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About the Authors
Sally Fallon is the author of Nourishing
Traditions: The Cookbook that Challenges Politically Correct Nutrition
and the Diet Dictocrats by Sally Fallon with Mary G Enig, Ph.D.
($25 New Trends Publishing, Tel: +1 877 707 1776 or +1 219 268 2601)
Mary Enig, Ph.D.
has a website on trans fatty acids at www.enig.com/trans.html
plus a website for her new book Know Your Fats: The Complete Primer
for Understanding the Nutrition of Fats, Oils and Cholesterol www.knowyourfats.com/
(order from Bathesda Press +1 301-680-8600)
Other websites include
the Weston a Price Foundation at www.westonaprice.org/
and an excellent soy website at www.soyonlineservice.co.nz/
This article apeared
in Nexus magazine and on their website at www.nexusmagazine.com
and on the website of Larry Clapp at Prostate
Health in 90 Days
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Each year, research on the
health effects of soy and soybean components seems to increase exponentially.
Furthermore, research is not just expanding in the primary areas under
investigation, such as cancer, heart disease and osteoporosis; new findings
suggest that soy has potential benefits that may be more extensive than
previously thought.
So writes Mark Messina, PhD, General Chairperson
of the Third International Soy Symposium, held in Washington, DC, in November
1999.1 For four days, well-funded scientists gathered in Washington made
presentations to an admiring press and to their sponsors – United Soybean
Board, American Soybean Association, Monsanto, Protein Technologies International,
Central Soya, Cargill Foods, Personal Products Company, SoyLife, Whitehall-Robins
Healthcare and the soybean councils of Illinois, Indiana, Kentucky, Michigan,
Minnesota, Nebraska, Ohio and South Dakota.
The symposium marked the apogee of a decade-long
marketing campaign to gain consumer acceptance of tofu, soy milk, soy
ice cream, soy cheese, soy sausage and soy derivatives, particularly soy
isoflavones like genistein and diadzen, the oestrogen-like compounds found
in soybeans. It coincided with a US Food and Drug Administration (FDA)
decision, announced on October 25, 1999, to allow a health claim for products
"low in saturated fat and cholesterol" that contain 6.25 grams
of soy protein per serving. Breakfast cereals, baked goods, convenience
food, smoothie mixes and meat substitutes could now be sold with labels
touting benefits to cardiovascular health, as long as these products contained
one heaping teaspoon of soy protein per 100-gram serving.
Marketing
The Perfect Food
"Just imagine you could grow the perfect
food. This food not only would provide affordable nutrition, but also
would be delicious and easy to prepare in a variety of ways. It would
be a healthful food, with no saturated fat. In fact, you would be growing
a virtual fountain of youth on your back forty." The author is Dean
Houghton, writing for The Furrow,2 a magazine published in 12 languages
by John Deere. "This ideal food would help prevent, and perhaps reverse,
some of the world's most dreaded diseases. You could grow this miracle
crop in a variety of soils and climates. Its cultivation would build up,
not deplete, the land...this miracle food already exists... It's called
soy."
Just imagine. Farmers have been imagining – and planting more soy. What was once a minor crop, listed in the 1913
US Department of Agriculture (USDA) handbook not as a food but as an industrial
product, now covers 72 million acres of American farmland. Much of this
harvest will be used to feed chickens, turkeys, pigs, cows and salmon.
Another large fraction will be squeezed to produce oil for margarine,
shortenings and salad dressings.
Advances in technology make it possible
to produce isolated soy protein from what was once considered a waste
product – the defatted, high-protein soy chips – and then transform something
that looks and smells terrible into products that can be consumed by human
beings. Flavorings, preservatives, sweeteners, emulsifiers and synthetic
nutrients have turned soy protein isolate, the food processors' ugly duckling,
into a New Age Cinderella.
The new fairy-tale food has been marketed
not so much for her beauty but for her virtues. Early on, products based
on soy protein isolate were sold as extenders and meat substitutes – a
strategy that failed to produce the requisite consumer demand. The industry
changed its approach. "The quickest way to gain product acceptability
in the less affluent society," said an industry spokesman, "is
to have the product consumed on its own merit in a more affluent society."3
So soy is now sold to the upscale consumer, not as a cheap, poverty food
but as a miracle substance that will prevent heart disease and cancer,
whisk away hot flushes, build strong bones and keep us forever young.
The competition – meat, milk, cheese, butter and eggs – has been duly
demonised by the appropriate government bodies. Soy serves as meat and
milk for a new generation of virtuous vegetarians.
Marketing costs money, especially when
it needs to be bolstered with "research", but there's plenty
of funds available. All soybean producers pay a mandatory assessment of
one-half to one per cent of the net market price of soybeans. The total – something like US$80 million annually4 – supports United Soybean's program
to "strengthen the position of soybeans in the marketplace and maintain
and expand domestic and foreign markets for uses for soybeans and soybean
products". State soybean councils from Maryland, Nebraska, Delaware,
Arkansas, Virginia, North Dakota and Michigan provide another $2.5 million
for "research".5 Private companies like Archer Daniels Midland
also contribute their share. ADM spent $4.7 million for advertising on
Meet the Press and $4.3 million on Face the Nation during the course of
a year.6 Public relations firms help convert research projects into newspaper
articles and advertising copy, and law firms lobby for favorable government
regulations. IMF money funds soy processing plants in foreign countries,
and free trade policies keep soybean abundance flowing to overseas destinations.
The push for more soy has been relentless
and global in its reach. Soy protein is now found in most supermarket
breads. It is being used to transform "the humble tortilla, Mexico's
corn-based staple food, into a protein-fortified 'super-tortilla' that
would give a nutritional boost to the nearly 20 million Mexicans who live
in extreme poverty".7 Advertising for a new soy-enriched loaf from
Allied Bakeries in Britain targets menopausal women seeking relief from
hot flushes. Sales are running at a quarter of a million loaves per week.8
The soy industry hired Norman Robert Associates,
a public relations firm, to "get more soy products onto school menus".9
The USDA responded with a proposal to scrap the 30 per cent limit for
soy in school lunches. The NuMenu program would allow unlimited use of
soy in student meals. With soy added to hamburgers, tacos and lasagna,
dieticians can get the total fat content below 30 per cent of calories,
thereby conforming to government dictates. "With the soy-enhanced
food items, students are receiving better servings of nutrients and less
cholesterol and fat."
Soy milk has posted the biggest gains,
soaring from $2 million in 1980 to $300 million in the US last year.10
Recent advances in processing have transformed the gray, thin, bitter,
beany-tasting Asian beverage into a product that Western consumers will
accept – one that tastes like a milkshake, but without the guilt.
Processing miracles, good packaging, massive
advertising and a marketing strategy that stresses the products' possible
health benefits account for increasing sales to all age groups. For example,
reports that soy helps prevent prostate cancer have made soy milk acceptable
to middle-aged men. "You don't have to twist the arm of a 55- to
60-year-old guy to get him to try soy milk," says Mark Messina. Michael
Milken, former junk bond financier, has helped the industry shed its hippie
image with well-publicized efforts to consume 40 grams of soy protein
daily.
America today, tomorrow the world. Soy
milk sales are rising in Canada, even though soy milk there costs twice
as much as cow's milk. Soybean milk processing plants are sprouting up
in places like Kenya.11 Even China, where soy really is a poverty food
and whose people want more meat, not tofu, has opted to build Western-style
soy factories rather than develop western grasslands for grazing animals.12
Cinderella's
Dark Side
The propaganda that has created the soy
sales miracle is all the more remarkable because, only a few decades ago,
the soybean was considered unfit to eat – even in Asia. During the Chou
Dynasty (1134-246 BC) the soybean was designated one of the five sacred
grains, along with barley, wheat, millet and rice. However, the pictograph
for the soybean, which dates from earlier times, indicates that it was
not first used as a food; for whereas the pictographs for the other four
grains show the seed and stem structure of the plant, the pictograph for
the soybean emphasizes the root structure. Agricultural literature of
the period speaks frequently of the soybean and its use in crop rotation.
Apparently the soy plant was initially used as a method of fixing nitrogen.13
The soybean did not serve as a food until
the discovery of fermentation techniques, some time during the Chou Dynasty.
The first soy foods were fermented products like tempeh, natto, miso and
soy sauce. At a later date, possibly in the 2nd century BC, Chinese scientists
discovered that a purée of cooked soybeans could be precipitated
with calcium sulfate or magnesium sulfate (plaster of Paris or Epsom salts)
to make a smooth, pale curd – tofu or bean curd. The use of fermented
and precipitated soy products soon spread to other parts of the Orient,
notably Japan and Indonesia.
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 "antinutrients". 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.14
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.15
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,16 and the phytates
in soy are highly resistant to normal phytate-reducing techniques such
as long, slow cooking.17 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.18 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.19 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.20
Soy Protein
Isolate: Not So Friendly
Soy processors have worked hard
to get these antinutrients 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 fiber,
then precipitated and separated using an acid wash and, finally, neutralized
in an alkaline solution. Acid washing in aluminum tanks leaches high levels
of aluminum 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.21 (In rats,
even low-level trypsin inhibitor SPI feeding results in reduced weight
gain compared to controls.22) But high-temperature processing has the
unfortunate side-effect of so denaturing the other proteins in soy that
they are rendered largely ineffective.23 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.24 Numerous artificial flavorings, particularly
MSG, are added to soy protein isolate and textured vegetable protein products
to mask their strong "beany" taste and to impart the flavor
of meat.25
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.26 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.27
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.28 A group of Central American children
suffering from malnutrition was first stabilized and brought into better
health by feeding them native foods, including meat and dairy products.
Then, for a two-week period, these traditional foods were replaced by
a drink made of soy protein isolate and sugar. 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.
FDA
Health Claim Challenged
The best marketing strategy for a product
that is inherently unhealthy is, of course, a health claim.
"The road to FDA approval," writes
a soy apologist, "was long and demanding, consisting of a detailed
review of human clinical data collected from more than 40 scientific studies
conducted over the last 20 years. Soy protein was found to be one of the
rare foods that had sufficient scientific evidence not only to qualify
for an FDA health claim proposal but to ultimately pass the rigorous approval
process."29
The "long and demanding" road
to FDA approval actually took a few unexpected turns. The original petition,
submitted by Protein Technology International, requested a health claim
for isoflavones, the estrogen-like compounds found plentifully in soybeans,
based on assertions that "only soy protein that has been processed
in a manner in which isoflavones are retained will result in cholesterol
lowering". In 1998, the FDA made the unprecedented move of rewriting
PTI's petition, removing any reference to the phyto-estrogens and substituting
a claim for soy protein – a move that was in direct contradiction to the
agency's regulations. The FDA is authorized to make rulings only on substances
presented by petition.
The abrupt change in direction was no doubt
due to the fact that a number of researchers, including scientists employed
by the US Government, submitted documents indicating that isoflavones
are toxic.
The FDA had also received, early in 1998,
the final British Government report on phytoestrogens, which failed to
find much evidence of benefit and warned against potential adverse effects.30
Even with the change to soy protein isolate, FDA bureaucrats engaged in
the "rigorous approval process" were forced to deal nimbly with
concerns about mineral blocking effects, enzyme inhibitors, goitrogenicity,
endocrine disruption, reproductive problems and increased allergic reactions
from consumption of soy products.31
One of the strongest letters of protest
came from Dr Dan Sheehan and Dr Daniel Doerge, government researchers
at the National Center for Toxicological Research.32 Their pleas for warning
labels were dismissed as unwarranted.
"Sufficient scientific evidence"
of soy's cholesterol-lowering properties is drawn largely from a 1995
meta-analysis by Dr James Anderson, sponsored by Protein Technologies
International and published in the New England Journal of Medicine.33
A meta-analysis is a review and summary
of the results of many clinical studies on the same subject. Use of meta-analyses
to draw general conclusions has come under sharp criticism by members
of the scientific community. "Researchers substituting meta-analysis
for more rigorous trials risk making faulty assumptions and indulging
in creative accounting," says Sir John Scott, President of the Royal
Society of New Zealand. "Like is not being lumped with like. Little
lumps and big lumps of data are being gathered together by various groups."34
There is the added temptation for researchers,
particularly researchers funded by a company like Protein Technologies
International, to leave out studies that would prevent the desired conclusions.
Dr Anderson discarded eight studies for various reasons, leaving a remainder
of twenty-nine. The published report suggested that individuals with cholesterol
levels over 250 mg/dl would experience a "significant" reduction
of 7 to 20 per cent in levels of serum cholesterol if they substituted
soy protein for animal protein. Cholesterol reduction was insignificant
for individuals whose cholesterol was lower than 250 mg/dl.
In other words, for most of us, giving
up steak and eating vegieburgers instead will not bring down blood cholesterol
levels. The health claim that the FDA approved "after detailed review
of human clinical data" fails to inform the consumer about these
important details.
Research that ties soy to positive effects
on cholesterol levels is "incredibly immature", said Ronald
M. Krauss, MD, head of the Molecular Medical Research Program and Lawrence
Berkeley National Laboratory.35 He might have added that studies in which
cholesterol levels were lowered through either diet or drugs have consistently
resulted in a greater number of deaths in the treatment groups than in
controls – deaths from stroke, cancer, intestinal disorders, accident
and suicide.36 Cholesterol-lowering measures in the US have fuelled a
$60 billion per year cholesterol-lowering industry, but have not saved
us from the ravages of heart disease.
Soy And
Cancer
The new FDA ruling does not allow any claims
about cancer prevention on food packages, but that has not restrained
the industry and its marketers from making them in their promotional literature.
"In addition to protecting the heart,"
says a vitamin company brochure, "soy has demonstrated powerful anticancer
benefits...the Japanese, who eat 30 times as much soy as North Americans,
have a lower incidence of cancers of the breast, uterus and prostate."37
Indeed they do. But the Japanese, and Asians
in general, have much higher rates of other types of cancer, particularly
cancer of the esophagus, stomach, pancreas and liver.38 Asians throughout
the world also have high rates of thyroid cancer.39 The logic that links
low rates of reproductive cancers to soy consumption requires attribution
of high rates of thyroid and digestive cancers to the same foods, particularly
as soy causes these types of cancers in laboratory rats.
Just how much soy do Asians eat? A 1998
survey found that the average daily amount of soy protein consumed in
Japan was about eight grams for men and seven for women – less than two
teaspoons.40 The famous Cornell China Study, conducted by Colin T. Campbell,
found that legume consumption in China varied from 0 to 58 grams per day,
with a mean of about twelve.41 Assuming that two-thirds of legume consumption
is soy, then the maximum consumption is about 40 grams, or less than three
tablespoons per day, with an average consumption of about nine grams,
or less than two teaspoons. A survey conducted in the 1930s found that
soy foods accounted for only 1.5 per cent of calories in the Chinese diet,
compared with 65 per cent of calories from pork.42 (Asians traditionally
cooked with lard, not vegetable oil!)
Traditionally fermented soy products make
a delicious, natural seasoning that may supply important nutritional factors
in the Asian diet. But except in times of famine, Asians consume soy products
only in small amounts, as condiments, and not as a replacement for animal
foods – with one exception. Celibate monks living in monasteries and leading
a vegetarian lifestyle find soy foods quite helpful because they dampen
libido.
It was a 1994 meta-analysis by Mark Messina,
published in Nutrition and Cancer, that fuelled speculation on soy's anticarcinogenic
properties.43 Messina noted that in 26 animal studies, 65 per cent reported
protective effects from soy. He conveniently neglected to include at least
one study in which soy feeding caused pancreatic cancer – the 1985 study
by Rackis.44 In the human studies he listed, the results were mixed. A
few showed some protective effect, but most showed no correlation at all
between soy consumption and cancer rates. He concluded that "the
data in this review cannot be used as a basis for claiming that soy intake
decreases cancer risk". Yet in his subsequent book, The Simple Soybean
and Your Health, Messina makes just such a claim, recommending one cup
or 230 grams of soy products per day in his "optimal" diet as
a way to prevent cancer.
Thousands of women are now consuming soy
in the belief that it protects them against breast cancer. Yet, in 1996,
researchers found that women consuming soy protein isolate had an increased
incidence of epithelial hyperplasia, a condition that presages malignancies.45
A year later, dietary genistein was found to stimulate breast cells to
enter the cell cycle – a discovery that led the study authors to conclude
that women should not consume soy products to prevent breast cancer.46
Phytoestrogens:
Panacea Or Poison?
The male species of tropical birds carries the drab plumage of the female
at birth and 'colors up' at maturity, somewhere between nine and 24 months.
In 1991, Richard and Valerie James, bird
breeders in Whangerai, New Zealand, purchased a new kind of feed for their
birds – one based largely on soy protein.47 When soy-based feed was used,
their birds 'colored up' after just a few months. In fact, one bird-food
manufacturer claimed that this early development was an advantage imparted
by the feed. A 1992 ad for Roudybush feed formula showed a picture of
the male crimson rosella, an Australian parrot that acquires beautiful
red plumage at 18 to 24 months, already brightly colored at 11 weeks old.
Unfortunately, in the ensuing years, there
was decreased fertility in the birds, with precocious maturation, deformed,
stunted and stillborn babies, and premature deaths, especially among females,
with the result that the total population in the aviaries went into steady
decline. The birds suffered beak and bone deformities, goiter, immune
system disorders and pathological, aggressive behavior. Autopsy revealed
digestive organs in a state of disintegration. The list of problems corresponded
with many of the problems the Jameses had encountered in their two children,
who had been fed soy-based infant formula.
Startled, aghast, angry, the Jameses hired
toxicologist Mike Fitzpatrick. PhD, to investigate further. Dr Fitzpatrick's
literature review uncovered evidence that soy consumption has been linked
to numerous disorders, including infertility, increased cancer and infantile
leukemia; and, in studies dating back to the 1950s,48 that genistein in
soy causes endocrine disruption in animals. Dr Fitzpatrick also analyzed
the bird feed and found that it contained high levels of phytoestrogens,
especially genistein. When the Jameses discontinued using soy-based feed,
the flock gradually returned to normal breeding habits and behavior.
The Jameses embarked on a private crusade
to warn the public and government officials about toxins in soy foods,
particularly the endocrine-disrupting isoflavones, genistein and diadzen.
Protein Technology International received their material in 1994.
In 1991, Japanese researchers reported
that consumption of as little as 30 grams or two tablespoons of soybeans
per day for only one month resulted in a significant increase in thyroid-stimulating
hormone.49 Diffuse goiter and hypothyroidism appeared in some of the subjects
and many complained of constipation, fatigue and lethargy, even though
their intake of iodine was adequate. In 1997, researchers from the FDA's
National Center for Toxicological Research made the embarrassing discovery
that the goitrogenic components of soy were the very same isoflavones.50
Twenty-five grams of soy protein isolate,
the minimum amount PTI claimed to have cholesterol-lowering effects, contains
from 50 to 70 mg of isoflavones. It took only 45 mg of isoflavones in
premenopausal women to exert significant biological effects, including
a reduction in hormones needed for adequate thyroid function. These effects
lingered for three months after soy consumption was discontinued.51
One hundred grams of soy protein – the
maximum suggested cholesterol-lowering dose, and the amount recommended
by Protein Technologies International – can contain almost 600 mg of isoflavones,52
an amount that is undeniably toxic. In 1992, the Swiss health service
estimated that 100 grams of soy protein provided the estrogenic equivalent
of the Pill.53
In vitro studies suggest that isoflavones
inhibit synthesis of estradiol and other steroid hormones.54 Reproductive
problems, infertility, thyroid disease and liver disease due to dietary
intake of isoflavones have been observed for several species of animals
including mice, cheetah, quail, pigs, rats, sturgeon and sheep.55
It is the isoflavones in soy that are said
to have a favorable effect on postmenopausal symptoms, including hot flushes,
and protection from osteoporosis. Quantification of discomfort from hot
flushes is extremely subjective, and most studies show that control subjects
report reduction in discomfort in amounts equal to subjects given soy.56
The claim that soy prevents osteoporosis is extraordinary, given that
soy foods block calcium and cause vitamin D deficiencies. If Asians indeed
have lower rates of osteoporosis than Westerners, it is because their
diet provides plenty of vitamin D from shrimp, lard and seafood, and plenty
of calcium from bone broths. The reason that Westerners have such high
rates of osteoporosis is because they have substituted soy oil for butter,
which is a traditional source of vitamin D and other fat-soluble activators
needed for calcium absorption.
Birth Control
Pills For Babies
But it was the isoflavones in infant formula
that gave the Jameses the most cause for concern. In 1998, investigators
reported that the daily exposure of infants to isoflavones in soy infant
formula is 6 to11 times higher on a body-weight basis than the dose that
has hormonal effects in adults consuming soy foods. Circulating concentrations
of isoflavones in infants fed soy-based formula were 13,000 to 22,000
times higher than plasma estradiol concentrations in infants on cow's
milk formula.57
Approximately 25 per cent of bottle-fed
children in the US receive soy-based formula – a much higher percentage
than in other parts of the Western world. Fitzpatrick estimated that an
infant exclusively fed soy formula receives the estrogenic equivalent
(based on body weight) of at least five birth control pills per day.58
By contrast, almost no phytoestrogens have been detected in dairy-based
infant formula or in human milk, even when the mother consumes soy products.
Scientists have known for years that soy-based
formula can cause thyroid problems in babies. But what are the effects
of soy products on the hormonal development of the infant, both male and
female?
Male infants undergo a "testosterone
surge" during the first few months of life, when testosterone levels
may be as high as those of an adult male. During this period, the infant
is programmed to express male characteristics after puberty, not only
in the development of his sexual organs and other masculine physical traits,
but also in setting patterns in the brain characteristic of male behavior.
In monkeys, deficiency of male hormones impairs the development of spatial
perception (which, in humans, is normally more acute in men than in women),
of learning ability and of visual discrimination tasks (such as would
be required for reading).59 It goes without saying that future patterns
of sexual orientation may also be influenced by the early hormonal environment.
Male children exposed during gestation to diethylstilbestrol (DES), a
synthetic estrogen that has effects on animals similar to those of phytoestrogens
from soy, had testes smaller than normal on manturation.60
Learning disabilities, especially in male
children, have reached epidemic proportions. Soy infant feeding – which
began in earnest in the early 1970s – cannot be ignored as a probable
cause for these tragic developments.
As for girls, an alarming number are entering
puberty much earlier than normal, according to a recent study reported
in the journal Pediatrics.61 Investigators found that one per cent of
all girls now show signs of puberty, such as breast development or pubic
hair, before the age of three; by age eight, 14.7 per cent of white girls
and almost 50 per cent of African-American girls have one or both of these
characteristics.
New data indicate that environmental estrogens
such as PCBs and DDE (a breakdown product of DDT) may cause early sexual
development in girls.62 In the 1986 Puerto Rico Premature Thelarche study,
the most significant dietary association with premature sexual development
was not chicken – as reported in the press – but soy infant formula.63
The consequences of this truncated childhood
are tragic. Young girls with mature bodies must cope with feelings and
urges that most children are not well-equipped to handle. And early maturation
in girls is frequently a harbinger for problems with the reproductive
system later in life, including failure to menstruate, infertility and
breast cancer.
Parents who have contacted the Jameses
recount other problems associated with children of both sexes who were
fed soy-based formula, including extreme emotional behavior, asthma, immune
system problems, pituitary insufficiency, thyroid disorders and irritable
bowel syndrome – the same endocrine and digestive havoc that afflicted
the Jameses' parrots.
Dissension
In The Ranks
Organizers of the Third International Soy
Symposium would be hard-pressed to call the conference an unqualified
success. On the second day of the symposium, the London-based Food Commission
and the Weston A. Price Foundation of Washington, DC, held a joint press
conference, in the same hotel as the symposium, to present concerns about
soy infant formula. Industry representatives sat stony-faced through the
recitation of potential dangers and a plea from concerned scientists and
parents to pull soy-based infant formula from the market. Under pressure
from the Jameses, the New Zealand Government had issued a health warning
about soy infant formula in 1998; it was time for the American government
to do the same.
On the last day of the symposium, presentations
on new findings related to toxicity sent a well-oxygenated chill through
the giddy helium hype. Dr Lon White reported on a study of Japanese Americans
living in Hawaii, that showed a significant statistical relationship between
two or more servings of tofu a week and "accelerated brain aging".64
Those participants who consumed tofu in mid-life had lower cognitive function
in late life and a greater incidence of Alzheimer's disease and dementia.
"What's more," said Dr White, "those who ate a lot of tofu,
by the time they were 75 or 80 looked five years older".65 White
and his colleagues blamed the negative effects on isoflavones – a finding
that supports an earlier study in which postmenopausal women with higher
levels of circulating estrogen experienced greater cognitive decline.66
Scientists Daniel Sheehan and Daniel Doerge,
from the National Center for Toxicological Research, ruined PTI's day
by presenting findings from rat feeding studies, indicating that genistein
in soy foods causes irreversible damage to enzymes that synthesise thyroid
hormones.67 "The association between soybean consumption and goiter
in animals and humans has a long history," wrote Dr Doerge. "Current
evidence for the beneficial effects of soy requires a full understanding
of potential adverse effects as well."
Dr Claude Hughes reported that rats born
to mothers that were fed genistein had decreased birth weights compared
to controls, and onset of puberty occurred earlier in male offspring.68
His research suggested that the effects observed in rats "...will
be at least somewhat predictive of what occurs in humans. There is no
reason to assume that there will be gross malformations of fetuses but
there may be subtle changes, such as neurobehavioral attributes, immune
function and sex hormone levels." The results, he said, "could
be nothing or could be something of great concern...if mom is eating something
that can act like sex hormones, it is logical to wonder if that could
change the baby's development".69
A study of babies born to vegetarian mothers,
published in January 2000, indicated just what those changes in baby's
development might be. Mothers who ate a vegetarian diet during pregnancy
had a fivefold greater risk of delivering a boy with hypospadias, a birth
defect of the penis.70 The authors of the study suggested that the cause
was greater exposure to phytoestrogens in soy foods popular with vegetarians.
Problems with female offspring of vegetarian mothers are more likely to
show up later in life. While soy's estrogenic effect is less than that
of diethylstilbestrol (DES), the dose is likely to be higher because it's
consumed as a food, not taken as a drug. Daughters of women who took DES
during pregnancy suffered from infertility and cancer when they reached
their twenties.
Question
Marks Over Gras Status
Lurking in the background of
industry hype for soy is the nagging question of whether it's even legal
to add soy protein isolate to food. All food additives not in common use
prior to 1958, including casein protein from milk, must have GRAS (Generally
Recognized As Safe) status. In 1972, the Nixon administration directed
a re-examination of substances believed to be GRAS, in the light of any
scientific information then available. This re-examination included casein
protein that became codified as GRAS in 1978. In 1974, the FDA obtained
a literature review of soy protein because, as soy protein had not been
used in food until 1959 and was not even in common use in the early 1970s,
it was not eligible to have its GRAS status grandfathered under the provisions
of the Food, Drug and Cosmetic Act.71
The scientific literature up to 1974 recognized
many antinutrients in factory-made soy protein, including trypsin inhibitors,
phytic acid and genistein. But the FDA literature review dismissed discussion
of adverse impacts, with the statement that it was important for "adequate
processing" to remove them. Genistein could be removed with an alcohol
wash, but it was an expensive procedure that processors avoided. Later
studies determined that trypsin inhibitor content could be removed only
with long periods of heat and pressure, but the FDA has imposed no requirements
for manufacturers to do so.
The FDA was more concerned with toxins
formed during processing, specifically nitrites and lysinoalanine.72 Even
at low levels of consumption – averaging one-third of a gram per day at
the time – the presence of these carcinogens was considered too great
a threat to public health to allow GRAS status.
Soy protein did have approval for use as
a binder in cardboard boxes, and this approval was allowed to continue,
as researchers considered that migration of nitrites from the box into
the food contents would be too small to constitute a cancer risk. FDA
officials called for safety specifications and monitoring procedures before
granting of GRAS status for food. These were never performed. To this
day, use of soy protein is codified as GRAS only for this limited industrial
use as a cardboard binder. This means that soy protein must be subject
to premarket approval procedures each time manufacturers intend to use
it as a food or add it to a food.
Soy protein was introduced into infant
formula in the early 1960s. It was a new product with no history of any
use at all. As soy protein did not have GRAS status, premarket approval
was required. This was not and still has not been granted. The key ingredient
of soy infant formula is not recognized as safe.
The Next
Asbestos?
"Against the backdrop of widespread
praise...there is growing suspicion that soy – despite its undisputed
benefits – may pose some health hazards," writes Marian Burros, a
leading food writer for the New York Times. More than any other writer,
Ms Burros's endorsement of a low-fat, largely vegetarian diet has herded
Americans into supermarket aisles featuring soy foods. Yet her January
26, 2000 article, "Doubts Cloud Rosy News on Soy", contains
the following alarming statement: "Not one of the 18 scientists interviewed
for this column was willing to say that taking isoflavones was risk free."
Ms Burros did not enumerate the risks, nor did she mention that the recommended
25 daily grams of soy protein contain enough isoflavones to cause problems
in sensitive individuals, but it was evident that the industry had recognized
the need to cover itself.
Because the industry is extremely exposed...contingency
lawyers will soon discover that the number of potential plaintiffs can
be counted in the millions and the pockets are very, very deep. Juries
will hear something like the following: "The industry has known for
years that soy contains many toxins. At first they told the public that
the toxins were removed by processing. When it became apparent that processing
could not get rid of them, they claimed that these substances were beneficial.
Your government granted a health claim to a substance that is poisonous,
and the industry lied to the public to sell more soy."
The "industry" includes merchants,
manufacturers, scientists, publicists, bureaucrats, former bond financiers,
food writers, vitamin companies and retail stores. Farmers will probably
escape because they were duped like the rest of us. But they need to find
something else to grow before the soy bubble bursts and the market collapses:
grass-fed livestock, designer vegetables...or hemp to make paper for thousands
and thousands of legal briefs.
References
1. Program for the
Third International Symposium on the Role of Soy in Preventing and Treating
Chronic Disease, Sunday, October 31, through Wednesday, November 3, 1999,
Omni Shoreham Hotel, Washington, DC.
2. Houghton, Dean, "Healthful Harvest", The Furrow, January
2000, pp. 10-13.
3. Coleman, Richard J., "Vegetable Protein – A Delayed Birth?"
Journal of the American Oil Chemists' Society 52:238A, April 1975.
4. See www/unitedsoybean.org.
5. These are listed in www.soyonlineservice.co.nz.
6. Wall Street Journal, October 27, 1995.
7. Smith, James F., "Healthier tortillas could lead to healthier
Mexico", Denver Post, August 22, 1999, p. 26A.
8. "Bakery says new loaf can help reduce hot flushes", Reuters,
September 15, 1997.
9. "Beefing Up Burgers with Soy Products at School", Nutrition
Week, Community Nutrition Institute, Washington, DC, June 5, 1998, p.
2.
10. Urquhart, John, "A Health Food Hits Big Time", Wall Street
Journal, August 3, 1999, p. B1
11. "Soyabean Milk Plant in Kenya", Africa News Service, September
1998.
12. Simoons, Frederick J., Food in China: A Cultural and Historical Inquiry,
CRC Press, Boca Raton, 1991, p. 64.
13. Katz, Solomon H., "Food and Biocultural Evolution: A Model for
the Investigation of Modern Nutritional Problems", Nutritional Anthropology,
Alan R. Liss Inc., 1987, p. 50.
14. Rackis, Joseph J. et al., "The USDA trypsin inhibitor study.
I. Background, objectives and procedural details", Qualification
of Plant Foods in Human Nutrition, vol. 35, 1985.
15. Van Rensburg et al., "Nutritional status of African populations
predisposed to esophageal cancer", Nutrition and Cancer, vol. 4,
1983, pp. 206-216; Moser, P.B. et al., "Copper, iron, zinc and selenium
dietary intake and status of Nepalese lactating women and their breastfed
infants", American Journal of Clinical Nutrition 47:729-734, April
1988; Harland, B.F. et al., "Nutritional status and phytate: zinc
and phytate X calcium: zinc dietary molar ratios of lacto-ovovegetarian
Trappist monks: 10 years later", Journal of the American Dietetic
Association 88:1562-1566, December 1988.
16. El Tiney, A.H., "Proximate Composition and Mineral and Phytate
Contents of Legumes Grown in Sudan", Journal of Food Composition
and Analysis (1989) 2:6778.
17. Ologhobo, A.D. et al., "Distribution of phosphorus and phytate
in some Nigerian varieties of legumes and some effects of processing",
Journal of Food Science 49(1):199-201, January/February 1984.
18. Sandstrom, B. et al., "Effect of protein level and protein source
on zinc absorption in humans", Journal of Nutrition 119(1):48-53,
January 1989; Tait, Susan et al., "The availability of minerals in
food, with particular reference to iron", Journal of Research in
Society and Health 103(2):74-77, April 1983.
19. Phytate reduction of zinc absorption has been demonstrated in numerous
studies. These results are summarised in Leviton, Richard, Tofu, Tempeh,
Miso and Other Soyfoods: The 'Food of the Future' – How to Enjoy Its Spectacular
Health Benefits, Keats Publishing, Inc., New Canaan, CT, USA, 1982, p.
1415.
20. Mellanby, Edward, "Experimental rickets: The effect of cereals
and their interaction with other factors of diet and environment in producing
rickets", Journal of the Medical Research Council 93:265, March 1925;
Wills, M.R. et al., "Phytic Acid and Nutritional Rickets in Immigrants",
The Lancet, April 8,1972, pp. 771-773.
21. Rackis et al., ibid.
22. Rackis et al., ibid., p. 232.
23. Wallace, G.M., "Studies on the Processing and Properties of Soymilk",
Journal of Science and Food Agriculture 22:526-535, October 1971.
24. Rackis, et al., ibid., p. 22; "Evaluation of the Health Aspects
of Soy Protein Isolates as Food Ingredients", prepared for FDA by
Life Sciences Research Office, Federation of American Societies for Experimental
Biology (9650 Rockville Pike, Bethesda, MD 20014), USA, Contract No. FDA
223-75-2004, 1979.
25. See www/truthinlabeling.org.
26. Rackis, Joseph, J., "Biological and Physiological Factors in
Soybeans", Journal of the American Oil Chemists' Society 51:161A-170A,
January 1974.
27. Rackis, Joseph J. et al., "The USDA trypsin inhibitor study",
ibid.
28. Torum, Benjamin, "Nutritional Quality of Soybean Protein Isolates:
Studies in Children of Preschool Age", in Soy Protein and Human Nutrition,
Harold L Wilcke et al. (eds), Academic Press, New York, 1979.
29. Zreik, Marwin, CCN, "The Great Soy Protein Awakening", Total
Health 32(1), February 2000.
30. IEH Assessment on Phytoestrogens in the Human Diet, Final Report to
the Ministry of Agriculture, Fisheries and Food, UK, November 1997, p.
11.
31. Food Labeling: Health Claims: Soy Protein and Coronary Heart Disease,
Food and Drug Administration 21 CFR, Part 101 (Docket No. 98P-0683).
32. Sheegan, Daniel M. and Daniel R Doerge, Letter to Dockets Management
Branch (HFA-305), February 18, 1999.
33. Anderson, James W. et al., "Meta-analysis of the Effects of Soy
Protein Intake on Serum Lipids", New England Journal of Medicine
(1995) 333:(5):276-282.
34. Guy, Camille, "Doctors warned against magic, quackery",
New Zealand Herald, September 9, 1995, section 8, p. 5.
35. Sander, Kate and Hilary Wilson, "FDA approves new health claim
for soy, but litte fallout expected for dairy", Cheese Market News,
October 22, 1999, p. 24.
36. Enig, Mary G. and Sally Fallon, "The Oiling of America",
NEXUS Magazine, December 1998-January 1999 and February-March 1999; also
available at www.WestonAPrice.org.
37. Natural Medicine News (L & H Vitamins, 32-33 47th Avenue, Long
Island City, NY 11101), USA, January/February 2000, p. 8.
38. Harras, Angela (ed.), Cancer Rates and Risks, National Institutes
of Health, National Cancer Institute, 1996, 4th edition.
39. Searle, Charles E. (ed.), Chemical Carcinogens, ACS Monograph 173,
American Chemical Society, Washington, DC, 1976.
40. Nagata, C. et al., Journal of Nutrition (1998) 128:209-213.
41. Campbell, Colin T. et al., The Cornell Project in China.
42. Chang, K.C. (ed.), Food in Chinese Culture: Anthropological and Historical
Perspectives, New Haven, 1977.
43. Messina, Mark J. et al., "Soy Intake and Cancer Risk: A Review
of the In Vitro and In Vivo Data", Nutrition and Cancer (1994) 21(2):113-131.
44. Rackis et al, "The USDA trypsin inhibitor study", ibid.
45. Petrakis, N.L. et al., "Stimulatory influence of soy protein
isolate on breast secretion in pre- and post-menopausal women", Cancer
Epid. Bio. Prev. (1996) 5:785-794.
46. Dees, C. et al., "Dietary estrogens stimulate human breast cells
to enter the cell cycle", Environmental Health Perspectives (1997)
105(Suppl. 3):633-636.
47. Woodhams, D.J., "Phytoestrogens and parrots: The anatomy of an
investigation", Proceedings of the Nutrition Society of New Zealand
(1995) 20:22-30.
48. Matrone, G. et al., "Effect of Genistin on Growth and Development
of the Male Mouse", Journal of Nutrition (1956) 235-240.
49. Ishizuki, Y. et al., "The effects on the thyroid gland of soybeans
administered experimentally in healthy subjects", Nippon Naibunpi
Gakkai Zasshi (1991) 767:622-629.
50. Divi, R.L. et al., "Anti-thyroid isoflavones from the soybean",
Biochemical Pharmacology (1997) 54:1087-1096.
51. Cassidy, A. et al., "Biological Effects of a Diet of Soy Protein
Rich in Isoflavones on the Menstrual Cycle of Premenopausal Women",
American Journal of Clinical Nutrition (1994) 60:333-340.
52. Murphy, P.A., "Phytoestrogen Content of Processed Soybean Foods",
Food Technology, January 1982, pp. 60-64.
53. Bulletin de L'Office Fédéral de la Santé Publique,
no. 28, July 20, 1992.
54. Keung, W.M., "Dietary oestrogenic isoflavones are potent inhibitors
of B-hydroxysteroid dehydrogenase of P. testosteronii", Biochemical
and Biophysical Research Committee (1995) 215:1137-1144; Makela, S.I.
et al., "Estrogen-specific 12 B-hydroxysteroid oxidoreductase type
1 (E.C. 1.1.1.62) as a possible target for the action of phytoestrogens",
PSEBM (1995) 208:51-59.
55. Setchell, K.D.R. et al., "Dietary oestrogens – a probable cause
of infertility and liver disease in captive cheetahs", Gastroenterology
(1987) 93:225-233; Leopald, A.S., "Phytoestrogens: Adverse effects
on reproduction in California Quail," Science (1976) 191:98-100;
Drane, H.M. et al., "Oestrogenic activity of soya-bean products",
Food, Cosmetics and Technology (1980) 18:425-427; Kimura, S. et al., "Development
of malignant goiter by defatted soybean with iodine-free diet in rats",
Gann. (1976) 67:763-765; Pelissero, C. et al., "Oestrogenic effect
of dietary soybean meal on vitellogenesis in cultured Siberian Sturgeon
Acipenser baeri", Gen. Comp. End. (1991) 83:447-457; Braden et al.,
"The oestrogenic activity and metabolism of certain isoflavones in
sheep", Australian J. Agricultural Research (1967) 18:335-348.
56. Ginsburg, Jean and Giordana M. Prelevic, "Is there a proven place
for phytoestrogens in the menopause?", Climacteric (1999) 2:75-78.
57. Setchell, K.D. et al., "Isoflavone content of infant formulas
and the metabolic fate of these early phytoestrogens in early life",
American Journal of Clinical Nutrition, December 1998 Supplement, 1453S-1461S.
58. Irvine, C. et al., "The Potential Adverse Effects of Soybean
Phytoestrogens in Infant Feeding", New Zealand Medical Journal May
24, 1995, p. 318.
59. Hagger, C. and J. Bachevalier, "Visual habit formation in 3-month-old
monkeys (Macaca mulatta): reversal of sex difference following neonatal
manipulations of androgen", Behavior and Brain Research (1991) 45:57-63.
60. Ross, R.K. et al., "Effect of in-utero exposure to diethylstilbestrol
on age at onset of puberty and on post-pubertal hormone levels in boys",
Canadian Medical Association Journal 128(10):1197-8, May 15, 1983.
61. Herman-Giddens, Marcia E. et al., "Secondary Sexual Characteristics
and Menses in Young Girls Seen in Office Practice: A Study from the Pediatric
Research in Office Settings Network", Pediatrics 99(4):505-512, April
1997.
62. Rachel's Environment & Health Weekly 263, "The Wingspread
Statement", Part 1, December 11, 1991; Colborn, Theo, Dianne Dumanoski
and John Peterson Myers, Our Stolen Future, Little, Brown & Company,
London, 1996.
63. Freni-Titulaer, L.W., "Premature Thelarch in Puerto Rico: A search
for environmental factors", American Journal of Diseases of Children
140(12):1263-1267, December 1986.
64. White, Lon, "Association of High Midlife Tofu Consumption with
Accelerated Brain Aging", Plenary Session #8: Cognitive Function,
The Third International Soy Symposium, November 1999, Program, p. 26.
65. Altonn, Helen, "Too much tofu induces 'brain aging', study shows",
Honolulu Star-Bulletin, November 19, 1999.
66. Journal of the American Geriatric Society (1998) 46:816-21.
67. Doerge, Daniel R., "Inactivation of Thyroid Peroxidase by Genistein
and Daidzein in Vitro and in Vivo; Mechanism for Anti-Thyroid Activity
of Soy", presented at the November 1999 Soy Symposium in Washington,
DC, National Center for Toxicological Research, Jefferson, AR 72029, USA.
68. Hughes, Claude, Center for Women's Health and Department of Obstetrics
& Gynecology, Cedars-Sinai Medical Center, Los Angeles, CA.
69. Soy Intake May Affect Fetus", Reuters News Service, November
5, 1999.
70. "Vegetarian diet in pregnancy linked to birth defect", BJU
International 85:107-113, January 2000.
71. FDA ref 72/104, Report FDABF GRAS – 258.
72. "Evaluation of the Health Aspects of Soy Protein Isolates as
Food Ingredients", prepared for FDA by Life Sciences Research Office,
Federation of American Societies for Experimental Biology (FASEB) (9650
Rockville Pike, Bethesda, MD 20014, USA), Contract No, FDA 223-75-2004,
1979.
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