By Tara Haelle
It may be tempting to park a child in front of the TV for a couple hours a day. But that peace and quiet may backfire if the child sleeps less at night.
A recent study found that the more TV preschool children watched during the day, the less sleep they generally got at night. The study looked at preschool-aged and elementary-aged children and was based on parents' observations.
The authors concluded that limiting the hours children spend watching TV may be best for their sleep schedules.
The study, led by Marcella Marinelli, PhD, of the Center for Research in Environmental Epidemiology in Barcelona, Spain, looked for links between how much TV children watched and how much sleep they got.
The researchers analyzed the data provided by the parents of 1,713 children in three Spanish cities.
Parents tracked their children's average hours watching TV each day when the children were 2 and 4 years old in two of the cities. The parents of the children in the third city tracked their kids' hours of daily TV time when their children were 6 and 9 years old.
The parents also reported how many hours of sleep their children got each night on average.
The researchers found that both boys and girls who spent more time watching TV tended to sleep for shorter periods of time.
During the first collection of data, when the children were younger, those who watched at least 1.5 hours of TV a day slept less compared to children who watched less TV.
During follow-up when the children were older, some who had previously watched TV for less than 1.5 hours were now watching it at least 1.5 hours a day or more.
These children also were found to be sleeping for shorter periods of time than their peers who were still watching TV less than 1.5 hours a day.
Then the researchers compared each hour of television watching to each hour of sleep across all the children to see if there was a link.
They found that the two were linked, even on weekends and after taking into account other factors that might influence sleep.
The more TV the children watched, the less sleep they got, even after considering any attention deficit hyperactivity disorder symptoms in the children and their levels of physical activity.
The researchers also considered the parents' mental health, the mother's IQ, the mother's physical health, the parents' level of education and the parents' marital status, but none of these factors changed the results.
"Children spending longer periods watching television had shorter sleep duration," the researchers wrote. "Parents should consider avoiding long periods of daily television exposure among preschool and school-aged children."
William Kohler, MD, the medical director of the Florida Sleep Institute in Spring Hill, Fla., said the study may have been more helpful if the authors had reported both the hours of sleep the children got and the hours of TV the children watched.
Nonetheless, he said, the study offers an important takeaway.
"The bottom line still is that diminished quality or quantity of sleep can lead to cognitive or behavioral problems," he said. "Anything that interferes with getting that sleep, such as the TV watching reported in this article needs to be eliminated or reduced."
The study was published March 10 in the journal JAMA Pediatrics. The authors reported no conflicts of interest.
The research was funded by the Spanish Ministry of Health, the Carlos III Institute of Health, the Generalitat de Catalunya-Consell Interdepartmental Research and Innovation Technology, the Generalitat Valenciana Health Department, the European Union, the European Commission, the Roger Torné Foundation, and the Caixa Fellowship of the Fourth Call for Aid to Research in Neurodegenerative Diseases.