Having been a vegan, and specifically a vegan chef & nutritional coach, for the last 5 years, I hear a LOT of ridiculous, non-factual claims & questions about diet. One of the biggest ones is around the idea of protein intake, "complete proteins", and people incorrectly thinking that it is hard for vegans to get enough protein.
Today, I want to break down a bit of this conversation on the most basic level. I'm not going to dive deep into the vegan vs dead animal diet, but focus on proteins & amino acids, how our body breaks them down and uses them, and a little history of the fallacious complete protein argument.
To start off, I will leave this one quote about veg diets, from Dr. John McDougall:
The reason it is important to correct this misinformation is that many people are afraid to follow healthful, pure vegetarian diets ― they worry about ‘incomplete proteins’ from plant sources. A vegetarian diet based on any single one or combination of these unprocessed starches (eg, rice, corn, potatoes, beans), with the addition of vegetables and fruits, supplies all the protein, amino acids, essential fats, minerals, and vitamins (with the exception of vitamin B12) necessary for excellent health. To wrongly suggest that people need to eat animal protein for nutrients will encourage them to add foods that are known to contribute to heart disease, diabetes, obesity, and many forms of cancer, to name just a few common problems.
So, what is protein?
Proteins are polymer chains made of amino acids linked together by peptide bonds. During human digestion, proteins are broken down in the stomach to smaller polypeptide chains via hydrochloric acid and protease actions. This is crucial for the absorption of the essential amino acids that cannot be biosynthesized by the body.
There are nine essential amino acids which humans must obtain from their diet in order to prevent protein-energy malnutrition and resulting death. They are phenylalanine, valine, threonine, tryptophan, methionine, leucine, isoleucine, lysine, and histidine.
The human body is made up largely of proteins (the second largest constituent after water), making up most of our muscle and many other tissues. Now, the mainstream understanding seems to be something like "eat lots of proteins, and they will become the tissues you need"... which is incorrect.
When we eat whole protein chains, our body has to break them down (as mentioned in the quote above)... Ever noticed how much energy it seems to take to digest dead animals? That is in part due to your body having to break down all those proteins into the amino acids it actually needs.
What are Amino Acids
Amino acids are organic compounds containing amine (-NH2) and carboxyl (-COOH) functional groups, along with a side chain (R group) specific to each amino acid. The key elements of an amino acid are carbon (C), hydrogen (H), oxygen (O), and nitrogen (N), although other elements are found in the side chains of certain amino acids. About 500 naturally occurring amino acids are known (though only 20 appear in the genetic code) and can be classified in many ways. They can be classified according to the core structural functional groups' locations as alpha- (α-), beta- (β-), gamma- (γ-) or delta- (δ-) amino acids; other categories relate to polarity, pH level, and side chain group type (aliphatic, acyclic, aromatic, containing hydroxyl or sulfur, etc.). In the form of proteins, amino acid residues form the second-largest component (water is the largest) of human muscles and other tissues. Beyond their role as residues in proteins, amino acids participate in a number of processes such as neurotransmitter transport and biosynthesis.
Put simply, amino acids are some of the most important building blocks of the human body; they are depended upon for new tissues, brain function, and much more. There are 2 basic categories of amino acids: essential (which our bodies cannot synthesize), and non-essential (which our bodies synthesize using the essentials).
Many sources also refer to conditional essentials, amino acids which our body produces normally, but which can be lost due to stresses & environment. What this means is that stressors from the outside world also affect your dietary needs... who would've guessed? Here is that breakdown on Wikipedia.
In the 1970s there was a fad started, which made the claim that humans need to eat complete proteins (foods containing all 9 essential amino acids) for good health, though it has long since been debunked. Like many things now known to be factually untrue (like the US being attacked at the Gulf of Tonkin), this claim still floats around and screws up many people's understandings of a healthy diet.
In reality, as long as you are getting the essential amino acids every day, there is no need for them to all come in any given meal. A related fact that has been shown clinically, but the mainstream still argues against, is that if you are eating enough calories and have a balanced, plant-based, whole-food diet, you are pretty much guaranteed to get (more than) the amino acids & "proteins" that you need.
The Essentials & Where to Get Them
- Helps produce red & white blood cells
- Helps transport neurotransmitters
- Grains: Buckwheat, Rice, Rye, Wheat
- Seaweed, Cantaloupe, Potatoes, Cauliflower, Corn
- Most Beans & Legumes
- Seeds: Hemp, Chia
- Helps produce energy & Hemoglobin
- Assists in Nitrogen growth in cells, especially kids
- Grains: Oats, Quinoa, Rice, Rye
- Seeds & Nuts: Almonds, Cashew, Chia, Hemp, Pumpkin, Sesame, Sunflower
- Fruits: Apples, Blueberries, Cranberries, Kiwis, Pumpkin
- Veggies: Cabbage & Spinach
- Beans & Lentils
- One of the best amino acids for stimulating muscle growth
- Helps regulate blood sugar through Insulin moderation
- Helps prevent & treat depression
- Veggies: Peas, Leafy Greens, Seaweed, Turnip Greens, Watercress
- Fruits: Apples, Avocado, Bananas, Blueberries, Dates, Figs, Olives, Pumpkin, Raisins
- Seeds & Nuts: Chia, Hemp, Sesame, Sunflower
- Used to produce Carnitine, needed to convert fatty acids into an energy source
- Aids in Collagen production
- Helps absorb Calcium
- Beans, Chickpeas, Lentils
- Seeds & Nuts: Almond, Cashew, Chia, Hemp
- Veggies: Parsley, Spirulina, Watercress
- Is the only amino acid containing sulfur, needed to form cartilage
- Aids in muscle growth and creation of Creatine
- Seeds & Nuts: Brazil Nut, Cacao, Chia, Hemp, Sunflower
- Grains: Oats, Rice, Wheat
- Fruits: Figs, Raisins
- Veggies: Seaweed & Onion
- Most Beans & Legumes
- Converts into Tyrosine (needed to synthesize proteins, brain chemicals, and hormones)
- Increases the lifespan of Endorphins (pain relieving chemicals)
- Endorphin deficiency is tied to Alcohol, Cannabis, Nicotine, and Opiate addictions
- Fruits: Avocado, Berries, Figs, Olives, Pumpkin, Raisins
- Most Beans, Nuts, and Seeds
- Veggies: Leafy Greens, Seaweeds
- Grains: Quinoa & Rice
- Supports healthy immune, nervous, cardiovascular systems
- Helps balance protein levels
- Produces Glycine & Serine (good for bones, skin, hair, and nails)
- Helps with fatty acid digestion
- Veggies: Leafy Greens, Watercress, Spirulina
- Fruits: Avocado, Figs, Raisins, Pumpkin
- Seeds & Nuts: Almond, Chia, Hemp, Sesame, Sunflower
- Grains: Quinoa, Wheat
- Necessary for a healthy nervous system (sleep, neurotransmitter function)
- Converted in the brain to Serotonin (the happiness chemical)
- Serotonin deficiency is tied to Alcohol, Cannabis, Nicotine, and Sugar addictions
- Grains & Beans: Chickpeas, Lentils, Oats, Quinoa
- Seeds: Hemp, Chia
- Fruits: Apples, Avocado, Bananas, Figs, Oranges, Pumpkin, Winter Squashes
- Veggies: Asparagus, Beets, Carrots, Celery, Leafy Greens, Onions, Parsley, Peas, Peppers, Seaweed, Sweet Potatoes, Watercress
- Necessary for muscle growth, recovery, and maintenance
- Most Beans, Legumes, Whole & Sprouted Grains
- Veggies: Spinach, Broccoli
- Seeds: Sesame, Hemp, Chia seeds
- Fruits: Apples, Apricots, Avocado, Blueberries, Cranberries, Figs,
The goal of this piece was not to try to convince you that you shouldn't eat proteins or anything like that (many of the EAA sources above are quite high in protein), but rather to shift the conversation away from protein and onto something much more focused, and honestly more relevant. Not only is daily in-take of enough of the 9 Essential Amino Acids necessary for basic health, but our physical & psychology symptoms can often be traced back to (or at least intensified by) deficiencies in Amino Acids & chemicals they allow our bodies to create.
Further Reading & Sources
- Vegan Health: Proteins & Amino Acids
- American Heart Association: Plant Foods Have a Complete Amino Acid Composition
- National Academies Press: Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids
- OneGreenPlanet: Need Protein? Here are 9 Amino Acids Found Abundantly in Plants