There is perhaps nothing worse than trying to make the right choices with the wrong information. Sadly, this is what happens every single day to people in our society due to the pervasive spread of misleading, faulty, or downright incorrect information. One of the most critical areas impacted by this, which shapes the quality of our health among so many other things, is nutrition. For example, many people live with the idea that plants either do not provide enough protein, if any, or the right type of protein. This then leads them to believe that animal foods are either an essential part of a proper human diet or that some specialized plant food combining or supplementation is required. But guess what, none of this is true!

If we are to have the right idea, we first have to have the right information. Yet despite living amidst the age of information with a wealth of knowledge at our fingertips, obtaining the right information about nutrition, especially as it relates to protein and plant and animal foods, is quite challenging. Therefore, the purpose of this article is to provide factual, up-to-date, and quality information to bust the myths that circulate about plant and animal protein. My intention is to clear up the confusion in this area for you and empower you to make the best choices for your health that are going to influence your current and future wellbeing positively.

Everything you think you know about protein, in other words, if you think of it as most people do, is wrong.

David L. Katz, MD, MPH, FACPM, FACP, FACLM

Going to the Root of Protein Misinformation

Before we examine the plant versus animal protein myths, let’s try to understand the common root behind all of the misinformation that we have out there today when it comes not just to protein, but the entire field of nutrition. If you have been doing your homework and personal research up to this point, you know that it all heavily points to one area: industry interests. It is no secret today that the milk, dairy, egg, and meat farmer groups have immense stakes in their business. In North America, 70% of protein is estimated to come from animal products. On a global basis, plants provide 65% of the protein sources. There is no coincidence in this reversal in numbers. Factory farming has become a HUGE business! It is also one that can easily grow and sustain itself if the “right” ideas are infused into the general populace. Examples of these ideas include fear-based conditioning that you need animal protein for good health or to build muscles, or that you need dairy for healthy bones. Even though all of these ideas have been exposed today as clever propaganda, they remain heavily ingrained in the majority of people.

It also does not help that biologically we are wired to crave sugar, salt, and fat. Therefore high-fat foods, like animal foods, are naturally addictive for people. Couple this with the fact that animal foods were always associated with the powerful and wealthy, and you have a virulent combination that attracts the masses to animal foods. However, while these three main areas require their own analyses and solutions, they are each heavily intertwined with the animal food equals the right type and quantity of protein idea. And it is one thing if we at least enjoy animal foods and eat them in healthy low amounts from the highest quality sources. But many people do not enjoy or wish to consume meat, dairy, or eggs, and often eat them based on the assumption that they “have to” in order to be healthy. Others, yet, do not realize the adverse health, economic, and environmental impacts of eating diets high in animal products.

Therefore, let’s explore what we know about plant and animal protein sources, as well as their quantities, by unraveling the common myths. The foundation of this analysis will be based on a 1994 study that was published in the American Journal of Clinical Nutrition, Plant proteins in relation to human protein and amino acid nutrition. It is both unfortunate and astonishing that even though we had this information for nearly three decades (at the very least), most people and organizations in our society continue to share inaccurate and outdated information about protein. This study, by the way, is free and available for all to read, which I highly invite everyone to do.

Now, of course, one study does not make for a cornerstone of reliable information. Our science today is rife with problems, including lots of skewed research that is conducted to appease specific industries and financial outcomes due to corporate conflicts of interest and scientific bias. If you would like to understand this better, watch my interview with Howard Jacobson, Ph.D., who co-authored the book Whole: Rethinking the Science of Nutrition with T. Colin Campbell, Ph.D. In this case, however, this study is neither alone nor refuted. We have ample evidence and information that backs everything it shares IF we look beyond the surface and ignore the loud distractors. So let’s examine the seven myths this study unveiled, and an eighth one, which is perhaps the most common myth of them all that plagues the human race today.

MYTH 1: Plant Proteins Are Incomplete

REALITY: Usual dietary combinations of protein are complete. Specific food proteins may be low in specific amino acids.

This is perhaps the most shocking piece of information when it comes to understanding plant proteins. Whether from school, or our parents or doctors, we have all been told, probably since we can remember, that plant protein is incomplete, and thus inferior compared to animal protein.

To get to the root of this myth, we will start by understanding that low does not equal or mean absent. Yet, for decades, the idea has been passed around that plant foods do not contain all of the essential amino acids. This made the idea of protein combining, which we will discuss in myth 3, appear reasonable. It is, after all, common for one myth to propagate another. The second piece of information that we must consider is: Low according to whom and what? It is all too often that nutrient values are created and changed periodically, as we try to understand how specific nutrients act and interact within human bodies. The truth is that nutrients are complex, and although we can try to apply reductionist science to this field, it will never sufficiently represent it.

Researchers like Michael Bluejay have examined and written extensively about this myth. In his analytical and research-based article, Setting the Record Straight, he shares that this information is neither new nor a secret. By analyzing data from various sources, including the USDA’s nutrient database, he shows that all plant foods ARE complete proteins in that they do contain all of the essential amino acids.

As for the point of being low in a specific amino acid, if we take this idea at face value, it may only be an issue if someone were to eat just one particular plant food all day and every day. But at that point, protein would be the least of their worries. Numerous other nutrients will be missing and out of balance as well. The same goes for animal foods. We cannot eat just one specific animal food all day and every day and think that we will be okay. Whether we isolate one plant or one animal food, we are bound to be left nutritionally-deficient in both cases. Either way, we can release the idea that plant protein is incomplete.

As an extreme example, even if you only ate one kind of grain, bean, potato, or vegetable as a protein source, and ate enough of that food, you could meet your protein and amino acid needs.

Reed Mangels, PhD, RD — The Vegetarian Resource Group

Myth 2: Plant Proteins Are Not As Good As Animal Proteins

REALITY: Quality depends on the source and dietary mixture of plant proteins, which can be equivalent to high-quality animal proteins.

There are many ways that this idea is presented and passed around when it comes to understanding plant versus animal protein quality. Some argue in favor of plant protein and others in favor of animal protein when it comes to optimal assimilation. The answer that one will arrive at depends on the context in which these two food groups are examined. Regardless, there is no doubt that plant foods are easier on the digestive system than animal foods, and this alone will have a significant impact on the protein digestion. Secondly, plant foods are also more nutrient-dense than animal foods and provide health benefits for healing and prevention that animal foods cannot. Thirdly, when we look more in-depth at where these ideas came from, we begin to see that for example the whole idea of plant proteins being seen as inadequate was concluded based on their comparison to egg proteins (as shared in a study from the early 1900s). So when plant protein, specifically the amino acid composition of various plant foods, was compared to the amino acid composition of eggs, of course, the plants seemed like they were lacking or less than optimal. But we have to stop and ask ourselves, why would we think that the egg of another species would be the ideal protein source for us or have the optimal amino acid profile to begin with? We could have just as easily turned the tables and concluded that the egg amino acid profile is too high or wrong for optimal human nutrition. When we start looking at the issue from multiple angles, and begin to ask critical questions, we expose ourselves to new answers and possibilities.

Today, we have become so blinded by the thinking that animal foods provide superior protein quality, that we fail to see the numerous health risks that they come with. We know today from many experts and scientific fields of study that animal foods, especially the low quality and high quantity that is present in the mainstream, increase the risk of weight and health problems. When we consume common animal foods today, we are exposing ourselves to numerous health imbalances due to the toxicity, pesticides, hormones, drugs, and genetically modified organisms that come along with animal foods. Many people have begun to source out wild or so-called “healthier” options, but the nature of animal foods is that they will always come with more risks, being higher up on the food chain than plant foods. Even a small amount of animal products can imbalance various functions in our body and cause damaging short-term and long-term health consequences. It would be one thing if the animal foods were somehow worth it from a health benefit, but they aren’t. So given that plant foods are capable of supplying us with enough protein and the right type of protein and safer protein, all while protecting our health, it should be obvious what our choice should be. That is, of course, if we want to enjoy optimal health, weight, and longevity.

Myth 3: Proteins From Different Plant Foods Must Be Combined to Create A Complete Protein

REALITY: Plant proteins do not need to be combined or consumed at the same time. The balance over the course of the day, and even over several days, as part of our regular and varied diet is what matters.

It appears that the root of this myth came from a 1971 book, Diet for a Small Planet: The Book That Started a Revolution in the Way Americans Eat, by Frances Moore Lappé. In it, the author stated that plant foods do not contain all the essential amino acids, and to be a healthy vegetarian, you needed to eat a combination of certain plant foods to get all of the essential amino acids. It was coined as protein complementing.

It was not an intentional mistake. Francis was a sociologist who was working on solutions to ending world hunger, and not a nutrition or health expert. She realized as part of her research the inefficiency of converting vegetable protein into animal protein (i.e., feeding animals plant foods so that we can eat the animals). Therefore, she shared that if people directly ate the plant food protein, many more people in the world could be fed, but that it appeared that certain plant foods should be consumed in combination together. In 1981, the author cleared up the misleading idea and recanted her claim about the need to combine any plant foods. Unfortunately, by that time, the idea had already spread like wild-fire and continues to infiltrate numerous sources to this day.

Our take-home message should be clear; we do not need to combine any plant foods to acquire some “complete” protein idea. Remember what myth #1 revealed: We only have to eat a variety of whole plant foods, and enough of them for our individual metabolic needs, to have our protein needs fully met.

Complete dietary protein does not require animal foods, and does not require any specific food combinations. Wholesome foods in any balanced, sensible assembly - even a strictly vegan assembly - will readily provide it.

David L. Katz, MD, MPH, FACPM, FACP, FACLM

Myth 4: Animal Studies Are Satisfactory At Determining Human Protein Needs

REALITY: Animal studies can be useful, but they may underestimate plant protein nutritional quality for humans.

We have to understand that many studies that have been done surrounding protein were done on various animals. This alone can have a large margin of error, as most animals have very different nutrition requirements than us. This is in addition to the fact that most studies, whether done on animals or humans, use isolated amino acids, which is not how we naturally consume our nutrients. We eat whole nutrients found in foods, and our bodies break them down into isolated components. Such a study design flaw can create anywhere from minimal to substantial differences in the results. All of this must be factored in before we solidify any conclusions. Yet in our society, we often run with claims, out of context, not understanding their full meaning or implications.

For example, in 1913, Mendel and Osborne did a study, which reported that rats grew better on animal than on vegetable sources of protein. If we draw conclusions right there and then, we will have to revisit the second myth above about the quality of protein depending on its source. However, and this is the case each time, we need to consider more of the context to get an accurate and full picture before jumping to any conclusions. As Dr. John McDougall shares, rat milk is 11 times more concentrated in protein than human breast milk. The extra protein supports this animal’s rapid growth to adult size in 5 months, while humans take 17 years to fully mature! Rats also appear to need a higher amount of protein as adults compared to humans (16-18% vs. 5-15%). Couple all that with their fundamental dietary differences, and we can see that we cannot equate what may work best for a rat, with what may work best for us humans.

Myth 5: Plant Proteins Are Not Well Digested

REALITY: Digestibility varies based on source and food preparation, and digestibility can be high.

As I shared in the second myth, there are many ways that people argue in favor of animal protein quality. This myth is one of them. Many people think that just because animal foods are protein-dense, they are automatically better. What is rarely considered is how much of that protein your body will be able to extract, how much work it takes your body to extract it, how efficiently it will be used, and the negative impacts high animal protein has on the body. Protein assimilation and bioavailability are essential considerations. When we examine them, we find that both regular plant foods and unique plant-like foods, such as Spirulina, can supply us with more protein per gram and better bioavailability than some animal foods in a direct comparison. It is estimated that we can digest anywhere from 70-100% of the protein in our food (plant and animal), and our body makes good use of all of the protein it needs. Now think about it: if we are eating much more protein than we need, which is common in North America, what difference does it make at the end of the day if a food varies in digestibility by a few points? You are still getting more than enough.

When it comes to food preparation, this opens up a whole new area of consideration as well. According to the Max Planck Institute and Dr. Gabriel Cousens in his book Conscious Eating, cooking foods coagulates around 50% of the protein. This makes it less bioavailable to our bodies. It is a fundamental biological fact that heat denatures proteins. That means it can change the protein’s shape or structure, and thus, function. A change in structure or function means they can become biochemically ineffective for our body’s use. This is just one example of why raw food diets have a lot of validity to them. Our society is just as equally obsessed with cooking everything, as it is with protein, so this is not commonly covered in nutrition literature. When we think about animal foods, they are almost all exclusively cooked in some form in our society, as opposed to plant foods, which can easily be eaten raw. This is something else worthy of consideration if we are focused on protein quality.

Myth 6: Plant Proteins Alone Are Not Sufficient To Achieve Adequate Protein Intake

REALITY: The intake and balance of intakes of indispensable (essential) amino acids and nitrogen are crucial, and can be adequately met from plant (alone) or plant and animal mixed sources.

This myth is perhaps one of the simplest to debunk if one only chooses to look at the quantity of protein, whether that be as a whole or as single amino acids, in plant foods. This information is not secret, and it is not hidden. The only thing preventing us from being empowered and properly informed about this fact is that most of us are not going to research our food. We will, however, eagerly read news headlines and run with whatever ideas they proclaim.

The truth of the matter is that plants are the original source of the essential amino acids. Animals do not make these, rather they, like us, convert one amino acid into another. Thus, when we eat animal protein, we are just eating their recycled amino acids, when we could be going to the source itself - plants. Most people are not aware of how complex protein digestion and synthesis is, and that our body makes most of the amino acids and proteins it needs as long as we support it with a proper diet. Proper, in this sense, meaning a diet composed mostly or entirely of whole plant foods. Such foods are capable of providing us with all the protein amounts and amino acid types that we need. Anyone who is consuming a diet of leafy greens and other non-starchy vegetables, starchy vegetables, fruits, legumes, unrefined grains, nuts, and seeds is obtaining both enough protein or more than enough protein, and also the right amino acids.

When it comes to plant protein being sufficient, we have ample examples of this all around us today, thanks to the increase in vegan, vegetarian, and plant-based communities. Unless someone is bluntly not eating enough calories, no one is suffering from any protein deficiency. Research routinely shows that just like omnivore diets, vegan diets also provide more protein than is required by the human body. We also have athletes and bodybuilders who excel on plant-based diets and have no shortage of protein by just eating enough whole plant foods for their needs. We also have information across thousands of years of human history, confirming that most cultures on Earth ate diets predominantly high in plant foods and low in animal foods. This includes Eastern cultures of Asia, tribal cultures of Africa, and native cultures of South, Central, and North America. Our human ancestors’ diets were also highly plant-based.

Myth 7: Plant Proteins Are Imbalanced, And This Limits Their Nutritional Value

REALITY: There is no evidence that amino acid imbalances are important. Possible imbalances can be created by inappropriate amino acid supplementation.

As you can imagine, or perhaps already know firsthand, over the years, there have been numerous attempts launched at attacking plant proteins as being inferior compared to animal proteins. However, while popular ideas may run wild with misinformation in many directions, for those who choose to look more in-depth, the results present facts that speak to the contrary. What we so often forget and neglect is that nature and our body have innate wisdom. In modern human times, due to reductionist science, we have attempted to isolate and dissect everything down to its molecular level and beyond. While this was beneficial to understanding many aspects of our world, it did not work out to our benefit when it came to the field of nutrition.

When we look at both the details and the whole picture, we begin to see that eating is easy, if and when, we follow nature and our body’s innate wisdom. We don’t need to analyze or count or stress over nutrients or calories. What we do need to do is just eat whole plant foods from a variety of plant food groups. It is that simple. It is our highly processed, highly animal-food-obsessed, and highly isolated nutrient diets that are causing us the majority of the health and weight problems we are seeing and experiencing today. When we ingest isolated nutrients, be they the macro- or micro-nutrients, especially from, or along with, synthetic counterparts, it is then that we risk creating the greatest and most detrimental imbalances within our body. Be that dealing with protein, or any other nutrient.

The industries that promote and offer isolated protein products of different amino acids are massive today and relevant to mention here too. It probably comes as no surprise that the protein supplementation industry has hitched an easy ride here amidst our fears of needing more or not getting enough protein. Anyone who begins a new workout, whether a strict plant consumer or a plant-and-animal consumer, has an automatic inclination to think that they need isolated protein support. This leads them to add to their diets all kinds of heavily processed protein shakes, protein bars, protein gels, and you name it. We can mostly thank cunning marketing campaigns by those food industries for this one. The isolated products come most commonly in the form of numerous protein shakes and protein bars. Very few people stop to consider both the short-term and long-term health consequences of consuming isolated amino acids, never mind the slew of synthetic and chemical ingredients they often come with, which are a huge problem in and of themselves. It is sad to think about how much money people are spending and wasting on isolated nutrients, causing unnecessary stress for their body, health, and wallet. The sports supplement market has today become a multi-billion dollar industry thanks to us consumers. As a report from Nutraceuticals World shares, “On the subject of proteins, they have remained the golden child of the sports nutrition industry.” This industry competes with the animal-product industry to gain users and preys on the idea that you need these isolated products, lest be “scrawny” or not get the muscle growth you desire.

In the end, there is nothing imbalanced or deficient about the whole, natural plant foods with which nature has provided us. What is imbalanced is how we feed ourselves in these modern times; we lack real food and high-quality food that was perfectly created for our human bodies and meant to offer protection, healing, and proper health.

Myth 8: More Protein Is Better

REALITY: High protein diets create various types of stress and imbalance within the body.

No matter how we look at it, there are many things in life where more does not mean better. On the contrary, it can be far from it. To illustrate this point, various examples can be used. Is eating more calories better? Not for most people. Is having more debt better? Far from it. Yet when it comes to more protein, we seem to think that more is better when the truth is quite the opposite.

As we know today from many sources and experts (and for some from personal experience), diets high in protein are linked with numerous health problems. (Here is a summary from a medical report compiled from various studies.) This includes the apparent stress and damage to our liver and kidneys, but also the less obvious such as a link to most chronic diseases, including cancer, heart disease, and osteoporosis. Diets high in protein, specifically animal protein, cause a strain on our blood pH balance. They and are associated with systemic acidosis, which raises the risk of cancer, immune dysfunction, kidney stones and kidney disease, auto-immune, and other chronic diseases.

So before you choose to focus on more protein in your diet, address where the idea of “not enough” first came from, and was it correct, to begin with. Anyone who digs deeper into this topic, and goes past the industry collusion and conditioning will find that a lack of protein is a non-existent issue whether we eat a 100% whole-foods, plant-based diet, or one that includes animal products. The key is simply eating enough food and a variety of food to have our protein needs not just met, but comfortably surpassed.

There is no real evidence of dietary protein deficiency. People are actually more likely to suffer from protein excess than protein deficiency. The adverse effects associated with long-term high protein/high meat intake diets may include disorders of bone and calcium balance, disorders of kidney function, increased cancer risk, disorders of the liver, and worsening of coronary artery disease. Considering all of these potential disease risks, there is currently no reasonable scientific basis to recommend protein consumption above the current recommended daily allowance.

Michael Greger, MD — Changing Protein Requirements

Conclusion

When it comes to having a correct understanding of protein today, I equate it to the phenomenon of growing up and learning the truth about a story that was meant to entertain us while we were young and naive. Perhaps the story of Santa Claus or the Tooth Fairy comes to mind. As part of our maturation process, we broaden our understanding of how the world works and must increasingly take accountability for our beliefs and choices. If we continue to depend on the ideas of others, we are bound to be gravely disappointed.

This is your invitation and opportunity. Our society is waking up, and one by one, we are dispelling myths, clearing up misinformation, and calling out lies. We are evolving and updating our information in every area, and protein is no exception. We have been told so many wrong things over the ages jus to get us to conform to a particular way of being. All too often, ideas get shared and spread to fulfill some specific agenda. Here, again, protein is no exception. The story we were told about protein got us to conform to a particular behavior; it got us to depend heavily on animal products for food. Whether it was due to fear about harming our health or due to social pressures of wanting to fit in, we took those flawed ideas about protein without question.

Today, as our human consciousness evolves, more of us are beginning to think for ourselves. We are becoming more accountable for our choices and the state of our health. We are asking more questions and seeking more answers; answers that numerous sources, organizations, and institutions are not always able, ready, or willing to provide to us. But if you are willing to be an independent thinker, I invite you to release the old paradigms and conditioning. Open your mind, sharpen your skills of discernment, and seize your mind’s potential. Don’t settle for ignorance or live life unconsciously driven by the ideas of others. Empowerment and liberation come with taking personal responsibility, and there is perhaps no more important area to which we should apply this than our health.

To conclude and provide you with a convenient summary, I invite you to watch the following short video from Dr. Michael Greger. He is a highly acclaimed medical doctor and author who has dedicated his life’s work to the study of the science of nutrition.

For further information about this topic and to learn more about protein myths, quantity, quality, and different food sources, consider any or all of the following resources:

  1. Protein: Too Much? Too Little? a recorded online video class by Evita Ochel

  2. Changing Protein Requirements by Michael Greger, MD ~ Nutrition Facts

  3. Protein: Everything You Think You Know is Wrong by David L. Katz, MD

  4. Setting the Record Straight by Michael Bluejay

  5. The Protein Myth ~ Physicians Committee for Responsible Medicine

  6. Plant Foods Have a Complete Amino Acid Composition by John McDougall, MD ~ American Heart Association

  7. How Plant Protein Wins Over Animal Protein ~ Joel Fuhrman, MD

  8. The Myth of Complementary Protein by Jeff Novick, MS, RD ~ Forks Over Knives

  9. ‘Complete’ and ‘Incomplete’ Protein is Complete BS by Ryan D. Andrews, RD, CSCS ~ Furthermore Equinox

  10. Vegetarian Protein Is Just As ‘Complete’ As Meat, Despite What We’ve Been Taught by Kristen Aiken ~ Huff Post

  11. 7 Ways Animal Protein is Damaging Your Health by Sofia Pineda Ochoa, MD ~ Forks Over Knives

  12. Plant vs. Animal Protein and Heart Disease by Michael Greger, MD ~ Nutrition Facts

  13. The No-B.S. Guide to Vegan Protein by Courtney Davison ~ Forks Over Knives

  14. Where Do You Get Your Protein? by John McDougall, MD

  15. Where Do You Get Your Protein? by Alan Goldhamer, D.C. ~ T. Colin Campbell Center for Nutrition Studies

  16. Protein in the Vegan Diet by Reed Mangels, PhD, RD ~ The Vegetarian Resource Group

  17. Do Vegetarians Get Enough Protein? by Michael Greger, MD ~ Nutrition Facts

  18. Are BCAA (Branched Chain Amino Acids) Healthy? by Michael Greger, MD ~ Nutrition Facts

  19. Protein and Amino Acid Requirements in Human Nutrition - World Health Organization (2007)

  20. Plant proteins in relation to human protein and amino acid nutrition ~ American Journal of Clinical Nutrition; May 1994 vol. 59 no. 5 1203S-1212S

  21. Meta-analysis of nitrogen balance studies for estimating protein requirements in healthy adults ~ American Journal of Clinical Nutrition; January 2003 vol. 77 no. 1 109-127