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Putting Soy in Accurate Perspective
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Summary:
Dr. Dahlman's published article in Today's Chiropractic March/April 2005 issue. A response to a ridiculously biased and incorrect article from the previous issue in the same magazine.
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To My Website
Readers: The November/December 2004 issue of Today’s Chiropractic
contained an article that relentlessly attacked soy and created the
incorrect perception that it’s not good for you. A perspective highly promoted by the Weston A. Price Foundation. I decided to research
the studies that were used to substantiate this perspective and found
that they were either all flawed or misinterpreted simply to support
the author’s point of view. In addition, in doing the research, I
found a basic cottage industry denouncing soy as a healthy food and
amazingly, they all relied on the same flawed and misinterpreted
studies. The original article follows my response that appeared in the
March/April 2005 issue.
By Dr. David Dahlman, DC ©2005
The anti-soy bias has grown to a fever pitch. Embraced by numerous
authors writing almost carbon copy essays and misinterpreting the same
flawed studies, an unbiased review of those studies along with others,
reveals a much different perspective. An example of misinterpreting a
study is the linking of soy to rickets by citing a 1919 study by
Mellanby using dogs and failing to note they were raised exclusively
indoors in the absence of sunlight or ultraviolet light.1 Another is
to link soy to goiters and fail to mention the researchers purposely
eliminated iodine from the diet or severely restricted it.2 And that’s
just the beginning.
There are many forms of soy consumed throughout the world such as raw
soybeans, steamed (edamame), soy milk, tofu, soy oil, soy lecithin, soy
meal, soy flour, soy protein concentrates (70% protein), soy protein
isolates (90-95% protein), fermented soy (tempeh, tamari, natto, miso)
and the active ingredients called isoflavones, the most common:
genistein and daidzein. Most of the critics are in agreement that the
dangers of soy revolve around the unfermented types and isoflavones of
soy, without regard to the growing body of emerging data suggesting
that intestinal microflora ferment unfermented soy and also affect
isoflavone absorption and metabolism.3
Historically, soy foods have been an integral part of the Asian diet.
This large body of accumulated epidemiological data has not shown that
soy consumption poses any substantial risk to human health. The
anti-soy faction are sure that soy is not a complete protein, prevents
mineral absorption and the action of digestive enzymes, causes rickets,
cancer, goiter and lowers thyroid hormones and is responsible for the
breakdown of muscle. Let’s take a look at each of these and other
claims.
Complete Protein
One controversy revolves around the completeness of soy as a protein.
The old method of evaluating protein quality know as the protein
efficiency ratio (PER) was based on the response of growing rats to a
particular protein source. Due to different protein needs for humans
compared to rats, early studies using PER values suggested soy was not
a complete protein. Updated methods for determining protein quality
known as the Protein Digestibility Corrected Amino Acid Score (PDCAAS)
adopted by the FDA and World Health Organization show soy having the
same score as egg white and milk protein.4,5,6,7
Mineral Absorption
Soy products provide a balance of nutrients including minerals and
their bioavailability depends on the form of the soy product and
whether fiber and/or phytic acid (inositol hexaphosphate) is present.
Phytic acid can bind minerals in the gastrointestinal tract. In diets
where soy represents a small percentage of total calories, other
mineral rich foods contribute to offset this issue. In diets high in
soy, removal of phytic acid increases mineral bioavailability and
cooking partially destroys phytic acid and again, as long as used in a
well balanced diet, creates no health concern.
Inhibition of Digestive Enzymes
Raw soybeans contain a family of protease inhibitors that can bind to
trypsin and other proteolytic digestive enzymes and inhibit their
action. As with other protease inhibitors, they can be destroyed by
heat increasing the digestibility of soy.4 This is not unique to soy,
protease inhibitors are ubiquitous in food. Raw soy flour has only
half as much trypsin protease inhibitor activity as raw potato and a
similar amount to raw egg. Animal studies suggest that protease
inhibitors may cause pancreatic cancer, however there is no direct
evidence of low levels being harmful to humans.4 In fact, recent
studies have suggested protease inhibitors may be anti-cancer agents.8
Thyroid
In addition to the misinterpreted study previously mentioned in the
first paragraph that purposely restricted iodine, there have been
additional in vitro and animal studies that link soy intake to
inhibition of thyroid peroxidase, lowered thyroid hormones and goiter.
Though Divi, Chang and Doerge believe they had found a link to goiter
in 1996 and 1997,9,10 a subsequent study by Chang and Doerge in 2000
found cases of goiter only in those predisposed or consuming diets
lacking in iodine. They also found that genistein can deactivate
thyroid peroxidase with no accompanying effect on thyroid hormones.11
In fact, the University of Minnesota recently found that the
consumption of isoflavone-rich soy protein, at levels that were as much
as 3-4 times the isoflavone intake in Japan, had little effect on
thyroid hormone levels in either pre- or postmenopausal women over a
three-month period.12,13
In addition, a recently conducted double-blind study six months in
duration, that involved 38 postmenopausal women who were not on hormone
therapy, found no differences in thyroid function, based on measures of
thyroid stimulating hormone (TSH), total T4 and T3, between subjects
given daily either a placebo or a soybean isoflavone extract that
provided 90 mg (equal to approximately three servings of soy) of
isoflavones.14
Improper conclusions have also been drawn from a New York Times article
in 1996 discussing 100 million cases of goiter in China.15 Goiter
occurs in inland areas of all continents because of diets insufficient
in iodine compared to costal areas that utilize fish and seaweed which
are iodine rich. In contrast, developed countries have better food
distribution and most salt is iodized specifically to prevent goiter.
Rickets
In the often misquoted study mentioned in the first paragraph of dogs
housed in the absence of sunlight and fed one of four cereal diets,
Mellanby in 1919 clearly established the role of diet in the cause of
rickets, but not because of soy. Mellanby soon established that all
four of his diets were relatively deficient in calcium and lacked
favorable calcium/phosphorus ratios.16 Interestingly, it was his work
that led to McCollum’s later discovery of Vitamin D and its deficiency
as being the cause of rickets.16 Vitamin D and it’s connection to
calcium and bone metabolism is now well established. It should also be
noted that neither Mellanby nor McCollum ever suggested soy as the
cause of rickets.
Cancer and Hormone Levels
Critics once again connect the unconnected in order to place blame on
soy. Asian and Japanese populations do have higher rates of
esophageal, stomach, liver and pancreatic cancer. It is a leap of
logic to conclude that soy is the only responsible variable.22
Epidemiological evidence shows the responsibility for some of these
cancers may well be a lack of refrigeration in the rural areas of these
countries as well as the consumption of much smoked or barbecued meat.
Liver cancer rates may be more specifically linked to higher rates of
Hepatitis B and the presence of alflatoxins in the food supply.
Clearly, there are many variables potentially responsible for high
cancer rates, not just soy.
Specific hormone related cancers (breast and prostate) are low in Asia
and may be linked to early intake of soy.23 It is hypothesized that
isoflavones weakly bind to estrogen receptors and block estrogen from
the receptors or they inhibit enzymes that promote cancer cell growth.23
Soy contains many anti-cancer agents such as isoflavones, protease
inhibitors, phytic acid and phytosterols (beta-sitosterols). Saponins
as well, possibly due to their anti-oxidant activity and/or ability to
regulate cellular proliferation are anticarcinogenic.8
One fact should be made clear. There is no estrogen in soy! The term
"phytoestogen"confuses people. A more accurate term may be
"estrogen-like phytoadaptogen". Unlike estrogens which are uniformly
agonists and anti-estrogens which are uniformly antagonists, adaptogens
will enhance or suppress activity depending on the physiological needs
of the tissue. This response is discussed in the literature as
selective estrogen response modifiers (SERMs). Most notable SERMs are
tamoxifen for breast cancer reduction and raloxifene to improve bone
mass.24,25 Many natural "SERMs"also exist.
Claims by critics of soy that the "amount of phytoestrogens that are in
a day’s worth of soy infant formula equal 5 days of birth control
pills"loses its impact when the preferential tissue response of
adaptogens is better understood accompanied by the realization there is
no estrogen in any soy product.
It is well documented that a low lifetime exposure to estrogen reduces
the risk of breast and prostate cancer. Recent research has taken a
closer look at specific estrogen metabolites, 16-alpha
hydroxy-estradiol and 4-hydroxy-estradiol and determined they are
genotoxic. Soy isoflavones may shift estrogen metabolism towards the
production of more beneficial metabolites such as 2- hydroxy-estradiol
and improve the 2:16 ratio.26,27
A word of caution for estrogen receptor positive breast cancer
patients. There is no conclusive evidence that isoflavones are
harmless or harmful under this circumstance.18 Unfortunate
misinterpretation by critics cite a study by Dees et al. claiming that
genistein causes breast cancer cell proliferation.28 This was an in
vitro study testing whether genistein would prevent breast cancer cell
growth (an anti-estrogen) in the presence of DDT. The study found
genistein unable to offset the effects of DDT. Logic suggests that if
it shifts estrogen metabolism to help eliminate the genotoxic forms of
metabolites, it may be beneficial for the treatment of breast cancer.
In men, studies report there are no adverse effects from soy
consumption on sperm quality though there may be small effects on sex
hormone-binding globulin and steroid hormones.28 Many studies show
that soy consumption may reduce prostate cancer risk.30-36
Multiple studies also suggest soy will reduce hot flashes and vasomotor
symptoms in women using soy foods, soy protein isolate and soy extracts
(40-80 mg. isoflavones per day).37,38,39 Bone health is also reported
improved as isoflavones promote bone conservation by stimulating
osteoblastic bone formation and inhibiting osteoclastic bone
breakdown. Specific mechanism is believed to be related to the
adaptogenic properties already discussed with regard to
estrogen.40,41,42
Muscle Protein Breakdown
Critics warn athletes who use a soy based protein powder that they may
actually be breaking down muscle instead of building it. In citing a
study with pigs fed either a casein based or soy based diet,
researchers claim the soy based diet resulted in muscle breakdown as
opposed to the casein based diet. The critics fail to reveal the
researchers say in the study they supplemented the casein fed pigs with
methionine, threonine and tryptophan.43 Regardless, no human eats a
diet of 100% soy or casein.
Cardiovascular Disease
In 1999, the FDA approved a health claim for soy protein and it’s
effect on lowering cholesterol saying, "Diets low in saturated fat and
cholesterol that include 25 grams of soy protein a day may reduce the
risk of heart disease".17 This health claim was approved only after an
extensive, yearlong review of the studies.18
In numerous controlled human clinical trials, Anderson, et al. found
that soy consumption rather than animal protein significantly decreased
serum concentrations of total cholesterol, LDL and triglycerides in
hypercholesterolemic individuals, but not in normolipidemic
individuals.19,20,21
Other Concerns
A by-product of high temperature or alkaline processing is
lysinoalanine. Critics of soy remind us that it is a toxin without
also mentioning that it is also found in milk or any other processed
protein. Milder processing techniques since the mid 1980’s have
resulted in "dramatic decreases"of lysinoalanine in processed foods.44
Additionally, stainless steel processing tanks have replaced aluminum
tanks leaving only naturally occuring aluminum in soy protein isolates.
Another complaint is the presence of hemagglutinin, a clot promoting
substance proven in vitro, not in vivo where other human biochemistry
and nutritional factors would negate its influence.
Studies have shown a greater incidence of insulin- dependent diabetes
mellitus in children who consumed soy infant formula.45 Considering
that some companies producing poor quality products will add free
glutamic acid (monosodium glutamate aka MSG) and/or aspartic acid to
their formulas, there is no argument that this is a product that
children should avoid.
Another concern for consumers is the growing trend toward genetically
modified crops including soy. Genetic modification of foods will have
yet unknown long term consequences. Buying products marked "Non GM"or
"Non GMO"is the safe way to avoid them.
In Summary
The most commonly quoted studies seem to be interpreted simply to
advance the argument rather than to understand it. Reading of the
titles or only the discussion portion of the studies by the soy critics
ignore the internal design of the study and have lead to wrong
conclusions. Common sense will find that one thing is certain. Rarely
will you find billions of people embracing a food for centuries only to
find they have been wrong.
1. Mellanby E. An experimental investigation on rickets. Lancet.1919; 1 :407 - 412
2. Drane, H.M. et al., "Oestrogenic Activity of Soya-Bean Products", Food, Cosmetics and Technology (1980) 18:425-427.
3. Messina M, Erdman J Jr, Setchell KD. Introduction to and
Perspectives from the Fifth International Symposium on the Role of Soy
in Preventing and Treating Chronic Disease. J Nutr 004;134(5):1205S-06S.
4. Erdman JW Jr, Fordyce EJ. Soy products and the human diet. Am J Clin Nutr 1989;49(5):725-37
5. Sarwar G, McDonough FE. Evaluation of protein
digestibility-corrected amino acid score method for assessing
protein quality of foods. J Assoc Off Anal Chem 1990;73(3):346-56
6. FAO/WHO/UNU Expert Consultation. Energy and Protein Requirements.
Geneva: World Health Organization;1985 (WHO techncal report, series 724)
7. U.S. Food and Drug Administration. Federal Register. 21 CFR, Part 101, et al. Part III. Food Labeling 1991
8. Kennedy AR. The evidence for soybean products as cancer preventative agents. J Nutr1995;125(3 Suppl):733S-43S
9. Divi RL, Chang HC, Doerge DR. Anti-thyroid isoflavones from
soybean: isolation, characterization, and mechanisms of action. Biochem
Pharmacol 1997; 54:1087-96.
10. Divi RL, Doerge DR. Inhibition of thyroid peroxidase by dietary flavonoids. Chem Res Toxicol 1996;9:16-23.
11. Chang HC, Doerge DR. Dietary genistein inactivates rat thyroid
peroxidase in vivo without an apparent hypothyroid effect. Toxicol Appl
Pharmacol 2000; 168:244-52.
12. Duncan AM, Merz BE, Xu X, Nagel TC, Phipps WR, Kurzer MS. Soy
isoflavones exert modest hormonal effects in premenopausal women. J
Clin Endocrinol Metab 1999; 84:192-7.
13. Duncan AM, Underhill KE, Xu X, Lavalleur J, Phipps WR, Kurzer MS.
Modest hormonal effects of soy isoflavones in postmenopausal women
[published erratum appears in J Clin Endocrinol Metab 2000
Jan;85(1):448]. J Clin Endocrinol Metab 1999; 84:3479-84.
14. Bruce B, Spiller GA, Holloway L. Soy isoflavones do not have an
antithyroid effect in postmenopausal women over 64 years of age. FASEB
J 2000; 11:193.
15. New York Times, June 6, 1996.
16. McCollum EV. A History of Nutrition. Cambridge, MA: Riverside Press; 1957.
17. U.S. Food and Drug Administration. Food labeling: health claims;
soy protein and coronary heart disease. Fed Regist
1998;63(217):62997-63015.
18. Henkel J. U.S. Food and Drug Administration. Soy: Health Claims
for soy protein, questions about other components. Available at:
www.fda.gov/fdac/features/2000/300_soy.html.
19. Anderson JW, Johnstone BM,Cook-Newell ME. Meta-analysis of the
effects of soy protein intake on serum lipids. N Eng J Med
1995;333(5):276-82.
20. Potter SM. Overview of the proposed mechanisms for the hypocholesterolemic effect of soy. J Nutr1995;125(3 Suppl):600S-11S.
21. Potter SM, Baum JA, Teng H, Stillman RJ, Shay NF, Erdman JW Jr.
Soy protein and Isoflavones: their effects on blood lipids and bone
density in post menopausal women. Am J Clin Nutr1998;68 (6
Suppl):1375S-79S.
22. Harras, A (ed.), Cancer Rates and Risks, National Institutes of Health, National Cancer Institute, 1996, 4th Edition.
23. Shu XO, Jin F, Dai Q, et al. Soyfood intake during adolescence and
subsequent risk of breast cancer among Chinese women. Cancer Epidemiol
Biomarkers Prev 2001;10(5):483-88
24. Riggs BL, Hartmann LC. Selective estrogen-receptor
modifiers-mechanisms of action and application to clinical practice. N
Eng J Med. 2003;348(7):618-29.
25. Katznellenbogen BS, Choi I, Delage-Mourroux R. Molecilar
mechanisms of estrogen action: selective ligands and receptor
pharmacology. J Steroid Biochem Mol Biol. 2000;74:279-85.
26. Xu X, Duncan Am, Merz BE, Kurzer MS. Effects of soy isoflavone on
estrogen and phytoestrogen metabolism in premenopausal women. Cancer
Epidemiol Biomarkers Prev 1998;7(12):1101-08.
27. Xu X, Duncan AM, Wangen KE, Kurzer MS. Soy consumption alters
endogenous metabolism in postmenopausal women. Cancer Epidemiol
Biomarkers Prev 2000;9(8):781-86.
28. Dees C., et al. Dietary estrogens stimulate human breast cells to
enter the cell cycle. Environmental Health Perspectives 1997;105(Suppl.
3):633-636.
29. Persky VW, Turyk ME, Wang L et al. Effect of soy protein on
endogenous hormones in post menopausal women. Am J Clin Nutr
2002;75(1):145-53.
30. Peterson G, Barnes S.Genistein and biochanin A inhibit the growth
of human prostate cancer cells but not epidermal growth factor receptor
tyrosine autophosphorylation. Prostate 1993;22(4):335-45. 31. Geller
J, Sionit L, Partido C, et al. Genistein inhibits the growth of
human-patient BPH and prostate cancer in histoculture. The Prostate.
1998; 34:75-79.
32. Barnes S. Effect of genistein on in vitro and in vivo models of cancer. J Nutr. 1995; 125:777S-783S.
33. Adlercreutz CH, Goldin BR, Gorbach SL et al. Soybean phytoestrogen
intake and cancer risk. J Nutr. 1995 Mar;125(3 Suppl):757S-770S.
34. Nagata C, Takatsuka N, Inaba S, et al. Effect of soymilk
consumption on serum estrogen concentrations in premenopausal Japanese
women. J Natl Cancer Inst 1998;90:1830- 5.
35. Habito RC, Montalto J, Leslie E, Ball M.J. Effects of replacing
meat with soyabean in the diet on sex hormone concentrations in healthy
adult males. Br J Nutr, October 2000, vol. 84, no. 4, pp. 557-563(7)
36. Mitchell JH, Cawood E, Kinniburgh D, Provan A, Collins AR, Irvine
DS. Effect of a phyto-estrogen food supplement on reproductive health
in normal males. Clin Sci 2001 Jun;100(6):613-8.
37. The role of isoflavones in menopausal health: consensus opinion of
The North American Menopause Society . Menopause 2000
Jul-Aug;7(4):215-29.
38. Eden J. Phytoestrogens and the menopause. Baillieres clin Endocrinol Metab 1998;12(4):581-87.
39. Dallas FS, Rice GE, Wahlqvist ML, et al. Effects of dietary
phytoestrogens in post menopausal women. Climacteric 1998;1(2):124-29.
40. Brynin R. Soy and its isoflavones: a review of their effects on bone density. Altern Med Rev 2002;7(4):317-27.
41. Migliaccio S, Anderson JJ. Isoflavones and skeletal health: are
these molecules ready for clinical application? Osteoporos Int. 2003
Jun;14(5):361-8.
42. Setchell KD, Lydeking-Olsen E. Dietary phytoestrogens and their
effect on bone: evidence from in vitro and in vivo, human
observational, and dietary intervention studies. Am J Clin Nutr.
2003;78(3 Suppl):593S-609S.
43. Lohrke, B. "Activation of Skeletal Muscle Protein Breakdown
Following Consumption of Soybean Protein in Pigs,"Br J Nutr, 2001 Apr;
85 (4): 447-57.
44. Boschin G, D’Agostina A, Rinaldi A, Arnoldi A. Lysinoalanine
Content of Formulas for Enteral Nutrition 2003. J. Dairy Sci. 86:2283-
2287
45. Fort P, Lanes R, Dahlem, S, Recker, B, Weyman-Daum, M, Pugliese,
M, Lifshitz, FJ, "Breast-feeding and insulin-dependent diabetes
mellitus in children,"Am Coll Nutr 1986; 5(5): 439-41.
Dispelling the "Joy of Soy"Myth
By Raquel Martin
A few decades ago, soybeans were not used as a food but were used
instead, and more appropriately, in crop rotation. However, the
discovery of long periods of fermentation has been found to be
essential in transferring soy into a healthy food. This process
significantly reduces the phytate content of soybeans, as well as the
trypsin inhibitors that interfere with many vital enzymes and amino
acids. Fortunately, fermented soy such as tempeh, miso, natto, tamari
and other fermented soy products can provide nourishment that is easily
assimilated.
When precipitated soy products like tofu are consumed with meat, the
mineral-blocking effects of the phytates are reduced.i However, when
consuming soy (tofu/bean curds) as a replacement for meat and dairy
products, mineral deficiencies occur. Such a diet can lead to an amino
acid deficiency.ii "Asian and Western children, who do not get enough
meat and fish products to counteract the effects of a high phytate
diet, are subject to rickets, and other growth problems."iii Contrary
to popular opinion concerning the healthy effect of consuming soy food
has on Asians, a New York Times article (June 6, 1996) cited 100
million cases of goiters at present in China.
We are told that soybeans are high in protein, but what we are not told
is that soybeans also block the action of the enzymes that are
essential in digestion of protein. Soy damages the enzymes that
manufacture thyroid hormones, as well as those enzymes essential to
proper thyroid functioning.iv v Besides this bad news, scientists have
known for years that isoflavones in soy products can cause enlarged
thyroid glands (goiter)vi.
How are soy protein isolates (S.P.I) made? They are manufactured by
mixing an alkaline solution to it in order to remove fiber. A toxin
called lysinoalanine is formed during alkaline processing.vii Then it
is separated by adding an acid. This is done in aluminum tanks, which
leach high levels of aluminum into the final product. It is then
spray-dried at high temperatures to make a protein powder. Nitrites,
which are potent carcinogens, are formed during spray drying. A final
indignity to this substance is brought on by the use of additional
high-temperature and pressure. This is what produces textured soy
protein. However when the soy is denatured in this way, the resulting
product becomes ineffective.viii And even though much of the trypsin
inhibitor content can be removed through high-temperature processing,
it’s note all removed during this processing. This remnant can vary as
much as fivefold.ix
This leftover anti-nutrient (a toxin) becomes more of a concern when
MSG is added in order to mask the unpleasant taste of this texturized
soy product. This in turn often creates more allergic reactions as well
as a need to increase vitamins E, K, D, B12, calcium, magnesium,
manganese, molybdenum, copper, iron and of course, zinc.x The effect of
mineral blocking enzyme inhibitors in soy can result in any number of
conditions, such as endocrine disruption (goiters), reproductive
disorders and allergic reactions.xi
Test animals fed soy protein isolates (SPI) develop enlarged thyroid,
as well as the enlargement of other glands, most particularly the
pancreas. Their diets, which are high in trypsin inhibitors, are also
subjected to pathological conditions of the pancreas, including
cancer.xii A biochemical pharmacology study confirms that fatigue, as
well as goiter problems, are associated with soy food.xiii
The National Center for Toxicological Research reports that soy
isoflavones (genistein and daidzein) "inhibit thyroid
peroxidase-catalyzed reactions essential to thyroid hormone
synthesis."xiv Japanese researchers studied the effects of consuming as
little as two tablespoons of soybean a day. Even when healthy people
were put on this diet for a short period of time suppressed thyroid
function and goiters developed, "especially elderly subjects."xv
Infants have also been found to suffer from hypothyroid problem when on
a soybean diet.xvi Another study confirms that autoimmune thyroid
disease is linked to children who have consumed soymilk formula on a
regular basis.xvii Doctors should be aware of the "potential
interaction between soy infant formula and thyroid function,"xviii says
the New Zealand Ministry of Health.
And a study comparing consumption of soy formula in non-diabetic
children found those who drank it, as infants were prone to
diabetes.xix Also, it is possible that allergies, so prevalent these
days, may have been exacerbated from consuming soy formula. For
instance, "the amount of phytoestrogens that are in a day’s worth of
soy infant formula equals 5 birth control pills,"says Mary G. Enig,
Ph.D., president of the Maryland Nutritionists Association. Nutritional
experts believe that this high amount of phytoestrogens can be linked
with early puberty in girls and hinders physical maturation in boys.xx
In 1998, the FDA had even received warnings from the British
Government’s final account on phytoestrogens, about their harmful
reactions.xxi But for reasons beyond the consumer’s knowledge FDA
bureaucrats have engaged in a "rigorous approval process"for S.P.I.
However, we can now protect ourselves by learning more about what’s
behind all these inconsistent reports as we become more aware of the
health industry’s claims and political propaganda concerning food
supplements.
Soy phytates reduce zinc and iron absorption. This is a concern because
numerous people, who are taking iron supplements due to low levels of
this mineral, are not realizing the cause of their iron deficiency.
Soybeans have one of the highest phytate levels of any grain or legume
that has been studied,xxii and even long periods of cooking at high
temperatures will not completely eliminate the phytate levels.xxiii
Phytates (an organic acid found within the outer portion of all seeds)
block the absorption of essential minerals (e.g. calcium, magnesium,
iron, and especially zinc. This is a concern because high levels of
zinc are needed in the brain, especially the hippocampus. Zinc plays an
important role in the transmission of the nerve impulse between brain
cells. Deficiency in zinc can be serious, as it’s needed in the
development of brain, immune and nervous system functioning. It also
plays a role in collagen formation and protein synthesis, as well as
our blood-sugar control mechanism and other systems in the body.
The U.S. Department of Agriculture, Agricultural Research Service, Food
& Nutrition Research Briefs (July 1997) provides information
showing how changes in zinc intake can affect cognitive function.xxiv
This suggests the importance of zinc in the pathological functioning of
the cerebral cortex.xxv Furthermore, age-related zinc deficiency in
cells may contribute to brain cell death in Alzheimer’s dementia.xxvi
Congenital abnormalities in an infant’s nervous system can be caused by
a deficiency of zinc during pregnancy and lactation. In children,
"insufficient levels of zinc have been associated with lowered learning
ability, apathy, lethargy, and mental retardation."xxvii The USDA
references a study of 372 Chinese school children with very low levels
of zinc in their bodies. The children who received zinc supplements had
the most improved performance—especially in perception, memory,
reasoning, and psychomotor skills such as eye-hand coordination. "Both
phytate and soy protein reduce iron absorption so that the iron in soy
foods is generally poorly absorbed."xxviii
As early as 1967, researchers found soy formula to have a negative
effect on zinc absorption and also a strong correlation between phytate
content and poor growth. Author Sally Fallon warns "a reduced rate of
growth is especially serious in the infant as it causes a delay in the
accumulation of lipids in the myelin, and hence jeopardizes the
development of the brain and nervous system."xxix It has even been
found to increase the deposition of fatty acids in the liver.xxx
Soy and Cancer
The promotional health claims about soy products that come from
vitamin/food manufacturer’s ads and multi-level marketers is then
passed on to medical doctors, as well as the media and are received as
gospel truth. Is this how we, the consumer, want to obtain information
that will affect our future health? Some of the hype about soy alleges
to aid in weight loss, protect the heart, prevent female discomforts
and the list goes on. One piece of literature from a vitamin company
goes so far as to state that the "Japanese, who eat 30 times as much
soy as North Americans, have a lower incidence of cancers of the
breast, uterus and prostate."xxxi I have not found clinical studies to
back this up and if it is true, it should also be pointed out that
these Asians and Japanese have a higher rate of other kinds of cancer
(esophagus, stomach, pancreas and liver).xxxii xxxiii Other literature
confirms that a high rate of thyroid cancer is linked to soy
consumption.xxxiv
In a 1996 study, researchers discovered that women who consumed the soy
protein isolates had a greater risk of experiencing abnormally
excessive cell growth, a symptom that can be a predecessor to
malignancies.xxxv A study called "Dietary Estrogens Stimulate Human
Breast Cells to Enter the Cell Cycle,"led researchers to conclude that
women should not consume soy products, thinking that they were
preventing breast cancer, when in fact dietary genistein found in soy
food actually stimulates breast cell growth xxxvi In fact, according to
Cancer Research "Genistein…is more carcinogenic than DES."xxxvii That’s
right DES the drug that caused death and disfigurement for countless
women.
Additionally, it takes a mere 45 mg of isoflavones in premenopausal
women to create a biological effect that will cause a reduction in
hormones needed for proper thyroid activity. Numerous women are on
thyroid medication, yet at the same time they are increasing their soy
intake. The two seem to be defeating each other’s purposes. Other
problems concerning a diet rich in soy food are highlighted from animal
studies at Brigham Young University’s Neuroscience Center. Researchers
found that consumption of phytoestrogens from soy for a relatively
short interval can significantly elevate estrogen levels in the brain
and can interfere with and thus decrease calcium-binding proteins in
the brain.xxxviii
Athletes should be aware that the "soy protein"drinks they are
consuming in order to build muscle tissue, may actually cause muscle
protein breakdown.xxxix Take a look at some of the studies, such as the
British Journal of Nutrition, which correlates strongly to
weight-training athletes, whose diets consist of inferior soy protein,
which may increase protein breakdown in skeletal muscle. Soybean
protein isolates were given to pigs for fifteen weeks. Cortisol levels
began to rise after their morning meal. Soy meals were causing the body
to break down muscle protein in order for it to get its required amino
acids.xl
This soy fad is resulting in numerous physiological abnormalities.
Shocking news on this subject comes from investigations made by
toxicologist, Mike Fitzpatrick, Ph.D., who confirms the facts that soy
consumption has been linked to disorders, such as infertility and
leukemia, and that soy foods are highly estrogenic. In 1992, the Swiss
health service estimated that 299 grams of soy protein provided the
estrogenic equivalent of the Pill.xli In fact other studies suggest
that isoflavones inhibit synthesis of estradiol and other steroid
hormones as well.xlii xliii But soy food can be very disruptive as
their isoflavones, genistein and diadzen, can create endocrine
dysfunction.
Elaine Hollingsworth in her book Take Control of Your Health and Escape
the Sickness Industry says, "Soybeans contain Hemagglutinin, a
clot-promoting substance that causes red blood cells to clump together.
These clustered blood cells are unable to properly absorb oxygen for
distribution to the body’s tissues, which can damage the heart."xliv In
his classic book, A Cancer Therapy - Results of 50 Cases, (p. 237) Dr.
Charlotte Gerson warns to stay away from soy products. "Genistein, a
component of soy, is more carcinogenic than DES."xlv
Hollingsworth says: "Increased level of tofu consumption was found to
be associated with indications of brain atrophy and cognitive
impairment in later life. They even found, at autopsy, swelling of the
brain cavities and a decrease in brain weight among heavy tofu
eaters.xlvi "Few people are aware that most soil contains aluminium. It
is one of the most prevalent minerals, but it doesn’t affect most
crops. Soy, however, has an affinity for aluminium and extracts it from
the soil and concentrates it in the beans. This contamination is
exacerbated by the aluminium tanks, which are used in the acid wash
soy, is subjected to. So, when you ingest soy in any form, you also
ingest aluminium, known for causing many health problems."xlvii
It seems like we, the consumer, have been duped by the producers and
their ad campaigns regarding the so-called "health"benefits obtained
from soy products. Dr. Joseph Mercola tells us that the propaganda,
from so many sources in the industry, has spread like a wild fire; and
that this aggressive publicity is just another "nail in the
coffin…"concerning a food that is not "designed to be eaten."xlviii
Never has there been a mention of the many studies that demonstrate the
toxicity to our thyroid, liver or endocrine glands.xlix
Portions of this article have been excerpted from The Estrogen
Alternative and Preventing Arthritis naturally: The Untold Story by
Raquel Martin. (Healing Arts Press, 2004)
i Sandstrom, B. et al., "Effect of protein level and protein source on
zinc absorption in humans", Journal of Nutrition 119(1): 48-53, January
1989; Tait, Susan et al., "The availability of minerals in food, with
particular reference to iron", Journal of Research in Society and
Health 103(2): 74-77, April 1983.
ii Enig MG, Fallon SA, Tragedy and Hype, The Third International Soy Symposium. Nexus Magazine, Vol. 7, No. 3, April-May 2000.
iii Martin, R., Gerstung, J, The Estrogen Alternative: Natural Hormone
Therapy with Botanical Progesterone (Foreword by John Hart, M.D.) (4th
Ed. 2004 in print) Healing Arts Press, Rochester, Vt. Citing: Mellanby,
Edward, "Experimental rickets: The effect of cereals and their
interaction with other factors of diet and environment in producing
rickets", Journal of the Medical Research Council 93:265, March 1925;
Wills, M.R. et al., "Phytic Acid and Nutritional Rickets in
Immigrants", The Lancet, April 8,1972, pp. 771-773.
iv Ishizuki, Y. et al., "The Effects on the Thyroid Gland of Soybeans
Administered Experimentally in Healthy Subjects", Nippon Naibunpi
Gakkai Zasshi (1991) 767:622-629.
v Doerge, Daniel R., "Inactivation of Thyroid Peroxidase by Genistein
and Daidzein in Vitro and in Vivo; Mechanism for Anti-Thyroid Activity
of Soy", presented at the November 1999 Soy Symposium in Washington,
DC, National Center for Toxicological Research, Jefferson, AR 72029,
USA.
viDrane, H.M. et al., "Oestrogenic Activity of Soya-Bean Products", Food, Cosmetics and Technology (1980) 18:425-427.
vii Rackis et al., ibid., p. 22; Rackis, et al., "Evaluation of the
Health Aspects of Soy Protein Isolates as Food Ingredients", prepared
for FDA by Life Sciences Research Office, Federation of American
Societies for Experimental Biology (9650 Rockville Pike, Bethesda, MD
20014), USA, Contract No. FDA 223-75-2004, 1979.
viii Wallace, G.M., "Studies on the Processing and Properties of
Soymilk", Journal of Science and Food Agriculture, 22:526-535, October
1971.
ix Rackis et al., ibid
x Rackis, Joseph, J., "Biological and Physiological Factors in
Soybeans", Journal of the American Oil Chemists’ Society, 51:161A-170A,
January 1974.
xi "Food Labeling: Health Claims: Soy Protein and Coronary Heart
Disease,"Food and Drug Administration 21 CFR, Part 101 (Docket No.
98P-0683).
xii Rackis, Joseph J. et al., "The USDA trypsin inhibitor study. I.
Background, objectives and procedural details", Qualification of Plant
Foods in Human Nutrition, vol. 35, 1985. p. 232.
xiii Martin, R., Gerstung, J, The Estrogen Alternative: Natural Hormone
Therapy with Botanical Progesterone (Foreword by John Hart, M.D.) (4th
Ed. 2004 in print) Healing Arts Press, Rochester, Vt. Citing: Divi, RL,
Chang HC, Doerge, DR, "Anti-thyroid Isoflavones from Soybean:
Isolation, Characterization, and Mechanisms of Action,"Biochem.
Pharmacol., 1997 Nov 15; 54(10):1087-96.
xiv Ibid: Divi, RL, Chang HC, Doerge, DR, "Anti-thyroid Isoflavones
from Soybean: Isolation, Characterization, and Mechanisms of
Action,"Biochem. Pharmacol.
xv Ishizuki, Y, Hirooka, Y, Murata, Y, Togashi, K, "The Effects on the
Thyroid Gland of Soybeans Administered Experimentally in Healthy
Subjects,"Nippon Naibunpi Gakkai Zasshi 1991 May 20; 67(5): 622-29.
xvi Shepard TH, Soybean goiter. New Eng J Med 1960; 262:1099-1103.
xvii Fort P, Moses N, Fusion, M, Goldberg, T, Leftists, F, "Breast and
Soy-Formula Feedings in Early Infancy and the Prevalence of Autoimmune
Thyroid Disease in Children,"J Am Coll Nutr 1990 Apr; 9(2): 164-67.
xviii Regulatory Guidance in Other Countries: New Zealand Ministry of
Health Position Statement on Soy Formulas (Adobe Acrobat file).
xix Fort P, Lanes R, Dahlem, S, Recker, B, Weyman-Daum, M, Pugliese, M,
Lifshitz, FJ, "Breast-feeding and insulin-dependent diabetes mellitus
in children,"Am Coll Nutr 1986; 5(5): 439-41.
xx Martin, R., Gerstung, J, The Estrogen Alternative: Natural Hormone
Therapy with Botanical Progesterone (Foreword by John Hart, M.D.) (4th
Ed. 2004 in print) Healing Arts Press, Rochester, Vt. Citing: "Soy
Infant Formula Could Be Harmful to Infants: Groups Want it
Pulled,"Nutrition Week, Dec 10, 1999; 29(46): 1-2.
xxi "IEH Assessment on Phytoestrogens in the Human Diet,"Final Report
to the Ministry of Agriculture, Fisheries and Food, UK, November 1997,
p. 11.
xxii El Tiney, A.H., "Proximate Composition and Mineral and Phytate
Contents of Legumes Grown in Sudan", Journal of Food Composition and
Analysis (1989) 2:6778.
xxiii Ologhobo, A.D. et al., "Distribution of phosphorus and phytate in
some Nigerian varieties of legumes and some effects of processing",
Journal of Food Science 49(1): 199-201, January/February 1984.
xxiv U.S. Department of Agriculture, Agricultural Research Service, Food & Nutrition Research Briefs, July 1997.
xxv Frederickson, CJ, Suh, SW, Silva, D, Frederickson, CJ, Thompson,
RB, "Importance of Zinc in the Central Nervous System: The
Zinc-containing Neuron,"J Nutr 2000 May; 130(5S Suppl): 1471S-83S.
xxvi Ho, LH, Ratnaike, RN, Zalewski, PD, "Involvement of Intracellular
Labile Zinc in Suppression of DEVD-Caspase Activity in Human
Neuroblastoma Cells,"Biochem Biophys Res Commun, 2000 Feb 5; 268(1):
148-54.
xxvii Pfeiffer CC, Braverman, E.R., "Zinc, The brain and behavior,"Biol Psychiatry, 1982 Apr; 17(4): 513-32.
xxviii Soy Nutritive Content, United Soybean Board. Enig, M. G.,
Fallon, S.A., "Tragedy and Hype, The Third International Soy
Symposium,"Nexus Magazine Vol. 7, No 3, April-May 2000. Enig, Mary G.
and Sally Fallon, "The Oiling of America", NEXUS Magazine, December
1998-January 1999 and February-March 1999; also available at
www.WestonAPrice.org.
xxix Sally Fallon, Nourishing Traditions: The Cookbook that Challenges
Politically Correct Nutrition and The Diet Dictocrats, 2nd edition, New
Trends Publishing, 1999.
xxx Rackis, Joseph J. et al., "The USDA trypsin inhibitor study. I.
Background, objectives and procedural details", Qualification of Plant
Foods in Human Nutrition, vol. 35, 1985.
xxxi Natural Medicine News (L & H Vitamins, 32-33 47th Avenue, Long
Island City, NY 11101), USA, January/February 2000, p. 8.
xxxii Harras, Angela (ed.), Cancer Rates and Risks, National Institutes
of Health, National Cancer Institute, 1996, 4th edition; AND Rackis,
Joseph J. et al., "The USDA trypsin inhibitor study. I. Background,
Objectives and Procedural Details", Qualification of Plant Foods in
Human Nutrition, vol. 35, 1985.
xxxiii Rackis, Joseph J. et al., "The USDA trypsin inhibitor study. I.
Background, objectives and procedural details", Qualification of Plant
Foods in Human Nutrition, vol. 35, 1985.
xxxiv Searle, Charles E. (ed.), Chemical Carcinogens, ACS Monograph 173, American Chemical Society, Washington, DC, 1976.
xxxv Petrakis, N.L. et al., "Stimulatory Influence of Soy Protein
Isolate on Breast Secretion in Pre- and Post-Menopausal Women", Cancer
Epid. Bio. Prev. (1996) 5:785-794
xxxvi Dees, C. et al., "Dietary estrogens stimulate human breast cells
to enter the cell cycle", Environmental Health Perspectives (1997)
105(Suppl. 3): 633-636.
xxxvii Cancer Research, June 1, 2001 - 61 (11): 4325-8.
xxxviii Lephart, E.D., Thompson, J.M., Setchell, K.D., Adlercreutz H,
Weber KS, Phytoestrogens decrease brain calcium-binding proteins...
Brain Res., (2000 Mar) 17; 859(1): 123-31.
xxxix Martin, R., Gerstung, J, The Estrogen Alternative: Natural
Hormone Therapy with Botanical Progesterone, (4th Ed.) Healing Arts
Press, Rochester, Vt. (2004 in print) Citing: Lohrke, B. "Activation of
Skeletal Muscle Protein Breakdown Following Consumption of Soybean
Protein in Pigs,"Br J Nutr, 2001 Apr; 85 (4): 447-57.
xl Lohrke, B. "Activation of Skeletal Muscle Protein Breakdown
Following Consumption of Soybean Protein in Pigs,"Br J Nutr, 2001 Apr;
85 (4): 447-57.
xli Bulletin de L’Office Fédéral de la Santé Publique, No. 28, July 20, 1992.
xlii Keung, W.M., "Dietary Oestrogenic Isoflavones are Potent
Inhibitors of B-hydroxysteroid Dehydrogenase of P. Testosteronii",
Biochemical and Biophysical Research Committee (1995) 215:1137-1144.
xliii Makela, S.I. et al., "Estrogen-specific 12 B-Hydroxysteroid
Oxidoreductase Type 1 (E.C. 1.1.1.62) as a Possible Target for the
Action of Phytoestrogens", PSEBM (1995) 208:51-59.
xliv Elaine Hollingsworth, "Take Control of Your Health and Escape the
Sickness Industry"(6th edition) Empowerment Press International.
Australia, 2000, http://www.doctorsaredangerous.com citing Charlotte
Gerson, of the Gerson Cancer Clinic in the U.S.A., Gerson Healing
Newsletter.
xlv (Cancer Research, June 1, 2001, 61(11): 4325-8).
xlvi Ibid: Hollingsworth, "Take Control of Your Health and Escape the
Sickness Industry,"cited in Journal Of The American College Of
Nutrition, April, 2000, and reprinted in Dr. William Campbell Douglass’
Second Opinion Newsletter.
xlvii Ibid: Hollingsworth, "Take Control of Your Health and Escape the Sickness Industry."
xlviii http://www.mercola.com/fcgi/pf/2004/jan/21/soy.htm
xlix Setchell, K.D.R. et al., "Dietary oestrogens - a probable cause of
infertility and liver disease in captive cheetahs", Gastroenterology
(1987) 93:225-233; Leopold, A.S., "Phytoestrogens: Adverse effects on
reproduction in California Quail,"Science (1976) 191:98-100; Kimura, S.
et al., "Development of Malignant Goiter by Defatted Soybean with
Iodine-free Diet in Rats", Gann. (1976) 67:763-765; Pelissero, C. et
al., "Oestrogenic Effect of Dietary Soybean Meal on Vitellogenesis in
Cultured Siberian Sturgeon Acipenser baeri".
Published: 3/1/2005
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