Lower Meat Consumption a Key to Fighting Global Warming, Study Says

A global transition to a vegetarian diet would have significant impacts in the battle against global warming and other environmental concerns, according to research conducted at Loma Linda University Health.

Food production has been identified as a major contributor to increased greenhouse gas emissions, consumes 70 percent of fresh water, and is responsible for 80 percent of the world’s deforestation. Improving agricultural technology and reducing food waste have been put forward as potential solutions to these environmental concerns. But Joan Sabaté, professor of nutrition and epidemiology at Loma Linda University School of Public Health, found that changes in food choices and diet patterns would have a far greater positive effect on environmental sustainability.

“Vegetarian Diets: Planetary Health and Its Alignment With Human Health” is a meta-analysis of 49 published research studies that focused on the impact that vegetarian and vegan diets have on greenhouse gas emissions and water and land use. When data from the 49 studies were combined, Sabaté found that shifting from current dietary norms to ovolactovegetarian and vegan diets would reduce greenhouse gas levels an average of 35 percent, reduce land use for food production by an average of 42 percent, and agricultural water use by an average of 28 percent.

“Many other studies have clearly demonstrated the health advantages of vegetarian and vegan diets. This analysis confirms that switching to these types of diets is also significantly eco-friendly as well,” Sabaté said.

Sabaté directs the environmental nutrition research program at Loma Linda University School of Public Health. This program explores the interrelationships between the environmental and health impacts of food choices and ultimately seeks to improve the sustainability, health, and equity of food systems. He is the editor of the book Environmental Nutrition: Connecting Health and Nutrition With Environmentally Sustainable Diets, published in 2019.

One early sign that people are increasing in their commitment to making dietary changes because of concerns about climate took place in January 2020. By choosing to serve all-vegan meals to hundreds of celebrities and guests, two major entertainment industry award shows—the Golden Globes Awards and the Screen Actors Guild Awards—increased public awareness and conversation about the link between sustainable agriculture and climate change.

While the field of sustainable diets and environmental impacts is still in its infancy, Sabaté says he has participated in a number of research studies that show a clear connection between diet and climate factors. In 2017 he was part of a group that published a well- known study on the climate benefits of replacing meat with beans in diets. Sabaté and other researchers working in Loma Linda University Health’s environmental nutrition program have published more than 30 papers that examined the relationship between food choices, environmental sustainability, and population health.

Sabaté says additional research is needed into how changes in agricultural approaches impact the environment in low- and middle-income countries. He also points to needed research comparing large-scale agricultural operations with small-operation family farms practices.

“In societies where daily meat consumption is the social norm, drastically reducing meat consumption is a major challenge,” Sabaté said. “In low- and middle-income countries, eliminating meat could adversely affect those populations’ already marginal nutritional status.”