Dramatically increased rates of chronic diseases among children could indicate a future strain on the country's social welfare system, a recent article in the Journal of the American Medical Association reported.

The study, co-authored by Harvard School of Public Health Professor Steven L. Gortmaker, examined rates of asthma, obesity, and attention deficit hyperactivity disorder (ADHD) in young children and explored both the causes and long-term effects of these ailments.

"We were looking for some common ideologies that are driving these conditions," Gortmaker said. "That's the most innovative part of the paper."

Gortmaker has studied chronic diseases for the entirety of his academic career, beginning with his first assistant professorship 30 years ago.

"At that time, asthma was pretty well defined," he said. "But ADHD was not as well defined, and obesity was not really recognized as a major health problem."

Gortmaker published his first paper documenting the increases in childhood obesity about 20 years ago, and he wrote about the growing rate of asthma in children in the mid-1990s.

For this recent paper, he and his associates examined genetic, birth-related, dietary, environmental, and cultural factors that can lead to greater risk of these chronic conditions in children.

And though they found that many cases are not immediately treatable due to genetic predisposition and similar causes, increased physical activity and a healthier diet beginning in childhood can prevent a substantial number of these chronic illnesses.

Gortmaker warned that a young child's susceptibility to advertising can make television media a strong adversary for parents trying to keep their kids healthy.

"Market tactics keep changing," Gortmaker said. "For example, most parents now tend to think their kids need a sports drink. Even more recently there's Vitamin Water, which is a ridiculous product."

He pointed to these "sugar waters" as one of the primary instances of excessive calorie consumption among children and young adults.

"Communities need to get involved and say we don't need this stuff," he said.

Excessive television watching from an early age—one of the factors that Gortmaker pointed to in the paper as a potential cause for all three conditions—can also lead to higher prevalence for ADHD and even for asthma, due to decreased exposure to fresh air.

Along with the growing rates of these conditions, Gortmaker and his fellow researchers found that the rates in certain subsections of the population are quite different.

"You see growing socioeconomic disparities in terms of obesity and asthma," Gortmaker said. "And my sense is that these disparities will continue for a whole range of reasons."

It is this increasing burden on the poor that he thinks may put a strain on the country's social welfare system.

"Stemming the tide of these new epidemics," the authors state in the paper, "will likely require major shifts at multiple levels in environmental factors that have exacerbated these trends."

But Gortmaker remains pessimistic that such changes will occur in the near future.

"There isn't any reason to think that the trends will reverse themselves at any time soon," he said.

—Staff writer Nathan C. Strauss can be reached at strauss@fas.harvard.edu.