Childhood obesity 'to blame for early puberty': Average age falls by five years in century, figures show
- Study at Plymouth University studied school children aged five to 15 years
- Found children who were obese at five had lower levels of specific protein and reached puberty sooner
- Tendency was more striking in girls than in boys, study found
Children are reaching puberty five years earlier than a century ago as obesity interrupts hormonal changes in the body, a study has found.
The onset of puberty in girls was 14.6 years in 1920, compared to 10.5 in 2010, researchers have found.
While in boys, sexual maturity consistently occurred around a year later than their female peers.
The scientists behind the study at Plymouth University found the childhood obesity epidemic could be to blame as weight gain causes harmful changes to a child's hormone levels, allowing puberty to happen earlier.
A new study has found a link between obesity and the declining age of puberty, especially in girls
Past studies have suggested early puberty could increase a child's chance of suffering cancer and other serious health problems later in life.
The team studied hormone levels in 347 schoolchildren aged five to 15 years old.
They found a child who is heavier at five tends to have lower levels of a protein called sex hormone-binding globulin (SHBG), and reaches puberty sooner.
The tendency was more striking in girls than boys, the team noted.
Share this article
The study focused on the role of SHBG, in children.
SHBG binds to the sex hormones androgen and oestrogen and while levels are initially high in childhood, they decline significantly before puberty, to allow sexual maturity to happen.
Researchers have suggested that hormonal disturbances associated with weight gain - combined with inflammation - could be the biological mechanism that explains the link between obesity and the declining age of puberty.
Lead researcher, Professor Jonathan Pinkney, at Plymouth University Peninsula Schools of Medicine and Dentistry, said: 'There are critical windows early in life which the die is cast for our long term health.
Scientists found hormonal changes and inflammation as a result of being overweight affect levels of a protein SHBG, causing puberty earlier
'We know that weight gain often begins early and we wanted to investigate how early weight gain might be linked to earlier puberty.
'Here we have found compelling evidence that hormonal effects of obesity, and associated inflammation, affect levels of SHBG and hence the age when puberty commences.
'As a higher proportion of youngsters around the world have become obese, the age of puberty dropped. We now know that the relation between these issues is more than coincidental.
'These findings have significant implications for children’s development and public health around the world.
'Reduction in the age of puberty, as a result of early weight gain, expedites physical and psychosocial development at a younger age, and this potentially means an earlier ability to reproduce as well as poorer long term adult health.
'The observed effects on puberty are another reason to take action against childhood obesity.'
The findings also open a debate about the role of the worldwide obesity epidemic in the general lowering of the age of puberty.
The World Health Organization recognises childhood obesity as one of the most serious global health challenges for the 21st century.
Figures from the UK’s National Child Measurement Programme 2012/13 show that almost a third of 10 to 11 year olds and more than a fifth of four to five year olds were either obese or overweight.
Worryingly, as well as now identified as contributing to the lowering age of puberty, obesity in childhood also increases the risk of heart disease and diabetes in later life.
The study was published in the Journal of Clinical Endocrinology and Metabolism.
Most watched News videos
- Russian soldiers catch 'Ukrainian spy' on motorbike near airbase
- Staff confused as lights randomly go off in the Lords
- Shocking moment man hurls racist abuse at group of women in Romford
- Moment fire breaks out 'on Russian warship in Crimea'
- Shocking moment balaclava clad thief snatches phone in London
- Shocking moment passengers throw punches in Turkey airplane brawl
- Gideon Falter on Met Police chief: 'I think he needs to resign'
- Shocking footage shows men brawling with machetes on London road
- Trump lawyer Alina Habba goes off over $175m fraud bond
- China hit by floods after violent storms battered the country
- Lords vote against Government's Rwanda Bill
- Mother attempts to pay with savings account card which got declined
