Girls are beginning to grow breasts at an earlier age, and starting their periods sooner too, and scientists suspect chemicals in plastic bottles may be behind this trend.
The findings back up recent studies that found earlier breast development in American girls over the past several years,
Lise Aksglaede of Rigshospitalet in Copenhagen, the lead researcher on the study, said. “At this point, we don’t know what is happening, and that is also what worries us.”
Aksglaede noted that she and her colleagues have seen an increasing number of girls with precocious puberty, meaning sexual maturation beginning before age eight.
To investigate whether this might represent a trend, or simply greater recognition of the problem by parents, the Denmark-based researchers looked at 1,100 girls who were studied in 1991-1993 and 995 examined between 2006-2008. The study participants ranged in age from 5.6 to 20 years old.
While the average age at which breast growth began was 10.88 years for the 1991 group, it was 9.86 for the 2006 group. Age at first menstruation was 13.42 for the 1991 group, and 13.13 for the 2006 group.
Most experts believe that the obesity epidemic may have something to do with earlier puberty in girls, Aksglaede noted, but she and her colleagues found no difference in the prevalence of overweight and obesity between the 1991 and 2006 groups.
There also were no differences in levels of several reproductive hormones between the two groups, although the 8- to 10-year-olds tested in 2006 actually had lower estrogen levels than girls of the same age tested in 1991.
Chemicals which can produce estrogen-like effects in the body may be responsible, Aksglaede said. However, she pointed out that the effects of such chemicals are extremely difficult to study, given that there are so many different chemicals out there, and that the levels girls are exposed are in constant flux.
Chemicals in plastics like the chemical bisphenol A (BPA) and phthalates have the potential to interfere with estrogen and other reproductive hormones.
While precocious puberty can have psychological consequences for girls, and may also stunt growth, the girls in the current study were still entering puberty at a relatively normal age.
“It is the first time we are seeing this in Europe,” the researcher said. “It might be happening in other countries, but it hasn’t been reported yet.”
Sources: The Times Of India