Vegetarians & Essential Amino Acids: Straight Facts
Ken Tough
Right. I'm not a vegetarian, but it bothers me that so many people
assert as fact that you can't get all essential amino acids from
non-animal sources, while others hold exactly the opposite (and seem
to survive to prove it). Let's settle it now.
Statement:
1) Plant sources can not provide cyanocobalbumin (vit B12), and some
must be obtained occasionally (every few years?) from somewhere.
Challenge:
2) Which essential amino acids can not be provided in sufficient
quantities through a properly balanced diet of plant foods?
--
Ken Tough Cornwall
k...@objectech.co.uk United Kingdom
Lela Tatum
Ken Tough wrote:
> Statement:
>
> 1) Plant sources can not provide cyanocobalbumin (vit B12), and some
> must be obtained occasionally (every few years?) from somewhere.
not to be nit-picky, but it's "cyanocobalamin" not cyanocobalbumin
>
> Challenge:
>
> 2) Which essential amino acids can not be provided in sufficient
> quantities through a properly balanced diet of plant foods?
vegetables and cereal grains usually contain limited amounts of both
lysine and methionine.
Lela
Dave Blake
In article <3T6afFA3evezEwy$@dial.pipex.com>, k...@objectech.co.uk says...
>
>>>> 2) Which essential amino acids can not be provided in sufficient
>>>> quantities through a properly balanced diet of plant foods?
>>>vegetables and cereal grains usually contain limited amounts of both
>>>lysine and methionine.
>
>>how does the following data compare with other plant & non-plant
>>sources for methionine?
>
>I had originally contained the discussion to plant / non-plant
>sources, but it might be interesting to also consider dairy
>products. I know they are a good source of tryptophan and
>vit B-12; how are they for methionine? Is it possible to say
>that a properly-balanced diet of plant-based foods plus dairy
>products will not be lacking in any essential amino-acids?
There have been several specific tests of the human
requirements for essential amino acids, and they
all find substantially lower requirements that
predicted by amino acid profiles and the theory that
you need all essential amino acids in the appropriate
ratios. I was vegan for 5 years while bike racing and
noticed no difference in any measure of personal
ability compared to before or after.
I think you are wasting your time on this one.
If you consume the RDA for protein from virtually
any legume, you will also consume about twice the
RDA for each essential amino acid. The essential
amino acids are not limiting in legumes.
--
Dave Blake
dbl...@phy.ucsf.edu
http://www.keck.ucsf.edu/~dblake/
Ken Tough
Lela Tatum <mp...@ttacs.ttu.edu> wrote:
>> 2) Which essential amino acids can not be provided in sufficient
>> quantities through a properly balanced diet of plant foods?
>vegetables and cereal grains usually contain limited amounts of both
>lysine and methionine.
Seems that pulses are pretty good in lysine, and for a lot of
people [like me], lentils (and chickpeas!) are nearly a staple.
Looks like methionine and tryptophan may be the worst culprits, but
how does the following data compare with other plant & non-plant
sources for methionine? This is from what seems to be an excellent
page about farming in palastine:
http://www.arij.org/pub/dryland/sec4.htm
------------------------------------------------------------
"
Proteins of food legumes are rich in lysine and poor in sulphur-
containing amino acids and tryptophan. Methionine is the most limiting
amino acid in all legumes (Table 1). In contrast, cereal grain proteins
are low in lysine but have adequate amounts of sulphur-containing amino
acids.
Table 1. Essential Amino Acid Composition for Some Food Legumes
(g/100g protein)
Amino Acid Beans Lentils Chickpeas Peas
Lysine 6.8 5.1 6.3 8.9
Threonine 3.3 3.0 3.4 4.2
Valine 5.4 5.1 5.5 8.2
Leucine 8.9 5.5 8.2 9.5
Isoleucine 6.0 5.8 6.0 7.4
Methionine 1.0 0.6 1.2 1.3
Tryptophan 1.0 0.6 0.8 0.7
Phenylalanine 5.5 4.0 4.9 4.6
Arginine 9.2 7.0 6.9 13.4
Histidine 2.8 2.1 2.3 2.7
"
--------------------------------------------------------------
Ken Tough
>>> 2) Which essential amino acids can not be provided in sufficient
>>> quantities through a properly balanced diet of plant foods?
>>vegetables and cereal grains usually contain limited amounts of both
>>lysine and methionine.
>Looks like methionine and tryptophan may be the worst culprits, but
>how does the following data compare with other plant & non-plant
>sources for methionine?
I had originally contained the discussion to plant / non-plant
sources, but it might be interesting to also consider dairy
products. I know they are a good source of tryptophan and
vit B-12; how are they for methionine? Is it possible to say
that a properly-balanced diet of plant-based foods plus dairy
products will not be lacking in any essential amino-acids?
--
Ken Tough
Dave Blake <dbl...@phy.ucsf.eduDELETETHISPART> wrote:
>I think you are wasting your time on this one.
>If you consume the RDA for protein from virtually
>any legume, you will also consume about twice the
>RDA for each essential amino acid. The essential
>amino acids are not limiting in legumes.
Those figures I posted seemed to show lower levels of methionine
and tryptophan than other AAs. I'm interested to know if this
is sort of a "normal ratio" among foods and bodily requirements.
I don't think I'm wasting my time because I'm seeking the truth,
not trying to prove it myself.
I'm trying to get a definitive statement that will either quash
or support all these people that constantly say "plants can't
supply certain essential nutrients (though I can't recall exactly
which ones they are, right now)."
BTW, dairy products are rich in methionine as well.
--
Ken Tough
hath...@stsci.edu
In article <eAhgrPAa...@dial.pipex.com>, Ken Tough <k...@objectech.co.uk> writes:
> Lela Tatum <mp...@ttacs.ttu.edu> wrote:
>
>>> 2) Which essential amino acids can not be provided in sufficient
>>> quantities through a properly balanced diet of plant foods?
>
>>vegetables and cereal grains usually contain limited amounts of both
>>lysine and methionine.
>
> people [like me], lentils (and chickpeas!) are nearly a staple.
>
> how does the following data compare with other plant & non-plant
> page about farming in palastine:
> http://www.arij.org/pub/dryland/sec4.htm
>
> ------------------------------------------------------------
> "
> Proteins of food legumes are rich in lysine and poor in sulphur-
> containing amino acids and tryptophan. Methionine is the most limiting
> amino acid in all legumes (Table 1). In contrast, cereal grain proteins
> are low in lysine but have adequate amounts of sulphur-containing amino
> acids.
>
> Table 1. Essential Amino Acid Composition for Some Food Legumes
> (g/100g protein)
>
> Amino Acid Beans Lentils Chickpeas Peas
> Lysine 6.8 5.1 6.3 8.9
> Threonine 3.3 3.0 3.4 4.2
> Valine 5.4 5.1 5.5 8.2
> Leucine 8.9 5.5 8.2 9.5
> Isoleucine 6.0 5.8 6.0 7.4
> Methionine 1.0 0.6 1.2 1.3
> Tryptophan 1.0 0.6 0.8 0.7
> Phenylalanine 5.5 4.0 4.9 4.6
> Arginine 9.2 7.0 6.9 13.4
> Histidine 2.8 2.1 2.3 2.7
> "
> --------------------------------------------------------------
>
How about this comparison:
Protein Scan of Hemp Seed
Amino Acid per mg/g of seed
Lysine 4.3
Threonine 3.7
Valine 3.0
Leucine 7.1
Isoleucine 1.5
Methionine 2.6
Tryptophan 0.6
Phenylalanine 3.5
Arginine 18.8
Histidine 2.5
(plus)
Aspartic Acid + Asparagine 19.8
Glutamic Acid + Glutamine 34.8
Phosphoserine 0.9
Serine 8.6
Proline 7.3
Glycine 9.7
Alanine 9.6
Cystine + Cysteine 1.2
Cystathionine 0.9
Tyrosine 5.8
Ethanolamine 0.4
---
Can someone supply a table listing the optimum amounts desired for each?
Possibly even a suggestion for supplements for the above to bring them
up to the best mix?
MBansch314
Here is the known variation in essential amino acid requirement in a
normal adult male population versus what the average vegan diet provides.
Requirement Vegan Diet
tryptophan 82 to 250mg 1.1 grams
valine 375 to 800mg 4.3 grams
phenylalanine 420 to 1,100mg 7.0 grams
leucine 170 to 1,100mg 6.0 grams
lysine 400 to 2,800mg 3.7 grams
isoleucine 250 to 700mg 4.0 grams
methionine 800 to 3,000mg 2.7 grams
threonine 103 to 500mg 2.9 grams
Methionine is the only one that may not be sufficient for some vegans.
The average intake for a vegan diet was published 1966 and the vegan diet
has improved greatly since then.
Marty B. "You are what you eat."