Has anyone ever told you plant proteins are incomplete?
Or that you need to combine different sources of plant-based proteins to make sure you get all your essential amino acids?
Well it’s mostly false and in this post I will tell you why.
The Idea Of Protein Combining
The idea of protein combining basically says that since some plant-based protein sources lack certain amino acids you should eat other protein sources along with them to get all the essential amino acids.
Amino acids are the building blocks of protein and essential amino acids are those that our body cannot make itself so you need to get them through your diet. There are nine of them: Histidine, Isoleucine, Leucine, Lysine, Methionine, Phenylalanine, Threonine, Tryptophan, Valine.
It was long believed that most plant proteins lack one or more of these nine essential amino acids so in a few decades ago the idea arose that you should combine different vegan protein sources that complement each other in regards to amino acids.
That way you could turn these “incomplete” proteins into “complete” proteins.
Why Is Protein Combining False?
Even though some plant-based foods are lower in certain amino acids than animal sources, they don’t completely lack them. In fact, it is almost impossible to become amino acid deficient unless you would start eating only one source of plant-based protein from now on.
Even the American Heart Association concluded in 2011 that “plant proteins can provide all the essential amino acids, and there is no need to combine complementary proteins.”
As so often the reason for this is because our body is a lot smarter than we think. Instead of using the amino acids from a meal right away it creates an amino acid pool in each cell where amino acids from multiple meals end up.
Think of this as a swimming pool of free amino acids that will be used to grow or repair tissue. So if a body process needs specific amino acids drawn from the pool for that process.
If a food is low in a specific amino acid the amino acids pool will make up for it and allow the body to continue building and repairing tissue. That’s why you don’t need to get a huge amount of all essential amino acids with every meal.
What matters isn’t even your essential amino acid into on a daily basis but your average protein intake over the course of multiple days. So as long as your diet is not focused around a single food you will be fine even if you eat nothing but plants for the rest of your life.
Of course, keep in mind that these findings apply to the general public. If you want to build muscle as a vegan there are definitely some plant-based sources that are better for this than others. I explain what those are here.