Protein. Most associate it with large slabs of red meat, or at the very least, dishes that can only come from animals. While many people do not know much about protein itself, we generally know the general truth that it is important to our well-being. However, bring up protein and you are almost guaranteed to get into a debate. There exists a plethora of examples of heated online arguments on the “protein debate”, whether they are between vegetarians and meat-eaters, or vegans and vegetarians, and so on. The arguments can vary on the actual importance of protein, the different types, as well as on the amounts we actually need. In order to better understand the reason behind the debates, let us first understand the different types of protein, the amounts needed, as well as why it is so important.
First, let us understand what protein is. Loosely defined, it is one of the seven essential nutrients our body needs. These nutrients are categorized into two categories: macronutrients and micronutrients. The latter category is reserved for vitamins, with protein falling into the former category, along with carbohydrates and lipids. Sounds simple enough – seemingly no cause for debate just yet! Let us elaborate on to why protein is considered to be an essential macronutrient, and look at some of the many roles protein has in our bodies.
Generally, protein has a role in the regulation as well as maintenance of the many functions of our body, including blood clotting, cell repair, vision, fluid balance, and the production of hemoglobin, hormones, antibodies, tissues, and enzymes. Protein is the primary component of our hair, muscles, nails, eyes and internal organs and acts as a carrier molecule for vitamins such as vitamin A and minerals such as iron in order for them to be utilized by our bodies. These are just some of the many functions protein has in our bodies, and after understanding these, we can move on to see what the many deficiency signs of this macronutrient look like.
When a diet is deficient in protein for a prolonged period of time, some of the symptoms can include swelling in the hands and feet, feelings of nausea and dizziness, anemic-type conditions, low immunity in the sense of constantly catching colds or flus, premature aging (wrinkling, dull and loose hair that falls out), low hormone levels, low vitamin A levels, muscular incoordination, a prolonged sense of weakness as well as fatigue, cataracts, slow recovery from external wounds, as well as mind, mood, and memory problems. A protein deficiency, as pointed out above, can be potentially very serious and dangerous, and the multitude of symptoms show just how important it is to be getting enough protein in our daily diets.
However, protein can still be further categorized based on what it is made up of. Protein itself is made up of amino acids, which are linked together by peptide bonds and contain carbon, oxygen, nitrogen, and sometimes sulfur. When we understand what types of amino acids there are, we can better understand why there are different types of protein available and why they differ from each other in a nutritional sense. Amino acids fall into three basic categories. The first one is called essential amino acids. The second is conditionally essential amino acids, and the third is non-essential amino acids.
Essential amino acids have the “essential” aspect to them because our bodies cannot produce them on their own, and they are therefore needed through our diet. The second category, conditionally essential, means that our bodies are not able to produce these amino acids until a certain age in our lives, and after that age, they are no longer required from our diet, and are therefore not essential anymore. The last category is non-essential, and these include all of the amino acids that our bodies are capable of producing on their own, and are therefore not necessary through diet.
Now that we know the three categories of the building blocks of protein better, we can begin to understand more about why this macronutrient can be a cause for so much controversy and misunderstanding. Based on what amino acids there are available in a given source of protein, that source is then either considered a “complete” protein, or an “incomplete” protein. A complete protein is when a given food has all the essential amino acids within it, which again, are the ones our body cannot produce on its own. An incomplete protein, on the other hand, is a type of protein source that does not include all of the essential amino acids our body needs in it.
Generally speaking, animal-based sources of protein, such as animal flesh, eggs, and milk, are complete proteins. This does not hold true for every single option, but generally. Plant-based sources, on the other hand, such as legumes, vegetables, grains are considered to be incomplete proteins. Again, this is not the case for every single option, but generally-speaking it does hold true.
This means animal-based sources tend to have all of the required amino acids within them, whereas vegetarian or vegan sources do not. This is where the popular notion that “vegetarians/vegans cannot get enough protein in their diet” arises from, and at surface value, it does seem like an accurate statement if this is everything we know and understand about protein. Generally speaking, 0.75g/1kg of an average body weight is ideal, but this can differ for children, athletes, pregnant women, those experiencing injuries, and so on.
However, what we must understand is that while animal-based sources generally are available as “complete”, we can still mix and match plant-based proteins with each other in order to turn two or more “incomplete” sources into a final and desirable “complete” source. Let us use an example to better understand this idea. The essential amino acids are as follows: isoleucine, leucine, methionine, phenylalanine, theonine, tryptophan, and valine. Legumes, for example, a plant-based “incomplete” option for protein, are high in the essential amino acid lysine (among others), but are low in tryptophan (again, among others). Grains, on the other hand, are low in lysine, but high in tryptophan. So while separately these two options are incomplete proteins, together they become a different story. All this means in the end that when you eat a type of legume with a type of grain, they are balancing each other out in this sense and together becoming a “complete” protein. The more you combine vegetarian or vegan sources of protein with each other, the more likely you are consuming protein in its ideal form – complete. This is called protein complementarity, and it is how vegans, vegetarians, as well as those who simply do not consume a lot of animal-based protein, still are able to get the recommended amounts.
Let’s look at an example of what the mixing and matching would look like for a lunch or dinner meal:
Incomplete Protein #1 (Kidney beans) + Incomplete Protein #2 (Buckwheat) = Complete Protein (Kidney beans and buckwheat)!
Of course in order to make sure you are getting the complete proteins in the necessary amounts, you should always aim to mix and match at every meal to ensure no deficiencies, and once you get the hang of it, it will come naturally and you won’t even think twice about it. Eating a salad? Add some nuts or seeds to it. Eating a lentil stir-fry? Mix in some vegetables or grains into it! It will keep your meals not only more protein-packed but also more layered and interesting.
So for people who claim vegetarians, vegans or those who consume small amounts of meat cannot get adequate sources of protein, that in itself is not true. However, if you are thinking about lessening your meat intake, or becoming a vegetarian or vegan, it is important to pay special attention to your complete protein intake to ensure you are going about it in a way that will not result in any deficiencies.
However, just as it is extremely important to ensure you are getting adequate amounts of protein on a daily basis, like most vitamins, minerals, and macronutrients, there are not only signs of deficiency, but also signs if excess – as in toxicity. When people often proclaim the importance of protein, unfortunately some overdo it, whether it be by food, or by relying on commercial protein powders or bars. Just as the deficiency is an important issue, so is toxicity. If a person has an excess of protein, it can cause an increased risk of kidney problems, as well as an increased risk of liver problems. It can also elevate our blood cholesterol levels and bacterial growth in our intestines. The acidity of protein excess can lead to bone calcium loss, which, in severe cases, can lead to osteoporosis and/or dental diseases.
So whether you are a vegetarian, vegan, omnivore, raw foodist, or so on, the actual importance of protein in our bodies should never be underestimated. Second, the type of protein should always be considered, and if it is coming from plant-based sources, always make sure to mix and match different types in order to successfully complement your proteins to create complete proteins. Third, even though it is important in our bodies, it does not mean we have to overdo it, as this can actually have detrimental affects in the long run. By being more informed on the truth of protein, we can aim to not only consume it in appropriate amounts, but also in the forms most beneficial to our bodies!
Photo courtesy of Viva Luxury