The true story of Soy has not been told.
The many serious health hazards from consuming soy have not been told.
The consumer has not been made aware of the dangers, in order for them to make an educated decision on whether or not to consume soy.
You have the right to know, and I’m going to tell you.
The Health Risks Of Soy Includes But Not Limited To:
Brain and Nervous System damage
Heart disease, arrhythmia
Increased Cancer Cell Proliferation
Infantile acute leukemia (IAL)
Infertility and reproductive problems
Cancer(s) / Breast / liver / uterine / colon / thyroid / pancreas / prostate
Causing the Reoccurrence of cancer(s)
Chromosome fragmentation, and errors in its orientation
DNA and chromosome damage
DNA double strand breaks
Immune system damage (including T-cell production, activity)
Immune system suppression (including suppression of T-cell production, activity)
Damage to the myelin sheath surrounding the nerves
Subtle changes in sexually dimorphic behaviors
Premature, delayed puberty, Pseudo-Puberty
Graves’ or Hashimoto’s Disease
Irritable Bowl Syndrome
According to a 1999 survey by the United Soybean Board, two-thirds of consumers surveyed believe soy products are “healthy,” up from 59 percent in 1997.
The popularity of soy foods is increasing. According to data from Spence Information Services, a San Francisco sales tracking firm, in 1998, sales of soymilk grew 53 percent in mainstream supermarkets and 24 percent in health food stores over the previous year. HealthFocus, another research firm, reports that 10 percent of shoppers in 1998, versus 3 percent in 1996, said they are eating more soy specifically because they believe it will reduce their risk of disease.
Think about all of the known but ignored “side-effects” listed above. Think about the number of people worldwide that have been seriously hurt and/or dying from eating soy, simply because these people were lied to with misinformation, persuading them to believe by the soy industry and their supporters.
While well known to much of the general scientific community, this data has been withheld from the general public, censored via denial by the soy industry, their scientists, the FDA (Food and Drug Administration), Health Canada, the news media, most governments, the mainstream medical system, the natural health industry, the alternative health system, American and Canadian Cancer Societies, and, of course, those that are making their living from producing, promoting and selling soy and soy ingredients like soy protein isolate, SPI.
Yet many of the representatives of current and past research I’ve presented within are available in the NIH Medline database, and go back as far as 1925, through current day. Other studies are from the US Department of Energy and NCTR, federally operated and funded, as well as other reputable research institutions from around the world.
These are well-designed studies, conducted in a manner that is consistent with generally recognized scientific procedures and principles. Research has been done in vivo, and in vitro.
These studies indicate there is agreement among qualified experts of the harm to human and animal health from the consumption of soy and soy protein ingredients, such as soy protein isolate, SPI.
SOY, THE UNTOLD STORY
The naturally occurring toxic ingredients in soy are called genistein, daidzein, (the major isoflavones in soybeans) and beta-Sitosterol.
Genistein in soy is a dietary topoisomerase II-poison. It accumulates in the body, building up a toxic load. Genistein causes DNA double strand breaks, leading to chromosomal aberrations and leukemia, including acute infant leukemia.
Genistein destroys myelin sheath protecting nerves, as in Alzheimer’s and Parkinson’s disease, and learning disabilities such as ADD/ADHD.
SOY IN THE ASIAN COMMUNITY
It has been argued that high levels of soy isoflavones such as genistein and daidzein in Asian diets protect the inhabitants of Japan and China from certain degenerative diseases, breast and prostate cancer. Actually, consumption of soy in traditional Asian diets is low.
Asians have been aware of the toxic, poisonous nature of soy as far back as during the Chou Dynasty (1134-246 BC).
Their major sources of protein are meat including organ meats, poultry, fish and eggs. When precipitated soy products such as tofu are consumed with meat, the mineral-blocking effects of phytates are reduced. (Phytates are phosphorus compounds that bind with minerals such as iron, calcium, and zinc and interfere with their absorption in the body).
SOY AND PREGNANCY
Pregnant women as well as their unborn child are at great risk from soy, since the toxic ingredient in soy, genistein, crosses the placenta and blood-brain barrier, “teratogenic,” causing birth defects.
SOY AND CHILDREN
Infants are vulnerable, as soy is found in many baby formulas.
The metabolism, physiology and biochemistry of a fetus, infant and child are fundamentally different from an adult. Vital organ systems are growing and maturing. These systems are susceptible to the toxic effects of pesticides and toxic chemicals. Organ systems such as the nervous system and brain can be permanently and subtly damaged by exposure to toxic substances in-utero or throughout early childhood that, at the same level, would cause no measurable harm to adults (Jacobson 1996, CDC 1997, NRC 2000).
The endocrine (hormone) system, immune system, is highly sensitive to toxic exposure, and enormous effort has been put into studying the effects of how pesticides and toxic chemicals interfere with normal endocrine signaling and function.
These research studies show that even at ultra-low doses, these toxic chemicals cause changes in hormone function and effects on organ development and function that often only appear later in life. (vom Saal 1997, Alworth 2002, Hayes 2003).
This is particularly relevant to fetal and childhood exposures via food and beverage, where the timing of the exposure is at least as important as dose.
SOY AND THE FDA
As both the FDA’s regulations and the federal courts have decreed, ‘Generally Recognized As Safe’ (GRAS) can only be imputed if there is an overwhelming consensus in the community of qualified experts. Unanimity is not required, however any significant and sound disagreement prevents the determination that consensus exists.
Even in the case of unanimity, United States law additionally prescribes that consensus cannot rest on hypotheses, instead consensus must be based on scientific evidence that clearly establishes safety.
The requisite consensus for Soy has never existed, as the FDA is aware. The predominant consensus among FDA’s very own experts has been that soy entails unique risks and cannot be presumed safe.
Therefore, even if expert consensus about the safety of soy and soy ingredients actually existed, it doesn’t, but, if it did, the law requires that safety must still be established through standard scientific tests.
Soy Does Not Have GRAS Status (general recognition as safe)
Up until 1894-95, China localized all soybean Production, at which time the Japanese began importing soybean oil for use as a fertilizer.
The earliest written reference to soybeans in the United States occurred in 1804.
Soybeans grown in the United States were originally utilized as a forage crop versus harvesting them for grain.
In 1941, the U.S. soybean acreage dedicated to grain production exceeded that grown for foraging and other purposes.
After WWII, the majority of the United States soybean production occurred in Iowa, Illinois, Minnesota, Indiana, Ohio, Missouri, and Nebraska, which in 2000 accounted for 72% of the total U.S. soybean production.
Two of the components of soy, the soy isoflavones daidzein and genistein, are chemicals, available over the counter (OTC) in both pill form and powders. They are advertised as dietary supplements for use by women to help lessen menopausal symptoms such as hot flashes.
Isoflavone are phytoestrogens, a weak form of estrogen that has a drug-like effect in the body. This is pronounced in postmenopausal women, at a time when high isoflavone levels increase the risk of cancer, particularly breast cancer. Isoflavones are like other estrogens, they are two-edged swords, conferring both benefits and risks.
According to the United Soybean Board, soybean oil accounts for 79 percent of the edible fats used annually in the United States. Viewing the ingredients for commercial mayonnaises, margarines, salad dressings, or vegetable shortenings often reveals soybean oil high on the list.
Genistein prompts undesirable effects such as the growth of breast tissue in males.
Soy protein is produced by and stored in the soybean, and is therefore considered a non-synthetic substance.
Soy protein isolate is a synthetic substance, due to the significant amount of processing required to separate, or “isolate,” soy protein from other soybean constituents.
Soy protein isolate is commonly added to commercial food products and is found as an ingredient in industrial compounds.
Procedure for the production of soy protein isolate: Utilizing defatted soybean flakes, results a >90% protein composition. The soybeans are cleaned, cracked, and de-hulled in order to obtain the meats. The meats are then flaked and extracted to remove excess oil. The flakes are de-solventized and mixed with water, producing a slurry. This slurry is extracted, separating the flakes from the slurry solution. An acid, typically hydrochloric acid (HCl), is added to the resulting protein solution to precipitate out the protein. This protein is washed with water and neutralized with a base, typically sodium hydroxide (NaOH), to reach a pH of 7. The resulting solution is spray-dried to produce the final product, soy protein isolate. [Trank, 1989]
Soy protein isolate is commonly used as an additive to various commercially available food products in order to increase their protein content.
So is Melamine.
Soy protein isolate is used in industrial products, such as spackling paste and adhesives.
Soy protein isolate is not currently listed as an approved food additive in the European Union. [FSA, 2004]
Soy protein isolate is not currently listed as an approved substance in the Japanese Standards of Organic Processed Foods. [JMAFF, 2000]
A thirty year study performed by the National Institutes of Health (NIH) indicated a connection between soy tofu and accelerated brain aging and shrinkage. [Ross, 2003]
In the 1950′s , soy protein slipped into the food chain around 1959, despite developmental research (funded by Archer Daniels Midland Company (ADM) and Mead Johnson) demonstrating conclusively that soy protein caused serious infertility problems in laboratory rats as well as their offspring. Documented in a series of papers in the “Journal of Nutrition” by Schultze, Liener et al.
In 1966, “The Committee for Food Safety” was concerned about soy’s carcinogenic properties.
In 1972, the Nixon administration directed a re-examination of substances believed to be GRAS (Generally Recognized As Safe), in light of any scientific information available at that time.
In 1974 the FDA obtained a literature review of soy protein, as soy protein had not been used in food until 1959, and was uncommon for use until the early 1970s. Soy protein was not eligible to have its GRAS status grand-fathered under the provisions of the Food, Drug and Cosmetic Act. The scientific literature up to 1974 recognized many ‘anti-nutrients’ (industry often refers to toxins as ‘anti-nutrients’) in factory-made soy protein, including trypsin inhibitors, phytic acid and genistein. The FDA was more concerned with toxins formed during processing, specifically nitrites and lysinoalanine. Even at low levels of consumption, averaging one-third of a gram per day at that time, the presence of these carcinogens was considered too great a threat to public health to allow GRAS status.
The only evaluation was done by The Life Sciences Committee of FASEB in its 1978 “Evaluation of Soy Products for Human Consumption” for the Food and Drug Administration (SCOGS-101 under contract to the FDA # 223-75-2004), which declined GRAS determination because of the risks of carcinogenic nitrosamines, lysinoalanines, and nitrite occurring during the modern processing, heat treatment. FASEB assumed the heat treatment was removing the natural poisons, and did not evaluate their safety at all.
There is no standardization as to how soy protein is processed. Toxin levels can vary widely.
The FDA has imposed no requirements for manufactures to use heat treatment, or any guidelines as to how long or how high the temperature needs to be.
The use of soy protein is codified as GRAS only for the limited industrial use as a cardboard binder. FDA officials called for safety specifications and monitoring procedures before granting of GRAS status for food, however these have not been performed. The use of soy protein is codified as GRAS only for the limited industrial use as a cardboard binder. Therefore soy protein is subject to pre-market approval procedures each time manufacturers intend to use it as a food or add it to a food.
The definitive textbook “Chemical Carcinogens” published by the American Chemical Society in 1976 has a chapter titled “Plant Carcinogens” that identifies soy isoflavones as known carcinogens.
In 1999, an application by Archer Daniels Midland Corp for GRAS determination of GRAS (GRN 00001) for isoflavones was declined due to the failure of the applicant to reveal health risks.
“Trouble for Soy Protein”, includes opposition to the grant of health claim labeling by the FDA as well as a lengthy discussion of GRAS. The material in “Doses Simplified” gives an idea of how toxic the levels of isoflavones are in the products. Both of these can be found here.
Soy may be in violation of “WHO/CODEX – Food Safety Standards,” WHO/CODEX General Standards for Soy Protein Products. World Health Organization, WHO/CODEX Standard 175-1989 and WHO/CODEX General Guidelines for the Utilization of Vegetable Protein Products (VPP) in Foods CAC/GL 4-1989. These standards do not allow approval of food ingredients that has been shown to have Sub acute toxicity, Chronic toxicity, Reproductive toxicity, Teralogenic effects, mutagenic effects, and fail to have scientific studies last at least 3 month in length. It is documented that soy produces those health hazards banned by the WHO. When the scientific studies go into the 2nd, 3rd and 4th month and longer, the serious health hazards start to show up in a variety of laboratory test animals.
Soy protein fails to meet, fulfill, and satisfy the 1958 “Delaney Amendment” to the FDA Reg.’s, which prohibits the use of any food additive, if it is found to cause cancer in any animal species or in man, at any dose level. (Same goes for Aspartame).
Soy has Self Determined GRAS Status. Meaning that a manufacturer provides its own evaluation of the “safety” of its product. The FDA then advertises it in the Federal Register, not a widely read document. If no citizen objects, the FDA approves it and a multi-million-dollar win is showered on the applicant. This then becomes the benchmark for every other promotion of similar products. The US Center for Food Safety and Applied Nutrition (CF-SAN ) does not investigate for itself, and there rarely is an objection because the ultimate consumer does not have a clue about the procedure. (You Do NOW!)
This “self-determination procedure,” is making the soy industry and those supporting it and making money from soy liable to legal action (Class Action Law Suit) from problems caused by soy being put in our food supply, soy poisoning our food supply worldwide. Read Part-3 of “The News Research On Why You Should Avoid Soy,” “Soy The Next Asbestos,” by Sally Sallon and Mary G. Enig, Ph.D.
The original petition submitted by Protein Technologies International (PTI) requested a ‘health claim’ be made for the soy isoflavones, (the plant estrogens found abundantly in soybeans), stating that “isoflavones lower cholesterol”. The submission provided weak and conflicting proofs, besieged by strong evidence of toxicity and hormone disruption. The FDA should have thrown out the petition. Instead, in 1998, the FDA violated the industry’s own regulations by taking the unprecedented step of rewriting PTI’s petition and substituting a claim for soy protein. Then the FDA sped up the decision, making progress by reducing the time in which members of the public could protest to only 30 days. In doing so, they disregarded the testimony of top scientists at the FDA’s own National Center of Toxicological Research, British government researchers, and other qualified experts, all of which were providing strong evidence of danger from allergens, protease, inhibitors, and other soy components as well as the plant hormones.
Researchers have compared the isoflavone in its two forms, as a glycoside (genistin, as it appears in plants) and aglucone (genistein). They found that both forms produced similar tumor growth rates, and that the conversion of genistin in the body begins with contact with saliva in the mouth.
The short-term use of dietary soy containing isoflavone levels found in modern soy foods stimulates breast proliferation. In Cancer Research, comparison of soy protein isolates containing varying levels of isoflavones found that estrogen-dependent tumor growth increases as the isoflavone content increased in the soy-containing diet.
Read your labels; not just food and beverage, remember too vitamins, minerals, and medications. Ensure they say “contains no Soy” or “contains no Soy ingredients”.
Some of the most common sources of soy protein are:
Tofu - made from cooked puréed soybeans processed into a custard-like cake. Can be stir-fried, mixed into “smoothies,” or blended into a cream cheese texture for use in dips or as a cheese substitute. It comes in firm, soft and silken textures.
Soymilk - the name some marketers use for a soy beverage, is produced by grinding de-hulled soybeans and mixing them with water to form a milk-like liquid. Often consumed as a beverage, used in recipes as a substitute for cow’s milk, and for lactose-intolerant individuals.
Soy flour - created by grinding roasted soybeans into a fine powder. Used in baked goods, often as an egg substitute for the added moisture content it brings. Soy flour is also found in cereals, pancake mixes, frozen desserts, and many other common foods.
Textured soy protein – made from compressed and dehydrated defatted soy flour. Often used as a meat substitute or as filler in dishes such as meatloaf.
Tempeh - made from whole, cooked soybeans formed into a chewy cake and used as a meat substitute.
Miso - fermented soybean paste used for seasoning and in soup stock.
Soy protein also is found in many “meat analog” products, such as soy sausages, burgers, franks, and cold cuts, as well as soy yogurts and cheese.
SOY AND THE ‘HEART DISEASE HEALTH CLAIM’
It is legal in the United States to label of soy (Genetically modified or otherwise) as beneficial for reducing heart disease risk. The labelling arrangements follow a petition submitted to the FDA by the American Soybean Association (ASA), whose corporate partners include the
biotechnology/agro-chemical companies American Cyanamid, Bayer, Dow, Du Pont, Monsanto, Novartis and Zeneca. These are some of the companies behind the genetic modification of our food.
In submitting its comments to the FDA on the health-claim labelling arrangements for soy, the American Dietetic Association (ADA) also stated: “ADA assumes that both FDA and PTI have looked extensively at the literature regarding potential safety concerns such as allergenic reactions and possible toxicological effects of soy. While we recognize that there is limited research in this area, we urge FDA to consider any safety and toxicological issues prior to finalizing this rule.”
Researchers and “Whistle-blowers” Daniel Doerge Ph.D and Daniel Sheehan Ph.D are two of the FDA expert scientists on soy who signed a Feb. 18, 1999 letter of protest to the FDA when the FDA granted soy this ‘health claim’ in 1999. This letter expressed serious concerns regarding the perceived safe use of soy, and included 26 documented scientific referenced studies, (abstracts), that provide links between eating soy and serious health dangers.
The two tried in vain to stop the FDA’s approval of this health claim of soy since it would be misinterpreted as a broader general endorsement beyond benefits for the heart.
The text of this letter was at one time carried on the abcnews.com website, however it has since been withdrawn. The link had been here, http://abcnews.go.com/onair/2020/2020_000609_soyfdaletter_feature.html
THE TEXT OF THIS LETTER IS NOW HERE:
DEPARTMENT OF HEALTH
and HUMAN SERVICES
Public Health Service
Food and Drug Administration
National Center For Toxicological Research
Jefferson, Ark. 72079-9502
Daniel M. Sheehan, Ph.D.
Director, Estrogen Base Program
Division of Genetic and Reproductive Toxicology
Daniel R. Doerge, Ph.D.
Division of Biochemical Toxicology
February 18, 1999
Dockets Management Branch (HFA-305)
Food and Drug Administration
Rockville, MD 20852
To whom it may concern,
We are writing in reference to Docket # 98P-0683;
“Food Labeling: Health Claims; Soy Protein and Coronary Heart Disease.”
We oppose this health claim because there is abundant evidence that some of the isoflavones found in soy, including genistein and equol, a metabolize of daidzen,
demonstrate toxicity in estrogen sensitive tissues and in the thyroid.
This is true for a number of species, including humans.
Additionally, the adverse effects in humans occur in several tissues and, apparently, by several distinct mechanisms.
Genistein is clearly estrogenic; it possesses the chemical structural
features necessary for estrogenic activity ( Sheehan and Medlock, 1995;
Tong, et al, 1997; Miksicek, 1998 ) and induces estrogenic responses in
developing and adult animals and in adult humans.
In rodents, equol is estrogenic and acts as an estrogenic endocrine disruptor during development (Medlock, et al, 1995a,b).
Faber and Hughes (1993) showed alterations in LH regulation following developmental treatment with genistein.
Thus, during pregnancy in humans, isoflavones per se could be a risk factor for abnormal brain and reproductive tract development.
Furthermore, pregnant Rhesus monkeys fed genistein had serum estradiol levels 50- 100 percent higher than the controls in three different areas of the maternal circulation ( Harrison, et al, 1998 ).
Given that the Rhesus monkey is the best experimental model for humans, and that a women’s own estrogens are a very significant risk factor for breast cancer, it is unreasonable to approve the health claim until complete safety studies of soy protein are conducted.
Of equally grave concern is the finding that the fetuses of genistein fed monkeys had a 70 percent higher serum estradiol level than did the controls ( Harrison, et al,
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.
In the human population, DES exposure stands as a prime example of adverse estrogenic effects during development.
About 50 percent of the female offspring and a smaller fraction of male offspring displayed one or more malformations in the reproductive tract, as well as a lower prevalence (about 1 in a thousand) of malignancies. In adults, genistein could be a risk factor for a number of estrogen-associated diseases.
Even without the evidence of elevated serum estradiol levels in Rhesus fetuses, potency and dose differences between DES and the soy isoflavones do not provide any assurance that the soy protein isoflavones per se will be without adverse effects. First, calculations, based on the literature, show that doses of soy protein isoflavones used in clinical trials which demonstrated estrogenic effects were as potent as low but active doses of DES in Rhesus monkeys (Sheehan, unpublished data).
Second, we have recently shown that estradiol shows no threshold in an extremely large dose-response experiment (Sheehan, et al, 1999), and we subsequently have found 31 dose-response curves for hormone-mimicking chemicals that also fail to show
a threshold (Sheehan, 1998a).
Our conclusions are that no dose is without risk; the extent of risk is simply a function of dose. These two features support and extend the conclusion that it is inappropriate to allow health claims for soy protein isolate.Additionally, 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 (cf., Kimura et al., 1976).
Moreover, there are significant reports of goitrogenic effects from soy consumption in
human infants (cf., Van Wyk et al., 1959; Hydovitz, 1960; Shepard et al., 1960; Pinchers et al., 1965; Chorazy et al., 1995) and adults (McCarrison, 1933; Ishizuki, et al., 1991).
Recently, we have identified genistein and daidzein as the goitrogenic isoflavonoid components of soy and defined the mechanisms for inhibition of thyroid peroxidase (TPO)-catalyzed thyroid hormone synthesis in vitro (Divi et al., 1997; Divi et al., 1996).
The observed suicide inactivation of TPO by isoflavones, through covalent binding to TPO, raises the possibility of neoantigen formation and because anti-TPO is the principal autoantibody present in auto immune thyroid disease. This hypothetical mechanism is consistent with the reports of Fort et al. (1986, 1990) of 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 that 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).
Assuming a dose-dependent risk, it is unreasonable to assert that the infant findings are irrelevant to adults who may consume smaller amounts of isoflavones.
Additionally, while there is an unambiguous biological effect on menstrual cycle length (Cassidy, et al, 1994), it is unclear whether the soy effects are beneficial or adverse.
Furthermore, we need to be concerned about transplacental passage of isoflavones as the DES case has shown us that estrogens can pass the placenta.
No such studies have been conducted with genistein in humans or primates.As all estrogens which have been studied carefully in human populations are two-edged swords in humans (Sheehan and Medlock, 1995; Sheehan, 1997), with both beneficial and adverse effects resulting from the administration of the same estrogen, it is likely that the same characteristic is shared by the isoflavones.
The animal data is also consistent with adverse effects in humans.
Finally, initial data fi-om a robust (7,000 men) long-term (30+ years) prospective epidemiological study in Hawaii showed that Alzheimer’s disease prevalence in Hawaiian men was similar to European-ancestry Americans and to Japanese (White, et al, 1996a).
In contrast, vascular dementia prevalence is similar in Hawaii and Japan and both are higher than in European-ancestry Americans.
This suggests that common ancestry or environmental factors in Japan and Hawaii are responsible for the higher prevalence of vascular dementia in these locations.
Subsequently, this same group showed a significant dose-dependent risk (up to 2.4 fold) for development of vascular dementia and brain atrophy from consumption of tofu, a soy product rich in isoflavones (White, et al, 1996b).
This finding is consistent with the environmental causation suggested from the earlier analysis, and provides evidence that soy (tofu) phytoestrogens causes vascular dementia.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.
Given the great difficulty in discerning the relationship between exposures and long latency adverse effects in the human population (Sheehan, 1998b), and the potential
mechanistic explanation for the epidemiological findings, this is an important study.
It is one of the more robust, well-designed prospective epidemiological studies generally available.
We rarely have such power in human studies, as well as a potential mechanism, and thus the results should be interpreted in this context.
Does the Asian experience provide us with reassurance that isoflavones are safe?
A review of several examples lead to the conclusion “Given the parallels with herbal medicines with respect to attitudes, monitoring deficiencies, and the general difficulty of detecting toxicities with long Iatencies, I am unconvinced that the long history of apparent safe use of soy products can provide confidence that they are indeed without risk.” (Sheehan, 1998b).
It should also be noted that the claim on p. 62978 that soy protein foods are GRAS is in conflict with the recent return by CFSAN 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.
Linda Kahl can provide you with details.
It would seem appropriate for FDA to speak with a single voice regarding soy protein
Taken together, the findings presented here are self-consistent and
demonstrate that genistein and other isoflavones can have adverse effects in
a variety of species, including humans.
Animal studies are the front line in evaluating toxicity, as they predict, with good accuracy, adverse effects in humans.
For the isoflavones, we additionally have evidence of two types of
adverse effects in humans, despite the very few studies that have addressed
this subject. While isoflavones may have beneficial effects at some ages or
circumstances, this cannot be assumed to be true at all ages. Isoflavones
are like other estrogens in that they are two-edged swords, conferring both
benefits and risk (Sheehan and Medlock, 1995; Sheehan, 1997).
The health labeling of soy protein isolate for foods needs to considered just as would
the addition of any estrogen or goitrogen to foods, which are bad ideas.
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 foods, so the public will be put at potential risk
from soy isoflavones in soy protein isolate without adequate warning and
Finally, NCTR is currently conducting a long-term multigeneration study
of genistein administered in feed to rats. The analysis of the dose
range-finding studies are near-complete or complete now. As preliminary
data, which is still confidential, maybe relevant to your decision, I
suggest you contact Dr. Barry Delclos at the address on the letterhead, or
Daniel M. Sheehan
Daniel R. Doerge
cc: Dr. Bernard Schwetz, Director, NCTR
Dr. Barry Delclos
The below list of abstracts will prove that it is, and has been, sufficiently scientifically documented that soy does cause a variety of serious adverse medical and developmental conditions, including but not limited to cancers.
The science establishes that soy is not medically necessary; instead, it is medically necessary to warn consumers of the serious health hazards in consuming soy and soy ingredients, in order to assist the consumer in making an informed, educated decision to avoid soy and soy ingredients, further assisting in disease prevention as well as obtaining, and maintaining good health:
“ there is no direct evidence for the beneficial effects of phytoestrogens in humans. All information is based on consumption of phytoestrogen-rich diets, and the causal relationship and the mechanisms of phytoestrogen action in humans still remain to be demonstrated … In addition, the possible adverse effects of phytoestrogens have not been evaluated … It is plausible that phytoestrogens, as any exogenous hormonally active agent, might also cause adverse effects in the endocrine system, i.e. act as endocrine disrupters.
Epidemiological studies suggest that diets rich in phytoestrogens (plant estrogens), particularly soy and unrefined grain products, may be associated with low risk of breast and prostate cancer.”
2003 – Information on the UK Expert Committee’s findings can be found in a report called:
“Committee on Toxicity of Chemicals in Food, Consumer Products and The Environment, Report on Phtoestrogens and Health,”
“After reviewing the data and conclusions in the report relating to soy-based infant formula, SACN considered that there is cause for concern about the use of soy-based infant formula. Additionally, there is neither substantive medical need for, nor health benefit arising from, the use soy-based infant formulae ”
“The phytoestrogen genistein induces thymic and immune changes: a human health concern?” – Yellayka S. and others:
Proving that soy damages the immune system.
The United Soybean Board and the Illinois Council on Food and Agricultural Research funded this study.
The soy industry released the results of their own study in May 2002. In this collection of abstracts and elsewhere, there is reference and scientific research showing how important a strong immune system is for a healthy body.
Amazing that this study was even released into the public domain.
We’ve come to realize it is common for industry and corporations in general to hide and suppress findings that are negative for their products and services. Often we must use the Freedom of Information laws to obtain data that should actually be easily and readily available.
“Use of soy-based infant formulas and soy/isoflavone supplements has aroused concern because of potential estrogenic effects of the soy isoflavones genistein and daidzein. Here we show that s.c. genistein injections in ovariectomized adult mice produced dose-responsive decreases in thymic weight of up to 80%. Genistein’s thymic effects occurred through both estrogen receptor (ER) and non-ER-mediated mechanisms, as the genistein effects on thymus were only partially blocked by the ER antagonist ICI 182,780.
Genistein decreased thymocyte numbers up to 86% and doubled apoptosis, indicating that the mechanism of the genistein effect on loss of thymocytes is caused in part by increased apoptosis. Genistein injection caused decreases in relative percentages of thymic CD4(+)CD8(-) and double-positive CD4(+)CD8(+) thymocytes, providing evidence that genistein may affect early thymocyte maturation and the maturation of the CD4(+)CD8(-) helper T cell lineage. Decreases in the relative percentages of CD4(+)CD8(-) thymocytes were accompanied by decreases in relative percentages of splenic CD4(+)CD8(-) cells and a systemic lymphocytopenia.
In addition, genistein produced suppression of humoral immunity.
Genistein injected at 8 mg/kg per day produced serum genistein levels comparable to those reported in soy-fed human infants, and this dose caused significant thymic and immune changes in mice. Critically, dietary genistein at concentrations that produced serum genistein levels substantially less than those in soy-fed infants produced marked thymic atrophy.
These results raise the possibility that serum genistein concentrations found in soy-fed infants may be capable of producing thymic and immune abnormalities, as suggested by previous reports of immune impairments in soy-fed human infants.”
2004 J Nutr. 2004 May;134(5):1145-1151. Ju YH, Clausen LM, Allred KF, and others, Department of Food Science and Human Nutrition and Department of Animal Sciences, University of Illinois at Urbana-Champaign, Urbana, IL 61801 USA, and Department of Physiology, University of Kentucky, Lexington, KY 40536; IMAGINutrition, and MetaResponse Science, Laguna Niguel, CA 92677, USA.
“beta-Sitosterol, beta-Sitosterol Glucoside, and a Mixture of beta-Sitosterol and beta-Sitosterol Glucoside Modulate the Growth of Estrogen-Responsive Breast Cancer Cells In Vitro and in Ovariectomized Athymic Mice,”
“Further evidence from current research that beta-Sitosterol, a compound common in soy oil, and also present in soy protein, can stimulate the growth of MCF-7 breast cancer cells
In summary, BSS and MC stimulated MCF-7 cell growth in vitro. Although BSSG comprises only 1% of MC, BSSG made MC less estrogenic than BSS alone in vitro. However, dietary BSS and MC protected against E(2) – stimulated MCF-7 tumor growth and lowered circulating E(2) levels.”
“Increased uterine cancer seen in mice injected with genistein, a soy estrogen, as newborns”
“Genistein is carcinogenic
Infant mice given genistein developed cancer of the uterus later in life. “The data suggest that genistein is carcinogenic if exposure occurs during critical periods in a young animal’s development.”
“Cross-species and interassay comparisons of phytoestrogen action,”
Humans are affected at lower doses than rodents.
“This paper compiles animal and human data on the biologic effects and exposure levels of phytoestrogens in order to identify areas of research in which direct species comparisons can be made. In vivo data show that phytoestrogens have a wide range of biologic effects at doses and plasma concentrations seen with normal human diets.
Significant in vivo-responses have been observed in animal and human tests for bone, breast, ovary, pituitary vasculature, prostate, and serum lipids.
The doses reported to be biologically active in humans (0.4–10 mg/kg body weight/day) are lower than the doses generally reported to be active in rodents (10–100 mg/kg body weight/day), although some studies have reported rodent responses at lower doses.
The similarity of reported proliferative and antiproliferative doses illustrates the need for fuller examination of dose-response relationships and multiple end points in assessing phytoestrogen actions.”
“Genistein induces apoptosis and topoisomerase II-mediated DNA breakage in colon cancer cells”
“DNA breakage in colon cancer cells occurred within 1 hour of treatment with genistein.”
1998 Cancer Res 1998 Sep 1;58(17):3833-8., and Cancer Res 1999 Mar 15;59(6):1388.
Hsieh C.Y., Santell R.C., Haslam S.Z., Helferich W.G., Department of Food Science and Human Nutrition, Michigan State University, East Lansing 48824, USA.
“Estrogenic effects of genistein on the growth of estrogen receptor-positive human breast cancer (MCF-7) cells in vitro and in vivo”
“Proliferation of cultured human breast cancer cells … Dees concluded that ‘ women should not consume particular foods, (eg. soy-derived products), to prevent breast cancer’.
IN SUMMARY, genistein can act as an estrogen agonist in vivo and in vitro, resulting in the proliferation of cultured human breast cancer cells (MCF-7) and the induction of pS2 gene expression. Here we present new information that dietary genistein stimulates mammary gland growth and enhances the growth of MCF-7 cell tumors in ovariectomized athymic mice.
Dr Craig Dees of Oak Ridge National Laboratory has also found that soy isoflavones cause breast cancer cells to grow. He reported that ‘low concentrations of genistein may stimulate MC-7 cells to enter the cell cycle’. Dees concluded that ‘ women “should not” consume particular foods, (eg. soy-derived products), to prevent breast cancer.”
1998 Am J Clin Nutr 1998 Dec;68(6 Suppl):1431S-1435S. McMichael-Phillips D.F. and others, Depart. of Epithelial Biology, Paterson Institute for Cancer Research, Christie Hospital NHS Trust, Manchester, United Kindgom
“Effects of soy-protein supplementation on epithelial proliferation in the histologically normal human breast”
“Soy foods stimulates breast proliferation after just 14 days
Forty-eight women with benign or malignant breast disease were randomly assigned a normal diet either alone or with a 60 gram soy supplement containing 45 mg isoflavones, taken for 14 days. The proliferation rate of breast lobular epithelium … significantly increased … after just 14 days of soy supplementation when both the day of menstrual cycle and age of patient were accounted for. Thus short-term use of dietary soy containing isoflavone levels found in modern soy foods stimulates breast proliferation.”
1998 Toxicol Lett. 1998 Dec 28;102-103:349-54. Strauss L., Santti R., Saarinen N., Streng T., Joshi S., Makela S., Institute of Biomedicine and Medicity Research Laboratory, University of Turku, Finland.
“Dietary phytoestrogens and their role in hormonally dependent disease,”
“Although epidemiological studies suggest that diets rich in phytoestrogens may be associated with low risk of breast and prostate cancer, there is no direct evidence for the beneficial effects of phytoestrogens in humans. It is plausible that phytoestrogens, as any exogenous hormonally active agent, might also cause adverse effects in the endocrine system.
Epidemiological studies suggest that diets rich in phytoestrogens (plant estrogens), particularly soy and unrefined grain products, may be associated with low risk of breast and prostate cancer. It has also been proposed that dietary phytoestrogens could play a role in the prevention of other estrogen-related conditions, namely cardiovascular disease, menopausal symptoms and post-menopausal osteoporosis.
However, there is no direct evidence for the beneficial effects of phytoestrogens in humans.
All information is based on consumption of phytoestrogen-rich diets, and the causal relationship and the mechanisms of phytoestrogen action in humans still remain to be demonstrated.
In addition, the possible adverse effects of phytoestrogens have not been evaluated.
It is plausible that phytoestrogens, as any exogenous hormonally active agent, might also cause adverse effects in the endocrine system, i.e. act as endocrine disrupters.”
“Dietary estrogens stimulate human breast cells to enter the cell cycle”
“Stimulates human breast cancer cells to enter the cell cycle
Dietary estrogens were found to increase enzymatic activity leading to breast cancer. “Our findings are consistent with a conclusion that dietary estrogens at low concentrations do not act as antiestrogens, but act like DDT and estradiol to stimulate human breast cancer cells to enter the cell cycle.”
“The Swiss Health Service estimates that 100 grams of soy protein provides the estrogenic equivalent of the contraceptive pill.” ( Foot Note #53)
1989 Cancer Res 1989 Sep 15;49(18):5111-7. – Markovits J., Linassier C., Fosse P., Pierre J., and others, Laboratorie de Pharmacologie Moleculair, URA 158 du CNRS, U 140 de I’NSERM, Institute Gustave Roussy, Villejuif, France.
“Inhibitory effects of the tyrosine kinase inhibitor genistein on mammalian DNA topoisomerase II”
“Genistein stimulates double strand DNA breaks.
Finally, genistein treatment of DC-3F cells results in the occurrence of protein-linked DNA strand breaks as shown by DNA filter elution. Viscometric (lengthening) studies demonstrate that genistein isn’t a DNA intercalator. Genistein is therefore an interesting compound because it induces cleavable complexes without intercalation. Taken together, our results show that genistein is an inhibitor of both protein tyrosine kinases and mammalian DNA topoisomerase II. This could be accounted for by the sharing of a common structure sequence between the two proteins at the ATP binding site.”
Dietary genistein results in larger MNU-induced, estrogen-dependent mammary tumors following ovariectomy of Sprague-Dawley rats
“Due to the estrogenic properties of soy-derived isoflavones, many postmenopausal women are using these compounds as a natural alternative to hormone replacement therapy (HRT).
Genistein at 750 p.p.m. increased the weight of estrogen-dependent adenocarcinomas in ovariectomized rats compared with the negative-control animals.
Genistein treatment also resulted in a higher percentage of proliferative cells in tumors and increased uterine weights when compared with negative-control animals.
Collectively, these effects are probably due to the estrogenic activity of genistein.
Plasma genistein concentrations in animals fed the isoflavone-containing diet were at physiological levels relevant to human exposure. Estradiol concentrations in ovariectomized animals not receiving an estradiol supplement were similar to those observed in postmenopausal women.
The data suggest that in an endogenous estrogen environment similar to that of a postmenopausal woman, dietary genistein can stimulate the growth of a mammary carcinogen MNU-induced estrogen-dependent mammary tumors.”
2004 — Ju YH, Clausen LM, and others, Department of Food Science and Human Nutrition and Depart. of Animal Sciences, University of Illinois at Urbana-Champaign, Urbana, IL 61801 USA, and Department of Physiology, University of Kentucky, Lexington, KY 40536; IMAGINutrition, and MetaResponse Science, Laguna Niguel, CA 92677, USA.
“beta-Sitosterol, beta-Sitosterol Glucoside, and a Mixture of beta-Sitosterol and beta-Sitosterol Glucoside Modulate the Growth of Estrogen-Responsive Breast Cancer Cells In Vitro and in Ovariectomized Athymic Mice”
“Further evidence from current research that beta-Sitosterol, a compound common in soy oil, and also present in soy protein, can stimulate the growth of MCF-7 breast cancer cells
In summary, BSS and MC stimulated MCF-7 cell growth in vitro. Although BSSG comprises only 1% of MC, BSSG made MC less estrogenic than BSS alone in vitro. However, dietary BSS and MC protected against E(2) – stimulated MCF-7 tumor growth and lowered circulating E(2) levels.”
“Effects of genistein or soy milk during late gestation and lactation on adult uterine organization in the rat”
Malnutrition from False nutritional beliefs.
“These experiments demonstrate that developmental exposure to dietary isoflavones, at levels comparable to the ranges of human exposure, modify expression of the estrogen-regulated PR in the uterus of sexually mature rats weeks after exposure ended.In utero and lactational exposure to estrogenic agents has been shown to influence morphological and functional development of reproductive tissues. Thus, consumption of dietary phytoestrogens, such as isoflavones, during pregnancy and lactation could influence important periods of development, when the fetus and neonate are more sensitive to estrogen exposure.
In this study, reproductive outcomes after developmental exposure to isoflavones were examined in Long-Evans rats maternally exposed to isoflavones via a commercial soy beverage or as the isolated isoflavone, genistein.
Since the PR is essential for regulating key female reproductive processes, such as uterine proliferation, implantation, and maintenance of pregnancy, its increased expression suggests that soy phytoestrogen exposure during reproductive development may have long-term reproductive health consequences.”
“Effect of soy-derived isoflavones on hot flushes, endometrial thickness, and the pulsatility index of the uterine and cerebral arteries”
“Daily administration of 72 mg of soy-derived isoflavones is no more effective than placebo in reducing hot flushes in postmenopausal women.”
2003 – File SE, Hartley DE, Alom N., Psychopharmacology Research Unit and Biochemical Neuropharmacology Group, Centre for Neuroscience Research, King’s College London, Hodgkin Building, Guy’s Campus, SE1 1UL, London
“Soya phytoestrogens change cortical and hippocampal expression of BDNF mRNA in male rats”
“significant reductions were found in brain-derived neurotrophic factor (BDNF) mRNA expression in the CA3 and CA4 region of the hippocampus and in the cerebral cortex in the rats fed the diet containing phytoestrogens, compared with those on the soya-free diet.”
“Brain-derived neurotrophic factor is reduced in Alzheimer’s disease”
“BDNF mRNA is reduced in the human Alzheimer’s disease hippocampus and temporal cortex, and suggest that a loss of BDNF may contribute to the progressive atrophy of neurons in Alzheimer’s disease.”
“Inactivation of thyroid peroxidase by soy isoflavones, in vitro and in vivo”
“implications for reproductive toxicity and carcinogenesis warrants further investigation
further study of auto-immune thyroiditis in children consuming Soy formula is warranted
the results were additive joint action of estrogenic chemicals lead to significant underestimations of risk”
“Detection of phytoestrogens in samples of second trimester human amniotic fluid”
“The study describes a method for measuring phytoestrogens daidzein and genistein in amniotic fluid. Such tests are needed, the authors assert, because “There is widespread concern that fetal exposure to hormonally active chemicals may adversely affect development of the reproductive tract.”
“Goitrogenic and estrogenic activity of soy isoflavones”
“Although safety testing of natural products, including soy products, is not required, the possibility that widely consumed soy products may cause harm in the human population via either or both estrogenic and goitrogenic activities is of concern.”
2002 – Jefferson W.N., Couse J.F., Padilla-Banks E., Korach K.S., Newbold R.R., Developmental Endocrinology Section, Laboratory of Molecular Toxicology, Environmental Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina 27709, USA.
“Neonatal exposure to genistein induces estrogen receptor (ER)alpha expression and multioocyte follicles in the maturing mouse ovary: evidence for ERbeta-mediated and nonestrogenic actions”
“These data taken together demonstrate alterations in the ovary following neonatal exposure to genistein. Given that human infants are exposed to high levels of genistein in soy-based foods, this study indicates that the effects of such exposure on the developing reproductive tract warrant further investigation.”
“Neurobehavioral effects of dietary soy phytoestrogens”
“short interval of consumption can significantly alter sexually dimorphic brain regions, anxiety, learning and memory … Alzheimer’s disease, especially in women.”
2002 Jan G. Hengstler, Carolin K. Heimerdinger and others, Institute of Legal Medicine, Department of Molecular Toxicology, University of Leipzig, Johannisallee 28, 04103 Leipzig, Germany; Institute of Toxicology and Department of Gynecology, University of Mainz, Mainz, Germany
“Dietary topoisomerase II-poisons: contribution of soy products to infant leukemia?”
“DNA double strand breaks leading to chromosomal aberrations and leukemia’s.
Further studies on the role of dietary topoisomerase II-poisons are “urgently” required”
“Dietary genistein negates the inhibitory effect of tamoxifen on growth of estrogen-dependent human breast cancer (MCF-7) cells implanted in athymic mice”
“Geistein overwhelmes the effects of Tamoxifen, Therefore Caution is warranted
Use of dietary isoflavone supplements by postmenopausal women with breast cancer is increasing.
Dietary genistein negated or overwhelmed the inhibitor effect of tamoxifen on MCF-7 tumor growth, lowered E2 levels in plasma, and increased expression of E-response genes (e.g., pS2, PR, cyclin D1) in ovariectomized and athymic mice.
Therefore, caution is warranted for postmenopausal women consuming dietary genistein while on TAM therapy for E-responsive breast cancer.”
“The phytoestrogen genistein induces thymic and immune changes: a human health concern?”
“Thymic and immune abnormality
Genistein injections in ovariectomized adult mice produce dose-responsive decreased in thymic weight of up to 80%. Genistein decreased thymocyte numbers up to 86% and doubled apoptosis.
There was a corresponding reduction in splenic cells.
caused significant thymic and immune changes in mice was comparable to those reported in soy-fed human infants.
These results raise the possibility that serum genistein concentrations found in soy-fed infants may be capable of producing thymic and immune abnormalities, as suggested by previous reports of immune impairments in soy-fed infants.”
“Transplacental transfer of the phytoestrogen daidzein in DA/Han rats”
“the placenta does not represent a barrier
The research found indications of a rapid transfer of daidzen from the mother to the fetus, but also that efficient extraction of daidzein from the maternal blood occurs. “Since dietary phytoestrogens account for a significant proportion of human exposure to potential endocrine modulators, and since the placenta does not represent a barrier to daidzein or related estrogenic isoflavones, the consequences of these exposures early in life should be examined and monitored carefully.”
“A pilot study of the effects of phytoestrogen supplementation on postmenopausal endometrium”
“hot flashes, night sweats, and vaginal dryness did not improve in the soy group.
This was a double-blinded, randomized, placebo-controlled trial comparing the effects of 6 months of dietary phytoestrogen supplementation versus placebo in postmenopusal women.
Phytoestrogens did not cause stimulation of the endometrium. Insomnia was more frequent over the 6-month study in the soy group, where as – hot flushes, night sweats and vaginal dryness improved from baseline in the placebo group “but not” in the soy group.”
“Dietary soy and increased risk of bladder cancer: the Singapore Chinese Health Study”
The Soyfood–bladder cancer risk association did not differ significantly between men and women and was not explained by other dietary factors.
The Soy-cancer relationship became stronger when the analysis was restricted to subjects with longer duration of follow-up. To our knowledge, this is the FIRST epidemiological report on the effect of dietary Soy on bladder cancer risk.”
“Effects of dietary genistein exposure during development on male and female”
“Genistein is a naturally occurring isoflavone that interacts with estrogen receptors and multiple other molecular targets.
Human exposure to genistein is predominantly through consumption of soy products, including soy-based infant formula and dietary supplements.
A dose range-finding study was conducted as a prelude to a multigeneration bioassay to assess potential toxicities associated with genistein consumption.
Dietary genistein thus produced effects in multiple estrogen-sensitive tissues in males and females that are generally consistent with its estrogenic activity.
These effects occurred within exposure ranges achievable in humans.”
“Neonatal exposure to genistein reduces expression of estrogen receptor alpha and androgen receptor in testes of adult mice”
“Our results exhibited that the disruption of gene expression continued for long term such as 3 months after administration of genistein even if no effect was found at conventional reproductive-toxicological levels. We have shown that neonatal administration of weak estrogenic compound (genistein) affects male reproductive organs at molecular levels in adulthood.”
“Exposure of infants to phyto-oestrogens from soy-based infant formula,”
“Soy has glycosides of genistein and daidzein or plant based chemicals that mimic estrogen
The daily exposure of infants to isoflavones in soy infant-formulas is 6-11 fold higher on a body-weight basis than the dose that has hormonal effects in adults consuming soy foods.
Circulating concentrations of isoflavones in the seven infants fed soy-based formula were 13000-22000 times higher than plasma oestradiol concentrations in early life, and may be sufficient to exert biological effects, whereas the contribution of isoflavones from breast-milk and cow-milk is negligible.”
“Effect of various genotoxins and reproductive toxins in human lymphocytes and sperm in the Comet assay”
“DNA damage to human sperm
The integrity of DNA is necessary not only for the noncancerous state, but also for the accurate transmission of genetic material to the next generation.
Human sperm exposed to the phytoestrogen daidzein had reduced DNA integrity.”
“Hypocalcemic tetany in ‘alternative’ soy milk nutrition in the first months of life”
Malnutrition … from … False nutritional beliefs.
“A 14 weeks old infant was admitted to the intensive care unit with life-threatening hypocalcemic-hyperphosphatemic spasms. Hypocalcemia-hyperphosphatemia was found to have been caused by feeding a high phosphate/ low calcium soy milk. The daily uptake of calcium was calculated to have been 3.3-6 mmol that of phosphate 30 mmol.
The parents strongly believed that soy milk formulas were equivalent to breast milk and cow’s milk formulas and lived on a strictly vegetarian diet. Therapy with calcium (at an initial dose of 2.25 mmol/kg/day) and 1.25 OH vitamin D3 (Rocaltrol, 0.25 microgram/day) normalized Ca, PO4, vitamin D and parathyroid hormone levels rapidly.
Vegetarian feeding had led to life-threatening hypocalcemic hyperphosphatemic spasms in the infant.
We conclude:. Vegetarian feeding had led to life-threatening hypocalcemic – hyperphosphatemic spasms in the infant, as well as, malnutrition and false nutritional beliefs have to be included as a potential cause of early hypocalcemia in infants.”
“Evidence that genistein, a protein-tyrosine kinase inhibitor, inhibits CD28 monoclonal-antibody-stimulated human T cell proliferation”
“Genistein blocks the production of T cells, needed for the immune system.
The authors conclude: “ … that genistein is a powerful immuno-suppressive agent …” and suggest that it has a potential use in the treatment of allograft rejection.