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May 3, 2010 -- Television watching at age 2 1/2 boosts a child's risk of having multiple school and health problems later in life, according to a new study.
The effects of too much TV too early was far-reaching and long-lasting, says study author Linda Pagani, PhD, professor of psycho-education at the Universite de Montreal and a researcher at the Sainte-Justine University Hospital Research Center in Montreal, Canada.
''You get a child who's more sedentary, has a higher BMI, is not eating properly, and not doing well in school socially and academically in the fourth grade," Pagani tells WebMD.
Numerous other studies have focused on the effects of television viewing on children, linking too much screen time to poorer school work and excess weight later. But Pagani says her new research is more comprehensive -- it looked at a variety of potential effects, not a single one. And she followed up on the children longer -- until age 10, or fourth grade.
Evaluating the effects of early TV viewing is important, she says. ?"From birth to age 5, you have enormous brain expansion. We're talking exponential."
And, according to her research, early television viewing is not doing the toddler brain any favors.
For the study, Pagani and her colleagues gathered data on 1,314 children born in Quebec, Canada, between 1997 and 1998.
Parents reported how many hours a week their children viewed television at 29 months and again at 53 months. The researchers gathered teacher and parent reports on academic performance, psychosocial and health habits, and the children's body mass index or BMI.
At age 29 months, the average TV viewing was 8.82 hours a week, Pagani found.? At 53 months, the average was 14.85 hours.
Although that may not sound high, Pagani notes that the range was wide. ''This is an average,'' she says, so many children watched more.
At 29 months, 11% of the toddlers were watching more than two hours a day. By age 53 months, 23.4% of the children were watching more than two hours a day.
Current recommendations by the American Academy of Pediatrics discourage television viewing for children under age 2 and suggest no more than one or two hours of? ''screen time" (TV, computers) daily for older children.
Television viewing had undesirable effects, even after the researchers adjusted for a number of variables that might account for the effects, such as family configuration and education of the mother, and the amount of TV they viewed as fourth graders.
"We considered all kinds of competing explanations," Pagani tells WebMD. But even after taking all the factors into account, the effects remained, she says.
"Basically we saw kids who watch excessive TV at 29 months were more likely to be less productive in class [in fourth grade] as rated by their teachers," she tells WebMD. "They were performing less well in mathematics. We also saw negative effects in anything that required effortful exercise -- how often they exercised, whether they liked to do anything that requires effort. And their body mass index was greater."
The children exposed to too much TV were also likely to be victimized, she found, explaining that social relationships take practice and effort. "Kids who do too much media, studies have shown this, tend to be socially isolated."
Not having social skills, she says, may make the kids targets for being teased and insulted by classmates.
Each additional hour of TV viewing at age 29 months (over the average for each child) was linked to a range of effects, Pagani found, including:
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The new findings are no surprise to Ed Christophersen, PhD, a clinical child psychologist at Children's Mercy Hospitals and Clinics in Kansas City, Mo., who reviewed the study results for WebMD.
The new research, he says, documents what he and his colleagues have believed about the link between too much TV and developmental and other problems.
''This study pulls together multiple measures that many of us thought were affected by early TV, but now we know they are," Christophersen tells WebMD. He reminds parents that TV time limits should also include "screen" time from computers and other media.
Most parents are aware of the hazards of too much screen time, says Rahil Briggs, PsyD, director of the Healthy Steps at Montefiore Medical Center and assistant professor of pediatrics at Albert Einstein College of Medicine in New York, who also reviewed the findings.
Parents rely on TV for a break, she finds. "I think it's because parents are overworked, exhausted, and really highly stressed.”
Although that's fine for occasional ''breathing room," she suggests parents think of other ways to relax without leaning on TV.
"Take your child to the park," she suggests, so he can learn to interact and you can still relax a bit.
"If you have to plop down in front of the TV, have a conversation with your kid about what you are watching," she says. "Make it an interactive experience."