High level of CO2 responsible for zinc deficiency, finds study

The study, titled ‘Inadequate zinc intake in India: Past, present and future’ conducted by the Harvard T H Chan School of Public Health, concentrated mainly on the southern States with rice-dominated diet – Tamil Nadu, Andhra Pradesh and Kerala. It revealed that the increased levels of CO2 can reduce the levels of zinc in the crop.

The study aimed at assessing the historical prevalence of inadequate zinc intake in the Indian States and the future prevalence of the same with an increase in the level of carbon dioxide.

“The increase in CO2 level boosts the CO2 release from soil, which reduces the zinc density in soil. In Tamil Nadu, zinc sulphate is required to make up for the zinc deficiency in rice crop. As zinc concentration is low in soil, grains too have a low concentration of zinc. Consuming these zinc deficient crops causes a zinc deficiency in infants in Tamil Nadu,” said Senthil Kumar, professor at Tamil Nadu Agricultural University.

The study found that the prevalence of inadequate absorbable zinc intake has increased from 17.1 per cent in 1983 to 24.6 per cent in 2011-12. “National grain fortification programmes, increased dietary diversity, bio-fortified crops and reduced CO2 emissions could all make a difference to slow or reverse the course,” it noted.

The study suggested the current total amount of grain consumption should be maintained to improve the current and future trends in the risk of inadequate zinc intakes. However, more coarse cereals like millets, sorghum and major grains such as rice and wheat should be consumed.

“Coarse cereals tend to have a higher zinc density than the widely-consumed grains, especially rice. Moreover, coarse cereals show no response to increasing CO2 concentrations, contrary to rice and wheat crops,” said Dr S Bhuvaneshwari, dietician, Apollo Hospitals.

“Zinc is required in the body to make proteins and genetic material of the cells, especially for the development of infants and pregnant women. Its deficiency can cause health problems such as diarrhoeal diseases, pneumonia and low immunity. People in Tamil Nadu rely mainly on rice diet, which is poor in zinc, and thus causes deficiency,” said Dr Mohan Kumar, consultant paediatrician, Institute of Child Health.