There are times when watching what my husband calls “the idiot box” is the only option for kids who can’t jump on a bike and go exploring outdoors. But it is an option with more health consequences than we thought, according to a new study on 111 children ages 3 to 8 published in the Archives of Pediatric and Adolescent Medicine.
We all know kids tend to become obese watching too much TV due to the tendency to snack mindlessly, but these results found the more kids watched, the higher their blood pressure, no matter the weight of the kid. In fact, of all forms of inactivity examined by researchers in the U.S. and Spain, being glued to the tube was the worst.
“These results show that sedentary behavior, and more specifically television-viewing, is related to blood pressure independent of body fat or obesity level,” says Dr. Joey Eisenmann, a kinesiologist at Michigan State University and one of the study’s co-authors.
During the course of one week, the children tested wore accelerometers, instruments that record the body’s acceleration in a vertical plane – sitting results in a score of zero, and walking and running produce progressively higher scores.
Anything under a score of 50 per day was listed as sedentary. The children were sedentary for five hours each day, and 1.5 of those hours were spent in front of a TV, computer or video game, on average.
Researchers found when they broke down screen time by activity, TV-viewing had the strongest connection with higher blood pressure. Kids watching from two to five hours of television each day had systolic and diastolic blood-pressure readings (the two numbers that indicate pressure caused by blood pumping from the top and bottom chambers of the heart, respectively) that were five to seven points higher than those of children watching less than half an hour of television a day.
“These results show that TV-viewing really is the worst of all possible sedentary activities,” says Dr. David Ludwig, director of the Optimal Weight for Life Program at Children’s Hospital Boston, who was not part of the study. The American Academy of Pediatrics says children under two should not watch any television and that older children should limit their viewing to one to two hours per day.
So what makes TV less healthy than playing video games or surfing the Internet?
Among the explanations: children may be downing sweet and salty junk food while lying around and this can push up blood pressure readings; watching too close to bedtime can stimulate their brains, interfere with hormones and cause them to miss precious hours of sleep; missing sleep can lead to weight gain and hypertension because the metabolism doesn’t recharge and renew itself overnight; and content of commercials encourages overeating of the wrong types of food, which can be habit-forming throughout life.
In previous studies involving the same group of children, about 20% had developed prehypertension or hypertension – often because of weight gain.
So what is a healthy dose of television watching for children? Like everything else, moderation. One show after homework, a Saturday morning cartoon after a soccer game. And try to replace good movies with harmful commercial television packed with ads marketed to the most vulnerable viewers.
Image: Aaron Escobar