1 15 years Invitations

The onset of female puberty has advanced one year in a decade and a half, according to the most comprehensive study in Europe on how it is changing the age of onset of adolescence. If in 1991 the average age of onset of puberty in girls stood at 10.88 years in 2006 had dropped to 9.86 years. Or, what is, and usually start puberty before the age of ten.

"We are not surprised that the age has dropped, but has fallen so much in so little time," said Lise Aksglaede email, a researcher at the University Hospital of Copenhagen (Denmark) and first author of the study. Their findings have been presented in the May issue of the medical journal Pediatrics.

Researchers point to endocrine disruptors - pollutants that act like hormones in the human body as the most likely cause of this trend. The possible consequences, yet little investigated, ranging from emotional disturbances to an increased risk of breast cancer and diabetes to reach adulthood.

Although the study was carried out in children in Denmark and its results can not be extrapolated literally to Spain, here also shows the same trend toward earlier puberty, agree on four experts consulted for this report.

"In Sant Joan de Deu, we puberties increasingly advanced in girls," says Lourdes Ibáñez pediatric endocrinologist. "We get cases of girls aged seven years who initiate breast development, which is unacceptable in our environment. And there are frequent consultations for breast development in girls of eight or nine years."

The onset of puberty is defined as the stage when the button is formed breast and pubic hair begins to grow. Age does not match the first rule - or menarche - which usually comes about three years later. According to the results of the Danish study, menarche has been advanced about four months in fifteen years. If in 1991 reached 13 years and five months on average in 2006 was recorded at 13 and unmes. In Catalonia, the average age of menarche is at 12 years and 9 months, according to a study published Vall d'Hebron hospital in 2004 in 'Clinical Medicine'.

The Danish study was based on more than two thousand volunteers, half of them tested between 1991 and 1993 and the other half between 2006 and 2008. All study participants were examined by a doctor, they analyzed the levels of estrogen in the blood and asked was measured weight and height. The same research team conducted the study using the same techniques with fifteen years apart, which allows to compare results and see the evolution of the stages of adolescence. "It's a prestigious research team and the studio is very well done," said Manolis Kogevinas, Municipal Institute epidemiologist Barcelona Medical Research (IMIM).

Previous studies had indicated that the trend toward more overweight among girls puberty and favors a more precocious menarche. But Danish researchers have found that, even comparing the same age girls with the same BMI, the stages of adolescence are ahead. "The weight differences may partly explain the progress of the age at menarche," said Aksglaede, but not enough to explain the breakthrough of the age of onset of puberty.

Has also been observed that puberty tends to be more precocious in immigrants and adopted children from other continents than girls of European families. But in this case have not been included either immigrants or adopted in the study.

More puzzling is the observation that female sex hormone levels have remained stable at all ages although the stages of adolescence are ahead. That is, the onset of puberty was recorded before although estrogen production does not start earlier.

What is it that triggers this advancement of the stages of adolescence? Although "not know", as acknowledged Aksglaede, his hypothesis is that it is of chemical pollutants that mimic the effects of estrogen in the body.





15 years Invitations