More than a third of children under five suffer from stunting in the country

Adding zinc to farmland soil can help prevent childhood stunting -- a condition due to chronic undernutrition -- in India, according to a study.

Chronic undernutrition is associated with poor brain development and long-lasting harmful consequences, such as reduced school performance and increased disease risks, the researchers said.

The study, published recently in the journal Scientific Reports, is the first large-scale research to examine the association between children's nutritional status or health outcomes and soil mineral availability in India, where more than a third of children under five suffer from stunting.

"Our results add to a growing body of literature suggesting that interventions like micronutrient-enriched fertilisers may have a positive effect on health," said study lead author Claire Morton, an undergraduate student in mathematics and computational science at Stanford University, US.

"This doesn't prove that those interventions would be cost-effective for India, but it's an exciting indication that they are worth testing," Morton said.

The researchers analysed health data from nearly 3 lakh children and one million women across India with over 27 million soil tests drawn from a nationwide soil health programme.

They found that that the presence of zinc in soil helps prevent stunted childhood growth, and iron in soil helps keep hemoglobin—a protein in red blood cells that carries oxygen—at healthy levels.

The results suggest that fortifying soil with minerals could be a beneficial health intervention, the researchers said.

The link between soil zinc and childhood stunting is particularly robust—a one standard deviation increase in satisfactory soil zinc tests is associated with approximately 11 fewer children stunted per 1,000, according to the study.

The researchers suggest that the potential benefits of using zinc-enriched fertilizers as health interventions deserves more consideration in India specifically and perhaps more generally.

"We're not saying that geography is destiny, but soils really do seem to play a role in shaping child health," said study senior author David Lobell, a professor of Earth system science in the Stanford Doerr School of Sustainability.

"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," Lobell added.