Brown Rice Protein Amino Acid Profile

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Brown rice protein is one of the most common vegan protein powder ingredients.

Here’s a graph of brown rice’s standard amino acid profile:

brown rice protein amino acid profile

(Data Source)

Even though it’s a bit tough to see, the essential amino acids are marked with a star (*).

You can compare the amino acid profile of other protein sources against brown rice using our amino acid profile comparison tool.

Here’s the data again in table form if you prefer:

Amino Acid % of total amino acids
Alanine 5.8
Arginine 8.2
Aspartic Acid 9
Cystine 2.2
Glutamic Acid 18
Glycine 4.6
Histidine* 2.4
Isoleucine* 4.5
Leucine* 8.3
Lysine* 3.1
Methionine* 2.9
Phenylalanine* 5.7
Proline 3.7
Serine 5.1
Threonine* 3.8
Tryptophan* 1.5
Tyrosine 5.5
Valine* 5.9

Is Brown Rice Protein a Complete Protein?

Let’s be clear here, brown rice is not a complete protein because rice has such a low amount of protein in it.

However, when brown rice protein is extracted, which is usually how it’s added to certain foods and supplements, it obviously has enough protein to be looked at further.

The second aspect of a complete protein is the balance of essential amino acids.

Let’s compare brown rice protein’s essential amino acid to the minimum standards of a complete protein set by the WHO (1).

 
Complete Protein (min %)
Brown Rice (%)
Histidine 1.5 2.4
Isoleucine 3 4.5
Leucine 5.9 8.3
Lysine 4.5 3.1
Methionine+Cysteine 1.6 5.1
Phenylalanine+Tyrosine 3 11.2
Threonine 2.3 3.8
Valine 3.9 5.9

Like many grains, brown rice protein is low in lysine.

That’s why it’s often paired with good plant-based sources of lysine like legumes when used in protein powders.

Overall Summary of Brown Rice Protein’s Amino Acid Profile

Brown rice is almost a complete protein (a bit lacking in lysine as noted in a comment below).

It contains all the essential amino acids, and its amino acids are well balanced, even more so than dairy milk.

Another comparable amino acid profile is spirulina, which is another great plant-based source of protein.

About the author

Dale Cudmore

Your friendly neighborhood vegan from Toronto. Chemical engineer turned semi-professional soccer player and freelance nutrition writer. I've been vegan for years and try to make life easier for others by sharing what I've learned.

8 comments

  • Thank you very much for your work! I myseld am an environmental engineering student looking to get into mixed martial arts and endurance competitions… We have some common ground!

  • Colin, thank you for putting this together. I have a hard time really picturing how this comparable because I do not have a whole number to base the percentages off of i.e is the total amino acids present in the protein source 1888 g’s or is it a different X? Thanks for the help

    • This is purely the distribution of amino acids in the protein brown rice.

      For example, 1 cup of brown rice is about 195 g, with 5 grams of protein.

      Since there’s 5 grams total of protein, there’s about 0.29 grams of alanine.

  • Hi, Dale!
    The percentage of lysine in brown rice is below of what is considered sufficient according to FAO/WHO recommendations (58mg/g or 5,8%) to be a high biological value protein (complete source), this deficiency makes it less well balanced than dairy, though still a good protein source in a varied diet.
    I’ve read on a lot of sites and papers that rice (be it brown or refined) is deficient in lysine, like most cereals.
    Anyway, thanks for the post and it’s data, I always end up around the site, I’d just like to point that out to help more people with useful info.
    If I am wrong please correct me so I can choose better what to eat!

      • The newest and apparently most complete source I found was this report by WHO/FAO/UNU
        (The tables about the subject are on pages 150 and 180, summarized after page 241) and this one by FAO
        I cited the lysine requirement for children 2 to 5 years old (based on an old report apparently), which is what I saw multiple times in a few studies as the one for high biological value protein , but for adults the requirements are more modest (actually 45mg/g of protein, rice is still lower than this unfortunately) like the one you cited and depending on which report or study (the one of 1985, 1991 or 2007 by FAO) the source is being based the values may vary, and even the same report might recommend the intake of a different age class for all ages, excepting infants, for regulatory purposes (requirements of children from 6m to 3y old for all ages, recently). Different ages have different necessities making the claim for a complete protein based also on the stage of life, which explains the different requirements we both cited.