Plant-based alternatives are often surrounded by a sustainability halo, which can lead to a higher willingness to pay.
However, without a defined toolset of sustainability indicators to assess the category’s sustainability performance, researchers in Scandinavia are querying whether plant-based alternatives are, in fact, more sustainable.
In a new systematic scoping review, published in Nature Food, a team from Stockholm University and the University of Copenhagen has split up the performance of plant-based alternatives into three categories: environmental, nutritional, and socio-economic performance. The results are in.
Are plant-based alternatives more environmentally sustainable?
In short, yes. The researchers examined ample assessments of environmental impact factors, determining that plant-based alternatives tend to have a lower environmental impact than conventional animal-based products.
In general, they are associated with less CO2 equivalent, less water use, and less land use, as well as lower ecotoxicity, acidification, and eutrophication potential.
There were some exceptions, however. One life cycle assessment, for example, found that almond milk is more water-intense than dairy milk and has a higher environmental footprint in general when assessed on a cradle to consumer system boundary assumption.
Two studies found that the production of plant-based dairy alternatives has a higher energy demand than conventional dairy.
The researchers examined 37 papers analysing the sustainability of plant-based alternatives, predominantly looking at alt meat and alt dairy. Just two studies assessed seafood or egg alternatives.
Future studies should compare seafood analogues with conventional fish, including impact factors specific to aquatic systems such as wild stock depletion, suggest the researchers.
Is this true? Could plant-based dairy, in some respects, be less environmentally friendly than its conventional counterpart? FoodNavigator put the question to the Good Food Institute (GFI), a non-profit advocating a switch to more sustainable foods.
According to Seren Kell, GFI Europe’s science and technology manager, the paper adds to the ‘growing body’ of scientific evidence that plant-based options are better for the environment than conventional meat and dairy.
“There is extensive data showing the overall trend is that conventional dairy cause around three times more greenhouse gas emissions and uses 2-20 times more freshwater than plant-based dairy.
“On a global scale, the 13 biggest dairy companies in the world cause the same amount of GHGs as the whole of the UK. Most of these emissions are from the cows themselves in the form of methane, and according to the UN, cutting methane emissions is essential to rapidly reduce the rate of global heating.”
The suggestion here is that the alt dairy category as a whole – even if potential exceptions exist – is the more environmentally sustainable option. “Plant-based dairy – as well as animal-free dairy produced using precision fermentation – can help provide people with the milk, cheese and butter they love but with a drastically reduced environmental impact.”
Are plant-based alternatives more nutritious?
Unlike the ‘high-level’ agreement observed across relevant literature that plant-based alternatives tend to have a lower environmental impact than their conventional counterparts, the researchers were unable to find a ‘clear agreement’ for nutritional performance.
The team found plant-based alternatives generally contained lower levels of proteins, with discernible differences depending on the commodity they are based on. One study, for example, found that burger patties made out of mycoprotein contained higher protein, whereas those made from soy had lower levels of protein, compared to that of beef patties.
In terms of sodium content, levels were higher in cheese alternatives based on coconut oil compared to levels found in cheese alternatives based on cashew nuts or soy.
In general, plant-based alternatives were found to have lower contents of saturated fat, with the exception of alt cheese made from a coconut oil base, and two legume-based burger patties.
“The total nutritional performance of plant-based alternatives, assessed with nutrient profiling models, was mostly higher, or no difference was discernible,” noted the study authors.
From GFI’s perspective, like all foods – including animal-based products – plant-based meat and dairy products vary in their nutritional quality. However, as suggested by the researchers, some studies do find plant-based alternatives to have better nutritional profiles, said Kell.
A recent review of 43 studies, published in Future Foods, found plant-based products tend to have better nutritional profiles compared to animal products, we were told. One paper found 40% of conventional meat products were classified as ‘less healthy’ compared to just 14% of plant-based alternatives – based on the UK’s Nutrient Profile Model, she continued.
Further, research published in the American Journal of Clinical Nutrition has found some sustainable protein products contain higher protein levels than conventional animal products, while other papers have found plant-based foods led to improved fibre consumption and reduced cardiovascular risk factors.
“It’s also worth noting that this sector is still in its infancy- and companies are optimising their recipes to make products healthier all the time, with producers of plant-based meat and dairy able to add ingredients that boost properties such as amino acids, vitamins and antioxidants, in a way that isn’t possible with conventional meat,” Kell told this publication.
Social inequality in plant-based?
To assess the social sustainability of plant-based alternatives, the researchers examined studies assessing nutritional adequacy. Consumer acceptance, willingness to buy and pay, and product price, were assessed as economic factors.
Researchers observed a ‘distinct lack’ of studies assessing the social and economic implications of shifting towards plant-based alternatives, however. Of those that were included, findings suggest that overall, plant-based alternatives received lower consumer acceptance and were higher in cost than conventional animal-based products. This could generate the impression that a plant-based diet is more expensive and seen as a luxury, leading to social inequalities, noted the study authors.
“We synthesised research showing that consumer acceptance and willingness to pay for plant-based alternatives is currently lower than for conventional meat but could increase to the same level after information concerning health or environmental consequences is provided.”
The researchers conclude that significant gaps in research exist on certain environmental issues and social sustainability. To prevent misled investments in the future, the researchers are calling for a new sustainability assessment framework.
“Guiding transformative investments requires a more rigorous, quantitative assessment of the sustainability implications of food system technologies,” said co-author Line Gordon, professor at the Stockholm Resilience Centre at Stockholm University.
Source: Nature Food
‘A systematic scoping review of the sustainability of vertical farming, plant-based alternatives, food delivery services and blockchain in food systems’
Published 3 November 2022
DOI: https://doi.org/10.1038/s43016-022-00622-8
Authors: A. Charlotte Bunge, Amanda Wood, Afton Holloran and Line J. Gordon.
