by Jaya Patel – 

Our current agricultural system is unsustainable. Food production releases at least 25% of greenhouse gases¹, contributing to climate change – an issue which threatens global food security. Not only do our diets harm the environment, but also human health. An article published in “Trends in Plant Science” explores how to approach these issues using a range of solutions².

Plant-based foods have a smaller environmental impact than animal products². The article describes how shifting diets away from animal-source foods will reduce both our resource consumption and carbon footprint. For example, greenhouse gas emissions approximately half when comparing the diet of a medium meat eater to one which includes no animal products³. In addition, this shift would benefit human health, potentially reducing global mortality by 6-10%⁴. However, in order to do this, we need government policies that encourage healthy and sustainable diets.

Another area of food security the article considers is nutrition – micronutrient deficiency is a global problem⁵. Modern food production has focused on high yield crops, leading to a decline in agricultural (and dietary) diversity. Currently, 95% of the world’s calories come from only 30 species⁵. Therefore, it is important to promote crop biodiversity and micronutrient enhancement (which involves breeding crops with the best nutritional quality). One example of this is quality protein maize (QPM), which is used in countries across Africa, South America and Asia. Evidence shows that the rate of growth in height in malnourished young children increased by 9% as a result of QPM consumption⁶. The use of enhanced crops could be an effective way of tackling malnourishment- however, there are some issues restricting this which must be addressed, such as a lack of seed availability and public awareness².

The article also outlines how agriculture can deal with climate change and improve food security. Evolutionary breeding is a technique which helps increase crop diversity through natural selection⁷. Only the plants best adapted to the climatic conditions will survive, creating a resilient evolutionary population (EP) able to cope with extreme weather that may occur. This approach could even have wider benefits, as it has been reported that EPs have produced high yields and been less affected by disease and insect damage, meaning less pesticide is required (Salimi et al, 2014 cited in Sangam et al, 2017). A more advanced technique, called genomic assisted breeding, allows the selection of specific traits in the development of stress-resilient crops². One example of this is submergence- and salt- tolerant rice used across Asia⁸ (see fig 1). However, the multinational companies producing such crops can restrict farmers access to seeds², so strengthening food security must also involve improving seed accessibility.

The key idea presented in the article is that agriculture, human health, and nutrition are interconnected, so they must be approached together. Diversifying our food system should be prioritised, to improve both food security and human health, alongside various plant breeding programmes to improve crop resilience as the climate changes.

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References

1. Tilman, D., Clark, M (2014). Global diets link environmental sustainability and human health. Nature, 515,518–522.
2. Sangam, D., et al. (2017). Diversifying Food Systems in the Pursuit of Sustainable Food Production and Healthy Diets. Trends in Plant Science, 22, 842-856.
3. Scarborough, P., et al. (2014). Dietary greenhouse gas emissions of meat-eaters, fish-eaters, vegetarians and vegans in the UK. Climatic Change, 125, 179-192.
4. Springmann, M., et al. (2016). Analysis and valuation of the health and climate change cobenefits of dietary change. PNAS, 113, 4146-4151.
5. Romanelli, C., et al. (2015). Connecting global priorities: biodiversity and human health: a state of knowledge review. Geneva: WHO.
6. Gunaratna, N., et al. (2010). A meta-analysis of community-based studies on quality protein maize. Food Policy, 35, 202-210.
7. Döring, T., et al. (2011). Evolutionary Plant Breeding in Cereals—Into a New Era. Sustainability, 3, 1944-1971.
8. Bailey-Serres, J., et al. (2010). Submergence Tolerant Rice: SUB1’s Journey from Landrace to Modern Cultivar. Springer Open, 3, 138–147.