A falsecolor angiogram of a healthy heart. ( Custom Medical Stock )
The proportion of American adolescents who exercise regularly, eat a healthy diet and are free of risk factors for future heart disease is "alarmingly low," says a major new survey of teen health. The comprehensive five-year assessment of teens' health status warns that the "disconcertingly high" rate of poor health habits among the nation's youth "may contribute to unacceptably high rates of adult-onset cardiovascular disease" as this cohort matures into adulthood.
The new survey, published Monday in the American Heart Assn.'s journal Circulation, culled data on teens from a yearly gauge of the nation's health called the National Health and Nutrition Examination Surveys (NHANES). From a representative sample of American adolescents--4,673 kids between the ages of 12 and 19--NHANES captured each subject's body-mass index, dietary intake details, physical activity levels, smoking behavior, blood pressure, total cholesterol and fasting blood glucose levels. Each subject was assigned a cardiovascular health index number on the basis of this mix of signposts.
In one of the study's most striking findings, virtually none of the teens surveyed ate a diet considered "ideal" from the standpoint of preventing cardiovascular disease. The ideal diet consisted of 4.5 cups of fruits and vegetables and three 1-ounce servings of whole grain daily, at least two servings of fish weekly, and less than 450 calories' worth sugar-sweetened beverages per week.
Among males, 90% followed diets that were considered "poor" and 10% had dietary habits that were considered "intermediate." Among girls, 86% had poor diets, and 14% had dietary habits considered intermediate. Boys were far likelier than girls to have poor or intermediate levels of blood pressure and fasting glucose, but girls were likelier to have less-than-ideal cholesterol readings.
Overall, Mexican American males and non-Latino black females fared most poorly in the survey. Almost half of African American girls were overweight or obese, and 60% had physical activity levels that were less than ideal. More than 40% of Mexican American boys were overweight or obese, and just as many had less-than-ideal levels of physical activity.
This all bodes poorly for the future of the nation's health, wrote the authors, who were led by Christina M. Shay of the University of Oklahoma's School of Public Health.
Though children are generally born in a "state of ideal cardiovascular health," the new study makes clear that poor habits established in childhood can powerfully redirect an individual's health trajectory. "Substantial evidence indicates that atherosclerosis has its origins in childhood," the authors of the new study assert.
In children as young as 6 years old who died of causes not related to heart disease, pathologists have detected fatty streaks in the large arteries in autopsies. By early adulthood, atherosclerosis--a narrowing of the arteries with fatty build-up--begins to turn into calcified coronary plaque. And by middle age, heart disease can be at an advanced stage.
In a "clinical perspective," the American Heart Assn. calls the prevalence of early cardiovascular risk factors "unacceptably high." The editors note that overconsumption and too little exercise have become features of the American landscape, and physicians have been unable to turn around bad habits, while insurers have done little to support preventive behavior change. Nothing short of a social movement will turn things around, they add.
"Broad social and cultural changes that infiltrate the entire population will be necessary to evoke changes in youth behaviors that will favorably influence cardiovascular health," American Heart Assn. writes.