A Scoping Review of the Environmental Impacts and Nutrient Composition of Plant-Based Milks

Dairy milk is a ubiquitous nutrient-dense beverage and ingredient, especially in Western diets. However, consumers are increasingly seeking alternatives to dairy, called plant-based milks (PBMs), to avoid allergens, pursue a plant-based diet, or reduce their environmental impacts. The base ingredients used in PBMs have a wide range of environmental impacts, which may translate to substantial variation across the impacts associated with PBMs themselves. To assess the state of the literature on this topic, we performed a scoping review of the environmental impacts of PBMs, following the guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for scoping reviews. Recent growth in the variety of PBMs available means that there is unlikely yet enough data for conclusive statements regarding environmental impacts of all PBM types, which makes this topic appropriate for a scoping review. We included all relevant documents found through searching scholarly databases. We found 20 studies covering 6 types of PBMs, but the literature does not examine many other types of PBMs. All studies examined use the life cycle assessment methodology. The most data regarding environmental impacts were available for soy- and almond-based milks, and the most common impact quantified was greenhouse gas emissions. We also examined the nutrient composition of PBMs compared with dairy using data from the USDA. PBMs attempt to replicate the organoleptic properties of dairy but often do not exactly match the nutrient profile of dairy. We identified a need for the application of a standardized methodology to facilitate more comprehensive assessment of environmental impacts of the wide variety of PBMs available, which are presented as environmentally preferable to dairy.