Tragedy and hype: the Third International Soy Symposium by Fallon Sally & Enig Mary G. in Nexus April-May 2000 p.19-24 p85-86.
The soy industry is huge and has many interested bodies: United Soybean Board American Soybean Association Monsanto Protein Technologies International Central Soya Cargill Foods Personal Products Company SoyLife Whitehall-Robins Healthcare and a whole lot of soybean councils. These are big names. Soy is BIG money.
Soy has been the focus of an intense decade-long (in 2000) marketing campaign to gain consumer acceptance of tofu soy milk soy ice cream soy cheese soy sausage and soy derivatives particularly soy isoflavones like genisein and idadzen – the oestrogen-like compounds found in soybeans.
Breakfast cereals baked goods convenience food smoothie mixes and meat substitutes can now be sold with labels touting benefits to cardiovascular health if these products contain one heap teaspoon of soy protein per 100-gram serving.
Soy is now in almost all Australian bread and a very wide range of other foods.
What was once a minor crop covers (in 2000) 72 million acres of US farmland. Much goes to feed chickens turkeys pigs cows salmon and to make margarine shortenings and salad dressings..
It is marketed 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 alternative animal products(meat milk cheese butter and eggs) have been demonised. Soy serves as meat and milk for virtuous vegetarians.
About US$80 million per year (in 2000) is spent on strengthening soybean’s place in the marketplace. Law firms lobby for favourable 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.
Marketers have targeted menopausal women middle-aged men and school menus. The NuMenu (in the US) now allows unlimited use of soy in student meals. By adding soy copiously dieticians can get the total fat content below 30% of calories thereby conforming to government dictates.
Processing good packaging massive advertising and a marketing strategy that stresses the Even in China where soy really is a poverty food and people want more meat not tofu they have opted to build Western-style soy factories rather than develop western grasslands for grazing animals.
Only a few decades ago the soybean was considered unfit to eat even in Asia. In Asia it was not first used as a food. Early on (1134-246BC Chou Dynastry) soy was used for the role its roots played in crop rotation fixing nitrogen in the soil not as a food. It was not used as a food until the discovery of fermentation techniques when tempeh natto miso and soy sauce started to be produced. Later (possible in the 2nd century BC) Chinese scientists discovered that a puree of cooked soybeans could be precipitated with calcium sulphate or magnesium sulphate (plaster of Paris or Epsom salts) to make a smllth pale curd – tofu or bean curd.
The Chinese did not eat unfermented soybeans because soybean contains large quantities of natural toxins or “antinutrients”.
First are potent enzyme inhibitors that block the action of trypsin and other enzymes needed for protein digestion. They can produce serious gastric distress reduced protein digestion and chronic deficiencies in amino acid uptake. In test animals diets high in trypsin inhibitors cause enlargement and pathological conditions of the pancreas including cancer.
Soybeans also contain haemagglutinin a clot-promoting substance.
Trypsin inhibitors and haemagglutinin are growth inhibitors. Weanling rats fed soy containing these antinutrients fail to grow normally. Fermentation deactivates the growth-depressant compounds. Precipitation concentrates it in the soaking liquid rather than in the curd. Fermentation and precipitation reduce but do not completely remove growth-depressant compounds.
Soy also contains goitrogens – substances that depress thyroid function.
Soybeans are high in phytic acid present in the bran or hulls of all seeds. Phytic acid can block the uptake of essential minerals – calcium magnesium copper iron and especially zinc. Although phytic acid is not a household word it has been extensively studied by scientists who are in general agreement that grain- and legume-based diets high in phytates contribute to widespread mineral deficiencies in Third World countries. The soybean has one of the highest phytate levels of any grain or legume that has been studied and the phytates in soy are highly resistant to normal phytate-reducing techniques such as long slow cooking.
Only a long period of fermentation will significantly reduce the phytate content of soybeans.
The Japanese get around this by traditionally eating a small amount of tofu or miso as part of a mineral-rich fish broth followed by a serving of meat or fish. The meat/fish reduces the mineral-blocking effect of the phytates.
Vegetarians who consume tofu and bean curd as a substitute for meat and dairy products risk severe mineral deficiencies.
Zinc is needed for optimal development and functioning of the brain and nervous system. It plays a role I protein synthesis and collagen formation. It protects against diabetes. It is needed for a healthy reproductive system. It is a key component in numerous vital enzymes and plays a role in the immune system.
Phytates found in soy interfere with zinc absorption more completely than with other minerals.
2nd-generation Japanese in America grow taller than their native ancestors. The reason postulated is the reduced-phytate diet in the US compared to Japan.
Children who do not get enough meat and fish to counteract the effects of a high phytate diet frequently suffer rickets stunting and other growth problems.
Soy protein isolate (SPI) is the key ingredient in most soy foods that imitate meat and dairy products including baby formulas and soy milk.
Soy protein isolate looks and smells terrible and used to be a waste product but now it is transformed by technology with the use of flavourings preservatives sweeteners emulsifiers and synthetic nutrients into something we eat. It is the food Cinderella.
Production takes place in industrial factories where a slurry of soybeans is first mixed with an alkaline solution to remove fibre the precipitated and separated using an acid wash and finally neutralised in an alkaline solution. Acid washing in aluminium taks leaches high levels of aluminium into the final product. The resultant curds are spray-dried at high temperatures to produce a high-protein powder. This is then extruded at high-temperature high-pressure to produce textured vegetable protein (TVP).
High-temperature processing has the unfortunate side effect of so denaturing the other proteins in soy that they are rendered largely ineffective. That’s why animals on soy feed need lysine supplements for normal growth.
Nitrites which are potent carcinogens are formed during spray-drying and a toxin called lysinoalanine is formed during alkaline processing.
Numerous artificial flavourings particularly MSG are added to soy protein isolate and textured vegetable protein products to mask their strong “beany” taste and to impart the flavour of meat.
In feeding experiments the use of soy protein isolate increased requirements for vitamins E K D and B12 and created deficiency symptoms of calcium magnesium manganese molybdenum copper iron and zinc.
Phytic acid remains in the textured vegetable protein greatly inhibit zinc and iron absorption.
SPI-fed animals develop enlarged organs particularly the pancreas and thyroid gland and had increased deposition of fatty acids in the liver.
A group of Central American children suffering malnutrition were first stabilised and brought into better health by feeding them native foods including meat and dairy products. These foods were then replaced by a drink made of soy protein isolate and sugar. The soy-sugar mixture had to be supplemented with vitamins A D B12 iron iodine and zinc. On SPI-feeding the children vomited “occasionally”; over half suffered from periods of moderate diarrhoea; some had upper respiratory infections; and others suffered from rash and fever. The researchers did not dare to use soy products to try to help the children recover from malnutrition.
Soy protein isolate leads to mineral blocking effects enzyme inhibitors goitrogenicity endocrine disruption reproductive problems and increased allergic reactions.
Substituting soy for animal protein reduces cholesterol levels by 7-20% but only cholesterol levels over 250 mg/dl not less (which is most of us). Studies in which cholesterol levels were lowered either through diet or drugs have consistently resulted in a greater number of deaths in the treatment group from stroke cancer internal disorders accident and suicide.
Japanese and Asians in general have much higher rates of oesophagus stomach pancreas and liver cancer and thyroid cancer. Soy causes these types of cancers in laboratory rats.
Just how much soy do Asians eat? A 1998 survey found average daily soy protein consumption in Japan was about eight grams for men and seven for women – less than two teaspoons. In China legume consumption varied from 0-58 grams with a mean of about 12 grams. Assuming two-thirds of legume consumption is soy then average daily consumption of soy is between 0-40 grams (3 tablespoons) with an average of about 9 grams (2 teaspoons). A survey found soy accounted for only 1.5% of calories in the Chinese diet compared with 65% from pork. Asians traditionally cook with lard. Fermented soy products make a delicious seasoning but except in times of famine Asians consume soy products only in small amounts as condiments and not as a replacement for animal foods. One exception is celibate monks living in monasteries and leading a vegetarian lifestyle – soy helps dampen their libido.
Women consuming soy protein isolate in 1996 research had an increased incidence of epithelial hyperplasia a condition that presages malignancies. Genistein was found to stimulate breast cells to enter the cell cycle which led the researchers to conclude that women should not consume soy products to prevent breast cancer.
In 1991 Richard and Valerie James bird breeders in Whangerai New Zealand started feeding their birds soy protein. 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 goitre immune system disorders and pathological aggressive behaviour. Autopsy revealed digestive organs in a state of disintegration.
Aghast started and angry they hired toxicologist Dr Mike Fitzpatrick to investigate. He did a literature review and uncovered evidence that soy consumption has been linked to numerous disorders including infertility increased cancer and infantile leukaemia and endocrine disruption. When the Jameses discontinued using soy-based feed the flock gradually returned to normal breeding habits and behaviour.
In 1991 Japanese researchers reported that consumption of as little as 30 grams (2 tablespoons) of soy per day for only one month resulted in a significant increase in thyroid-stimulating hormone. Subjects complained of constipation fatigue and lethargy. 25 grams of soy protein isolate contains 50-70mg of isoflavones.
The claim that soy prevents osteoporosis is extraordinary given that soy foods block calcium and cause vitamin D deficiencies. A suggested 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.
It is the isoflavones in infant formula that give the Jameses most cause for concern after their experience with their baby birds. Daily exposure of infants to isoflavones in soy infant formula is 6 to 11 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 13000 to 22000 times higher than plasma oestradiol concentrations in infants on cow’s milk formula.
An infant exclusively fed soy formula receives the oestrogenic equivalent (based on body weight) of at least five birth-control pills per day. Scientists have known for years that soy-based formula can cause thyroid problems in babies.
Normal 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. Soy infant feeding began in earnest in the early 1970s cannot be ignored for its effects on normal male development and may account for the surge in learning disabilities in males. Sons born to vegetarian mothers indicated a five-fold greater risk of delivering a boy with hypospadias a birth defect of the penis.
Girls are entering puberty much earlier than normal with 1% showing signs of puberty by age 3 and 14.7% by age 8. The most significant dietary association with premature sexual development is with soy infant formula. Daughters of women who took DES (with lower oestrogenic effects than soy) during their pregnancy suffered from infertility and cancer when they reached their twenties.
Scientists and industry representatives are pleading to pull soy-based infant formula off the market.
Dr Lon White showed a significant statistical relationship between two or more servings of tofu a week and “accelerated brain aging” with lower cognitive functioning and a greater incidence of Alzheimer’s disease and dementia.
All food additives not in common use prior to 1958 must have GRAS (Generally Recognized As Safe) status. Soy protein was not used in food until 1959 and not commonly until early 1970s. The scientific literature up to 1974 recognised many antinutrients in factory-made soy protein including trypsin inhibitors phytic acid and genistein. The FDA was most concerned with toxins formed during processing specifically nitrites and lysinoalanine. Even at low levels of consumption – averaging one-third of a gram per day – the presence of these carcinogens was considered too great a threat to public health to allow GRAS status. To this day soy protein is codified as GRAS only for limited industrial use as a cardboard binder. GRAS status for soy infant formula was not and still has not been granted. The key ingredient of soy infant formula is not recognised as safe. (April-May 2000)
The industry is extremely exposed. The number of potential plaintiffs can be counted in the millions.
Juries will hear something like this: “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. The industry lied to the public to sell more soy.”
Scientists protest FDA’s soy protein ruling by Sheehan Daniel M. and Doerge Daniel R. in Nexus Oct-Nov 2000 p11-13.
Drs Sheehan and Doerge are from the US Food and Drug Administration’s National Center for Toxicological Research. They wrote a protest letter ahead of a new FDA ruling “authorizing the use on food labels and in food labelling of health claims on the association between soy protein and reduced risk of coronary heard disease”. The FDA disregarded contradictory evidence and the new ruling came into effect on 26/10/1999.
Sheehan and Doerge focus on the relationship between soy and breast cancer in women accelerated brain ageing in men and developmental disorders in infants. The two researchers were interviewed for the ABC’s 20/20 program in the US and told it that they had tried in vain to stop the FDA’s recommendation because it could be misinterpreted as a broader general endorsement beyond solely having benefits for the heart. (http://abc.news.go.com/onair/2020/2020_000609_soy_feature.html)
They write: “There is abundant evidence that some of the isoflavones found in soy including genistein and equol a metabolise of daidzein demonstrate toxicity in estrogen-sensitive tissue and in the thyroid.
Genistein is clearly estrogenic and induces estrogenic responses in developing and adult animals and humans. It acts as an estrogenic endocrine disrupter during development (Medlock et al 1995ab) During pregnancy in humans isoflavones per se could be a risk factor for abnormal brain and reproductive tract development.
Pregnant rhesus monkeys fed genistein had serum estradiol levels 50-100% higher than controls. Fetuses of genistein-fed monkeys had a 70% higher serum estradiol level than did controls. (Harrison et al 1998). Development is recognized as the most sensitive life-stage for estrogen toxicity because of the indisputable evidence of a very wide variety of frank malformations and serious functional deficits in experimental animals and humans.
About 50% of female offspring and a smaller fraction of male offspring displayed one or more malformations in the reproductive tract as well as a lower prevalence of malignancies.
They conclude that no dose is without risks.
Isoflavones are inhibitors of the thyroid peroxidase which makes T3 and T4. Inhibition can be expected to generate thyroid abnormalities including goiter and autoimmune thyroiditis. There exists a significant body of animal data that demonstrates goitrogenic and even carcinogenic effects of soy products (Kimura et al 1976)
Genistein and daidzein are the goitrogenic isoflavonoid components of soy.
Fort et al (1986 1990) report a doubling of risk for autoimmune thyroiditis in children who had received soy formulas as infants compared to infants receiving other forms of milk.
The serum levels of isoflavones in infants receiving soy formula are about five times higher than in women receiving soy supplements who show menstrual cycle disturbances including an increased estradiol level in the follicular phase (Setchell et al 1997). While there is unambiguous biological effect on menstrual cycle length (Cassidy et al 1994) it is unclear whether the soy effects are beneficial or adverse.
We need to be concerned about transplacental passage of isoflavoines as estrogens can pass the placenta.
In a robust well-designed prospective epidemiological study White et al (1996a) found soy (tofu) caused vascular dementia in men. Given that estrogens are important for maintenance of brain function in women that the male brain contains aromatase the enzyme that converts testosterone to estradiol and that isoflavones inhibit this enzymatic activity (Irvine 1998) there is a mechanistic basis for the human findings.
Sheehan (1998b) writes: “Given the parallels with herbal medicines with respect to attitudes monitoring deficiencies and the general difficulty of detecting toxicities with long latencies I am unconvinced that the long history of apparent safe use of soy products can provide confidence that they are indeed without risk.”
The claim that soy protein foods are GRAS (Generally Recognized As Safe) is in conflict with the recent return by CFSAN (Center for Food Safety and Applied Nutrition FDA) to Archer Daniels Midland of a petition for GRAS status for soy protein because of deficiencies in reporting adverse effects in the petition. Thus GRAS status has not been granted.
Estrogenic and goitrogenic drugs are regulated by FDA and are taken under a physician’s care. Patients are informed of risks and are monitored by their physicians for evidence of toxicity. There are no similar safeguards in place for soy foods.