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Every morning in Africa, a gazelle wakes up. It realizes that it must run faster than the fastest lion or it will be killed.
Every morning in Africa, a lion wakes up. It realizes that it must run faster than the slowest gazelle, or it will starve to death.

The moral?

The
(Partial) Vindication Of Soy Protein
Readers
note: this is one of my favorite articles, and in my opinion, one of
my best. However, this article was turned down by several magazines.
At first I could not figure out why. I have been writing articles for
many magazines for years (see bio) and I know a good article when I
see one..if I say so myself. Then it hit me. The article goes against
what the mags think people want to hear about their protein products.
Soy has been bashed for so long, and the market for other proteins like whey has becomes so big, that they didn't want any article showing soy
in a positive light. Once an industry or an individual has set a position
on something, they would rather ignore new evidence to the contrary
then change their position. As for me, if I find new information on
something that alters my position, that's fine by me. I just change
it to reflect the new information, which is exactly what I had to do
with my view on soy proteins. The article did finally get published
in MuscleMag International. MMI might have its faults, but they are
one of the most open minded and flexible magazines and didn't have any
problems with publishing this article with them. Hope you all find it
useful.
Not more than a
month ago, I was standing in a field of soy beans in Peoria Illinois doing a commercial for a Japanese film crew. The guy to the right of
the camera was holding up my little cue card as I said "Soy products
have been shown to reduce cholesterol and possibly prevent cancer, yada,
yada, yada..." I found it hard to keep a straight face and say nice
things about soy protein as I have always considered soy protein basically
a waste of time for bodybuilders. However, this commercial was for "normal"
people so I did not feel like a "sell-out" for saying positive things
about soy protein. On the plane ride home, with a glass of red wine
firmly in hand, I decided to take a closer look into the properties
of soy proteins and see if there were not some useful applications of
this protein for bodybuilders after all.
The bodybuilding
community has been pretty hard on soy protein generally relegating it
to "crap" status among most bodybuilders and bodybuilding nutritionists.
I will be the first to admit I have helped the negative reputation of
soy among bodybuilders along by telling them how inferior it is to such
proteins as whey or egg in various articles and my book. I still think
soy protein is inferior to such proteins as whey and egg, but I do believe
that it has some potentially useful applications if used correctly and
tweaked just right. More on that later.
The Downside
of Soy
So why does soy
have such a bad reputation among bodybuilders? On the surface, it would
appear that soy protein is pretty lousy stuff for most athletes. Soy
protein has a low BV score of 74. What does that mean? There are several
ways of assessing protein quality. You have the protein efficiency ratio
(PER), the net protein utilization (NPU) and the biological value (BV).
The PER is an outdated measure of protein quality and is not used much
anymore by most supplement manufacturers or nutritionists "in the know"
about protein quality. The NPU is a little better than the PER, but
fails to take several important factors into account involved with proteins, such as absorption and digestibility, so it too is not used much either.
That brings us to the BV. The BV is the most accurate indicator of biological
activity of a protein and measures the actual amount of protein deposited
per gram of protein absorbed. As a rule, high BV proteins are better
for nitrogen retention, immunity, IGF-1 stimulation, and are superior
for reducing lean tissue loss during various wasting states than their low BV counterparts. That is, as a general rule, high BV proteins are
more anti-catabolic than low BV proteins. As most people already know,
the highest BV protein available is whey protein with whole egg a close
second (see chart), which is why bodybuilders and other athletes rely
heavily on these two protein foods and tend to avoid soy and other proteins
with low BV scores.
In addition to its
low BV score, soy has several other nutritional drawbacks that make bodybuilders avoid the stuff like it was fake D-bol. One reason soy
is so low on the BV scale is it is lacking in the sulfur containing
amino acid methionine. The sulfur containing amino acids (cysteine being
the other one) are particularly important for protein synthesis/growth,
proper immune system function, and the body's production of glutathione
(GSH). GSH is one of the most important anti-oxidants found in the body
and protects cells and serves to detoxify a variety of harmful compounds
such as hydrogen peroxide, carcinogens, reactive oxygen species, and
many others. In particular, GSH is also partly responsible for keeping
low density lipoproteins (LDL) from oxidizing and clogging our arteries.
Several studies have shown soy protein to be inferior to whey for the
production of GSH and improvements in immunity. Though soy has a reputation
for reducing cholesterol in man and animals, in one study rats fed soy
protein that was not fortified with methionine as 13% of total calories,
had an increase in cholesterol and an increase susceptibility of LDL
cholesterol to peroxidation . So not only did the rats cholesterol go
up, the LDL fraction oxidized easier potentially leading to clogged
arteries. It is well established that an increased susceptibility of
LDL to peroxidation is an essential step for the development of atherogenesis.
These rats were found to have low levels of GSH and did not grow as well as another groups of rats fed casein.
If that were not
bad enough to convince you to avoid soy, it gets worse. Soy protein contains something known as "anti -nutrients" that block the digestion
and absorption of many nutrients. Two of the more important anti-nutrients
found in soy are Lectins and protease inhibitors. Lectins are nasty
constituents of various plants and can cause all sorts of problems from
interfering with the absorption of important nutrients to intestinal
damage. Proteases are enzymes that assist in the digestion of proteins. Soy has several protease inhibitors that interfere with the enzyme trypsin
and chymotrypsin, both of which are important for the digestion and
absorption of proteins in the gastrointestinal tract. Finally, soy is
rich in estrogenic compounds such as genistein and diadzein. There are
over 300 plant derived phytoestrogens found that vary substantially
in their physiologic effect and potency in animals and man. As any bodybuilder
worth his weight belt already knows, a change in the testosterone/estrogen
ratio in favor of estrogen can lead to increased bodyfat and other ill
effects as it relates to the strength athletes goals.
BV of common
proteins
Whey=104
Whole egg=100

Egg white=88

Casein=77
Soy=74
The Upside of
Soy
"You mean there
could possibly be an upside?" you are thinking. I realize the previous
section does not paint a very pretty picture of soy proteins, but I
did not give you the entire story. As I said, on the surface soy looks
like a pretty miserable protein for the hard training bodybuilder trying
to eke out some new muscle tissue and/or lose bodyfat. The problem of
the anti- nutrients found in soy protein has been taken care of as the
manufacturers of high quality soy protein isolates remove them or dramatically
reduce their activity during processing, so this is not a big point
of concern anymore. Also, the addition of methionine to soy isolates
greatly improves its BV and nutritional value, though it still does
not reach the BV of whole egg or a good whey protein for that matter.
Rats fed soy protein enriched with methionine grew at a similar rate
as those fed casein.
As for the estrogenic
compounds found in soy, that's a bit more complicated. For years, soy
protein has been found to reduce cholesterol in a wide range of animalsspecies
and man. One recent study found that when they separated the estrogenic
compounds from soy, it failed to have the usual cholesterol lowering effects. This does not come as a big surprise as the cholesterol lowering
protective effects of estrogen are well known. However, soy protein
appears to have several mechanisms by which it lowers cholesterol (i.e.
isoflavones, endocrine effects, fiber, saponins, etc.) and its mechanism
on cholesterol probably depends on the animal species being studied.
In addition to soy proteins ability to reduce cholesterol, epidemiological
research also suggests soy can reduce certain forms of cancer and longevity
companies such as the Life Extension Foundation are now recommending soy protein isolate for the treatment of certain cancers.
Ok, now here is
where things start to get interesting as it applies the bodybuilders. Though soy proteins contain these estrogenic compounds, it appears that
they are "tissue specific." One study that used Rhesus monkeys found
that soy proteins had no effects on the reproductive hormones of these
animals. Testosterone, DHEAS, sex hormone binding globulin (SHBG), testicular
weight, prostatic weight, and other measurements were taken. They found
no difference between male animals who ate soy protein that contained
the plant estrogens and those who ate soy with the estrogens removed,
leading researchers to conclude: "thus, the isoflavones (genistein and
diadzein) in soy protein improve cardiovascular risk factors without apparent deleterious effects on the reproductive system..., " and "Genistein's
effects appear to be tissue specific, with estrogen agonist effects
on plasma lipid concentrations, plasma lipoprotein distributions and
preservation of bone mass that are similar in magnitude to mammalian
estrogens, but without estrogenic effects..." They finally conclude
"Our data support an interpretation that soy beans estrogens have tissue
specificity in part because of their mixed estrogen agonist and antagonist
properties." From this and other data, it seems the phyto estrogens
in soy can lower cholesterol and improve heart disease risk without
systemic estrogenic effects (i.e. gyno, bodyfat increases, etc.) that
would normally be seen if say a bodybuilder took estrogen pills or from
the conversion of certain steroids to estrogen. This study is a little
more relevant to us humans being it was done with male monkeys which
are far more similar animals to people than rats. However, I think that
an upper level of soy protein that contains phyto estrogens could cause
systemic estrogenic effects if enough were taken, but that's only speculation
on my part. Also, the use of soy isolates by men might be better cycled
rather than taken all the time being we are not 100% sure at this time
about the long term estrogenic potential of soy proteins in athletes.
The ability of soy protein to lower cholesterol without other estrogenic
effects could be useful to bodybuilders using anabolic steroids who
tend to see a rise in cholesterol and/or LDL.
Now I have saved
the best part for last regarding the upside of soy proteins. Soy protein
has been found to raise thyroid output in a wide range of animals from
rats to rabbits and pigs. Studies done with human subjects have been
harder to quantify (what else is new?), but several studies suggest
an effect on thyroid hormones in people eating soy protein isolate.
Soy protein has been shown to raise thyroid hormone output which could
be a real advantage to bodybuilders trying to shed some fat. The intake
of various high quality proteins has been associated with higher levels of thyroid hormone, but soy appears to have thyroid hormone raising
abilities unique to that of other proteins. Though some research has
shown changes in T3 and thyroid stimulating hormone (TSH), the real
effect appears to be with T4 which is elevated consistently in the studies
done using animals-and to a lesser degree people-eating soy proteins.
Also, some studies have found changes in the insulin/glucagon ratio that would favor reductions in cholesterol and possibly bodyfat. At
this time, exactly how soy proteins have this effect on thyroid output
is not well understood, but their working on it.
So what does the
above information mean to the bodybuilder? There are two points I think
are the most relevant to strength athletes. (1) Though thyroid hormones
are considered catabolic hormones, they are actually more catabolic
to fat and carbohydrates, but stimulate protein synthesis if adequate
calories are eaten and the amounts of thyroid hormones are not to high.
This could be useful for increasing protein synthesis and reducing bodyfat.
More research needs to be done in this area of course. (2) When a person
diets the success of that diet is quickly brought to a screeching halt
when the body figures out what you are up to and reduces the output of thyroid hormones. This is a reaction by the body brought on by a
reduced caloric intake which reduces metabolic rate and a new caloric
set point is established and the dieter is now screwed! The use of soy
protein isolate to boost thyroid output could be exactly what the doctor
ordered to keep thyroid levels raised during reduced calorie intake
when dieting if the above evidence with soy proteins and thyroid function
holds true in humans on reduced calories diets. Lets hope it does!
Solving The Soy
Dilemma
Taking all of the
above information on soy protein that we have looked at in this article
I think we come up with something of a dilemma for the bodybuilder.
For the average person, there is no real dilemma here as they don't
care much about protein quality. Unfortunately, if a bodybuilder starts
to replace too much of the other high quality proteins in their diet
in favor of soy to reap some of the potential benefits of soy, than
he (or she) runs the risk of losing muscle due to this lower quality
protein. This would be particularly noticeable during a reduction in
calories (i.e.dieting). The lower the calorie intake the higher the
quality of protein needs to be to maintain lean body mass. Make no mistake
about it, soy protein does not have the nitrogen retaining, anti catabolic,
muscle building abilities of proteins such as whey, whole egg, red meat,
etc. However, soy does appear to have some other real benefits to the
bodybuilder. So what do we do? So far, it appears that a person does
not need to eat a great deal of soy protein isolate to get the benefits.
Estimates of ten - thirty grams a day of a high quality soy protein
isolate should do the trick for most people.
This is how I solve
the dilemma and I have found this strategy works well for people. By
mixing a high quality whey protein powder with a high quality soy isolate
in a 2:1 ratio and eating that two - three times a day, the bodybuilder
can have the best of all possible worlds (as it relates to the high
BV, immune enhancing, nitrogen retaining abilities of the whey and the
cholesterol lowering/thyroid stimulating abilities of the soy). To date,
I have no reason to believe that mixing these two proteins will negate or interfere with the benefits or properties of either protein, but
there is scant research in this area with healthy athletes. Anecdotally,
the people I have told to do this mixture have given me mostly positive
feedback so far.
Plain and simple,
mix in a blender two scoops of whey protein to one scoop of high quality
soy protein isolate and take the mixture two-three times per day. In
fact, I think with a few other key ingredients, this could make a real
nice pre mixed meal replacement product for use when dieting. For now
however, you can make it yourself and you might be surprised at the
results...
Bibliography

Forsythe, W.
A., Soy Protein, Thyroid Regulation and Cholesterol Metabolism. J. of
Nutri. (review), 125 (3 suppl): 619S-623S, 1995.
Anthony, A.S,
et al, Soybean Isoflavones Improve Cardiovascular Risk Factors Without
Affecting the reproductive System of Peripubertal Rhesus Monkeys. J.
of Nutri., 125: 43-49, 1995.
Hosokawa, Y.,
et al, Hepatic Cysteine dioxygenase Activity and Sulfur Amino Acid Metabolism
In Rats: Possible Indicators In the Evaluation Of Protein Quality. J.
of Nutri. 118: 456-461, 1988.
Hajos, G., et
al, Effects of Proteolytic Modification and Methionine Enrichment On the Nutritional Value of Soya Albumins For Rats. Nutri. Biochem. 7:481-487,
1996.
Gotoh, N., Inhibition
of Glutathione Synthesis Increases The Toxicity of Low Density Lipoprotein
To Human Monocytes and Macrophages. J. Biochem. 296:151-154, 1993.

Potter, M. S.,
Overview of Proposed Mechanisms For the Hypocholesterolemic Effect of
Soy. J. Nutri. 125 (3 suppl): 606S-611S, 1995.
Friedman, M,
Improvements In The safety Of Food by SH-containing amino Acids and
Peptides. J. Agric. Food Chem (Review). 42:3-20, 1994.
Moundras, C.,
Remesy, C., Levrat, M., Demigne, C., Methionine Deficiency in Rats Fed
Soy Protein Induces Hypercholesterolemia and Potentiates Lipoprotein Susceptibility to Peroxidation. J. Metabolism. 44(9): 1146-1152, 1995.

Bounus, G., Gold,
P. The Biological Activity of Undenatured Dietary Whey Proteins: Role
Of Glutathione. Clin. Invest. Med. 14(4): 296-309, 1991.
Schmuck, A. Dork,
K., Anadrol Causes Breast To Grow On Top Of Bodybuilders Head. J. of
ill Repute, 11:15-20, 1636, (just checking to see if anyone is actually reading my references!)

by William D. Brink