Scientists say watching TV hastens puberty

Study finds it is a matter of light and radiation

John Hooper in Rome
Monday June 28, 2004
The Guardian

Does watching television bring on early puberty? Many parents would not doubt that repeated exposure to Sex and the City or the kind of sensual variety shows common on Italian TV could as easily turn their daughters into Lolitas as stir up the latent testosterone in their sons.
But researchers from Florence University have come up with an alternative explanation: watching screens, regardless of the subject matter, helps to advance adolescence.
A study carried out last month in the Tuscan town of Cavriglia detected a huge increase in production of the hormone melatonin in children deprived of TV, computers and video.
Among the functions ascribed to melatonin is that of slowing down the progress of children to sexual maturity.
Roberto Salti said: "We may thus be able to explain a phenomenon of recent years, which is the bringing forward of puberty in young children."
Vast amounts of research have been conducted to the effect of television on children. But most has focused on the psychological, rather than physiological, effects.
"In our study television does not feature, as it does in other scientific studies, as a source of strong emotions, capable of unleashing emotive reactions that contribute to development," said Roberto Tarquini, another member of the team. "For us, it is just a source of light and radiation."
The researchers studied 74 children aged between six and 12 who normally watched television for an average of three hours a day. In the week preceding the experiment they were encouraged to do so a bit more.
They were then deprived of TV, computers and video games for seven days. In addition, their families were asked to use less artificial light.
At the end of the period the children's melatonin levels had risen by an average of 30%. The increases were particularly marked in the youngest children.
Alessandra Graziottin, director of the Centre for Gynaecology and Medical Sexology in Milan and a former president of the International Society for the Study of Women's Sexual Health, said the results were "very interesting and plausible".
She told the newspaper La Repubblica: "Studies in the US have shown that the greater the exposure to television the greater the number of early sexual experiences, including teen pregnancies."
Melatonin is known to have an influence on sleep patterns. But whether it also determines the onset of puberty is still a subject of research and debate. The Florence University scientists said they were planning a joint study with US researchers aimed at putting an end to the uncertainty.
Dr Graziottin said the results could also help to explain another phenomenon of recent years. "Sleep disturbances, nightmares, difficulty in getting to sleep and so on, are ever more common among children. Melatonin has a role in this area too and it is quite possible there is a link with exposure to television."
Setting up the experiment had not been easy, Mr Tarquini said. "Some of the parents and grandparents were frightened. They didn't know how they were going to keep the children occupied without television."
Some of the younger children were reported to have cried when their TV was removed, but the mayor of Cavriglia, Enzo Brogi, presented each child with a book and board game, which seems to have helped.
Parents organised card games, ball games and fishing expeditions. They encouraged their children to listen more to the radio and arranged a collective reading of Antoine de Saint-Exupéry's The Little Prince. The experiment ended on May 16 with a midnight ceremony in which the mayor symbolically smashed a television set in the town square.
The Ansa news agency quoted one of the children as saying seven days was not enough for all the activities that had been planned.
However, La Repubblica reported that the activities also included simulations of well-known TV quiz shows.
What researchers have said about children and television
February 1997 Children recall more of what they see on television than of what they read (Centre for child and media studies at Leiden University, Netherlands)
July 1997 Watching TV for more than six hours a day significantly increases levels of psychological trauma in children aged eight to14 (Case Western Reserve University)
March 1998 Children who watch four or more hours of television a day weigh more than children who watch fewer than two hours a day (Johns Hopkins Bayview Medical Centre)
September 2002 Television can enhance children's intellectual development (University of Texas at Austin)
January 2003 Restricting TV viewing at home may lead teens to watch their favourite programmes at friends' homes (Ohio State University)
March 2003 Watching television is not related to weight, but video games may be (University of Texas)
March 2004 Around 95% of parents think it is important to control children's exposure to TV and computers, but more than 60% allow them to view these as long as they want. (Wake Forest University Baptist Medical Centre)