Ditch the meat, save the planet: Oxford study touts environmental and health benefits of plant-based foods

Amid the shift toward plant-based foods for health and environmental sustainability, research from the UK University of Oxford reveals that replacing meat and dairy with plant-based food alternatives would reduce nutritional imbalances, mortality and disease risks, environmental resource use and pollution. Consumers can minimize diet costs by prioritizing unprocessed foods like peas, soybeans and beans.

The author, Dr. Marco Springmann, senior researcher on Environment and Health, says previous studies on plant-based meat and dairy alternatives “rarely consistently” combine nutritional, environmental and cost assessments. He notes this limits the ability to identify co-benefits and trade-offs across domains.

The study assessed the nutritional, health, environmental and cost perspectives of meat and milk alternatives available in high-income countries. It compared them with the animal products they intend to replace and the unprocessed plant-based foods they are made from. 

Although processed plant-based foods such as veggie burgers and plant milks were associated with fewer climate benefits and higher costs than unprocessed legumes, the research notes these processed alternatives still offered “environmental, health and nutritional benefits compared to animal products.” 

The research highlights little need to develop novel meat and milk replacements as suitable alternatives are “available and affordable.” 

“Our nutritional, health, environmental and cost analyses suggest that if one is prepared to consider foods for their properties instead of whether they are completely mimicking meat or dairy — and surveys suggest that consumers are — then unprocessed legumes are, for the most part, superior to processed alternatives,” reveals the report.  

The findings are also relevant to low- and middle-income countries where legumes are more readily available than processed meat and milk alternatives. 

Soybeans and peas for the win

The study, published in PNAS, compares how replacing meat and dairy with plant alternatives would impact nutrition, health, economics and the environment. 

“We considered comparisons along multiple and complementary units of measurement, including per serving and calorie; and we included comparisons per product as well as per overall diets in dedicated replacement analyses,” details the report. 

Multicriteria analysis of meat and milk alternatives, with scores based on nutritional, health, environmental and cost changes (Image credit: University of Oxford).The study states that unprocessed plant-based foods “were the best overall performers for replacing meat and dairy in high-income countries.” Obtaining the same levels of calories from peas and soybeans instead of animal products reduced nutritional imbalances (48%), mortality (11%), food-related greenhouse gas emissions (60%), land use (56%), water use (43%) and diet costs (41%). 

Processed alternatives such as veggie burgers and soy milk did not have the same benefits in health, costs and greenhouse gas emissions, but they were linked to reduced land and water use. Moreover, the research links these products to 33% greater improvements in nutritional imbalances by complementing nutrients, such as vitamin B12. 

Nutrient intake of plant-based foods

Although research increasingly links plant-based foods and protein to health benefits, some experts warn that many plant-based diets may worsen prevalent micronutrient and protein deficiencies. 

For example, in a perspective published in Frontiers in Nutrition earlier this year, Alice Stanton, professor at the University of Medicine and Health Sciences in Dublin, Ireland, urges dietary guidelines not to exclude meat and dairy. 

She states that plant-based diets’ protections against non-communicable diseases “appear to be more strongly associated with reduced intakes of calories and salt, and increased intakes of fruit, vegetables, nuts and whole grains, rather than with reduced intakes of animal-source foods.” 

The University of Oxford research assessed the intake of various macro- and micronutrients, focusing on key nutrients where people generally fail to meet recommendations. Switching to plant-based foods helped reduce mortality (5–6%) and lower nutritional imbalances from 10% to 5–6%.

The main nutrient changes were lower saturated fat intake (41%) and increases in fiber (20%) and potassium (12%). The study also found smaller reductions in zinc (8%), vitamin A (6%) and vitamin B12 (4%) intake. 

Soybeans, peas and beans were the plant-based products most strongly linked to these health benefits, followed by veggie burgers, tempeh, veggie sausages and tofu. Soybeans, almonds, almond milk, oat milk and soy milk offer the largest reductions in nutritional imbalances among milk alternatives. 

The study calls for supportive public policies and food environments to increase consumption of plant-based alternatives.Although unprocessed plant-based foods performed best in the assessment, the author cautions that replacing meats with soybeans could increase nutritional deficiencies such as vitamin B12. 

Moreover, many processed meat alternatives are classified as ultra-processed foods, which have been linked to overeating and weight gain in randomized controlled trials.

Increasing uptake

The author expects that increasing uptake of assessed plant-based alternatives might be contingent on supportive public policies and food environments. 

“Increasing consumption of legumes, for example, could benefit from public information campaigns such as national guidelines outlining how they can form part of healthy and sustainable meals, alignment of agricultural subsidies and business approaches that focus less on single products, but on integrating legumes in meals and diets,” reads the report. 

The high prices of processed plant-based foods limit consumers’ uptake of them. In addition to scaling and improving production, the study suggests that a “true cost approach,” integrating health and environmental costs into prices, could help signal meat and dairy’s health and environmental benefits. 

“However, political and economic issues could arise as the livestock sector holds considerable political influence in many markets, and various interest groups aim to influence the political debate,” cautions the research. 

The study also warns that replacing all meat and dairy with one or two alternative foods could increase pressures on natural resource use. “Adopting a whole diet perspective could address such issues of overreliance by diversifying replacement foods and balancing nutritional, environmental and cost aspects at the level of diets and meals,” it concludes.