who start developing breasts and begin to menstruate at an earlier age. Dr Lise Aksglaede and her colleagues analyzed the data on 1100 girls aged between 5.6 and 20 years old between 1991 to 1993 and 995 girls between 2006 and 2008.

The results of the study showed that girls start to grow breasts at 10,88 years on average in early 90's, and at 9.86 between 2006 and 2008. The average age when girls start their periods was 13.42 in 1991 to 1993 and 13.13 between 2006 and 2008.

What causes early puberty?

Scientists say that there is no explanation why puberty starts earlier. There are several theories explaining early puberty. Previous studies showed the link between the onset of early puberty and obesity in childhood. This was explained by the fact that obese children have increased level of leptin, protein that is involved in hormones triggering puberty. But the researchers in this study did not find any difference in the prevalence of overweight girls in both groups of participants.

Usually, girls enter puberty between ages 9 and 15 on average, while boys show signs of puberty between 11 and 17. In general, the age of first periods declined around 0.3 per decade from the middle of the 19th century until the middle of the 20th century.

Puberty is considered precocious when the signs of puberty start before age 7 or 8 in girls and age 9 in boys. In some cases, early puberty is caused by genetic factors, brain tumor or indicates pituitary gland disorder.

Some scientists believe that early puberty is triggered by hormones in food, such as artificial bovine growth hormone in milk and meat. Also exposure to estrogen-like chemicals found in water and plastic items is thought to cause the early hormonal changes in children.

Nowadays there is no clear answer to the causes of early puberty. It is known that early puberty has psychological impact on children, who are not ready to cope with hormonal changes at an early age. Also children, who enter puberty earlier, are more likely to start sex life earlier as well as use alcohol and drugs.