By Margot Sanger Katz, New York Times

For the first time in over a decade, the death rate in the United States is rising, the Centers for Disease Control and Prevention has reported. The news is the latest in a string of headlines about the shortening lives of Americans, particularly the white middle-aged: “Disparity in Life Spans of the Rich and the Poor Is Growing.” “White Americans Are Dying Younger as Drug and Alcohol Abuse Rises.” “U.S. Suicide Rate Surges to a 30-Year High.”

But there are happier trends that have received a lot less attention: The health of American children is improving sharply, and the health gap between the rich and the poor among children and young adults is shrinking. The research suggests that future generations of Americans may not reach old age with the same ailments and inequalities as today’s older Americans.

Death rates among children always tend to be low, but the new data show large reductions in the number of American children who die. The mortality rate for children has declined by 52 deaths per 100,000 children between 1990 and 2010, according to new research in Science. To put that in context, the recently reported rise in suicides was an increase of fewer than three per 100,000 people. And the death rates fell faster for children living in the poorest counties in the country.

The good news for children suggests that it is possible that today’s distressing trends can be stopped, or even reversed. A growing body of evidence indicates that good health early in childhood can pay dividends later in life. That means that today’s children and young adults may enjoy longer lives and fewer health problems than their parents.

There are also new signs that public policy can help reduce inequality in the health of rich and poor Americans. A gulf between the life spans of rich and poor Americans who have reached middle age is widening. But, among children, the gap is narrowing substantially. If those trends hold, income level may turn out to be less predictive of life span than the studies of adults suggest.

“We know there’s a relationship between economic inequality and health, but it’s not a completely mechanical relationship,” said Janet Currie, an economics professor and the director of the Center for Health and Well-Being at Princeton University, who conducted two recent studies on the reduced death rates among American children. “There are things we can do to make the health of poor people better. And we actually have done a lot of these things very successfully, and no one is talking about it.”

Currie can’t be sure what precise factors have led to the reductions in death rates for poor young Americans, but she has some theories. Public health insurance, through the Medicaid and Children’s Health Insurance programs, expanded to cover more children and pregnant women throughout the 1980s and 1990s. Research has shown measurable benefits to the children with access to the program: There was less infant mortality; they were hospitalized less often as they grew older; they were more likely to finish high school and attend college; and they earned more money in early adulthood.

“It’s very encouraging to see that these improvements are happening at younger ages,” said Laura Wherry, an assistant professor of health services research at UCLA, who has studied the long-term health benefits of Medicaid expansion.

Recent public health interventions may also be giving poor children a health boost. We have known for decades that smoking is bad for people’s health, but richer Americans were quicker to quit than their poorer neighbors. That means that poorer, older Americans are more likely to have smoked at some time in their life, and probably had more exposure to secondhand smoke from their parents when they were young. As smoking rates have declined among lower-income groups, and fewer parents smoke around their children, the poor may see benefits from having less lifetime exposure to smoke.

The largest mortality declines were for black boys. The paper (pdf) documenting the reductions, published by the National Bureau of Economic Research, called the change in death rates for African-American boys and men “stunning declines.” Research on more recent mortality trends shows continued reductions in death rates among black Americans since 2010.

To examine how childhood mortality trends were affected by family income, Currie and her co-author, Hannes Schwandt, an assistant professor of economics at the University of Zurich, looked at the counties in the United States with the greatest concentrations of poor and rich children. By examining the rates that children died in those places over time, they were able to infer differences in the death rates of children at different places on the economic ladder.

If American children are growing up with less exposure to cigarettes and other environmental toxins, it is possible they will remain healthier than their parents, even as they get older. Currie said there was reason for optimism that current life expectancy estimates undercounted the health today’s children might enjoy as adults.

There are reasons for caution, too. Obesity rates among children and young adults are much higher than they were a generation ago. Obese children will be at higher risk for a range of ailments as they age, particularly heart disease.

David Cutler, a health economist at Harvard University who worked on the study of older Americans, said the research on children was heartening. He also pointed to his own recent research on the elderly, which showed declines in deaths from heart disease and in disability from blindness. The medical system and expanded social services may be making big improvements for young and old, he said. But he still worries about today’s middle-aged Americans, whose rates of suicide, drug overdose and alcohol-related deaths have been rising. Those are causes of death that may be less sensitive to health care interventions.

“The social part is the part that scares me,” he said.

To Learn More:

Mortality Inequality: The Good News from a County-Level Approach (by Janet Currie, Hannes Schwandt, National Bureau of Economic Research) (pdf)

U.S. Has Highest Mortality Rate for Newborns of any Industrialized Country (by Noel Brinkerhoff and Danny Biederman, AllGov)

More Kids Are Living in Poverty and Exposed to Air Pollution (by Matt Bewig, AllGov)

Cancer Rates Down for Adults, Up for Children (by Ken Broder, AllGov California)