A new report surfaced last week in a noted British medical journal, The Lancet, that recommends a near-vegan eating style as a way to promote greater sustainability of the food system, lessen the environmental impact of animal agriculture and improve health of the world’s population. Of course, this is the same journal that published a notorious study – later debunked and retracted – suggesting a link between the measles/mumps/rubella vaccine and autism, which ignited the current anti-vaccination movement.
Created by the EAT-Lancet Commission, a collaboration between the EAT Forum (founded through the Stordalen Foundation), the Stockholm Resilience Centre and the Wellcome Trust, the investigation and report were funded by EAT and the Wellcome Trust. The founder and chair of the Stordalen Foundation is a billionaire Norwegian physician who is a vegan. The co-chair of the EAT-Lancet Commission and lead author of the report is a Harvard professor well-known for his strong stance against meat in the diet. But he’s not a fan of potatoes, either. Wait, aren’t they plants?
Reading beyond the headlines hailing this report, is it really advisable for everyone to adopt a near-vegan eating pattern? Before we call on governments and health agencies around the world to endorse such a radical change in traditional food production and consumption, we need to explore the societal, environmental and nutritional implications of doing so.
Is a near-vegan diet more sustainable?
As technology has transformed our world over the past century, people have become more concerned about its impact on the environment. Like most other industries, agriculture has embraced technology to help farmers produce food more efficiently. And this is a good thing when you consider that 40% of the labor force in the U.S. was engaged in farming 100 years ago while only 2% is today. That means farmers must produce more food for a population that has tripled from 104.5 million in 1919 to 326.8 million today while the amount of farm land and water has remained the same or been reduced. And they have been very successful in doing that.
According to the Environmental Protection Agency, U.S. agriculture accounts for around 9% of total U.S. greenhouse gas emissions compared to 28% for electricity, 28% for transportation and 22% for industry. And a 2017 study revealed that removing all animals from the food supply and replacing all of those calories with plant crops would only reduce total U.S. greenhouse gas emissions by 2.6%.
Farmers from all sectors of the industry are working toward sustainability in their practices to protect and enhance the land and conserve water and other resources so their farms can continue to produce food for future generations. And equally important, creating a sustainable farm allows them to make a living so they can stay in business so we’ll all have food to eat.
U.S. cattle ranchers are producing the same amount of beef today as they were 40 years ago with one-third fewer cattle. Likewise, through improved cow breeding and feeding, dairy farmers produce milk today with 90% less land and 65% less water than in the mid-20th century, resulting in a 63% smaller carbon footprint. In 1950, there were 25 million dairy cows but only 9 million today while milk production has increased by 60%.
And in the egg industry, innovations in nutrition and breeding since 1960 have increased egg production by 27% while decreasing daily hen feed by 26%, water use per dozen eggs produced by 32% and hen death by 57% while lowering greenhouse gas emissions by 63%.
Finally, half of all fertilizers used in the U.S. to grow fruit, vegetables and grains are organic fertilizers made from livestock manure. Eliminating animal agriculture would mean replacing them with chemical fertilizers that are very energy intensive to produce.
Will a near-vegan diet feed the world?
In the U.S. only 1 in 10 adults currently eats the minimum number of fruits or vegetables recommended in federal dietary guidelines according to a Centers for Disease Control and Prevention study. Dietitians are continually challenged to help people find ways to enjoy eating more of these nutrient-rich foods.
Will eliminating most of the meat, eggs and dairy foods from the food supply force folks to eat more of these wholesome plant foods? The even bigger question: is there enough land to grow the amount of produce and grains we would need to replace the calories and other nutrients provided by animal foods? Will eliminating livestock grazing free up more land to produce more food for people to eat?
According to the World Bank, 37.2% of the world's total land area is considered agricultural but only 10.9% is arable or capable for growing crops like fruits, vegetables and grains. That’s less than a third of the total agricultural land. The other 70% of agricultural land is marginal and not suitable for growing crops due to lack of water and/or poor soil quality. It is only good for grazing ruminant animals that can digest grass - goats, sheep and cows. In addition, 85% of cattle feed is not digestible by humans like grass, wheat and oat straw, sugar cane tops and corn silage (husks, leaves and stems). Thus, these ruminant animals convert food with poor-quality protein from plants inedible for humans into high-quality protein food with a variety of nutrients not always plentiful in plant-based foods.
Will a near-vegan diet adequately nourish the world?
I love fruits, veggies and grains. I eat a lot of them. But I also enjoy eating meat, dairy and eggs. I have friends who are vegans and vegetarians and I respect their right to choose that eating pattern and they respect mine to include animal foods in my diet. A vegan diet can be nutritionally adequate and promote health just like those including animal foods. Having said that, it is more challenging to meet these nutrient needs but it can be done with careful planning and some supplementation of vitamins only found in animal foods. The bigger question is whether we can nourish an entire population (country, continent or world) with only plant foods.
The previously mentioned 2017 study compared the current U.S. food production system to a modeled one where animal agriculture and animal-derived foods are eliminated. The plant-only agriculture system produced 23% more food but met fewer of the essential nutrient requirements for people in the U.S. The plant-only diets projected more nutrient deficiencies, a need to consume a greater amount of food and more calories. Researchers concluded that removing animal foods from the U.S. food supply resulted in diets that did not support people’s nutritional needs without nutrient supplementation.
Animal foods like meat, poultry, fish, eggs and dairy provide high-quality protein with all the essential amino acids in amounts necessary for building and maintaining all body tissues. In addition, each of these foods supplies additional nutrients that are not always present in significant amounts in plant-based foods.
On the other hand, fruits and vegetables contribute nutrients like vitamins A and C, folic acid, potassium, fiber and phytonutrients that are not provided by or are present in smaller amounts in animal foods. And grains are a source of fiber, several B vitamins along with iron, magnesium, and selenium.
That’s why a diet with a variety of foods from all groups helps ensure an adequate intake of all nutrients. Leaving out one or more groups makes it more difficult. For example, you would have to eat 1.25 cups cooked spinach (50 calories) or 3.75 oranges (335 calories) to get the same amount of calcium in a cup of 1% low-fat milk (100 calories). And it takes 3 cups of cooked quinoa (660 calories) or 1.7 cups of black beans (385 calories) to obtain the protein in 3 ounces of lean cooked beef (156 calories). In addition, some vegetables, grains, nuts and seeds contain oxalate and phytates that can bind minerals like calcium, iron and zinc and keep them from being absorbed. On the other hand, the lactose and vitamin D in milk enhance the absorption of calcium.
The U.S. Department of Agriculture’s MyPlate, the graphic representation of the U.S. Dietary Guidelines, is a plant-based eating pattern with three-quarters of the plate comprising fruits, vegetables and grains. Including animal foods in the diet can help boost intake of plant foods. One way to encourage people to eat more plant foods is to pair fruits, vegetables and grains with meat, eggs and dairy: yogurt and fruit, cheese and bread, beef/pork/chicken in a vegetable stir-fry with rice, a fish taco in a whole grain tortilla with chopped tomato and bell pepper or an omelet layered with vegetables and cheese.
Putting it all together
Sustainability is essential to protecting the environment and feeding and nourishing the world. In the U.S. farmers and ranchers have worked diligently to become more efficient in producing more food with fewer resources. This has significantly reduced the impact on land, water and chemical use. Unfortunately some other countries, especially developing ones, have not been as successful or even have the ability to harness technology to improve productivity. Rather than radical changes to the world’s food system, a better solution would be to direct resources to helping farmers throughout the world to work more efficiently and sustainably.
Because sustainability is also about sustaining health through sufficient food that delivers adequate nutrition as well as sustaining farmers’ abilities to maintain financial security in order to continue producing enough food, it cannot simply be viewed through the narrow lens of environmental impact. Food and meals are an integral part of our lives. People choose foods for many reasons, not just for nutrition and health but also for taste, cost, availability and cultural, religious and family traditions. Dietitians play a critical role in helping people adopt eating habits that not only ensure health but also accommodate these other factors. Finding appealing ways for individuals to consume more plant-based foods like fruits, vegetables, grains, nuts and legumes can boost nutrition and still be compatible with eating appropriate amounts of animal foods to obtain essential nutrients. Creating this balance will have long-term influences on enjoyment of eating, nutritional adequacy, health status and the environment of our planet.