"The
(Partial) Vindication Of Soy Protein"
By Will Brink, author of:
Muscle
Building Nutrition
http://musclebuildingnutrition.com
Muscle Gaining Diet, Training Routines by Charles Poliquin &
Bodybuilding Supplement Review
Diet
Supplements Revealed
http://aboutsupplements.com
Real World Fat Loss Diet & Weight Loss Supplement Review
"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...
About
the Author - William D. Brink
Will Brink is a columnist, contributing consultant, and writer
for various health/fitness, medical, and bodybuilding publications.
His articles relating to nutrition, supplements, weight loss,
exercise and medicine can be found in such publications as Lets
Live, Muscle Media 2000, MuscleMag International, The Life Extension
Magazine, Muscle n Fitness, Inside Karate, Exercise For Men Only,
Body International, Power, Oxygen, Penthouse, Women’s World
and The Townsend Letter For Doctors.
He is the
author of Priming The Anabolic Environment and Weight Loss Nutrients
Revealed. He is the Consulting Sports Nutrition Editor and a monthly
columnist for Physical magazine and an Editor at Large for Power
magazine. Will graduated from Harvard University with a concentration
in the natural sciences, and is a consultant to major supplement,
dairy, and pharmaceutical companies.
He has been
co author of several studies relating to sports nutrition and
health found in peer reviewed academic journals, as well as having
commentary published in JAMA. He runs the highly popular web site
BrinkZone.com which is strategically positioned to fulfill the
needs and interests of people with diverse backgrounds and knowledge.
The BrinkZone site has a following with many sports nutrition
enthusiasts, athletes, fitness professionals, scientists, medical
doctors, nutritionists, and interested lay people. William has
been invited to lecture on the benefits of weight training and
nutrition at conventions and symposiums around the U.S. and Canada,
and has appeared on numerous radio and television programs.
William has
worked with athletes ranging from professional bodybuilders, golfers,
fitness contestants, to police and military personnel.
See
Will's ebooks online here:
Muscle
Building Nutrition
A complete guide bodybuilding supplements and eating to gain lean
muscle
Diet
Supplements Revealed
A review of diet supplements and guide to eating for maximum fat
loss
He can be contacted at: PO Box 812430
Wellesley MA. 02482.
BrinkZone.com
Email: will@brinkzone.com
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