Padded bras for kindergarteners with growing breasts to make them more comfortable? Sixteen percent of U.S. girls experiencing breast development by the age of 7? Thirty percent by the age of 8? Clearly something is affecting the hormones of U.S. girls—a phenomenon also seen in other developed countries. Girls in poorer countries seem to be spared—until they move to developed countries.
No scientists dispute that precocious or early-onset puberty is on the rise but they do not agree on the reasons. Is it bad diets and lack of exercise that cause growing obesity? Is it soft drinks themselves, even when not linked to obesity? Is it the common chemicals known as endocrine disrupters that exert estrogen-like effects (and also cause obesity)? Is it the many legal, unlabeled hormones used in the U.S. to fatten livestock? Some researchers even believe precocious puberty could be triggered by sociological factors like having no father in the home or even stress.