All casein protein powders are derived from milk, so they aren’t vegan.
But if you’re looking for a slow-digesting protein powder to take before sleeping, some plant proteins are better than others.
We’re going to quickly look at how the essential amino acid profiles of different types of plant proteins like soy, pea, and brown rice stack up against casein.
Table of Contents
Does a Vegan Version of Casein Exist?
In the future, there might actually be a vegan casein protein powder, but there aren’t any on the market right now.
Casein is just a specific group of proteins, so in theory it’s possible to create those protein structures synthetically. However, there’s not much demand for it, so don’t expect to see vegan casein any time soon.
Casein Amino Acid Profile
As said, there are many different casein protein molecules, and these can all have slightly different amino acid profiles.
One study compared casein protein from different animal sources (buffalo, cow, goat, sheep, camel), and produced this graph that illustrates the variation in casein:
There can be a significant amount of variation. For example, there’s a leucine level of 106 mg/g in cow casein, but only 69 in goat casein.
Obviously almost all casein powder comes from cows, but even that will have a varying amino acid profile.
The point here is that casein covers a wide variety of proteins, so as long as we can find a plant-based one with a similar amino acid profile, it should have a similar effect to what is expected of casein.
Amino Acid Profile of Casein Vs Soy, Pea, and Brown Rice
Using data from studies and my pages on pea protein amino acids and brown rice protein amino acids, I compiled the table below.
I included whey protein so we have a benchmark for how much it differs from casein.
In order to compare how much a protein source differs from casein, I calculated the mean squared error for each alternative. If you don’t know what that is, just know that a larger number means there’s more of a difference, and vice-versa.
| Amino acid | Casein | Whey | Soy | Pea | Brown Rice |
|---|---|---|---|---|---|
| Histidine | 2.8 | 1.6 | 2.3 | 2.5 | 2.4 |
| Isoleucine | 5.5 | 4.5 | 4.3 | 4.8 | 4.5 |
| Leucine | 8.3 | 11.6 | 7.2 | 8.5 | 8.3 |
| Lysine | 7.4 | 9.1 | 5.5 | 7.5 | 3.1 |
| Methionine | 2.5 | 2.2 | 1.1 | 1.9 | 5.1 |
| Phenylalanine | 4.5 | 3.1 | 4.6 | 5.5 | 11.2 |
| Threonine | 4.4 | 4.3 | 3.3 | 3.7 | 3.8 |
| Tryptophan | 1.1 | 2.3 | 1.1 | 1 | 1.5 |
| Valine | 6.5 | 4.5 | 4.5 | 5 | 5.9 |
| Mean Squared Error | 23.72 | 13.69 | 4.74 | 72.18 |
It turns out that pea protein is quite similar to casein protein when it comes to essential amino acids.
Soy protein falls somewhere in the middle of whey and casein.
This is pretty good news since most vegan protein powders are mainly composed of pea protein, so it’s easy to find.
Pea protein seems to be the best plant protein alternative to casein based on their essential amino acid profiles. Note that we are assuming that digestion speed is mainly dependent on amino acid composition, which I believe is reasonable.
What’s the Best Vegan Pea Protein Powder?
I’ve tested well over 30 vegan protein powders at this point, and most of them are pea protein or blends of pea protein with another source.
If you’d like to see my recommendations, see my page on the best vegan protein powders.
Is Casein Protein Even Necessary?
A final question I’d like to pose is whether or not digestion speed of protein is even that important.
The theory behind drinking casein shakes before sleeping is to slowly release protein to be used during the night, but there’s little to no scientific evidence supporting this. In other words, it’s bro-science.
Most current research shows that protein timing doesn’t actually matter much.
At most it likely makes a small difference. Your results are going to be way more influenced by overall diet and workout quality and consistency
