Chinese scientists use genetics to boost iron content of corn, offer hope to anaemia sufferers worldwide

Gene-based method can more than double the iron content compared to existing corn varieties, team behind study published in Science says
Iron deficiency, the most common cause of anaemia, affects more than 40 per cent of children under five and a third of expectant mothers globally

Science

Holly Chik

Published: 6:30pm, 10 Dec 2023

Why you can trust SCMP

A new method to boost the iron content of corn could potentially address deficiencies of the essential mineral worldwide, Chinese scientists behind the development said.

The fortified grain was being grown in trials in the central province of Henan, offering hope for high-yield, iron-rich future harvests, state broadcaster CCTV reported on Sunday.

According to the researchers, their gene-based method helped to increase the iron content of corn kernels to 70.5 mg per kg, or more than double that of existing varieties.

The team from the Institute of Crop Sciences at the Chinese Academy of Agricultural Science and Henan Agricultural University published their findings in the peer-reviewed journal Science last week.

Iron is a key nutrient for development and cell growth in the immune and neural systems, as well as in regulating energy metabolism. The US National Institutes of Health recommends that men take 8mg and women 18mg of iron daily.

Iron deficiency is the most common cause of anaemia, a condition when the body does not have enough healthy red blood cells. It can result from inadequate intake of dietary iron, increased need during periods of growth and blood loss from parasitic worm infection or menstruation in adolescence.

US-China joint study challenges corn origins theory

The World Health Organization estimates that about 40 per cent of children aged between six months and five years are anaemic, as are more than one-third of expectant mothers and 30 per cent of females aged between 15 and 49 years.

It recommends industrial fortification of staple foods like corn with iron, highlighting that this has been done for years in several countries in the Americas and Africa where corn is a major part of the diet.

In the recently published study, the Chinese team identified a gene that regulates iron concentrations in corn kernels, and found that increasing its expression levels raised the iron content. Gene expression is the process by which information stored in DNA directs the formation of cells.

Lead author Li Wenxue, head of corn molecular breeding research at the Institute of Crop Sciences, said the team had been able to load iron into the corn kernels without compromising yield, thereby solving a long-standing problem.

“Taking iron supplements is a feasible solution [for deficiencies] but the cost is quite high,” an institute statement quoted Li as saying.

“Boosting the iron content of daily crops could fundamentally improve the iron nutritional status of a wide population at a low cost, which is of particular significance to developing countries where corn is the staple food.”

International surveys show corn is the third most consumed staple food in the world, after rice and wheat.

A study published last year in the Food Security journal said while people in 161 countries ate corn, this was much more common in low and lower-middle income countries and in Africa.

People ate more than 50kg (110lbs) of corn each in nine countries in eastern and southern Africa every year, as well as seven others in South America, the researchers found.