Soyfoods are without effect on the age of onset of menarche
In many countries throughout the world, the age at which puberty occurs among girls—manifested as breast development, appearance of pubic hair, and onset of menarche—has been commencing earlier. For example, the mean age at onset of menarche (AOM) in Korea decreased from 16.9 to 13.8 years between 1920 and 1985. In the United Kingdom, between 1910 and 1993, it decreased from 13.5 to 12.3 years. And in the United States the AOM decreased by an average of 3 to 5½ months from 1960 to 1990….