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Increasing CO2 threatens human nutrition

An Author Correction to this article was published on 01 October 2019


Dietary deficiencies of zinc and iron are a substantial global public health problem. An estimated two billion people suffer these deficiencies1, causing a loss of 63 million life-years annually2,3. Most of these people depend on C3 grains and legumes as their primary dietary source of zinc and iron. Here we report that C3 grains and legumes have lower concentrations of zinc and iron when grown under field conditions at the elevated atmospheric CO2 concentration predicted for the middle of this century. C3 crops other than legumes also have lower concentrations of protein, whereas C4 crops seem to be less affected. Differences between cultivars of a single crop suggest that breeding for decreased sensitivity to atmospheric CO2 concentration could partly address these new challenges to global health.

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Figure 1: Percentage change in nutrients at elevated [CO2] relative to ambient [CO2].
Figure 2: Percentage change (with 95% confidence intervals) in nutrients at elevated [CO2] relative to ambient [CO2], by cultivar.


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We thank L. S. De la Puente, M. Erbs, A. Fangmeier, P. Högy, M. Lieffering, R. Manderscheid, H. Pleijel and S. Prior for sharing data from their groups with us; H. Nakamura, T. Tokida, C. Zhu and S. Yoshinaga for contributions to the rice FACE project; and M. Hambidge, W. Willett, D. Schrag, K. Brown, R. Wessells, N. Fernando, J. Peerson and B. Kimball for reviews of earlier drafts or conceptual contributions to this project. V.R. thanks A. L. Harvey for her efforts in producing the phytate data included here. The National Agriculture and Food Research Organization (Japan) provided the grain samples of some rice cultivars. We thank the following for financial support of this work: the Bill & Melinda Gates Foundation; the Winslow Foundation; the Commonwealth Department of Agriculture (Australia), the International Plant Nutrition Institute, (Australia), the Grains Research and Development Corporation (Australia), the Ministry of Agriculture, Forestry and Fisheries (Japan); the National Science Foundation (NSF IOS-08-18435); USDA NIFA 2008-35100-044459; research at SoyFACE was supported by the US Department of Agriculture Agricultural Research Service; Illinois Council for Food and Agricultural Research (CFAR); Department of Energy’s Office of Science (BER) Midwestern Regional Center of the National Institute for Climatic Change Research at Michigan Technological University, under Award Number DEFC02- 06ER64158; and the National Research Initiative of Agriculture and Food Research Initiative Competitive Grants Program Grant no. 2010–65114–20343 from the USDA National Institute of Food and Agriculture. Early stages of this work received support from Harvard Catalyst | The Harvard Clinical and Translational Science Center (National Center for Research Resources and the National Center for Advancing Translational Sciences, National Institutes of Health Award 8UL1TR000170-05).

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Authors and Affiliations



S.S.M. conceived the overall project and drafted the manuscript. A.Z., I.K., J.S. and P.H. performed statistical analyses. P.H. and A.D.B.L. provided substantial input into methods descriptions. A.J.B., E.C. and V.R. analysed grain samples for nutrient content. G.F., T.H., A.D.B.L., R.L.N., M.J.O., H.S., S.S., M.T. and Y.U. conducted FACE experiments and supplied grain for analysis. N.M.H. and P.H. assisted with elements of experimental design. K.A.S. and L.H.D. assisted with data collection and analysis. All authors contributed to manuscript preparation.

Corresponding author

Correspondence to Samuel S. Myers.

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The authors declare no competing financial interests.

Extended data figures and tables

Extended Data Table 1 Percentage change in nutrient content at elevated [CO2] relative to ambient [CO2]
Extended Data Table 2 Original data combined with previously published FACE data from studies 3, 4, 6 and 7
Extended Data Table 3 Original data combined with previously published FACE and chamber data from studies 1–10
Extended Data Table 4 Percentage change in nutrient content at elevated [CO2] compared with ambient [CO2] for all nutrients
Extended Data Table 5 Countries whose populations receive at least 60% of dietary iron and/or zinc from C3 grains and legumes
Extended Data Table 6 Literature reporting nutrient changes in the edible portion of crops grown at elevated and ambient [CO2]

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Myers, S., Zanobetti, A., Kloog, I. et al. Increasing CO2 threatens human nutrition. Nature 510, 139–142 (2014).

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