Emily Mahaffy

The Potential of

Plant-Based Proteins

It may surprise you that around the world, plant-based proteins constitute a greater percentage of total protein intake than all animal-based proteins. This may seem odd from our American perspective, but globally nearly 60% of protein intake is from plant-based proteins (FAO, 2017). As the United States looks to create more environmentally sustainable food products, the flood of new plant-based products will continue. However, are we still gaining the nutritional value we need from these plant-based sources? The answer is yes! But there are some key differences between plant- and animal-based sources that must be considered when building new diets. Today we’ll be looking at one main macronutrient: proteins. The main difference between plantbased and animal-based proteins is their differing amino acid structure. To put it in layman's terms: Proteins are made up of amino acid chains. You and I need 20 amino acids to be healthy. Luckily for us, our body naturally makes 11 out of 20 amino acids. However, we need to consume the remaining 9 essential amino acids through our diets. Once we eat protein sources that contain these essential amino acids, our body breaks the proteins back down into their amino acids. With our 20 amino acid “building blocks,” our body then synthesizes protein for our personal growth, development, and other functions. There is also an important distinction between complete versus incomplete proteins that must be addressed. Complete proteins naturally contain all the essential amino acids that we need. Animal-based proteins, like whey and meat, are complete proteins. On the other hand, plant-based proteins are incomplete proteins. They do not contain all the essential amino acids we need. Luckily, this is not a problem! There is a wide range of plant-based proteins that allows us to consume these essential amino acids in combination. What really matters is how we consume these plantbased proteins. So let’s talk about bioavailability. Essentially, this means: how “available” are these proteins to be digested, absorbed, and assimilated? If we had a scale from 0 to 100, animal proteins are near the top of the scale (100). Around the 75 to 50 mark plant proteins start to appear on the scene. This is because plant proteins have a few limitations to digestion and absorption. (Note: this does not mean that plant proteins are not as good; they have the same amino acids, just in different combinations.) Limits to absorption are mostly due to structural issues. Plant proteins have many more “protective” folds than animal proteins. These folds block digestive enzymes trying to break down the protein molecule. Additionally, there are other chemicals in plants that inhibit digestive

enzymes. Because of these factors, plant proteins are better suited for oxidation rather than protein synthesis. But there is a solution to this: we can prepare plant proteins in different ways to make plant proteins more bioavailable. For instance, cooking and heating your fruits and veggies helps with enzyme inhibition. We can also soak nuts, seeds, and certain beans to get rid of phytic acid, which makes plant proteins less bioavailable. On the other hand, there are also more technical plant protein modifications that could work, such as blending multiple plant-based protein sources, combining plant- and animal-based protein sources, fortifying plant-based proteins, and selective breeding. So, as we try to switch to a more plant-based diet in an attempt to be more climate conscious, keep in mind that increasing protein intake and variety, as well as using different methods of cooking, may be what you need to meet your nutritional goals!

Works Cited Berrazaga, I., Micard, V., Gueugneau, M., & Walrand, S. (2019). The Role of the Anabolic Properties of Plant- versus Animal-Based Protein Sources in Supporting Muscle Mass Maintenance: A Critical Review. Nutrients, 11(8), 1825. https://doi.org/10.3390/nu1108182

Day, P. (1996). The Biology of Plant Proteins. Critical Reviews in Food Science and Nutrition, 36:sup001, 39-47, DOI: 10.1080/10408399609527758

FAO. (2017). FAOSTAT food balance sheets.

The Natural Athletes Clinic. (2020, June 30). Plant Based Protein Vs. Animal Based Protein - Biochemical Differences in Absorption and Utilization [Video]. Youtube. https://youtu.be/S4y1rOWpDQI.