Children who grow up in poorer households are more are more likely to hit puberty early, according to new research.
The Australian study, which tracked almost 4,000 children from birth, found boys were four times as likely to risk starting puberty early, at 10 or 11 years old, while the rate is double that for girls than those growing up in wealthier families.
University of Auckland based-researcher Professor Melissa Wake says the same link would be found in New Zealand children.
“Early puberty may be one of the ways in which social disadvantage gets under the skin and influences children’s later life chances, both in terms of economic prosperity and health,” she says.
The MCRI study examined a range of factors including economic disadvantage, harsh physical environment, or absence of a father in trying to determine if social circumstances played a role in kick starting developmental changes.
Parents taking part were asked to report signs of children's puberty from eight, nine, 10 and 11, including growth spurts, pubic hair and skin changes. They also reported other developments such as breast growth and menstruation and voice deepening and facial hair in boys.
Researchers then compared the socio-economic position of families with children who started puberty on time, and those who started early.
At 10 to 11, about 19 per cent of all boys and 21 per cent of all girls were classified in the early puberty group.
Study lead, Associate Professor Ying Sun says the research could help policy-makers managing adult health issues associated with early onset of puberty.
“Our findings raise a possibility that the timing of puberty may play a role in the links between early social disadvantage, and health problems later in life.
“If our research can improve the understanding of these links, we can potentially inform new public health initiatives that improve the health and well-being of all children for the rest of their lives.”
Associate Professor Sun also says that disadvantage may be linked to early puberty for evolutionary reasons. Children may be programmed to start the reproductive process earlier to ensure their genes are passed on to the next generation.
Senior author Professor George Patton also noted the importance of understanding the impact early puberty can have on children’s emotional development.
“Early maturation has links in girls with emotional, behavioural and social problems during adolescence including depressive disorders, substance disorders, eating disorders and precocious sexuality.
“Early puberty also carries risks for the development of reproductive tract cancers and cardio-metabolic diseases in later life. Given the recent trend towards earlier pubertal maturation in many countries, a clearer understanding of factors influencing pubertal timing is important.”
The study was published in the journal Pediatrics.