From Mail Online:
More and more girls are starting puberty at primary school age, research shows. A study of 1,000 girls found that breast development now begins on average a year earlier than 20 years ago - around the age of nine years and ten months. It underlines a long-term trend that has seen the average age at which girls hit puberty fall sharply. In the 19th century it was around 15.
Scientists yesterday spoke of the serious implications for girls' physical and emotional health. There are fears that early puberty could put girls at higher risk of breast cancer and heart disease because of the increased exposure to oestrogen.
Dr Anders Juul, of Copenhagen University Hospital in Denmark, which carried out the research, said: 'If girls mature early, they run into teenage problems at an early age and they're more prone to diseases later on.