Eating plant-based foods is better for the environment than going for meat and dairy products and more nutritious products are frequently more environmentally sustainable, new research reveals. According to a British study, led by researchers at the universities of Oxford and Aberdeen, many meat alternatives such as plant-based sausages or burgers had a fifth to less than a tenth of the environmental impact of meat-based counterparts. The study, which was published in The Proceedings of the National Academy of Sciences (PNAS) on August 8th, assessed the environmental impact of more than 57,000 products sold in supermarkets, including many processed foods with multiple ingredients. In addition, the scientists linked this environmental footprint to the nutritional value of foods. They found that products that were more sustainable tended to be more nutritious, including meat alternatives. There were of course also exceptions to this trend such as sugary beverages, which had a low environmental impact but also scored poorly for nutritional quality. “By estimating the environmental impact of food and drink products in a standardised way we have taken a significant first step towards providing information that could enable informed decision-making,” said lead author Dr Michael Clark from the University of Oxford.

The researchers used publicly available information to calculate a standardised score for the environmental impact of the most common food and drink products sold in UK supermarkets, focusing on multi-ingredient products. “While previous analyses compared the impacts of food commodities such as fruits, wheat, and beef, most food products contain numerous ingredients. However, because the amount of each ingredient in a product is often known only by the manufacturer, it has been difficult to assess their environmental impacts,” the authors write in the abstract. “This work is very exciting – for the first time we have a transparent and comparable method for assessing the environmental footprint of multi-ingredient processed foods. These types of foods make up most of the supermarket shopping that we do, but until now there was no way of directly comparing their impact on the environment,” said Pete Scarborough, Professor of Population Health at the University of Oxford. The scientists identified individual ingredients of a product and known percent composition by analysing back-of-package ingredient lists which provide all ingredients in order of size. The information on each individual ingredient was then paired with environmental and nutrition databases. The analysis makes use of foodDB, a Big Data research platform that collects and processes data daily on all food and drink products available in 12 online supermarkets in the UK and Ireland, and a comprehensive review of 570 studies of the environmental impact of food production, which includes data from 38,000 farms in 119 countries. The percentages of all ingredients within each product were then used to estimate the impact and nutritional quality of each whole product. The environmental impact was estimated for four indicators: greenhouse gas emissions, land use, water stress, and eutrophication potential (when bodies of water become enriched with nutrients, often causing harmful algal blooms and ultimately killing other life). These four scores were combined into a single estimated composite environmental impact score per 100g of product.

The study found that those products made of fruits, vegetables, sugar, and flour, such as soups, salads, bread and many breakfast cereals, have low impact scores. Many of the products with the lowest impact were composed mainly of water, such as sugary drinks. Products with an intermediate environmental impact were many desserts and pastries. Those products made of meat, fish and cheese were at the high end of the scale. Jerky, biltong, and other dried beef products, which typically have more than 100g of fresh meat per 100g of final product, had the highest environmental impact. When looking at specific types of food products, such as meat and their alternatives, lasagne, cookies and biscuits, and pesto sauces, the researchers found large variation within these types of foods. For these food types, lower-impact products often had one half to one tenth the environmental impact of higher-impact products. For sausages, for example, there was a clear difference in the impacts based on the most prevalent meat in the product. With regard to the environment, sausages primarily containing beef or lamb had on average a 240% higher impact than pork sausages, which had a 100% higher impact than chicken and turkey sausages, which in turn had a 170% higher impact than vegan and vegetarian sausages. A limitation of the analysis is that information on ingredient sourcing, such as the country of origin or agricultural production method is lacking from ingredient lists, which would help to increase the accuracy of the environmental impact estimates. For example, Brazilian beef has a very different environmental footprint than British beef from grass-fed animals.

The authors write that “assessing and communicating the environmental impacts of food products will be integral to achieving the food system transformations that are urgently needed to prevent rapid environmental degradation. (…) The algorithm developed here could help enable this transformation by providing a framework that derives first estimates of the environmental impacts of food products in countries with ingredient list regulations that are similar to those in the United Kingdom.” The researchers conclude that replacing meat, dairy, and eggs with plant-based alternatives could have large environmental and health benefits in places where consumption of these foods is high. They point out that there are multiple ways to achieve this dietary change, including direct and large substitutions (e.g., beans instead of beef) or smaller transitions between like-for-like products. They admit that in some cases, large substitutions may be difficult because of taste preferences, cultural norms, or lack of access to appropriate alternatives while “smaller transitions could be more palatable” instead. “This work could support tools that help consumers make more environmentally sustainable food purchasing decisions. More importantly, it could prompt retailers and food manufacturers to reduce the environmental impact of the food supply thereby making it easier for all of us to have healthier, more sustainable diets,” said Professor Scarborough. According the authors, understanding and communicating the environmental impacts of food products is key to enabling transitions to environmentally sustainable food systems. “We still need to find how to most effectively communicate this information in order to shift behaviour towards more sustainable outcomes, but assessing the impact of products is an important step forward,” added Dr Michael Clark. (ab)