Seitan – A High Lysine Food
Awhile back, a reader sent me a copy of a 2009 paper that analyzed the amino acid amounts in wheat gluten protein (1).
The USDA nutrient database does not give amino acid amounts for wheat gluten and it doesn’t include seitan at all. I have long suspected that seitan would be a good source of the amino acid lysine (which is generally the limiting amino acid in vegan diets), but I had no way to verify this until getting the 2009 paper.
Upon doing some calculations I estimate that White Wave seitan has approximately 656 mg of lysine per serving, making it one of the highest sources of lysine among plant foods. I have added this information to Table 3 of Protein at VeganHealth.org. You can see more details about how I came up with this amount in the footnotes of the table, if interested.
There is one disconcerting thing about the 2009 paper – it has no amounts for tryptophan and no explanation as to why. And if you add up the amounts of the other amino acids in mg/g of protein, it comes to almost exactly 1 g, leaving no room for tryptophan. I have written the authors to find out why this might be.
The paper is rather technical and not being a laboratory scientist, I didn’t even understand most of it. If any readers would like to take a look at it, let me know through the contact form.
In any case, I feel confident now that seitan is a good source of lysine and I have added it to my protein recommendations as an option for getting your daily amount of lysine.
Addendum of November 7, 2012:
I have communicated with one of the paper’s authors, Dr. Ine Rombouts who told me that the protein in wheat is 80% gluten and that gluten is very low in tryptophan – that it only has negligible amounts. The other 20% of wheat protein is made up of albumins and globulins which have more tryptophan. This is why wheat has tryphtophan but wheat gluten does not.
Reference
1. Rombouts I, Lamberts L, Celus I, Lagrain B, Brijs K, Delcour JA. Wheat gluten amino acid composition analysis by high-performance anion-exchange chromatography with integrated pulsed amperometric detection. J Chromatogr A. 2009 Jul 17;1216(29):5557-62. Epub 2009 Jun 3. | link
November 2nd, 2012 at 3:33 pm
Shouldn’t seitan have roughly the same amino acid profile as wheat flour?
November 3rd, 2012 at 7:53 am
That is good to know, since I have often thought of gluten (seitan) as a pretty low nutrition food, since it is mostly just the protein of the wheat. Thank you, Jack!
November 7th, 2012 at 1:02 pm
I have a suspicion that it’s precisely because it’s a proteiny food – with barely any calories coming from carbs or fats – that it has so much lysine. When you look at the table you can see that the ratio between lysine to other amino acids in Seitan isn’t much different than the same ratio in many other vegan proteins. For example – the number of Seitan servings needed to get enough methionine is still more than 3 times lower than the amount of Seitan servings you need to eat to get enough lysine for a day.
November 7th, 2012 at 1:05 pm
Yonatan,
Yes, that’s true. But it was possible that, like for tryptophan in wheat gluten, it might have been particularly low in lysine, making it a low-lysine food even despite the fact that there is so much protein per serving. Luckily, that turns out not to be the case.
November 7th, 2012 at 1:10 pm
For those following the comments of this post by email, I just added this addendum above:
I have communicated with one of the paper’s authors, Dr. Ine Rombouts who told me that the protein in wheat is 80% gluten and that gluten is very low in tryptophan – that it only has negligible amounts. The other 20% of wheat protein is made up of albumins and globulins which have more tryptophan. This is why wheat has tryphtophan but wheat gluten does not.
November 27th, 2012 at 10:17 pm
Not infrequently, I suffer from low hemoglobin counts (and tend to have very low ferritin, too). I read in Vegan for Life that taking 1,500 mg of Lysine daily increased iron counts in one study. I am wondering how many weeks or months it would be advisable to continue this regime before re-testing to see if it has helped.
November 27th, 2012 at 10:27 pm
Denise,
3 – 6 months.
April 21st, 2017 at 4:12 pm
Most of the resources I’ve found state that gluten/seitan is very *low* in lysine. Why the discrepancy? I love seitan and would love to make it the main protein in my diet, but most sources seem to recommend against that.
April 22nd, 2017 at 4:59 pm
Chris,
I don’t know why other sources say that seitan is low in lysine. If they have better evidence than what I listed in this blog post, I’d be interested to see it.
May 23rd, 2017 at 8:14 am
A 2009 paper (link below) analysing the amino acid composition of wheat gluten shows that it contains 1.4 mol% lysine, which is about 2% by mass. This is only 40% of the target for a balanced protein (50mg lysine per g protein). So you would likely have a lysine deficiency if you were depending mainly on seitan to reach your daily protein target. Because seitan is so protein dense, you could still get enough lysine from it without too much trouble, but you would need to substantially exceed your daily protein requirements.
https://cdn.fbsbx.com/v/t59.2708-21/18072068_10155260225077152_8862614648214519808_n.pdf/Wheat_gluten_amino_acid_composition_anal.pdf?oh=a96cb392bf471539f344f223b01fa19a&oe=592641B7&dl=1