"If you repeat a lie often enough, it becomes truth."
It is disturbing, even immoral, that so many people are denied information that could do so much for their personal health, as well as for the health of our economy, our society, our environment, other sentient beings and our planet as a whole. Never in history, in the scientific research conducted on health and nutrition, the evidence has been so clear and consistent: a whole-food plant-based diet is the best choice to promote optimal health, both in the short and long run (1, 2, 3).
Such diet is rich in whole foods like legumes (beans, peas, lentils, etc.), vegetables (leafy and starchy vegetables, such as broccoli, sweet potato, beets and carrots), whole grains (oats, rice, quinoa, millet, couscous, etc.), fruit, seeds (flax, chia, etc.), nuts (walnuts, almonds, etc.), spices and aromatic herbs (turmeric, ginger, mint, etc.).
Despite the controversy, and the resulting confusion found in books, blogs, media or even at the doctor’s office, there’s no doubt left about the benefits of this diet – at least among those who rely on an impartial analysis of the whole body of scientific evidence.
Nevertheless, every time I say to someone that I follow a strictly plant-based diet (also known as vegan diet), in other words, that I do not consume any foods of animal origin, the first thing I heard is “And now? Where do you get the protein that you need so much?”; as if plants do not have all the protein necessary to nurture and preserve human health.
The focus on the consumption of abundant amounts of protein – particularly animal protein – is so entrenched in our culture that, more often than not, warnings are spoken to draw people’s attention on how they will struggle to find the much-needed protein to support the healthy functioning of their bodies, if they choose to not consume foods of animal origin. However, when one analyzes the current medical literature, there is not a single case of protein deficiency, except in a situation where there is an inadequate consumption of the necessary amount of calories needed to safeguard the body’s healthy metabolism. Actually, even those who are vegan consume, daily, on average, 70% more protein than what they need (4).
Following the same train of thought, here’s something that stuns me: even though I’m constantly asked by everyone if a plant-based diet is truly healthy, no one has ever done that same question about a conventional omnivore diet. No one has ever asked me, “Hey, are you including in your diet the recommended daily dose of five to nine servings of fruits and vegetables?” No one has told me, “You know, the World Health Organization recommends that we ingest 35 grams of fiber per day, and since there is no fiber in animal foods, my advice is that you increase your intake of vegetables, legumes, and whole grains.” No one has ever told me, “My God, your omega-6/omega-3 ratio is supposed to be 3-to-1, but yours is 15-to-1. Quick, eat less animal fat and vegetable oils (both rich in omega-6) and increase your vegetable consumption (rich in omega-3)”. Nothing. Not even a remark on the properly researched positive association between the risk of developing cardiovascular diseases, the leading cause of death in the world, with the consumption of animal protein, cholesterol and saturated fat (nutrients exclusively and abundantly found in any piece of beef, pork, chicken, fish, seafood, as well as in eggs, dairy products and the remaining products of animal origin). Not even a reference on the relevance of antioxidants, flavonoids, vitamins, and minerals – micronutrients that promote the ideal functioning of almost all cells in our body, which can only be acquired in sufficient amounts with a daily intake of large quantities of fruits, vegetables, legumes and whole grains.
On top of that, “experts” love to make a distinction between good and bad fats, good and bad carbohydrates, good and bad cholesterol. But everyone appears to be on the same page on protein. Regardless of its kind, the more the better.
I can even understand part of the justification for such dissonance. The subject of nutrition is quite emotional, and it looks like that nothing prompts more vivacity among people than the topic of protein in the diet.
Since its discovery, in 1839, by the hands of the Dutch chemist Gerhard Mulder, protein, a chemical macromolecule which contains the chemical element nitrogen, appears to be the most sacred of all nutrients (5). As a matter of fact, the word “protein” derives from the Greek “proteios”, which means “of paramount importance”.
However, in the last two centuries, despite its paramount importance, deeply different stances on the benefits of a greater or lesser intake of protein have been debated, and also on the merits of animal protein versus vegetable protein. Throughout this whole time, solid scientific evidence, which clearly supports a diet with little but adequate protein, favoring vegetable sources (6), has surfaced. However, until now, the scientific evidence has been losing the battle against the major industries – which emphasize diets with lots of protein, favoring animal sources. We just need to look around to notice that we live in a society in which we are erroneously induced, as I intend to demonstrate, to believe that foods of animal origin are the only and worthy protein source in our diet, and are essential to promote the health of our species, the Homo Sapiens.
As I keep exploring the scientific field of human nutrition, I have been noticing that the generalized confusion about the subject is mainly fed by a campaign of misinformation, strongly financed and perpetuated by the rich and powerful lobbies of the meat and dairy industries, as well as by those of protein supplementation and fitness. The ones that have been spending millions of euros in marketing, in order to convince society that the consumption of animal foods are absolutely necessary in order to thrive. And, since we all enjoy to hear good things about our bad habits, we are more than willing to believe and share this false information with others.
.
Before we begin to unfold what the scientific evidence has to tell us, I want to clearly explain what proteins and amino acids are; how they are made and what is their intent.
What are proteins and amino acids? And what is their role?
Protein, fat, and carbohydrates – the so-called macronutrients – represent, together with water, the majority of what we eat. And only a tiny part of that comes from minerals, vitamins and other chemical compounds – known as micronutrients. Furthermore, protein, fat, and carbohydrates are the source of all calories we eat.
Proteins – crucial compounds in the structuring and functioning of the bodies – are comprised of amino acids joined together in long strings by peptide bonds that twist and fold in three-dimensional space and produce centers to facilitate the biochemical reactions of life that either would run out of control or not run at all without them. Interestingly, many of the underlying physiopathologic mechanisms of noninfectious and chronic diseases are the result of derangements of proteins.
There are 20 different amino acids known to be essential and basic components when it comes to building all proteins found in nature, including the human body. And they do it by presenting themselves in different sequences, akin to the 26 letters of our alphabet, which are arranged in different order to form all the words of a dictionary.
We, homo sapiens, like any other animal, can synthesize some of these amino acids based on our metabolic needs, using the chemical elements carbon, nitrogen, sulfur, oxygen, and hydrogen. Therefore, these amino acids do not necessarily have to be present in the constitution of the food we eat, and, because of that, they are called “non-essential amino acids”. Yet, we cannot synthesize 9 of the 20 amino acids, and these have to be present in the food we ingest. For that reason, they are called “essential amino acids”.
Plants (and some microorganisms) are the first source of all amino acids, without which the survival of all other living beings would be unfeasible. Not only they produce all of the 11 amino acids regarded as “non-essential” to the human body, plants are also the primary synthesizers of the 9 amino acids known as “essential” (7,8). These 9 amino acids can only be found in food of animal origin, like meat, fish, eggs, and milk, because they are consumed and incorporated throughout the emergent trophic levels of all food chains, based on the primary consumption of plants.
After every bite, the stomach acid and the different digestive enzymes, found in our gastrointestinal tract, decompose the proteins in the food we eat into individual amino acids. These amino acids are then absorbed through the gut wall into the bloodstream, which, in turn, takes them to all the cells of our body. After entering the cells, these amino acids are used to form new proteins, required for the body’s proper functioning.
This process of disassembling and reassembling the amino acids into different proteins is akin to what happens when we purchase a necklace of colored beads to replace one we lost. Since the colored beads of the new necklace are not ordered like the previous ones, we must disassemble it. That way we can build a new necklace based on the former’s color sequence. This is precisely the phenomenon that happens in our body when new proteins are formed to replace those shattered, excreted or the ones that cannot function anymore.
Different proteins are produced to perform specific functions in the human body: there are motor proteins, others that act as structural materials, thereby helping our cells to keep their shape; proteins that act as enzymes that catalyze biochemical reactions; proteins that act as hormones and chemical messengers – just to mention some of their vital roles in the human body.
As previously mentioned, to repair and grow the tissues of the human body, proteins need to be regularly replaced. Nevertheless, since our body has a highly efficient system of reutilization and preservation of amino acids (9, 27), the amino acid requirements in our diet are small.
When we are children, we use a significative portion of our food-sourced proteins to fuel our growth. But, when we’re adults, we rely on them mainly for maintenance purposes – tissue repair and replacement of proteins lost by the body in the form of dead cells of the skin and gut, in the menstrual flow, in semen, hair, nails and other forms of non-recyclable proteins. The amount lost per day (already discounting the portion that is eliminated in the urine and stool) is minuscule – less than 5 grams (10). Adding to this value, and taking into consideration the extremely slow pace of the human body’s growth, the protein requirements for the growth of new tissues are also extremely tiny (11, 12).
An important point which should be emphasized is the fact that, with the exception of a small reserve of amino acids, and in contrast with what happens with the fats and carbohydrates found in the diet, the excess of amino acids ingested throughout the day is not stored for future use. So, when we consume protein beyond our needs, this excess must be metabolized, particularly by our liver, and then excreted through the kidneys. As we can read in an upcoming article, this protein excess, particularly the one of animal origin, causes, directly or indirectly, serious harmful effects as time goes on (future article: “The harmful effects of animal protein”).
Having said that, it obvious that we need protein in our diets. However, we just don’t require half of what most people think they need. To aggravate this matter, we have been obsessed with deconstructing food based on its individual nutrients and, as we keep doing it, we have been developing an unhealthy obsession for certain nutrients – and protein is, possibly, the number one among them.
The narrow-minded practice of deconstructing foods based on their several nutrients, assigning them specific physiological effects, but neglecting the synergistic effects of the context as a whole, only tends to thicken the confusion about what constitutes healthy or unhealthy foods. The more we think that a specific nutrient characterizes one food in particular, the more we walk towards ignorance. All the nutrients found in one food work together to foster healthiness or disease. Ultimately, one food, in its wholeness (and its inherent quality when it comes to promoting health or disease) is more important than the sum of its parts.
Yes, there is calcium in cheese and iron in a steak. But what about the baggage that comes with them? When we ignore this crucial concept, we can even say that Coca-Cola is healthy just because it has a high water content. Likewise, dairy cannot be considered healthy simply because it is one of the top sources of calcium in the modern diet. What about the cholesterol, saturated fat, animal protein, xenoestrogens, antibiotics and other toxins and pollutants? What is the baggage that comes with calcium found in broccoli? Fiber, lots of vitamins and minerals, like Vitamin C and iron, and also thousands of other antioxidants and phytonutrients. When, in our diets, we give preference to plant-based foods, we only get bonuses as baggage.
Having said that, I cannot argue about the harms of the emphasis given to the excessive intake of protein if, sometimes, I don’t plunge into the world of reductionist nutrition. For instance, this will be extremely important to show you that there are significant differences in the human body’s physiological responses, which derive from the consumption of animal protein instead of opting for plant protein. However, I will make the effort to never ignore the big picture.
.
To sum it up, unless we are in a situation of food shortage, those who think that there are no unhealthy foods, as long as we indulge them in moderation, are wrong. “Don’t forget your protein” can effectively be the worst advice that healthcare professionals can give. Taking life out of our years and, potentially, years out of our lives.
Let’s suppose that someone important in your life unexpectedly has a heart attack. While he is recovering in a hospital environment, both of you promise each other to do everything feasible to make sure that this never happens again, because the next one can be deadly. After some research, you then find the advantages of a whole-food plant-based diet, which has been proving to be able to revert even advance cases of ischemic coronary disease (13, 14, 15, 16, 17, 18).
Excited about that, you decide to change your diet. In the first appointment with the cardiologist, you decide to disclose your steps towards a healthier diet. However, and based on a lack of nutritional education that the cardiologist has been accumulating throughout his medical career, he promptly replies: “I strongly recommend you not to go ahead with that idea. Foods of plant origin have deficiencies in certain amino acids, which may lead you to develop an insufficiency in some of those. To adopt a healthy diet is definitely a good idea but, to make it balanced, you must include foods that have enough protein, like meat, milk, and eggs.” Sadly, following this medical advice can mean a death sentence.
Unfortunately, the doctor's advice was based on a false premise. Most people think that protein equals animal protein; and, even when they are aware that plants also have protein, there is still the concern about its poor quality and incompleteness.
.
On the subject of protein in our diet, the following questions are the source of a great share of confusion:
My goal is to focus on all these questions, showing you the scientific evidence and the consensus that there is around these questions, aiming to finally clarify all this misinformation.
Nevertheless, I want to make it clear right away that there is no scientific evidence whatsoever regarding the existence of protein deficiency (19, 20), except in a case of food shortage – situations in which protein, as well as many other nutrients and calories, are consumed in insufficient amounts (21, 22, 23). Not even the pathologies induced by a profound malnutrition – as is the case of the disease of Kwashiorkor – have their cause in protein depletion, but rather in an energy (caloric) deficiency of the diet (20). As a matter of fact, in 90% of countries and territories in the world, people consume more protein than what they need (24), and that brings serious problems (25).
Researchers in the field of nutrition know (or they should know) that is virtually impossible to plan a whole-food plant-based diet (rich in fruits, vegetables, legumes, whole grains, nuts, seeds and spices), adequate in terms of calories, which can then be proved to be deficient in the supply of amino acids necessary for the body’s proper functioning (26). The only possible exception may be a diet exclusively based on fruits (future article: “Foods of plant origin provide “complete” protein”).
.
Bibliography:
