Key crops eaten by a large portion of the world’s population have lower levels of zinc and iron when grown at the elevated carbon dioxide levels that scientists predict will occur by the middle of the century, according to a new study.
The research, detailed in this week’s issue of the journal Nature, found that wheat, rice and soybeans grown in high carbon dioxide conditions have lower levels of these important nutrients. The finding has major global health implications, as nearly 2 billion people around the world receive 70 percent or more of their dietary zinc and iron from these types of crops.
“Zinc deficiency can cause child mortality from infectious diseases because the immune system is not functioning properly, and iron deficiency can cause maternal mortality and reductions in IQ and work productivity, and increased mortality from infectious diseases,” said the study's first author Samuel Myers, a researcher at the Harvard School of Public Health in Boston.
Howard Frumkin, dean and professor of environmental and occupational health sciences at the University of Washington, in Seattle, said the new study provides the strongest evidence to date that climate change could threaten the nutritional value of foods with respect to zinc and iron.