All proteins are made by plants. I repeat just in case is not clear. All proteins are initially made by plants. Plants are the only organisms able to take nitrogen from the air, break it down and incorporate it to amino acids to create proteins.
Proteins are made up by amino acids, and all the essential amino acids originate from plants. Essential meaning that we have to get them from our diet. Animals have only the ability to take those proteins from the plants and recycle them, second hand proteins (1).
The idea that plant protein was inferior to animal protein came about from studies performed on rodents more than a century ago. Scientists observed that rats didn’t grow as well on plants as they did on their own milk. However, rats don’t grow as well on human breast milk either. Rat milk has ten times more protein than human milk, because rats grow ten times faster than humans do. So, that doesn’t proof in any way that animal protein is better for humans than plant protein (2).
* Grams per 100 milliliters (in terms of % of calories, cow’s milk has four times more protein than human milk; 21% vs. 5%)(4)
** Time required to double birth weight
The American Heart Association questioned the completeness of plant proteins on a publication in 2001. Dr. John McDougall challenged them, and they ended up changing the statement and acknowledging that “plant proteins provide all the essential amino acids, and there is no need to combine complementary proteins” (5).
The myth that plant proteins are incomplete, and that we have to combine certain foods at meals have been dismissed by the nutrition community decades ago, but obviously many health care professionals haven’t heard the old news yet.
We know that plant proteins are complete proteins and that we don’t need to eat animal foods in order to get enough protein from our diet. However, which proteins are better for us, plant or animal? The answer to this question coming next…