Abstract #LB6

# LB6
A life cycle assessment framework combining nutritional and environmental health impacts of diet: A case study on milk.
Katerina Stylianou1, Martin Heller2, Victor Fulgoni3, Ying Wang*4, Gregory Keoleian2, Olivier Jolliet1, 1Environmental Health Sciences, School of Public Health, University of Michigan, Ann Arbor, MI, 2Center for Sustainable Systems, School of Natural Resources and Environment, University of Michigan, Ann Arbor, MI, 3Nutrition Impact LLC, Battle Creek, MI, 4Innovation Center for US Dairy, Rosemont, IL.

While there is considerable effort to understand the environmental impact of a food or diet, nutritional effects are not usually considered in food-related life cycle assessment (LCA). To address this, we developed a novel Combined Nutritional and Environmental Life Cycle Assessment (CONE-LCA) framework that evaluates and compares in a parallel manner environmental and nutritional effects of food items or diets expressed in disability-adjusted life years (DALYs). We applied this framework in a proof-of-concept case study to investigate the environmental and nutritional human health effects associated with the addition of one serving of fluid milk to the present American adult diet. We also investigated 2 replacement scenarios where a serving of fluid milk is substituting an isocaloric portion of the average diet and sugar-sweetened beverages (SSB). Epidemiologically based nutritional impacts and benefits linked to milk intake were compared with several environmental impacts considered in LCA (global warming and particulate matter), carried to a human health endpoint. Given the evidence considered, a fluid milk consumption increase by a serving led to an overall health benefit; nutritional benefits from consumption exceed the environmental impact from production also expressed in µDALY/person/day by close to a factor 2.5. This factor was increased to nearly a factor of 5 when substitution of the average diet, and up to close to a factor 10 SSB were substituted. The initial analysis of uncertainty of the case study suggested that present findings are only suggestive; refined impact assessment factors and the inclusion of additional nutritional and environmental categories are needed to improve certainty. This case study provides the first quantitative epidemiological-based estimate of the complements and trade-offs between nutrition and environment human health burden expressed in DALYs, pioneering a new approach in LCA. We recommend further testing of this CONE-LCA approach to other food items, to characterize potential trade-offs between environmental and nutritional impacts when making recommendations about sustainable diets and food choices.