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
animals species 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.
Soy Protein and Bodybuilders
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...
>> Click here for Will Brink's Bodybuilding Revealed
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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? 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. |
