Climate Change and Nutrition
by Laura M. Rosch, DO, FACOI
June 3, 2025
My master's thesis, completed at the University of Illinois in 1985, focused on iron deficiency anemia (IDA). While my research then highlighted the prevalence of IDA, I could not have foreseen the dramatic exacerbation of this nutritional deficiency due to climate change. The World Health Organization (WHO, 2015) estimates that 1.62 billion people globally suffer from IDA, disproportionately impacting women and children in low- and middle-income countries. Climate change significantly intensifies this public health crisis.
The link between IDA and climate change is multifaceted and deeply concerning. IDA stems from insufficient iron intake, impaired absorption, or heightened physiological demands, resulting in debilitating fatigue, weakness, and cognitive impairment. However, climate change fundamentally alters our food systems, diminishing both the availability and nutritional value of iron-rich foods.
Climate change's impact on agriculture is profound. Increased temperatures, erratic rainfall patterns, and extreme weather events drastically reduce crop yields, particularly affecting staple crops like legumes and whole grains, crucial sources of dietary iron. Research from the Intergovernmental Panel on Climate Change (IPCC), and studies by Porter et al. (2014) and Myers et al. (2014), demonstrate that climate change not only lowers crop yields but also reduces the iron content within these crops. Elevated atmospheric carbon dioxide levels further compound this nutritional depletion.
The consequences are particularly devastating for vulnerable populations. Climate change-induced food insecurity disproportionately affects developing nations, severely limiting access to iron-rich diets. The Food and Agriculture Organization (FAO, 2018) underscores climate change's direct threat to global food security, potentially driving millions deeper into hunger and malnutrition. In already vulnerable regions, such as sub-Saharan Africa, the combined effects of climate change amplify existing nutritional deficiencies, leading to increased IDA rates, especially among women and children already at high risk of food insecurity. This results in significantly higher maternal and infant mortality rates.
Addressing the interconnected challenges of IDA and climate change necessitates a multi-pronged approach. This includes promoting sustainable agricultural practices, strengthening food security initiatives, implementing targeted nutritional interventions, and fostering international collaboration to mitigate climate change. The human cost of inaction is unacceptable. We require a concerted and immediate global response to prevent this devastating confluence of factors from further compromising global health. Combating IDA must now explicitly account for the realities of climate change. Only through comprehensive strategies that integrate environmental sustainability with nutritional health can we effectively protect vulnerable populations from the escalating threat of IDA in our changing world.
1. World Health Organization (WHO). (2015). Worldwide prevalence of anemia 1993–2005: WHO global database on anemia. Geneva: World Health Organization.
2. Porter, J. R., Xie, L., Challinor, A. J., et al. (2014). Food security and food production systems. In *Climate Change 2014: Impacts, Adaptation, and Vulnerability*. Cambridge University Press.
3. Myers, S. S., Zanobetti, A., Kloog, I., et al. (2014). Increasing CO2 threatens human nutrition. *Nature*, 510(7503), 139-142.
4. Food and Agriculture Organization (FAO). (2018). The State of Food Security and Nutrition in the World 2018: Building climate resilience for food security and nutrition. Rome: FAO.