Soy and Health

[Guest guest]

Interesting article from

http://www.immunepro.com/

Proteins Duke it Out for Prominence,

but Only One is a True Champion

Carlon M. Colker, M.D.

Although debated for years, it is now not merely a widely held belief, but an

accepted fact, that athletes and people who exercise need more protein than

sedentary non-exercising individuals.1-9 But as protein has gained in popularity

and finally assumed its rightful place as king of the macronutrients, a new war

has begun. The battlefield has been drawn, pitting all available sources of

protein against each other in an all-out brawl to see which rules. In the words

of Apollo Creed- when he was set to face the Italian Stallion- " Sounds like a

damn monster movie! " Of course, if you've been paying attention to the media,

you know that two top contenders have emerged.

Hold the fort down fight fans, and let's get ready to rumble! In the blue

corner, a lower quality protein weighing in without all the essential amino

acids, a debatable cardio-protective effect, and a known and worrisome

phytoestrogen content soy protein. In the red corner, the highest quality and

biologics value protein, weighing in with all the essential amino acids, immune

enhancing powers, and offering greater cancer protection than soy - whey

protein!

Sounds like a mismatch to me. Of all the protein sources out there, you might

wonder why these two have emerged as top dogs. The answer is that whey protein

is in contention as a result of a wellspring of supporting research and

scientific fact. Soy protein, on the other hand, has emerged for honors simply

because of clever exaggerations of flimsy studies, as well as misleading

propaganda driven by a powerful and profit oriented soy lobby.

Sorry soy enthusiasts, if I've touched a sore spot. But let's examine this issue

further and include the important basic differences, as well as some of the

latest research on both these proteins.

The Big Lie

First of all, I'm tired of hearing all this garbage about soy being a complete

protein (meaning it contains all the essential amino acids our bodies can't

synthesize from other sources and must instead directly consume). Don't let

anyone shove this lie down your throat. Soy protein is not a complete protein

because it lacks the amino acid methionine. This is a non-debatable scientific

fact.

Whey protein, on the other hand, lacks no essential amino acids. As a result, it

has a much higher biological value in terms of similarity to our own human

protein. Whey protein beats soy protein hands down in this category simply

because whey protein needs no fortification or additive to make it complete. It

is complete in its natural form.

Perhaps the greatest coup for soy fans of late was approval by the FDA for

soy-containing products to be listed as able to reduce the risk of heart disease

This government seal of approval was not only premature, but also potentially

dangerous. There was, and still is, no solid scientific research to back such

cavalier support by our government. I wonder how a government steeped in the

practice of forcing products to be thoroughly researched and tested before

claims can be made, would do something so reckless.

The fact is, soy has no more impressive research to support such broad-based

government support than that which supports whey protein in the area of heart

health. The research supporting soy as cardio-protective is almost completely

epidemiological and observational across broad spectrums of the population. In

fact, as far as whey protein is concerned, nearly a decade ago the Chinese

demonstrated the cholesterol and plasma lipid lowering ability of whey

protein.10 But this, along with piles of subsequent research, hasn't motivated

the government to give whey protein the same whorish kiss it gave soy.

Much Ado About Estrogen

I think what's really going on starts with the soy lobbyists. Soy is big

business. Nearly a million metric tons have come into this country this past

year alone; nearly $500 million worth of soy products moved off supermarket

shelves just last year.11 When big bucks are on the line, lobbyists find the

motivation to aggressively seduce government.

A lot of support for soy being heart healthy stems from soy enthusiasts focusing

on the estrogenic effect of soy. Soy contains genistein and other phytoestrogens

that are hormonally akin to estrogen. Unfortunately, it now appears these folks

have jumped the gun. A landmark study in the Journal of the American Medical

Association looked at estrogen therapy and the prevention of heart disease.

The study showed that over four years, estrogen treatment did not reduce the

rate of heart disease in postmenopausal women. In fact, it increased the rate of

blood clots and gallbladder disease! The conclusion of this comprehensive study

of nearly 3,000 subjects sent a clear message to physicians that, while it might

help bone density and lessen the chance of hip fractures, estrogen therapy does

not protect the heart. Thus, it should not be given for preventing heart

disease. " Based on the finding of no overall cardiovascular benefit and a

pattern of early increase in risk of CHD (coronary heart disease) events, we do

not recommend starting this treatment for the purpose of secondary prevention of

CHD. " 12

Thus, those taking soy as an estrogen analog for protection against heart

disease have been woefully misled by the propaganda. In fact, as the research

clearly shows, the road of estrogenic substances is filled with perils., Why the

soy supporters and the FDA have ignored this, is beyond, my comprehension. I

should highlight here that, unlike soy protein, whey protein has no

phytoestrogen content. And, while the exact mechanism remains unclear, the

cardioprotective effect, if any, probably has more to do with a powerful

antioxidant effect that benefits the entire body, not just the heart.

There are other problems with exposure to estrogens and estrogen-like

substances, namely cancer. Somehow soy got labeled a cancer preventive! The

absurdity of this flawed logic makes me laugh; the potential health

ramifications of the misinformation make me cry.

Receptor Site Skirmish

The theory behind soy as a cancer preventive stems from the fact that the

phytoestrogens in soy protein, although estrogen-like in function, are weaker

receptor stimulators than the estrogens in our bodies. When this weaker estrogen

is put in the body, it competes with the body's own estrogens for receptor

sites. A temporary " blocking " effect is exerted because these estrogen-like

compounds don't stimulate the receptor to the same degree as actual estrogens.

This is the mechanism of action of tamoxifin, a chemotherapy agent many soy

supporters say soy protein is akin to.

The problem with this theory: While an estrogen-like substance might have a

weaker stimulatory property on one area of receptors in the body, it may be

stimulatory to the same degree as true estrogen at other receptor sites. It's

for this reason drugs with more estrogen site specificity are currently being

developed. New drugs like raloxifene appear to have estrogen site selectivity so

that, for the postmenopausal female, the risk of osteoporosis is reduced without

stimulating uterine or breast cancer.13

So, while phytoestrogens in soy might be weaker estrogens at some sites in the

body and thus help prevent cancer spurred by the body's own unopposed estrogens,

it has no receptor site specificity, and thus may actually stimulate cancer, in

other areas of the body.14

In fact, in recent discussions with prominent cancer specialists and colleagues

at the world renowned Memorial Sloan Kettering Cancer Center in New York, the

subject of soy protein came up. All three specialists I spoke with are telling

successfully treated breast cancer survivors to avoid soy. Of even greater

interest was that they maintained this recommendation even for those individuals

whose cancer was deemed " non-estrogen dependent " (i.e., estrogen receptor

negative). They said they did this " just to be on the safe side. "

Russian Roulette?

But, thankfully, the public is getting hip. In a recent New York Times article,

prominent physician researchers called our attention to the potential perils of

soy. Dr. Margo Woods at tufts University School of Medicine, Dr. Burke

at Wake Forest University School of Medicine, Dr. Helferich at the

University of Illinois, and even the FDA's own research biologist at the

National Center for toxicological Research, have all voiced very serious

concerns. "

My recommendation would be to examine your family history carefully. If you have

a history of cancer (especially breast), consider soy a danger.

But if it's cancer prevention you're interested in, without playing Russian

roulette with the phytoestrogens found in soy, take a good look at whey protein.

More than a decade ago, whey protein demonstrated an ability to prevent cancer

and tumor growth.15

The current thought is, in much the way whey protein may be cardio-protective,

the key mechanism of action has to do with whey's unique ability to bolster the

immune system by increasing intracellular antioxidant power.

We have all heard of vitamins E and C and their antioxidant ability in the

bloodstream. But, a far more powerful and target-specific antioxidant exists

within each living cell called gamma-L-glutamyl-L-cysteinyl-glycine, more easily

referred to as GSH (Glutathione). This powerful antioxidant exerts its action

within the cell. In fact, it cannot only be synthesized inside the cell from

smaller molecules since there is no efficient transport mechanism to get GSH

from the blood stream into the cells.

The key building block for GSH is an amino acid called cysteine. When two

molecules of cysteine are coupled and then linked by a disulfide bond, the

result is a molecule called cystine. This cystine molecule is not only stable,

but travels easily through the body and into each living cell. Once in the cell,

it's broken down into cysteine molecules; and used to form GSH.

Because of whey protein's unmatched biological value, bioavailability,

impressive solubility, level of absorption, and high percentage content of

cystine residues and branch chain amino acids (23 percent), it's the superior

form of protein supplementation for athletes.16 Though moderate exercise has

been shown to improve immunity, intense exercise has been shown to reduce GSH

levels, which are associated with immunosuppression.17 This negative effect on

immunity is directly related to the intensity and duration of the physical

activity and immune status of the athlete. Over the past decade it has been

shown that whey protein possesses immune enhancing properties that can help the

athlete recover and avoid over training syndrome.18

Unlike soy protein, which is profoundly deficient in these and other

sulfur-containing amino acids whey protein (in particular, the concentrate form)

contains an abundance of highly biologically active cystine residues, thus

making it a powerful immuno-modulator against cancer, toxins, infections, or any

other bodily insult.19

Staggering News

In support of the notion of whey being protective, against cancer, a recent

study published by the American Association for Cancer Research compared whey

Protein to soy protein and casein ( a low order milk protein). The article

concluded that " Whey appears to be at least twice as effective as soy in

reducing both tumor incidence and multiplicity. " 20 This staggering news has

profound ramifications with respect to choosing between soy protein and whey

protein.

Furthermore, the same " cysteine donor " effect unique to whey and not found in

soy, that seems to be at work in preventing cancer, has recently been shown to

enhance muscular performance and decrease muscular fatigue. Another recent study

concluded that prolonged supplementation with a product designed to augment

antioxidant defenses resulted in improved volitional performance. " 21 Remember,

this characteristic is unique to whey and something soy simply cannot achieve

because it is not a cysteine donor.

Going back to the issue of soy containing phytoestrogens, the problem may be

worse for men than for women.

The research indicates that these phytoestrogens are not as weak and harmless as

soy enthusiasts would lead you to believe. In fact, when genistein (the main

phytoestrogen in soy) Was given to mice in doses similar to those contained in

an average soy-based diet, in only nine days testosterone concentration was

dramatically reduced. The reduction seemed to stem from a decrease in production

of luteinizing hormone, secreted by the anterior pituitary gland.22 In fact,

several other animal studies clearly indicate the rather frightening feminizing

effect of unopposed estrogen stimulation in the form of dietary

phytoestrogens.23,24

My own fight card says soy loses yet another round. Stick with whey, unless of

course you want to get in touch with your feminine side.

Moreover, another recent, study by Dr. Liu of UCLA Medical Center,

demonstrated the influence of estrogen on weakening ligaments and thus

increasing the probability of injury. This would explain why women are up to six

times as likely as men to suffer an anterior cruciate ligament tear.25 Although

this research is somewhat controversial and preliminary, it warrants careful

examination. As with the concerns over soy protein negatively influencing

thyroid function in children, don't discard these possible early indicators of

what could become a serious health issue as the soy juggernaut rolls on

unopposed.

As we near the end of the final round, know that the research continues to mount

supporting whey as the protein of choice and, unless used carefully only in

select cases as a medicinal food, soy is far inferior and dangerously

problematic. In this head-to-head battle, soy protein is simply outclassed by

whey. But since the Don Kings of the soy industry are showing no signs of

letting up on the pro-soy hype, something tells me this mismatch is destined for

a rematch.

References

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11. Burros M. Doubts cloud rosy news on soy. The Science Times The New York

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25. Female hormones blamed for knee injury; The NewYork Pbst, Jan. 29, 2000.