The seeds of vulnerability to asthma, heart disease and other chronic adult health problems are planted early in life, according to a study published online today in the American Journal of Public Health.
The study is the first known to assess the long-term health impact of low birth weight and socioeconomic disadvantage using a nationally representative sample of children.
Information on the 4,387 children in the study was first collected in 1968 as part of the Panel Study of Income Dynamics. They were followed for four decades, until 2007 when they were between 39- and 56-years-old.
"Our study shows that interventions and policies that promote early childhood health and reduce childhood socioeconomic disadvantage generate immediate gains in well-being that can justify their existence," said Robert Schoeni, an economist at the University of Michigan who co-authored the study with Rucker Johnson at the University of California, Berkeley.
For the study, the authors defined low birth weight as under 5.5 pounds. They found that low birth- weight children were much more likely to have asthma, hypertension, diabetes, stroke, heart attack, and heart disease as adults.
Nearly 26 percent of study participants who weighed under 5.5 pounds when they were born had asthma at age 50, compared with only about 16 percent of those who weighed more at birth. Even within families and after controlling for general health in childhood, the effect of birth weight was pronounced.
Those who grew up in poverty were also more likely to have one of these fatal, debilitating conditions by age 50.
The current findings support a growing body of evidence on the impact of early life factors in the development of later life health and disease risk.