Childhood stunting is linked with low zinc levels in soil

Over two billion people worldwide are micronutrient deficient, impacting learning, IQ, motor skills, and immune system function. Zinc deficiency, particularly in children under five, caused 116,000 deaths globally 2011. Rising CO2 levels may cause 175 million more people to be zinc deficient by 2050. In developing countries, many populations are at greater risk for mineral deficiencies due to low bioavailable mineral concentrations in crops. 

Researchers from Stanford University found that adding zinc to farming soil can help prevent childhood stunting, a condition due to chronic undernutrition linked to impaired brain development and long-term adverse effects, including reduced academic achievement and an increased risk of disease.

This is the first study to examine the relationship between children’s nutritional status and soil mineral availability in India, where stunting affects more than a third of children under 5.

The researchers used over 27 million soil tests from a large-scale soil health initiative to assess health information from over 300,000 children and 1 million women throughout India. They found that zinc in the soil helps prevent stunted childhood growth, and iron helps keep hemoglobin at healthy levels. The results show that adding minerals to soil might be a healthy intervention.

The link between soil zinc and childhood stunting is particularly robust, with a one standard deviation increase in satisfactory soil zinc tests associated with approximately 11 fewer children stunted per 1,000. In India. Health interventions with zinc-enriched fertilizers deserve more consideration.

Study lead author Claire Morton, an undergraduate in mathematics and computational science at Stanford University, said, “Our results add to a growing body of literature suggesting that interventions like micronutrient-enriched fertilizers may positively affect health. This doesn’t prove that those interventions would be cost-effective for India. However, it’s an exciting indication that they are worth testing.”

The result shows that low soil zinc availability is associated with childhood stunting.

Study senior author David Lobell, the Gloria and Richard Kushel Director of Stanford’s Center on Food Security and the Environment and professor of Earth system science in the Stanford Doerr School of Sustainability, said, “Even if this is only a small role, understanding it could help to identify better approaches to solving child stunting in India, which is one of the single biggest and longstanding challenges in global food security.”

The researchers conclude that further study is needed in India, specifically and globally, to fully understand the potential advantages of using zinc-enriched fertilizers as health interventions.

The Stanford Sustainability and Earth Summer Undergraduate Research program and the Stanford King Center on Global Development funded the study.

Journal Reference:

1. Claire M. Morton, David B. Lobell, et al.Soil micronutrients linked to human health in India. Scientific Reports. DOI: 10.1038/s41598-023-39084-8