CO₂ makes crops less nutritious

RISING carbon dioxide levels may increase future crop yields but there is a catch: food will be less nutritious.

We already know that wheat exposed to higher CO₂ has a lower protein content. To see whether it affects concentrations of trace elements and toxins, Petra Högy from the University of Hohenheim in Germany and colleagues grew wheat under CO₂ concentrations expected by 2050. The team found an 8 per cent drop in iron and a 14 per cent increase in lead (Plant Biology, DOI: 10.1111/j.1438-8677.2009.00230.x). On the upside, levels of the heavy metal cadmium dropped…