Vegan Diets Cut Emissions, Water Pollution and Land Use by 75%, Major Study Finds

An analysis of diets and farms led by the Livestock, Environment and People (LEAP) project at Oxford University found that vegan diets have a major reduction in environmental impacts, from land and water use to emissions to pollution.

The study, published in the journal Nature Food, analyzed diets of 55,504 people and reviewed 38,000 farms based in 119 countries. What they found is that regardless of where or how food is produced, animal-based diets had higher impacts on the environment than diets of people who consumed less or no animal-based products.

Vegan diets had about 75% less emissions and land use compared to diets with high meat consumption, defined as more than 100 grams of meat consumed per day. Vegan diets also had nearly 54% less water use than high meat diets and about 73% less water pollution via runoff. Plant-based diets also had less impact on biodiversity.

“Our dietary choices have a big impact on the planet,” Peter Scarborough, lead author of the study and professor of Nuffield Department of Primary Care Health Sciences at Oxford, said in a statement. “Cutting down the amount of meat and dairy in your diet can make a big difference to your dietary footprint.”

Overall, people following vegan diets had about one-third of the environmental impact of people with high meat consumption. People who consumed low amounts of meat (less than 50 grams of meat per day) had about 30% less impact across different categories compared to those consuming 100 or more grams of meat per day.

“Even in ‘worst case scenarios’ where most foods that are eaten in low meat diets are produced by methods with high environmental impact and most foods that are eaten in high meat diets are produced with low impact methods, low meat diets still have substantially lower environmental impact,” Scarborough explained.

The negative environmental impacts of growing food and raising livestock is well-known. A separate study published in 2021 found that food-system emissions made up about 34% of total global emissions as of 2015, and agriculture makes up over 70% of freshwater use, a 2023 study reported.

But the recent analysis of various diets is one of the most comprehensive of its kind, showing that less meat consumption can lead to drastic reductions in environmental impacts.

“This study represents the most comprehensive attempt to link food consumption data to the data on the environmental impacts of food production,” said Richard Tiffin, professor at the University of Reading, as reported by The Guardian. “Encouraging high-meat-eaters to reduce meat consumption and encouraging vegetarians to become vegans should result in lower emissions. However, it’s hard to justify changes to the diets of moderate omnivores on the basis of these results, other than to switch to a completely vegan diet.”

According to the study, dietary changes will be necessary to feed more people as the human population continues to grow, while also limiting environmental impacts. The authors noted that high-income countries will need to greatly reduce the amount of animal-based foods and drinks they consume to keep environmental impacts within safe boundaries.