Comprehensive Assessment of Human Health Impacts and Benefits of Fruits and Vegetables in a LCA Context

Abstract

Nutritional effects from the 'use stage' of the life cycle of food products can have a substantial effect on human health; yet, they are often not considered in life cycle assessment (LCA). In this study we explore the trade-offs between environmental and nutritional health effects associated with increased consumption of fruits and vegetables in the US diet.We employ the Combined Nutritional and Environmental Life Cycle Assessment (CONE-LCA) framework that compares environmental and nutritional effects of foods in a common endpoint metric, Disability Adjusted Life Years (DALY). Starting from one serving of 161 g fruits and 123 g vegetables as functional unit (FU), associated life cycle emissions, e.g. greenhouse gases and particulate matter (PM) precursors, and intake of pesticide residues in food are linked to health impacts in DALY/FU. Global warming and PM human health impacts are assessed following a traditional LCA approach. For PM, we couple emissions with an epidemiology-based dose-response to estimate impacts. For pesticide residues exposure, we use publically available health impacts derived by combining exposure modelling of pesticide residue with toxicological studies for numerous pesticide active ingredients. The nutritional assessment is based on effect factors estimated using the 2010 health burden attributable to corresponding dietary risk factors in DALY from the global burden of disease (GBD) and daily consumption food consumption based on the National Health and Nutrition Examination Survey (NHANES) 2009-2012.One fruits serving is linked to 0.07 g PM2.5-eq (0.03 g PM2.5-eq/servingvegetables, Figure 1), 40% due to NH3 as PM precursor, corresponding to 0.08 mu DALY (0.03 mu DALY/servingvegetables). From a nutritional perspective, adding one serving of fruits to the average US diet could result in an avoided health impact of 19.0 mu DALY (respective avoided impact for vegetables: 5.25 mu DALY). Overall, adding one fruits serving to the average US diet may lead to substantial health benefits: nutrition-related avoided impact (benefit) is 50 times higher than environmental health impacts (Figure 2). The benefit is slightly enhanced when increased fruit intake is substituted by food associated with adverse health outcomes, such as trans-fat and red meat, with the benefit mainly linked to avoided nutritional health impact. Benefits exceed impacts even when considering an uncertainty factor of 400 for the impacts due to pesticide residues for the increased fruit consumption scenario but not for the increased vegetable consumption scenario.THE CONE-LCA framework enables the comparison of environmental and nutritional impacts and benefits of food items on human health using a common metric. The preliminary results of this case study indicate the importance of considering nutritional effects in food-LCA and suggest that nutritional health effects of food items, and specifically of fruits and vegetables, can be substantial compared to environmental impacts. This approach could be extended to other human health impacts (e.g. water use) and used in making sustainable diets decisions.[GRAPHICS]