While considerable effort has been put toward understanding the environmental impact of a food or diet, nutritional effects are not usually considered in food-related life cycle assessment (LCA). To address this, researcher Katerian Stylianou of the University of Michigan and colleagues have 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).

They have 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. They also investigated two replacement scenarios where a serving of fluid milk was substituted for 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 researchers reported in an abstract prepared for the late breaking research session at the Joint Annual Meeting for the American Society of Animal Scientists and American Dairy Science Assn. in Orlando, Fla., July 12.

The work 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.

The researchers said further testing of this CONE-LCA approach to other food items is recommended to characterize potential trade-offs between environmental and nutritional impacts when making recommendations about sustainable diets and food choices.