Consequences of Under-Nutrition May be Reversible after Age 2, Study Finds.
Many experts assert that the damage children suffer if malnourished in the “1,000 day window of opportunity” — pregnancy and the first two years of life — is irreversible and cannot be offset by interventions later in childhood.
But a new study co-authored by a BU School of Public Health researcher calls that into question. The study, published online in the American Journal of Clinical Nutrition, looks at the effects of stunting, or impaired growth in height, in children.
The researchers found that children who were shorter than expected at 1 year of age were often behind in school at 8 years of age and scored lower on cognitive tests than their counterparts who had healthy heights at age 1. But children who experienced greater than expected “catch-up” growth (stunted at 1, but recovered by 8 years old) were more likely to be in age-appropriate classes at age 8 and to have higher scores on standard tests of cognition, when compared to children who remained relatively short.
The researchers concluded that “improvements in child growth after early faltering might have significant benefits on schooling and cognitive achievement.”
Study co-author Kirk Dearden, associate professor of international health and a researcher with the Center for Global Health and Development, said the findings indicate that interventions that improve nutritional status and offer early childhood stimulation—even after the first two years of life—may help to counter the effects of early stunting.
“We’re saying, ‘don’t stop after the first two years, because there’s potential for kids to catch up in growth, learning and cognition.’ Just because kids aren’t doing well in the first year or so doesn’t mean it’s over,” he said.
Dearden is the principal investigator of NIH-funded research at BUSPH that examines nutrition, schooling and cognition; the article’s first author is Benjamin Crookston of Brigham Young University.
The study examined the relationship between growth recovery and cognitive abilities among 8,000 children in Ethiopia, India, Peru and Vietnam enrolled in the “Young Lives” study. The international study is designed to evaluate connections between post-infancy nutritional status, as it relates to growth in height, and school enrollment and cognitive achievements in mathematics, reading and vocabulary.
Because malnutrition is a key factor in stunting, the authors said, their findings reinforce the need “to prevent nutritional insults in early life,” while also emphasizing the importance of promoting child growth beyond the first two years of life.
“Although early interventions are critical,” they said, “interventions to improve nutrition of preprimary and primary school–age children also merit serious consideration.”
In an editorial accompanying the study, Rafael Pérez-Escamilla of the Yale School of Public Health said the findings underscore “previous empirical evidence suggesting that the brain is a highly plastic organ with remarkable ability to improve its function even when interventions start after exposure to nutritional insults during the first 1000 days of life.”
He urged additional studies to examine the potential impacts of nutritional interventions during the 2nd and 3rd years of life and the mechanisms by which nutrition has such important long-term impacts.
Submitted by: Lisa Chedekel
Chedekel@bu.edu