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The Hidden Dangers of Soy Allergens
The huge rise in allergic reactions to soy is in line with the increasing
use of soy products in processed foods during the 1990s, and should be
regarded as a major public health concern.
Extracted from Nexus Magazine, Volume 11, Number 5 (August-September 2004)
PO& nbsp;Box 30, Mapleton Qld 4560 Australia. editor nexusmagazine.com
Telephone: +61 (0)7 5442 9280; Fax: +61 (0)7 5442 9381
From our web page at: www.nexusmagazine.com
by Kaayla T. Daniel, PhD, CCN (c) 2004
From Chapter 23 of her book
The Whole Soy Story: The Dark Side of America's Favorite Health Food
(NewTrends Publishing, 2004)
Website: http://www.wholesoystory.com
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THE RISE IN SOY ALLERGIES
Soy is one of the top allergens-substances that cause allergic reactions. In
the 1980s, Stuart Berger, MD, labelled soy one of the seven top
allergens-one of the "sinister seven". At the time, most experts listed soy
around tenth or eleventh-bad enough, but way behind peanuts, tree nuts,
milk, eggs, shellfish, fin fish and wheat. Today, soy is widely accepted as
one of the "big eight" that cause immediate hypersensitivity reactions.1-4
Allergies are abnormal inflammatory responses of the immune system to dust,
pollen, a food or some other substance. Those that involve an antibody
called immunoglobulin E (IgE) occur immediately or within an hour. Reactions
may include coughing, sneezing, runny nose, hives, diarrhoea, facial
swelling, shortness of breath, a swollen tongue, difficulty swallowing,
lowered blood pressure, excessive perspiration, fainting, anaphylactic shock
or even death.4-9
Delayed allergic responses to soy are less dramatic, but are even more
common. These are caused by antibodies known as immunoglobulins A, G or M
(IgA, IgG or IgM) and occur anywhere from two hours to days after the food
is eaten. These have been linked to sleep disturbances, bedwetting, sinus
and ear infections, crankiness, joint pain, chronic fatigue,
gastrointestinal woes and other mysterious symptoms.4-9
Food "intolerances", "sensitivities" and "idiosyncrasies" to soy are
commonly called "food allergies", but differ from true allergies in that
they are not caused by immune system reactions but by little-understood or
unknown metabolic mechanisms.7-9 Strictly speaking, gas and bloating-common
reactions to soy and other beans-are not true allergic responses. However,
they may serve as warnings of the possibility of a larger clinical picture
involving allergen-related gastrointestinal damage.
PROFIT vs RISK
The soybean industry knows that some people experience severe allergic
reactions to its products. In a recent petition to the US Food and Drug
Administration (FDA), Protein Technologies International (PTI) identified
"allergenicity" as one of the "most likely potential adverse effects
associated with ingestion of large amounts of soy products". Yet PTI somehow
concluded that "the data do not support that they would pose a substantial
threat to the health of the US population".10
This statement is hardly reassuring to the many children and adults who
suffer allergies to soy products. And it ignores a substantial body of
evidence published during the 1990s showing that some of these people learn
for the first time about their soy allergies after experiencing an
unexpectedly severe or even life-threatening reaction.
Severe reactions to soy are rare compared to reactions to peanuts, tree
nuts, fish and shellfish, but Swedish researchers recently concluded that
"Soy has been underestimated as a cause of food anaphylaxis" (Foucard T.,
Malmheden Yman, I., Allergy 1999, 53(3):261-265).11
A BAD HAMBURGER
The Swedes began looking into a possible soybean connection after a young
girl suffered an asthma attack and died after eating a hamburger that
contained only 2.2 per cent soy protein. A team of researchers collected
data on all fatal and life-threatening reactions caused by food between 1993
and 1996 in Sweden, and found that the soy-in-the-hamburger case was not a
fluke and that soy was indeed the culprit. They evaluated 61 cases of severe
reactions to food, of which five were fatal, and found that peanut, soy and
tree nuts caused 45 of the 61 reactions. Of the five deaths, four were
attributed to soy. The four children who died from soy had known allergies
to peanuts but not to soy. The amount of soy eaten ranged from one gram to
10 grams-typical of the low levels found when soy protein is used as a
meat-extending additive in ready-made foods such as hamburgers, meatballs,
spaghetti sauces, kebabs and sausages or as an extender in breads and
pastries.
When soy is "hidden" in hamburgers and other "regular" foods, people often
miss the soy connection. And allergic reactions to soy do not always occur
immediately, making cause and effect even harder to establish. As reported
in the Swedish study, no symptoms-or very mild symptoms-occurred for 30 to
90 minutes after the consumption of the food containing soy; then the
children suffered fatal asthma attacks. All had been able to eat soy without
any adverse reactions right up until the dinner that caused their deaths.
The Swedish study was not the first to report "fatal events" after eating
soy. Food anaphylaxis is most often associated with reactions to peanuts,
tree nuts, shellfish and occasionally fish or milk, but soy has its own rap
sheet. Anaphylactic reactions to bread, pizzas or sausage extended with soy
protein date back at least to 1961. Subsequent studies have confirmed that
the risk may be rare but is very real.12-20
The increasing amount of "hidden" soy in the food supply is undoubtedly
responsible for triggering many allergic reactions not attributed to soy.
French researchers who studied the frequency of anaphylactic shocks caused
by foods reported that the food allergen remained unknown in 25 per cent of
cases. They noted the prevalence of "hidden" and "masked" food allergens and
stated that they saw "a strikingly increased prevalence of food-induced
anaphylactic shock in 1995 compared to a previous study from 1982".21 This
period coincided with a huge increase in the amount of soy protein added to
processed foods. (In fact, the amount has continued to rise. Per capita
consumption of soy protein increased from 0.78 g/day in 1998 to 2.23 g/day
in 2002, according to industry estimates obtained by the Solae Company
which, in March 2004, filed a petition seeking FDA approval of a health
claim for soy protein and cancer reduction.21a)
None of these studies has attracted much media attention. Nor have health
agencies issued alerts. For example, Ingrid Malmheden Yman, PhD, of the
Sweden National Food Administration and co-author of the study, wrote to the
Ministry of Health in New Zealand at the request of an allergy sufferer. Two
years before the article (first published in Swedish) came out in English,
she informed the agency that children with severe allergy to peanut should
avoid intake of soy protein. To be on the safe side, she further advised
parents to make an effort to "avoid sensitisation" by limiting consumption
of both peanuts and soybeans during the third trimester of pregnancy and
during breastfeeding, and by avoiding the use of soy formula.22
Controversy has raged since the 1920s as to whether or not babies could be
sensitised to allergens while still in utero. In 1976, researchers learned
that the foetus is capable of producing IgE antibodies against soy protein
during early gestation, and newborns can be so sensitised through the
breastmilk of the mother that they later react to foods they've "never
eaten".23, 24 Families who need to take these precautions seriously include
those with known peanut and/or soy allergies, vegetarians who would
otherwise eat a lot of soy foods during pregnancy or breastfeeding, and
parents considering the use of soy infant formula.
Because the numbers of children with allergies to peanuts are increasing, we
can expect to see greater numbers of children and adults reacting severely
to soy. Peanuts and soybeans are members of the same botanical family, the
grain-legume type, and scientists have known for years that people allergic
to one are often allergic to the other.
Other children at risk for an undetected but potentially life-threatening
soy allergy include those with allergies to peas, lima beans or other beans,
a diagnosis of asthma, rhinitis, eczema or dermatitis, or family members
with a history of any of those diseases. Reactions to foods in the same
botanical family can be cumulative, resulting in symptoms far more severe
than either alone.25-32
SOY'S ALLERGENIC PROTEINS
Scientists are not completely certain which components of soy cause allergic
reactions. They have found at least 16 allergenic proteins, and some
researchers pinpoint as many as 25 to 30. Laboratories report immune system
responses to multiple fractions of the soy protein, with no particular
fraction being the most consistently antigenic, i.e., capable of causing the
production of an antibody.33-36
Some of the most allergenic fractions appear to be the Kunitz and
Bowman-Birk trypsin inhibitors. Food processors have tried in vain to
deactivate these troublesome proteins completely without irreparably
damaging the remainder of the soy protein (see chapter 12). Having failed to
accomplish this, the soy industry has decided to promote these
"antinutrients" as cancer preventers. To date, its proof remains slim,
although cancer statistics might improve if enough people died from
anaphylactic shock first.
Although extremely rare, death from allergic reaction to trypsin inhibitor
has been a matter of public record since the New England Journal of Medicine
carried a report in 1980.37, 38 The Kunitz trypsin inhibitor has been
identified as one of three allergic components in soy lecithin-a soy product
often considered hypoallergenic (i.e., it has diminished potential for
causing an allergic reaction) because it is not supposed to include any soy
protein, but invariably contains trace amounts.39
Soybean lectin-another antinutrient now promoted as a disease preventer-has
also been identified as an allergen.40 Whenever there is a damaged
intestinal lining or "leaky gut", soy lectins can easily pass into the
bloodstream, triggering allergic reactions (see chapter 14). Indeed, this is
very likely because both soy allergens and saponins (an antinutrient
discussed in chapter 15) can damage the intestines.
Histamine toxicity can also resemble allergic reactions. In allergic
persons, mast cells release histamine, causing a response that strongly
resembles an allergic reaction to food. In cases of histamine toxicity, the
histamine comes ready-made in the food. This is most often associated with
reactions to cheese and fish, but soy sauce also contains high levels of
histamine. Researchers who have calculated the histamine content of foods
consumed at a typical oriental meal report that histamine intake may easily
approach toxic levels.41
PROCESSING MATTERS
The way that the soybean is grown, harvested, processed, stored and prepared
in the kitchen can affect its allergenicity. Raw soybeans are the most
allergenic, while old-fashioned fermented products (miso, tempeh, natto,
shoyu and tamari) are the least. Modern soy protein products processed by
heat, pressure and chemical solvents lose some of their allergenicity, but
not all. Partially hydrolysed proteins and soy sprouts, which are quickly or
minimally processed, remain highly allergenic.42, 43
The industry newsletter, The Soy Connection, states that highly refined oils
and lecithin "are safe for the soy-allergic consumer".44
Unfortunately, many allergic persons who have trusted such reassurances have
ended up in the hospital. Highly susceptible people cannot use either
safely. Adverse reactions to soy oils-taken either by mouth as food or via
tube-feeding-range from the nuisance of sneezing to the life-threatening
danger of anaphylactic shock.45-51
If soy oil and lecithin were 100 per cent free of soy protein, they would
not provoke allergic symptoms. Variable conditions and the quality control
and processing methods used when the vegetable oil industry separates
soybean protein from the oil make the presence of at least trace amounts of
soy protein possible, even likely. Though healthier in many respects, the
cold-pressed soy oils sold in health food stores can be deadly for the
allergic consumer. They may contain as much as 100 times the amount of trace
protein found in the highly refined soy oils sold in supermarkets.52, 53
Soy protein is likely to appear in margarine. Above and beyond any stray
protein that remains after the processing of the soy oil, soy protein
isolates or concentrates are commonly used by food manufacturers to improve
the texture or spreadability of these products. This occurs most often in
low-fat or "low trans" products (see chapter 6).
PARENT WARNING!
HIDDEN SOY - HIDDEN SOY ALLERGIES
If your child is allergic to peanuts, you must eliminate all soy as
well as all peanuts from your child's diet. Your child's life may depend
upon it.
Take care, even if your child has never reacted poorly to soy in the
past. Some sensitive children have "hidden" soy allergies that manifest for
the first time with a severe-even fatal-reaction to even the low levels of
"hidden" soy commonly found in processed food products. Those at the highest
risk suffer from asthma as well as peanut allergy.
Other risk factors are other food allergies, a family history of
peanut or soy allergies, a diagnosis of asthma, rhinitis or eczema, or a
family history of these diseases.
(Source: Letter from Ingrid Malmheden Yman, PhD, Senior Chemist,
Sweden National Food Administration, to the New Zealand Ministry of Health,
30 May 1997)
HIDDEN DANGER
People allergic to soy protein face constant danger. Hidden soy exists in
thousands of everyday foods, cosmetics and industrial products such as inks,
cardboards, paints, cars and mattresses. The four Swedish fatalities are
only the best known of thousands of reported cases of people who experienced
severe allergic reactions to soy after inadvertently eating foods that
contained soybean proteins.54-56
Of 659 food products recalled by the FDA in 1999, 236 (36 per cent) were
taken off the market because of undeclared allergens. The three factors
responsible for the undeclared allergens were: omissions and errors on
labels (51 per cent), cross contamination of manufacturing equipment (40 per
cent), and errors made by suppliers of ingredients (five per cent). It
wasn't inspectors, however, but ticked-off US consumers who fingered 56 per
cent of the undeclared allergens.57
During 2002, the Canadian Food Inspection Agency (CFIA), which takes soy
allergies seriously, recalled bagels, doughnuts, rolls, pizza and other
items containing undeclared soy protein.58 Although agencies in many
countries claim to be stepping up efforts to enforce labelling laws,
enforcement is difficult even when officials make it a priority. The chief
problem is that few methods reliably detect and quantify minute amounts of
allergens in foods.59
Even when soy-containing ingredients are accurately listed on food labels,
consumers may easily miss the soy connection. A 2002 study of 91 parents of
children allergic to peanuts, milk, egg, soy, and/or wheat revealed that
most parents failed to identify allergenic food ingredients correctly, and
that milk and soy presented the most problems. Only 22 per cent of the
parents with soy allergies correctly identified soy protein in seven
products. The researchers concluded, "These results strongly support the
need for improved labelling with plain-English terminology and allergen
warnings as well as the need for diligent education of patients reading
labels".60
THE MARGARINE CONNECTION
Allergies to pollen dust, dander and foods are on the increase
wherever margarine replaces butter. That's the conclusion of Finnish
researchers who found that children who developed allergies ate less butter
and more margarine compared with children who did not develop allergies.
Nearly all commercially marketed margarines are made with soy oil.
The study showed that children with eczema, dermatitis and other itchy
skin conditions consumed an average of 8 grams of margarine for every 1,000
calories compared to 6 grams among children without allergies, and 9 grams
of butter compared to 11 grams of butter or more among the children without
the allergies.
Laboratory testing revealed that the allergic children had a higher
ratio of polyunsaturated to saturated fat and a lower percentage of myristic
acid (an indicator of saturated fat intake) than children without allergies.
They also showed lower levels of the EPA/DHA polyunsaturated oils found in
fish.
The inescapable conclusion: butter is better.
(Source: Dunder, T., Kuikka L. et al., "Diet, serum fatty acids and
atopic diseases in childhood", Allerg 2001, 56(5):425-428)
CLEARING THE AIR
Allergic reactions occur not only when soy is eaten but when soybean flour
or dust is inhaled. Among epidemiologists, soybean dust is known as an
"epidemic asthma agent". From 1981 to 1987, soy dust from grain silo
unloading in the harbour of Barcelona, Spain, caused 26 epidemics of asthma,
seriously jeopardising the health of 687 people and leading to 1,155
hospitalisations. No further epidemics occurred after filters were
installed, but a minor outbreak in 1994 established the need for diligent
monitoring of preventive measures.61, 62
Reports of the epidemic in Barcelona led epidemiologists in New Orleans to
investigate cases of epidemic asthma that occurred from 1957 to 1968 when
more than 200 people sought treatment at Charity Hospital. Investigations of
weather patterns and cargo data from the New Orleans harbour identified soy
dust from ships carrying soybeans as the probable cause. No association was
found between asthma epidemic days and the presence of wheat or corn on
ships in the harbour. The researchers concluded, "The results of this
analysis provide further evidence that ambient soy dust is very asthmogenic
and that asthma morbidity in a community can be influenced by exposures in
the ambient atmosphere".63
The first report of "occupational asthma" appeared in the Journal of Allergy
in 1934. W. W. Duke described six persons whose asthma was triggered by dust
from a nearby soybean mill and predicted that soy could become a major cause
of allergy in the future.64 Today it is well established that soybean dust
is an occupational hazard of working in bakeries, animal feed factories,
food processing plants, and health food stores and co-ops with bulk bins.
Dust explosions are a safety hazard at soybean processing plants.64-68
Most victims develop their "occupational asthma" over a period of time. In
one well-documented case, a 43-year-old woman spent six years working at a
food processing plant, in which soybean flour was used as a meat extender,
before she developed asthma. Symptoms of sneezing, coughing and wheezing
would begin within minutes of exposure to soy flour and resolve two hours
after the exposure ceased.69
Rare reactions to soy have also occurred in asthmatic patients using
inhalers with bronchodilators containing soy-derived excipients.
Bronchospasms with laryngospasms and cutaneous rash have occurred even in
patients who were otherwise not affected by soy allergy.70
FORMULA FOR DISASTER:
AROUND THE WORLD WITH SOY ALLERGIES
Allergic reactions occur to soy formula in children all over the
world, particularly those affected by other allergies:
. Victoria, Australia - Soy milk allergies in 47 per cent of 97
children with cow's milk allergies;
. Berlin, Germany - Soybean allergies in 16 per cent of children with
atopic dermatitis;
. Bonn, Germany - Soybean allergies in 10 per cent of children with
suspected food allergy;
. Milan, Italy - Soybean allergies in 17 per cent of children with
food intolerance; soybean allergies in 21 per cent of 704 atopic children;
. Rome, Italy - Soy allergies found in 22 per cent of 371 children
with food allergy;
. Malmö, Sweden - Soybean allergies in 35 per cent of infants with
cow's milk allergies;
. San Diego, USA - Soybean allergies found in 25 per cent of infants
sensitive to cow's milk;
. Bangkok, Thailand - Soybean allergies in 17 per cent of children
sensitive to cow's milk;
. Thailand - Soy allergies in 4 per cent of 100 asthmatic children;
. New Haven, CT, USA - Soy and milk allergies found in 62 per cent and
soy and gluten allergies found in 35 per cent of infants and children with
multiple gastrointestinal allergies;
. Ohio, USA - Sensitivity to soy formula found in 5 per cent of 148
children with respiratory allergies.
(Source: Literature review on Dr Matthias Besler's website,
http://www.food-allergens.de.contents-2000.html
for full citations, see endnotes 110-121)
FUDGING STATISTICS ON SOY INFANT FORMULA
For years, the soy industry billed soy formula as "hypoallergenic". Herman
Frederic Meyer, MD, of the Department of Pediatrics, Northwestern University
Medical School, Chicago, categorised soy formulas as "hypoallergic
preparations" in his 1961 textbook, Infant Foods and Feeding Practice, and
named Mull Soy, Sobee, Soyalac and Soyola products as good examples.71
Over the years, the soy industry has promoted this and similar
misinformation in advertising, labels and educational literature by ignoring
relevant studies in favour of largely irrelevant studies based on guinea
pigs.72, 73
As late as 1989, John Erdman, PhD, a researcher honoured in 2001 by the soy
industry for his "outstanding contributions to increasing understanding and
awareness of the health benefits of soy foods and soybean constituents",
claimed "hypoallergenicity" for soy in the American Journal of Clinical
Nutrition. A subsequent Letter to the Editor corrected his misinformation.74
,75
The soy industry today has shifted from claiming hypoallergenicity for soy
to minimising its extent. That has been fairly easy, for no one seems to
know quite how many sufferers there are. Estimates are rough at best because
diagnoses of allergy include anything from parental complaints of spitting,
fussiness, colic and vomiting to laboratory provings using RAST and ELISA
tests, to clinical challenges and elimination diets.
Because the tests are not completely reliable and anecdotal evidence tends
to be taken lightly, many cases are not counted. The figures cited most
often delineate 0.3 to 7.5 per cent of the population as allergic to cow's
milk and 0.5 to 1.1 per cent as allergic to soy. However, evidence suggests
that soy protein is at least as antigenic as milk protein, especially when
gastrointestinal complaints and delayed hypersensitivity (non-IgE) reactions
are taken into account.76-81
On the soy industry website "Soy and Human Health", Clare Hasler, PhD, of
the University of Illinois Urbana, Champaign, picks the low 0.5 per cent
figure and claims that soy protein is rated 11th among foods in terms of
allergenicity.82
This may have been true in the 1970s (her source is dated 1979), but soy is
widely acknowledged as one of the "big eight" today.
Indeed, one prominent researcher puts soy in the "top six" and another in
the "top four" foods causing hypersensitivity reactions in children.83, 84
Soy formula is a far from optimal solution for bottle-fed infants who are
allergic to dairy formulas. The plant oestrogens in soy can interfere with
proper development of the infant's thyroid, brain and reproductive systems.
Soy formula also falls short as a solution to cow's milk allergy (see
chapter 22 and elsewhere in this article).
Symptoms such as diarrhoea, bloating, vomiting and skin rashes sometimes go
away when infants are switched from dairy formula to soy, but the relief is
usually only temporary. In many infants, the symptoms return with a
vengeance within a week or two.
As Dr Stefano Guandalini, of the Department of Pediatrics, University of
Chicago, writes, "A significant number of children with cow's milk protein
intolerance develop soy protein intolerance when soy milk is used in dietary
management".85
Interestingly enough, researchers recently detected and identified a soy
protein component that cross-reacts with caseins from cow's milk.86 Cross
reactions occur when foods are chemically related to each other.
Adverse reactions caused by soybean formulas occur in at least 14 to 35 per
cent of infants allergic to cow's milk, according to Dr Matthias Besler of
Hamburg, Germany, and the international team of allergy specialists who help
him with the informative website,
http://www.food-allergens.de/contents-2000.html
Dr Guandalini's helpful website, http://www.emedicine.com/ped/topic2128.htm
reports the results of an unpublished study of 2,108 infants
and toddlers in Italy, of which 53 per cent of the babies under three months
old who had reacted poorly to dairy formula also reacted to soy formula.
Although experts generally attribute this high level of reactivity to the
immature-hence vulnerable-digestive tract of infants, this study showed that
35 per cent of the children over one year old who were allergic to cow's
milk protein also developed an allergy to soy protein. In all, 47 per cent
had to discontinue the soy formula.88
Infants who are allergic to dairy formulas are allergic to soy formulas so
often that researchers have begun advising paediatricians to stop
recommending soy and start prescribing hypoallergenic hydrolysed casein or
whey formulas.
A study of 216 infants at high risk for developing allergies revealed
comparable levels of eczema and asthma whether they were drinking cow's milk
formula or the more "hypoallergenic" soy formula.
Upon conclusion of the study, the message was clear: only "exclusive
breastfeeding or feeding with a partial whey hydrolysate formula is
associated with the lower incidence of atopic disease and food allergy. This
is a cost-effective approach to the prevention of allergic disease in
children".89
No one can make a good argument that soy formula is hypoallergenic, but many
still say that its soy proteins may be less sensitising than cow's milk
proteins. When babies develop soy intolerance, the blame tends to go to
earlier damage done to the intestines by cow's milk protein.90
This has led some physicians to recommend starting infants off from birth on
soy formula. This does not stop a tendency to develop food allergies. As C.
D. May, of the Department of Pediatrics, National Jewish Hospital and
Research Center, Denver, put it, "Feeding a soy product from birth for 112
days did not prevent a brisk antibody response to cow milk introduced
subsequently, comparable to or greater than the antibody response seen when
cow milk products were fed from birth".91
BOWELLED OVER
People diagnosed with "allergic colitis" suffer from bloody diarrhoea,
ulcerations and tissue damage, particularly to the sigmoid area of the
descending colon. The leading cause in infants is cow's milk allergy, but 47
to 60 per cent of those infants react the same way to soy formula.
Curiously, inflammatory changes in the mucus lining of the intestines appear
even in infants who seem to be tolerating soy: no diarrhoea, no hives, no
blood in the stool or other obvious allergic signs. One study showed that
clinical reactions occurred in 16 per cent of the children on soy formula,
but that histological and enzymological intestinal damage occurred in an
additional 38 per cent of the children. This second group showed damage to
the intestinal cells and tissues as viewed under a microscope and through
blood tests, indicating increased levels of xylose (an indigestible sugar
used to diagnose "leaky gut" and other intestinal disorders). The
researchers also found depleted levels of sucrase, lactase, maltase and
alkaline phosphatase-evidence that the infants' digestive capacity was
compromised, their stress levels were increased and immune systems
challenged.92
Most gastrointestinal problems connected to soy formula involve non-IgE
delayed immune reactions.93 However, local IgE reactions may contribute to
these problems by triggering the formation of immune complexes that alter
the permeability of the gut mucosa. As C. Carini, the lead author in an
Annals of Allergy study published in 1987, wrote, "The resultant delayed
onset symptoms could be viewed as a form of serum sickness with few or many
target organs affected".94
The baby's small intestine is at special risk. Scanning electron microscopy
and biopsies have revealed severe damage to the small intestine, including
flattening and wasting away of the projections (known as villi) and cellular
overgrowth of the pits (known as crypts). Allergic reaction may not be the
sole cause here, as the observed destruction dovetails with that caused by
soy antinutrients known as lectins and saponins, with the lectins possibly
doing double duty as allergic proteins (see chapters 14 and 15). Villi are
the projections clustered over the entire mucous surface of the small
intestine where nutrient absorption takes place. Flattening and atrophy of
the villi lead to malnutrition and failure to thrive, with a clinical
picture very similar to that found in children and adults afflicted with
coeliac disease.95-97
Coeliac disease is a serious malabsorption syndrome most commonly associated
with gluten (a protein fraction found in wheat and some other grains) and
dairy intolerance. Few people know that there is also a connection with soy.
Some adults with coeliac disease experience diarrhoea, headache, nausea and
flatulence even on a gluten-free diet when they eat a tiny amount of soy.
And a study of 98 infants and children with multiple gastrointestinal
allergies revealed that 62 per cent had both soy and milk allergies and 35
per cent both soy and gluten.98, 99
OUTGROWING SOY ALLERGIES
Allergy specialists say that "most" young children "outgrow" their
sensitivities.100 This makes sense-to a point. If infants develop soy
allergies because of immature digestive tracts and immune systems, the risk
of developing a soy allergy would decrease with age and many children would
outgrow their soy allergies. Yet other studies-even by the same
authors-reveal that only a minority of subjects outgrows them.
One study showed that only 26 per cent of children suffering from soy, egg,
milk, wheat and peanut allergies lost their hypersensitivity after one year.
While peanut-soy's even more allergenic relative-may have skewed those
results, another study found that only two out of eight infants outgrew soy
allergies after 25 months.101-103
And many children who "successfully" outgrow food allergies develop
respiratory allergies. A study of 322 children showed that only six per cent
still experienced food sensitivity after five years, but 40 per cent of
those children "grew into" respiratory allergies. This was true for milk,
egg, chocolate, soy and cereals, in that order.104 Yet this study is often
cited as proof that most children "successfully" outgrow their allergies.
Children are more likely to outgrow allergies to cow's milk or soy than
allergies to peanuts, fish or shrimp, but will continue to react to them if
they eat these foods often enough. And treatment of these allergies requires
total exclusion of the offending food. Soy-induced enterocolitis, for
example, will resolve after six months to two years of strictly avoiding
soy.105 As families of allergic youngsters know, keeping soy off the dinner
table and out of the meals and snacks provided at daycare centres and
schools can be challenging. Even in non-vegetarian families, soy is
ubiquitous in the processed food supply. As a result, sensitisation to soy
has increased, is not necessarily outgrown, and can either re-emerge or
develop later in life.
FRANKENSOY'S MONSTER
Soy allergies may also be on the rise because of genetically modified (GM)
soybeans. The York Nutritional Laboratories in the UK, one of Europe's
leading laboratories specialising in food sensitivity, found a 50 per cent
increase in soy allergies in 1998, the very year in which genetically
engineered beans were introduced to the world market. York's researchers
noted that one of the 16 proteins in soybeans most likely to cause allergic
reactions was found in concentrations higher by 30 per cent or more in
Monsanto's GM soybeans. The York researchers sent their findings to British
Health Secretary Frank Dobson, urging the government to act on the
information and impose an instant ban on GM food, pending further safety
tests being conducted. Dr Michael Antonion, a molecular pathologist at Guy's
Hospital in central London, observed: "This is a very interesting if
slightly worrying development. It points to the fact that far more work is
needed to assess their safety. At the moment, no allergy tests are carried
out before GM foods are marketed and that also needs to be looked at."106,
107
People allergic to GM soybeans may not even be allergic to soy. The culprit
can be foreign proteins introduced into the soybean. People allergic to
Brazil nuts but not to soy have shown allergies to GM soybeans in which
Brazil nut proteins were inserted to increase the level of methionine and
improve the overall amino acid profile of soy.108
Scientists say that such problems can be prevented by doing IgE-binding
studies, by accounting for physicochemical characteristics of proteins and
referring to known allergen databases. That might have identified the Brazil
nut problem, but there is no way to assess the risk of de novo
sensitisation, which happens when experiments generate new allergens.109 ?
READER'S SURVIVAL GUIDE:
KICKING SOY OUT OF YOUR LIFE
Those who are allergic to soy must exclude all soy from their diets. This
can be a challenge. Soy lurks in nearly everything these days, even in
products where we would not reasonably expect it. In the USA, it's in
Bumblebee canned tuna, Chef Boyardee Ravioli, Hershey's chocolate, many of
the Baskin Robbins 31 flavours, McDonalds and other fast-food burgers, some
Pizza Hut pizzas, many luncheon meats, most breads, muffins, doughnuts,
lemonade mixes, hot chocolate, some baby foods, and tens of thousands of
other popular products.
If you absolutely must keep soy out of your life or that of your children,
memorise the following:
. Soy goes by many aliases. Food processors are less likely to list the
three-letter word "soy" than a technical term such as "textured vegetable
protein (TVP), "textured plant protein", "hydrolysed vegetable protein
(HVP)", "vegetable protein concentrate", "vegetable oil" or "MSG (monosodium
glutamate)". Ingredient lists also include words such as "lecithin",
"vegetable oil", "vegetable broth", "bouillon", "natural flavour" or
"mono-diglyceride" that do not necessarily, but are likely to, come from
soy.
. Food labels and ingredient lists change. Check them every single time.
Manufacturers can switch the ingredients used in food products without
warning. Allergic consumers need to check the labels every time they make a
purchase and ask about ingredients every time they eat at a restaurant or
purchase food at a deli. To make things easier, many allergic people carry
cards listing foods on their "no" lists.
. Products may be mislabelled or contain undeclared soy. The only solution
here is to hope and pray, and make your own food from scratch using known
ingredients.
. Cross-contamination occurs. Improperly cleaned pans, plates, utensils and
cutting boards at restaurant or delis, bins at health food stores or vats at
the factory can contaminate food with traces of soy. All it takes is a bit
of old soy oil or soy protein residue to trigger severe reactions in people
who are highly susceptible.
. Soy may be in the package as well as its contents. Soy protein isolate
used in the manufacture of paperboard boxes can flake off and migrate into
food. In the future, some foods may be shrink-wrapped in an edible soy-based
plastic.
. Soy can be breathed in as well as eaten. Expect soy dust in some bakeries
and shipyards, and in the bulk bin aisle of your health food store.
. Soy may be in your pills. Vitamins, over-the-counter drugs and
prescriptions may contain an unwanted dose of soy. Beware of pills with soy
oil bases, vitamin E derived from soy oil, and soy components such as
isoflavones. The inhaler Atrovent is just one of many pharmaceutical
products containing unexpected soy.
. Soy is the latest thing in just about everything. Soy inks, paints,
plastics, carpets, mattresses, cars, etc. are just a few of the industrial
products that may be green for the environment but deadly for highly
allergic persons.
. Kiss with care. Finally, someone who is exquisitely sensitive to soy could
die from contact with the lips of someone who has just eaten soy. Unlikely
as this might seem, it has happened with peanuts, soy's even more allergenic
relative. ?
About the Author:
Kaayla T. Daniel, PhD, CCN, is the author of The Whole Soy Story: The Dark
Side of America's Favorite Health Food (NewTrends Publishing, 2004). She is
a board-certified clinical nutritionist and a health educator who teaches
classes and workshops on disease prevention, optimum health and maximum
longevity. Dr Daniel can be reached through her website,
http://www.wholesoystory.com
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