Stunting: concept, causes, consequences, and cure: PLOS Medicine 15th Anniversary
As part of the 15th Anniversary celebration, Specialty Consulting Editor Lars Åke Persson discusses PLOS Medicine‘s impact in the field of maternal and child health, highlighting a pair of research articles on stunting.
As parents and workers in child health, we look at the child and feel happy when it is growing well. In Europe and elsewhere, parents put marks on the child’s bedroom wall: now the child has reached this height! In Somalia, mothers tie a string around the child’s belly: if it loosens and slides down, the child is not growing well. At child health clinics globally, growth is monitored and plotted on the road-to-health charts. If we notice deviations, we worry and ask ourselves: What could be the causes, what shall we do?
In the current Sustainable Development Goal era, ambitious global nutrition goals have been set. One of these targets set by the World Health Assembly is to reduce stunting among children less than five years by 40% by 2025. WHO defines stunting as the impaired growth and development that children experience from poor nutrition, repeated infection, and inadequate psychosocial stimulation. Children are stunted if their height-for-age is less than -2 standard deviations of the WHO Child Growth reference. The total number of stunted children in the world has decreased, but still, 150 million children below the age of five years are stunted. This number is just a fraction of the number of children who are slowing down their linear growth due to different causes.
A few years ago, PLOS Medicine published a paper by Goodarz Danaei and colleagues on risk factors for childhood stunting in 137 low- and middle-income countries. A slowing down of growth as early as the fetal stage and harsh environmental conditions were the leading risk factors for stunting in that extensive analysis. In another PLOS Medicine research report based on the Malnutrition and Enteric Disease Study (MAL-ED) birth cohort, the authors reported similar findings. Factors leading to stunting are established early in life. The findings in these two reports are not unique. There is a consensus that the causes of stunted growth are primarily found early in life or even before conception. Conditions and environment of the girl who later becomes a mother are central. The counting of stunted children thus summarizes the quality of early life and environmental conditions of children. This understanding only partly matches the description of stunting by the WHO.
Stunted growth in childhood is associated with several short- and long-term health and social conditions. A child with restricted linear growth may also have an impaired defense against infections. A girl with stunted growth may as an adult pregnant woman have difficulties at the time of childbirth. But some of these associated long-term conditions such as cognitive development, productivity, and adult health may be statistical associations without a causal relationship, as recently pointed out. Stunting does not cause some of these conditions, which share the same root causes with stunting.
What actions are needed so that we reach the goal of 40% reduction of stunting by 2025? Still, promotion of breastfeeding, complementary feeding, and measures against child infections dominate. All these are very much needed for child health and survival, but have very small or no effects on stunting. Actions are required to promote the health and nutrition of adolescent girls. The first pregnancy frequently comes too early. Prenatal nutrition in food-insecure situations, and other pre-pregnancy or early pregnancy interventions are needed. In the Danaei paper, the authors conclude: “Reducing the burden of stunting requires a paradigm shift from interventions focusing solely on children and infants to those that reach mothers and families and improve their living environment and nutrition.”
The current focus on stunted growth in children has got global attention, targets have been set, and resources for nutrition have been mobilized. The mismatch between evidence and action to prevent stunting creates a risk: there may be a backlash when programs to reduce stunting result in no effect on stunting prevalence. There is a need for specificity in nutrition interventions. The efforts to promote optimal infant and child feeding are needed for disease prevention and thriving and should not be evaluated by monitoring of stunting. Prevention of stunting requites a multi-generational perspective, multisectoral action, and a shift of emphasis to early life and environmental conditions. Addressing the root causes of stunting could also decrease the risk of some of the long-term problems, which share the same root causes with the stunting problem.
Lars Åke Persson is pediatrician and epidemiologist with a focus on global child health and work experiences from a number of African and Asian countries. Earlier Director, Public Health Sciences Division, International Centre for Diarrheal Disease Research, Bangladesh, and Professor of International Child Health at Uppsala University. From 2016 Professor of Public Health Evaluation at London School of Hygiene & Tropical Medicine and based at the Ethiopian Public Health Institute, Addis Ababa. His research focuses community-based interventions for child health and survival, prenatal nutrition interventions and short- and long-term effects, and social conditions in family and society and effects on child health. He is also a Specialty Consulting Editor for PLOS Medicine.
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