Environmental, nutritional and social assessment of nuts

Abstract

Nuts are considered an important protein source in sustainable dietary patterns but are seldom studied in detail. Here a multi-criteria decision analysis was used to rank 10 nuts and seeds against 11 environmental, nutritional, and social criteria and provide greater insight into the sustainability impacts of this food group. Weights were defined based on correlation and variance between indicator values, and values were aggregated with a partially non-compensatory method. Several sensitivity analyses tested various sources of uncertainty through the use of country-level data, the use of a fully compensatory aggregation method, and changes to criteria weights. Walnuts and sunflower seeds performed consistently well across sustainability criteria and were ranked in the top two positions in the baseline assessment and most sensitivity analyses. In contrast, cashews performed relatively poorly across most criteria, and were ranked last. Dietary shifts in favor of more sustainable nuts can improve the overall environmental, nutritional and social impacts of nut production and consumption by an average of 23%. Although increasing consumption of walnuts and sunflower seeds may lead to improved sustainability outcomes for total global nut consumption, more research is needed to deepen the understanding of the complex socio-economic factors impacting nut and seed sustainability. The social risk assessment method used in this study can also inform future social impact measurement methods for other food groups.