They have yet to discover the reason behind the phenomenon but believe it could be linked to unhealthy lifestyles or exposure to chemicals in food…

Scientists are worried that young girls are ill-equipped to cope with sexual development when they are still at primary school – and that exposure to hormones earlier could increase their risk from breast cancer.

“We were very surprised that there had been such a change in a period of just 15 years,” Anders Juul, head of the Department of Growth and Reproduction at the University hospital in Copenhagen, told the Sunday Times.

“If girls mature early, they run into teenage problems at an early age and they’re more prone to diseases later on.