Junior couch potatoes, listen up: Watching two or more hours of television a day may spell high cholesterol levels--and possibly heart disease--in adulthood.
UC Irvine researchers today will tell American Heart Assn. conferees in Dallas that the sedentary lifestyle and junk-food eating habits of such young TV addicts bodes poorly for a healthy adult heart.
"Watching two hours or more of TV daily turned out to be a stronger predictor of elevated cholesterol in children than any other factor we looked at," said Dr. Kurt V. Gold, a pediatric resident at UCI Medical Center in Orange.
In a study of 1,066 mostly Anglo children and adolescents, UCI researchers found that 88 had blood cholesterol levels of at least 200 milligrams, and 53% of them watched television an average of two or more hours a day. Those who watched television four or more hours a day were nearly four times as likely to have high cholesterol.
The researchers found about 140 children who had cholesterol levels of 175 to 199 milligrams, and a third of those also watched TV two or more hours a day.
A level of 240 milligrams is considered dangerous in adults. And the American Academy of Pediatrics advises dietary counseling for any child with cholesterol levels of 175 milligrams or above.
Participants in the study, ranging in age from 2 to 20, were mostly middle- and upper-middle-class children from Orange County. The data was collected by seven groups of Orange County pediatricians from early 1989 through mid-1990, according to Nathan Wong, a UCI epidemiologist who supervised the data analysis.
There is ongoing debate among medical experts whether lowering cholesterol levels in adults significantly decreases the risk of cardiac disease. And there is concern among physicians about the advisability of switching youngsters to a low-cholesterol diet during their growth years.
"A high blood cholesterol in and of itself does not necessarily predict that youngsters will go on to join that class of adults with high blood cholesterol or heart disease," said Dr. Ronald E. Kleinman, associate professor of pediatrics at Harvard Medical School and chairman of the academy's committee on nutrition.
But according to pediatrician William H. Dietz, director of clinical nutrition at the Boston Floating Hospital of the New England Medical Center: "A good case can be made that high cholesterol levels in children are a risk factor for cardiovascular disease in adulthood, although the evidence is circumstantial."
Dietz, whose 1985 study demonstrated the correlation between television and obesity in children, called the UCI study "significant because it's the second cardiovascular risk factor to be linked to TV viewing.
"What it means is that TV viewing is clearly a marker for both nutritional and behavioral practices that are likely to contribute to high cholesterol levels in children."
Participating pediatricians tested children for cholesterol levels and asked their parents to respond to questions about dietary and exercise habits, as well as the average number of hours their child watched television.
"What we found is that those kids who watched fewer hours of television were more likely to also participate in continuous physical activity and have better dietary habits," Wong said. "The kids who watched more TV tended to have more unhealthy dietary habits, including things like not removing chicken skin or eating high-fat food."
Co-researcher and pediatrician Dr. Paul Y. Qaqundah, who provided most of the patients for the survey, noted that the American Academy of Pediatrics recommendation called for screening of cholesterol levels in children only when there was a family history of heart disease or high cholesterol.
In previous surveys, Qaqundah said, "We found that only a third of children with high cholesterol levels had a history in their families (of coronary disease)."
For that reason, he and his fellow researchers believe that television viewing habits--and the sedentary lifestyle it implies--should be a risk factor doctors take into account.
"We have always said that the TV screen does not give you high cholesterol," Qaqundah said. "It's the inactivity that can lead to it."
Cholesterol tests are now available in grocery stores, pharmacies and shopping malls. But parents should not draw conclusions about their child's health without consulting a physician, Qaqundah warned. If a child's diet is changed without medical supervision, it can be especially harmful.
"We have to be balanced," he said. "We cannot be raising underdeveloped kids. We want healthy kids."
He said an average child's diet should be limited to 30% fats and should include fruits, vegetables, greens, poultry and some fish.
The bottom line is sensible diet and exercise from the cradle is the way to prevent heart disease, Gold said. "We've got to begin with the kids."
High Cholesterol and TV Viewing
(Chance of having a cholesterol level of 200 milligrams or higher.)
Hours of television watched (When compared to children who watch TV less than two hours a day.)
2-4 hours/day: 1.9%
More than 4 hours/day: 3.9%