Lowdown on Soy as a protein source
It's not as good for you as we thought.
The Chinese did not eat unfermented soybeans as they did other legumes such
as lentils because the soybean contains large quantities of natural toxins or
"anti-nutrients". First among them are potent enzyme inhibitors that block
the action of trypsin and other enzymes needed for protein digestion. These
inhibitors are large, tightly folded proteins that are not completely
deactivated during ordinary cooking. They can produce serious gastric
distress, reduced protein digestion and chronic deficiencies in amino acid
uptake. In test animals, diets high in trypsin inhibitors cause enlargement
and pathological conditions of the pancreas, including cancer. Soybeans also
contain haemagglutinin, a clot-promoting substance that causes red blood
cells to clump together.
Trypsin inhibitors and haemagglutinin are growth inhibitors. Weanling rats
fed soy containing these antinutrients fail to grow normally.
Growth-depressant compounds are deactivated during the process of
fermentation, so once the Chinese discovered how
to ferment the soybean,
they began to incorporate soy foods into their diets. In precipitated products,
enzyme inhibitors concentrate in the soaking liquid rather than in the curd.
Thus, in tofu and bean curd, growth depressants are reduced in quantity but
not completely eliminated. Soy also contains goitrogens - substances that
depress thyroid function.
Soybeans are high in phytic acid, present in the bran or hulls of all seeds.
It's a substance that can block the uptake of essential minerals - calcium,
magnesium, copper, iron and especially zinc - in the intestinal tract.
Although not a household word, phytic acid has been extensively studied;
there are literally hundreds of articles on the effects of phytic acid in the
current scientific literature. Scientists are in general agreement that
grain- and legume-based diets high in phytates contribute to widespread
mineral deficiencies in third world countries. Analysis shows that calcium,
magnesium, iron and zinc are present in the plant foods eaten in these areas,
but the high phytate content of soy- and grain-based diets prevents their
absorption. The soybean has one of the highest phytate levels of any grain or
legume that has been studied, and the phytates in soy are highly resistant to
normal phytate-reducing techniques such as long, slow cooking. Only a long
period of fermentation will significantly reduce the phytate content of
soybeans. When precipitated soy products like tofu are consumed with meat,
the mineral-blocking effects of the phytates are reduced. The Japanese
traditionally eat a small amount of tofu or miso as part of a mineral-rich
fish broth, followed by a serving of meat or fish.
Vegetarians who consume tofu and bean curd as a substitute for meat and dairy
products risk severe mineral deficiencies. The results of calcium, magnesium
and iron deficiency are well known; those of zinc are less so. Zinc is called
the intelligence mineral because it is needed for optimal development and
functioning of the brain and nervous system. It plays a role in protein
synthesis and collagen formation; it is involved in the blood-sugar control
mechanism and thus protects against diabetes; it is needed for a healthy
reproductive system. Zinc is a key component in numerous vital enzymes and
plays a role in the immune system. Phytates found in soy products interfere
with zinc absorption more completely than with other minerals. Zinc
deficiency can cause a "spacey" feeling that some vegetarians may mistake for
the "high" of spiritual enlightenment.
Milk drinking is given as the reason why second-generation Japanese in
America grow taller than their native ancestors. Some investigators postulate
that the reduced phytate content of the American diet - whatever may be its
other deficiencies - is the true explanation, pointing out that both Asian
and Western children who do not get enough meat and fish products to
counteract the effects of a high phytate diet, frequently suffer rickets,
stunting and other growth problems.
SOY PROTEIN ISOLATE: NOT SO FRIENDLY
Soy processors have worked hard to get these anti-nutrients out of the
finished product, particularly soy protein isolate (SPI) which is the key
ingredient in most soy foods that imitate meat and dairy products, including
baby formulas and some brands of soy milk.
SPI is not something you can make in your own kitchen. Production takes place
in industrial factories where a slurry of soy beans is first mixed with an
alkaline solution to remove fibre, then precipitated and separated using an
acid wash and, finally, neutralised in an alkaline solution. Acid washing in
aluminium tanks leaches high levels of aluminium into the final product. The
resultant curds are spray- dried at high temperatures to produce a
high-protein powder. A final indignity to the original soybean is
high-temperature, high-pressure extrusion processing of soy protein isolate
to produce textured vegetable protein (TVP).
Much of the trypsin inhibitor content can be removed through high-temperature
processing, but not all. Trypsin inhibitor content of soy protein isolate can
vary as much as fivefold. (In rats, even low-level trypsin inhibitor SPI
feeding results in reduced weight gain compared to controls.) But
high-temperature processing has the unfortunate side-effect of so denaturing
the other proteins in soy that they are rendered largely ineffective. That's
why animals on soy feed need lysine supplements for normal growth. Nitrites,
which are potent carcinogens, are formed during spray-drying, and a toxin
called lysinoalanine is formed during alkaline processing. Numerous
artificial flavourings, particularly MSG, are added to soy protein isolate
and textured vegetable protein products to mask their strong "beany" taste
and to impart the flavour of meat. In feeding experiments, the use of SPI
increased requirements for vitamins E, K, D and B12 and created deficiency
symptoms of calcium, magnesium, manganese, molybdenum, copper, iron and
zinc. Phytic acid remaining in these soy products greatly inhibits zinc and iron
absorption; test animals fed SPI develop enlarged organs, particularly the
pancreas and thyroid gland, and increased deposition of fatty acids in the
liver. Yet soy protein isolate and textured vegetable protein are used
extensively in school lunch programs, commercial baked goods, diet beverages
and fast food products. They are heavily promoted in third world countries
and form the basis of many food giveaway programs.
In spite of poor results in animal feeding trials, the soy industry has
sponsored a number of studies designed to show that soy protein products can
be used in human diets as a replacement for traditional foods. An example is
"Nutritional Quality of Soy Bean Protein Isolates: Studies in Children of
Preschool Age", sponsored by the Ralston Purina Company. A group of Central
American children suffering from malnutrition was first stabilised and
brought into better health by feeding them native foods, including meat and
dairy products. Then, for a two-week period, a drink made of soy protein
isolate and sugar replaced these traditional foods. All nitrogen taken in and
all nitrogen excreted was measured in truly Orwellian fashion: the children
were weighed naked every morning, and all excrement and vomit gathered up
for analysis. The researchers found that the children retained nitrogen and that
their growth was "adequate", so the experiment was declared a success.
Whether the children were actually healthy on such a diet, or could remain so
over a long period, is another matter. The researchers noted that the
children vomited "occasionally", usually after finishing a meal; that over
half suffered from periods of moderate diarrhoea; that some had upper
respiratory infections; and that others suffered from rash and fever.
It should be noted that the researchers did not dare to use soy products to
help the children recover from malnutrition, and were obliged to supplement
the soy-sugar mixture with nutrients largely absent in soy products -
notably, vitamins A, D and B12, iron, iodine and zinc.
Click here: article26</A>: ARE SOYA PRODUCTS HEALTHY?
I found this in: http://www.worldwidehealthcenter.net/
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Now to the demanding task of reversing the damage done.