Should Plant-Based and Other Alternative Proteins Supplant Animal-Derived Proteins?

Article by NCFIL Executive Director William Aimutis

For the past few years, media coverage emphasized the growing need for plant-based and other alternative proteins to replace animal-derived proteins in the human diet. The reasons seem logical given increased awareness of healthier eating, improved animal welfare, and food animals’ potential damage to the environment.

But hold on! Does it make good sense to eliminate animal proteins in favor of plant, algae, microbial, insect, and cell-based proteins in the future? Will these alternative protein sources sufficiently feed a growing global population? Will they be better for our environment? Are they healthier? The answer to these questions is maybe.

Protein: Global Food System Challenge

Five years ago, the World Health Organization went on record saying the biggest challenge for the global food system in the 21^st century will be the demand for all forms of protein. Unfortunately, it is a tale of two different worlds that puts us in this position.

First, global demand for protein will double by 2050 as the world population continues to increase to 10 billion people or more. This is further complicated by populations becoming more affluent and able to purchase more protein for consumption to satisfy their growing appetite. The other challenge for protein supplies stems from over-consumption in developed countries. People in these countries eat nearly twice the recommended daily allowances needed to sustain good nutrition.

All protein sources supply amino acids, essential nutrients to maintain life. Some sources are better at providing essential amino acids that are nitrogenous compounds the human body needs to sustain life. In fact, only animal-based proteins provide these nutritional elements in sufficient quantities in our diets to maintain proper bodily functions. While alternative proteins also provide amino acids, the levels of essential amino acids range from absent to only present in very low concentrations.

Protein + Quality of Life

Although this sounds like a negative comment about alternative proteins, keep in mind people consume a wide variety of foods daily. Even if we reject consuming animal proteins, chances are we will survive. However, quality of life may deteriorate as we age. Elderly vegetarians and vegans who followed strict plant-based diets for years often show signs of depression and low immune response, due to zinc, calcium, selenium, and vitamin B12 deficiency. Although millions of vegans demonstrate no health impairments from low micro- and macronutrient intakes, they should be aware of the risk of potential dietary deficiencies.

Interestingly, vegetarian and vegan dieters often consume less total protein than omnivorous eaters yet are closer to the daily recommended amounts for protein consumption (McCarty, Barroso-Aranda, & Contreras, 2009). Data generated in rodents showed animals consuming a vegan diet also had lower methionine levels. Studies (Bartke, 2005) have shown that reduced dietary methionine achieves “aging retardation” like calorie-restricted diets and a suppression of inflammatory agents caused by superoxide generation. Furthermore, low-fat vegan diets combined with exercise training may increase longevity by decreasing circulating insulin and other hormones associated with obesity.

Older adults should consume adequate amounts of high-quality dietary protein from a variety of protein sources to prevent age-related muscle loss (Domic, et al., 2022). While plant-based proteins can meet the dietary needs of older adults for sustenance, other whole-food protein sources will supplement any essential amino acid deficiencies from maintaining a vegan diet. Further research is recommended to substantiate the impact of a vegan diet on older adults, especially regarding the consequences of this dietary lifestyle on skeletal muscle mass and strength.

Pregnant women following a vegan diet should be aware of an increased risk for small-for-gestational age newborns and lower birthweights (Avnon et al., 2021). Vegan women can maintain their lifestyle but should regularly consult with a dietician to follow fetal growth during their pregnancy. Alternatively, a mother-to-be can mitigate the risk of smaller babies by consuming a lacto-ovo diet or using dietary supplements during pregnancy.

Nutritional Value of Animal-Based + Plant-Based Proteins

Can the nutritional value of plant-based or other alternative proteins be as complete as animal-based? Nutritionally, plant-based proteins vary in their amino acid contents, often lacking some amino acids that are essential for human growth and homeostasis. It is possible to blend a variety of plant and other sources to balance the amino acids content and make products more nutritionally complete. However, there are other factors missing from plant-based and other alternative protein sources that can only be isolated from animal-based proteins, especially dairy. For example,

• Children need several growth factors only found in cow’s milk to utilize calcium from the diet for bone development and maturation. The most bioavailable calcium sources are cow milk derived. Other factors like immunoglobulins derived from the whey fraction of bovine milk protect young children from gastrointestinal diseases.
• Red meats provide iron and vitamin B-12 to protect against anemia.
• Egg proteins provide respectable levels of sulfur-containing amino acids that contribute substantially to maintaining integrity of human cellular systems to detoxify compounds involved in multiple disorders, including vascular disease, cancer, and Alzheimer’s.

Animal-based proteins do have negative health connotations when consumed in excess, such as high cholesterol and saturated fats. Of course, it is advised the consumer only consume the amount of meat protein recommended by regulatory and nutritional experts. Also, they’ll be doing themselves a favor for healthy eating as well as helping the environment by consuming less.

Are Alternative Proteins Better for the Environment?

Swiss manufacturer Bühler Group has conducted a thorough analysis of the impact of alternative protein manufacture on sustainability. Alternative proteins, specifically plant-based, are certainly better for some parts of our environment because they reduce the global reliance on animal-based protein. Less land use, reduction of food system emissions, and improved biodiversity in our ecosystem are often referenced as key points in improving sustainability.

While these facts are true, other components in the increased alternative protein production supply chain are considered negative consequences, including heavy reliance on stainless steel, water, electricity, and natural gas used in protein manufacture. Life cycle analysis studies conducted the last few years often miss critical components of protein manufacture and give a false belief these proteins are better for the environment. While they may meet these claims, alternative proteins are still a stress on natural resources, and more thorough analysis is needed. Bühler has committed multiple resources to improving the manufacturing of alternative proteins to meet significant sustainability goals by 2025. Other manufacturers in this industry sector will surely follow Bühler efforts.

Willing to Compromise on Protein?

As time progresses toward 2040 and the population grows, will there be enough protein on Mother Earth to nutritionally support us? It is foreseeable that people will make compromises to follow their beliefs that we can exist without animal proteins.

Examples of future compromise include:

• Not raising companion animals as pets. Pet foods utilize large amounts of protein that could be redirected toward human foods.
• Further developing bioengineered plants to increase protein manufacture
• Putting more acreage into production with genetically modified or genetically edited plant hybrids
• Consuming far less protein, especially in the developed world, than currently consumed
• Being rationed or taxed by regulatory officials to limit protein consumption
• Experiencing human life longevity decreases, thus reducing lifetime demand for protein

Will consumers willingly accept these compromises? Probably not!

We Need All Protein Types

The solution? We must focus on producing proteins from all available sources to meet future protein demand and to sustain healthy populations. Our focus should not be to eliminate any group of protein from commercial consideration, but rather to consider how we produce all forms of protein in a sustainable manner healthy for our environment and the human consumer.

This will be our challenge for the next few decades—improve all characteristics of the supply chain, starting at the basic elements of genetics (animal, plant, insect, etc.), agricultural practices, protein manufacturing processes, and ultimately dietary consumption of moderate amounts of protein.

Two final challenges are to convince consumers they should consume some alternative protein sources they may find objectionable. We can only accomplish this by manufacturing foods delivering optimized sensory characteristics to the consumer that are healthy in overall formulation. Early generations of meat and dairy alternative products did not meet these characteristics, and the consumer will keep demanding more from us.

Agricultural and food scientists have made progress in improving the challenges faced with both animal and alternative proteins. For example, current animal husbandry practices have focused on reducing methane production from animals by reducing feed ingredients that contribute to ruminant methane production.

Protein extraction, concentration, and isolation technologies have improved alternative protein flavor and functionality, but we still are not offering products that all consumers would seek out to purchase. Food product developers have several new tools, including flavor masking agents, at their disposal to formulate good tasting food products that are nutritionally complete.

We must deliver upon our promises for the sake of Mother Earth and ultimately mankind’s survival.

References

Avnon, T., Dubinsky, EP, Lavie, I., Bashi, TB-M, Anbar, R., and Yogev, Y. (2021) The impact of a vegan diet on pregnancy outcomes. J. Perinatology 41:1129-1133.

Bartke, A. (2005). Minireview: role of the growth hormone/insulin-like growth factor system in mammalian aging. Endocrinology 146:3718-3723.

Domic, J., Grootswagers, P., van Loon, LJC, & de Groot, LCPGM. 2022. Perspective: Vegan diets for older adults? A perspective on the potential impact on muscle mass and strength. Adv. Nutrition 13:712-725.

McCarty, MF, Barroso-Aranda, J, & Contreras, F. (2009). The low-methionine content of vegan diets may make methionine restriction feasible as a life extension strategy. Medical Hypotheses. 72:125-128.