Contributing factors might be the use of soy in baby formula and ingredients in cattle feed.
Note articles on soy milk on our Hormones page.
ARTICLE: A large study released by the American Academy of Pediatrics suggests that boys are entering puberty earlier now than several decades ago — or at least earlier than the time frame doctors have historically used as a benchmark.
The study, widely considered the most reliable attempt to measure puberty in American boys, estimates that boys are showing signs of puberty six months to two years earlier than was reported in previous research, which historically taught that 11 ½ was the general age puberty began in boys. But experts cautioned that because previous studies were smaller or used different approaches, it is difficult to say how much earlier boys might be developing.
The study echoes research on girls, which has now established a scientific consensus that they are showing breast development earlier than in the past. The study, which was to be announced at the national conference on Saturday and published online in the journal Pediatrics, did not try to determine what might be causing earlier puberty, although it mentioned changes in diet, less physical activity and other environmental factors as possibilities. Experts said that without further research, implications for boys are unclear.
“This should perhaps set a standard going forward for being very attentive to puberty in boys and being mindful that they’re developing earlier,” said Dolores J. Lamb, a molecular endocrinologist at Baylor College of Medicine and president of the American Society for Reproductive Medicine. She was not involved in the study.