It is well-known that meat has a significant impact on Earth and climate change, as shown by previous research. Now, a new study by Oxford scientists has confirmed that plant-based diets have the least impact on the environment.
The study assessed the environmental impacts of different diets: high and low meat, pescatarian (those who eat fish), vegetarian and vegan using dietary data from over 55,000 individuals. The findings by the team, from the Livestock, Environment and People (LEAP) project at the University of Oxford, showed that the dietary impacts of a plant-based diet were about a third of those of high meat eaters, according to a press statement on the Oxford Alumni website.
Data on the environmental impact of each diet was examined considering its link to greenhouse gas emissions, land use, water use, water pollution risk and biodiversity loss, according to the statement. The assessment also took into account how and where food is produced. The paper is published in Nature Food.
The food system is estimated to be responsible for 70% of the world’s freshwater use and 78% of freshwater pollution, according to the statement. Humans have affected the majority of land area and deforestation continues to play a main role in biodiversity loss.
“Our dietary choices have a big impact on the planet. Cherry-picking data on high-impact plant-based food or low-impact meat can obscure the clear relationship between animal-based foods and the environment,” said lead author Peter Scarborough.
The new findings showed that high-meat diets have the biggest impact on many important environmental indicators, such as climate change and biodiversity loss. Reducing the consumption of meat and dairy can make a substantial difference, he added.
Notably, the study that compared to high meat eaters, vegans contributed to just 27% of the impacts for water pollution, 46% for water use and 34% for biodiversity. There were at least 30% differences between low and high meat eaters across most of the indicators.
A 2019 systematic review published in the journal Sustainability found similar results, indicating that a plant-based diet is the best solution for the future. However, it also acknowledged the difficulty in practising it as the dietary recommendations might not sit well with cultural expectations and norms. The researchers suggested linear programming wherein a dietary pattern that is healthy and similar to the environmental impact of a vegan diet can be identified, based on the foods currently consumed by populations in different regions.