Is plant-based the best for the planet? Research says context is everything

10 Feb 2023 --- New research suggests that 100% plant-based eating is not necessarily the best route to a healthy population and planet. Meat, fish, eggs and dairy are highly nutrient-dense and could play an indispensable role in diets and a healthy ecosystem, particularly in low-income nations.

NutritionInsight speaks with the study’s researchers, the UK Soil Association, the Vegan Society and ProVeg International on the findings that envision a flexitarian future.

The cross-institutional study published in The Journal of Nutrition included researchers from the Global Alliance for Improved Nutrition (GAIN), the Food and Agriculture Organization of the United Nations (FAO), Stanford University and Cornell University, among others. 

Nutrition unlike those found in plants
The scale at which animal-sourced foods (ASFs) are produced and consumed is critical. Whereas overconsumption is linked to chronic disease in developed economies, the same ASFs may provide a compact source of nutrition in regions suffering from undernutrition like Sub-Saharan Africa. 

“ASFs can be environmentally damaging, but they are also an essential part of food security and nutritious diets, so we cannot simply write them off as unsustainable,” says lead author, Dr. Ty Beal, research advisor at GAIN.

Meat consumption in high-income countries should be reduced on the path to more sustainable food systems.He explains that ASFs are rich in bioavailable nutrients commonly lacking globally, including iron, zinc, calcium, vitamins B12 and D, choline, EPA, DHA and essential amino acids.

ASFs also contain unique beneficial compounds that are important to health and not found in plant sources, including creatine, anserine, taurine, cysteamine, 4-hydroxyproline, carnosine, conjugated linoleic acid, certain bioactive peptides and many others, he adds. 

Co-author on the study Christopher Gardner, Ph.D, at Stanford School of Medicine says producing the paper was “eye-opening.”

“My research is focused domestically in the US, where animal-source food consumption levels are among the highest in the world, and where the emphasis among my community of health professionals consistently leans toward decreasing current consumption levels,” says Gardner.

“But there are clearly geographic locations and certain populations that can benefit from increasing animal-source foods, and ways to approach this that optimize environmental factors.”

Commenting on the study, Jasmijn de Boo, VP at ProVeg International, agrees that there is no “one-size-fits-all” approach to providing nutrition in areas like sub-Saharan Africa.

“Circumstances in the local context will dictate the diet of the population. However, the paper points out that as populations develop, the nutritional situation also changes, with alternative foods becoming more available and acceptable.”

The researchers from Cornell University and GAIN also point out that as two-thirds of the global population have lactose malabsorption, plant-based alternatives to milk can play an important role.

The destruction of the Amazon Basin for animal feed or cattle ranching may deprive local communities of resources they need for food sovereignty, notes the Vegan Society.Global imbalances
Today the regions with the highest consumption of animal-source foods are Central and Eastern Europe, Central Asia and high-income countries.

These are the regions that most stand to benefit from reducing ASFs for the health of people and the planet. 

The study’s researchers advise against too much ASF consumption, particularly when it comes to red meat and saturated fat, which are linked to non-communicable diseases. 

ProVeg’s De Boo emphasizes that red meat has long been under scrutiny for health risks. 

She notes that the World Health Organisation evaluated 800 studies on red meat and processed red meat in 2015 and concluded that red meat is “probably carcinogenic to humans” while processed red meat “is carcinogenic to humans.” 

“On that basis, ProVeg would not recommend eating red meat where possible.” 

Moreover, a study last month concluded that ruminant animals, such as cows, were responsible for the highest risks to health and the environment when examining different diets. 

The fight for land
One of the main arguments for an exclusively plant-based diet is land use. 

De Boo highlights that growing food exclusively for direct human consumption, rather than as animal feed and for biofuel production, could potentially increase available food calories by as much as 70%, which could feed an additional 4 billion people. 

And while even the Vegan Society agrees that “it may be possible for some animals to be part of sustainable farming systems,” it says animals are “not necessary for sustainable and productive agriculture.” 

The Soil Association argues that livestock can play an important role in restoring degraded land.Tim Newthorpe, senior campaigns and policy officer at the Vegan Society, points out that an estimated 74% of the land animals farmed globally are in factory farming systems.

“And those that are not [factory farmed] are usually grazed on land with poor biodiversity value due to overgrazing or fertilizer application to increase productivity. These include the most damaging farming systems such as cattle grazing in the Amazon Basin.”

Destruction of the Amazon Basin and monopolization of land to grow soy to feed intensively farmed animals also means less productive resources for communities, smallholders and women farmers, reveals AC Baker, senior policy and research advisor at the Vegan Society. 

Animals’ role in regenerative agriculture
The review authors underscore that livestock can be produced sustainably through circular and diverse agroecosystems but that their production must align with cultural and local ecological contexts.  

“In some cases, livestock plays an important role in livelihoods, particularly among women,” points out Beal. “ASFs are highly valued and are a part of traditional diets in many cultures.”

Ruminant animals can also improve soil health and regeneration of degraded land, according to the Soil Association in the UK.

Rob Percival, head of policy at the Association, notes that grazing animals reduce the need for chemical fertilizers as they naturally spread their manure across fields.

“Without animals, most farmers rely on fossil fuel-based chemical fertilizers to feed their crops. When they react with oxygen, they produce nitrous oxide – a greenhouse gas that is 300 times worse for the climate than carbon dioxide.”

Food technology is helping high-income countries introduce more plants into their diets via familiar meat-like formats. Diverse grasslands also support biodiversity, he adds, providing homes for bees, birds and butterflies and other wildlife. 

But restoring degraded land is not necessarily dependent on livestock, argues De Boo, which can also be done through agroforestry and rewilding. 

A 2017 report from the Food Climate Research Network found that reversion to many lands’ natural wooded state could achieve greater sequestration levels than continued grazing, she points out. And wild herbivores might also be a better option for biodiversity.

Context is everything 
There is no one-size-fits-all approach or overall amount of ASF that is healthy and environmentally sustainable. 

It depends on the local context and health priorities and will inevitably change over time as populations develop, as nutritional concerns evolve and as alternative foods from new technologies become more accessible. 

Policymakers, donors, international organizations or civil society groups aiming to increase or decrease ASF consumption should take these factors into account, say the review’s authors. 

It is well documented that the consumption of meat and milk is low in low-income areas, which suggests that these animal-based products are too expensive for many people, adds De Boo. 

Besides the need to lower the cost of nutrient-rich food, it seems likely that the more plant-based dietary recommendations are, the more affordable they are in most world regions. 

Since many people struggle to afford animal-based foods, food-based dietary guidelines must inform citizens about how they can meet their nutritional needs with plant-based sources.

The Vegan Society adds that globally, we need to move toward diets that do not involve exploiting animals.  

“However, where poverty and inequality limit access to diverse fruits, vegetables, nuts, seeds and wholegrains for some people, it may not always be possible to eliminate animal products while maintaining optimal nutrition,” says Newthorpe.  

“Resolving these global inequities is an essential part of this transition.”

By Missy Green