An Australian study has found a link between poverty and early puberty - which could lead to an array of problems later in life.
Disadvantaged children are up to four times more more likely to hit puberty early, an Australian study has found.
Early puberty could be linked to problems in adolescence, including depressive disorders, substance disorders, eating disorders and "precocious sexuality."
A researcher on the team says the same link would likely be found among New Zealand kids.
Scientists from the Murdoch Children’s Research Institute in Melbourne found boys who grew up in very disadvantaged homes had more than four times the risk of starting puberty early, at 10 or 11 years of age.
In girls, the risk of starting puberty was double.
Lead author, associate professor Ying Sun, said the findings raised the possibility that the timing of puberty could play a role in the links between early social disadvantage, and health problems later in life.
Associate professor Sun said that disadvantage may be linked to early puberty for evolutionary reasons.
In the face of hardships - such as economic disadvantage or harsh physical environment - children may be programmed to start the reproductive process earlier to ensure their genes are passed on to the next generation, he said.
Senior author Professor George Patton said early maturation had 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.”
University of Auckland’s Professor Melissa Wake, who was a member of the Melbourne-based research team, said early puberty could be one of the ways in which social disadvantage got “under the skin".
She said it could influence children’s later life chances, in terms of both economic prosperity and health.
Wake, now Cure Kids professor of child health research at the Liggins Institute and the University of Auckland faculty of medical and health sciences, said other factors implicated in early puberty among New Zealand and overseas kids could include mental health issues, prematurity and obesity.
“Findings like these highlight the importance of tackling these issues at a society-wide level.”
About 3700 children were surveyed for the study and parents were asked to report on signs of children’s puberty at age eight to nine, and 10 to 11 years.
These included a growth spurt, pubic hair and skin changes, breast growth and menstruation in girls, and voice deepening and facial hair in boys.
The paper, published in the journal Pediatrics, compared the socioeconomic position of families with children who started puberty early with those who started on time.
At 10/11 years of age, about 19 percent of boys and 21 percent of girls were classified in the early puberty group.