Tragedy and Hype: The Third International Soy Symposium
– Part II
by Sally Fallon and Mary G. Enig, PhD
All Rights Reserved. ©2000
Phytoestrogens – Panacea or Poison?
The male species of tropical birds carries the drab
plumage of the female at birth and “colors up” at maturity, somewhere
between nine and 24 months. In 1991, Richard and Valerie James, bird
breeders in Whangerai, New Zealand, purchased a new kind of feed for
their birds, one based largely on soy protein.47 When soy-based
feed was used, their birds “colored up” after just a few months. In
fact, one bird food manufacturer claimed that this early development
was an advantage imparted by the feed. A 1992 ad for Roudybush feed
formula showed a picture of the male crimson rosella, an Australian
parrot that acquires beautiful red plummage at 18 to 24 months, already
brightly colored at 11 weeks old.
Unfortunately, in the ensuing years, there was decreased
fertility in the birds with precocious maturation, deformed, stunted
and still-born babies, and premature deaths, especially among females,
with the result that the total population in the avaries went into steady
decline. The birds suffered beak and bone deformities, goitre, immune
system disorders and pathological aggressive behavior. Autopsy revealed
digestive organs in a state of disintegration. The list of problems
corresponded with many of the problems the Jameses had encountered in
their two children, who had been fed soy-based infant formula.
Startled, aghast, angry…the Jameses hired toxicologist
Mike Fitzpatrick to investigate further. Dr. Fitzpatrick’s literature
review uncovered evidence that soy consumption has been linked to numerous
disorders, including infertility, increased cancer and infantile leukemia;
and, in studies dating back to the 1950s,48 that genistein
in soy causes endocrine disruption in animals. Dr. Fitzpatrick also
analyzed the bird feed and found that it contained high levels of phytoestrogens,
especially genistein. When the Jameses discontinued using soy-based
feed, the flock gradually returned to normal breeding habits and behavior.
The Jameses embarked on a private crusade to warn the
public and government officials about soy foods, particularly the endocrine
disrupting isoflavones (genistein and diadzen.) Protein Technologies
International (PTI) received their material in 1994.
In 1991, Japanese researchers reported that consumption
of as little as 30 grams or 2 tablespoons of soybeans per day for only
one month resulted in a significant increase in thyroid stimulating
hormone.49 Diffuse goitre and hypothyroidism appeared in
some of the subjects and many complained of constipation, fatigue and
lethargy, even though their intake of iodine was adequate. In 1997,
researchers from the FDA’s National Center for Toxicological Research
made the embarrassing discovery that the goitrogenic components of soy
were the very same isoflavones.50
Twenty-five grams of soy protein isolate, the minimum
amount PTI claimed to have cholesterol-lowering effects, contains at
least 50 mg of isoflavones. It took only 45 mg daily of isoflavones
in premenopausal women to exert significant biological effects including
reduction in hormones needed for adequate thyroid function. These effects
lingered for three months after soy consumption was discontinued.51
One hundred grams of soy protein, the maximum suggested
cholesterol-lowering dose (and the amount recommended by Protein Technologies
International), can contain almost 600 mg of isoflavones,52
an amount that is undeniably toxic. In 1992, the Swiss health service
estimated that 100 grams of soy protein provided the estrogenic equivalent
of the pill.53
In vitro studies suggest that isoflavones inhibit synthesis
of estradiol and other steroid hormones.54 Reproductive problems,
infertility, thyroid disease and liver disease due to dietary intake
of isoflavones have been observed for several species of animals including
mice, cheetah, quail, pigs, rats, sturgeon and sheep.55
It is the isoflavones in soy that are said to have a
favorable effect on postmenopausal symptoms, including hot flashes and
protection from osteoporosis. Quantification of discomfort from hot
flashes is extremely subjective and most studies show that control subjects
report reduction in discomfort in amounts equal to subjects given soy.56
The claim that soy prevents osteoporosis is extraordinary,
given that soy foods block calcium and cause vitamin D deficiencies.
If Asians indeed have lower rates of osteoporosis than Westerners, it
is because their diet provides plenty of vitamin D from shrimp, lard
and sea food; and plenty of calcium from bone broths. The reason that
Westerners have such high rates of osteoporosis is because they have
substituted soy oil for butter, which is a traditional source of vitamin
D and other fat-soluble activators needed for calcium absorption.
Birth Control Pills for Babies
But it was the isoflavones in infant formula that gave
the James family the most cause for concern. In 1998, investigators
reported that the daily exposure of infants to isoflavones in soy infant
formula is six to eleven times higher on a body weight basis than the
dose that has hormonal effects in adults consuming soy foods. Circulating
concentrations of isoflavones in infants fed soy-based formula were
13,000 to 22,000 times higher than plasma estradiol concentrations in
infants on cows’ milk formula.57
Approximately 25% of bottle-fed children in the US receive
soy-based formula – a much higher percentage than in other parts of
the Western world. Fitzpatrick estimated that an infant exclusively
fed soy formula receives the estrogenic equivalent (based on body weight)
of at least five birth control pills per day.58 By contrast,
almost no phytoestrogens have been detected in dairy-based infant formula
or in human milk, even when the mother consumes soy products.
Scientists have known for years that soy-based formula
can cause thyroid problems in babies. But what are the effects of soy
products on the hormonal development of the infant, both male and female?
Male infants undergo a “testosterone surge” during the first few months
of life, when testosterone levels may be as high as those of an adult
male. During this period, the infant is programmed to express male characteristics
after puberty, not only in the development of his sexual organs and
other masculine physical traits, but also in setting patterns in the
brain characteristic of male behavior. In monkeys, deficiency of male
hormones impairs the development of spatial perception (which, in humans,
is normally more acute in men than in women), of learning ability and
of visual discrimination tasks (such as would be required for reading.)59
It goes without saying that future patterns of sexual orientation may
also be influenced by the early hormonal environment. Male children
exposed during gestation to diethylstilbesterol (DES), a synthetic estrogen
that has effects on animals similar to those of phytoestrogens from
soy, had testes smaller than normal on maturation.60
Learning disabilities and behavioral problems, especially
in male children, have reached epidemic proportions. Soy infant feeding
— which began in earnest in the early 1970s — cannot be ignored as a
probable cause for these tragic developments.
As for girls, an alarming number are entering puberty
much earlier than normal, according to a recent study reported in the
journal Pediatrics.61 Investigators found that one
percent of all girls now show signs of puberty, such as breast development
or pubic hair, before the age of three; by age eight, 14.7% of white
girls and almost 50% of African-American girls had one or both of these
characteristics. New data indicate that environmental estrogens such
as PCBs and DDE (a breakdown product of DDT) may cause early sexual
development in girls.62 In the 1986 Puerto Rico Premature
Thelarche study, the most significant dietary association with premature
sexual development was not chicken — as reported in the press — but
soy infant formula.63 The Woman, Infants and Children (WIC)
program, which supplies free infant formula to welfare mothers, stresses
soy formula for African Americans because they are supposedly allergic
to milk.
The consequences of truncated childhood are tragic.
Young girls with mature bodies must cope with feelings and urges that
most children are not well-equipped to handle. And early maturation
in girls is frequently a harbinger for problems with the reproductive
system later in life – including failure to menstruate, infertility
and breast cancer. Parents who have contacted the Jameses recount other
problems associated with children of both sexes who were fed soy-based
formula, including extreme emotional behavior, asthma, immune system
problems, pituitary insufficiency, thyroid disorders and irritable bowel
syndrome — the same endocrine and digestive havoc that afflicted the
James’ parrots.
Dissention in the Ranks
Organizers of the Third International Soy Symposium
would be hard pressed to call the conference an unqualified success.
On the second day of the conference the London-based Food Commission
and the Weston A Price Foundation of Washington, DC held a joint press
conference in the same hotel to present concerns about soy infant formula.
Industry representatives sat stony faced through the recitation of potential
dangers and a plea from concerned scientists and parents to pull soy-based
infant formula from the market. Under pressure from the Jameses, the
New Zealand government had issued a health warning about soy infant
formula in 1998. It was time for the American government to do the same.
On the last day of the conference, presentations on
new findings related to toxicity sent a well-oxygenated chill through
the industry’s giddy helium hype. Dr. Lon White reported on a study
of Japanese Americans living in Hawaii. It showed a significant statistical
relationship between two or more servings of tofu per week and “accelerated
brain aging.”64 Those participants who consumed tofu in midlife
had lower cognitive function in late life and a greater incidence of
Alzheimers and dementia. “What’s more,” said Dr. White, “those who ate
a lot of tofu, by the time they were 75 or 80, looked five years older.”65
White and his colleagues blamed the negative effects on isoflavones,
a finding that supports an earlier study in which post-menopausal women
with higher levels of circulating estrogen experienced greater cognitive
decline.66
Scientists Daniel Sheehan and Daniel Doerge from the
National Center for Toxicological Research ruined PTI’s day by presenting
findings from rat feeding studies indicating that genistein in soy foods
causes irreversible damage to enzymes that synthesize thyroid hormones.67
“The association between soybean consumption and goiter in animals and
humans has a long history,” wrote Dr. Doerge. “Current evidence for
the beneficial effects of soy requires a full understanding of potential
adverse effects as well.” Dr. Claude Hughes reported that rats born
to mothers fed genistein had decreased birth weights compared to controls
and onset of puberty occurred earlier in male offspring.68
His research suggested that the effects observed in rats “…will be at
least somewhat predictive of what occurs in humans. There is no reason
to assume that there will be gross malformations of fetuses but there
may be subtle changes, such as neurobehavioral attributes, immune function
and sex hormone levels.” The results, he said “…could be nothing or
could be something of great concern…if mom is eating something that
can act like sex hormones, it is logical to wonder if that could change
the baby’s development.”69
A study of babies born to vegetarian mothers, published
in January 2000, indicated just what those changes in baby’s development
might be. Mothers who ate a vegetarian diet during pregnancy had a fivefold
greater risk of delivering a boy with hypospadias, a birth defect of
the penis.70 The authors of the study suggested that the
cause was greater exposure to phytoestrogens in soy foods popular with
vegetarians. Problems with female offspring of vegetarian mothers are
more likely to show up later in life. While soy’s estrogenic effect
is less than that of diethylstilbestrol (DES), the dose is likely to
be higher because it’s consumed as a food, not taken as a drug. Daughters
of women who took DES during pregnancy suffered from infertility and
cancer when they reached their twenties.
GRAS Status
Lurking in the background of industry whoopla for soy
is the nagging question of whether it’s even legal to add soy protein
isolate to food. All food additives not in common use prior to 1958,
including casein protein from milk, must have GRAS (Generally Recognized
As Safe) status. In 1972, the Nixon administration directed a reexamination
of substances believed to be GRAS in the light of any scientific information
then available. This reexamination included casein protein which became
codified as GRAS in 1978. In 1974, the FDA obtained a literature review
of soy protein because, as soy protein had not been used in food until
1959 and was not even in common use in the early 1970s, it was not eligible
to have its GRAS status grandfathered under the provisions of the Food,
Drug and Cosmetic Act.71
The scientific literature up to 1974 recognized many
antinutrients in factory-made soy protein, including trypsin inhibitors,
phytic acid, and genistein. But the FDA literature review dismissed
discussion of adverse impacts with the statement that it was important
for “adequate processing” to remove them. Genistein could be removed
with an alcohol wash but it was an expensive procedure that processors
avoided. Later studies determined that trypsin inhibitor content could
be removed only with long periods of heat and pressure, but the FDA
has imposed no requirements for manufacturers to do so.
The FDA was more concerned about toxins formed during
processing, specifically nitrites and lysinoalanine.72 Even
at low levels of consumption — averaging one-third of a gram per day
at the time — the presence of these carcinogens was considered too great
a threat to public health to allow GRAS status. Soy protein did have
approval for use as a binder in cardboard boxes and this approval was
allowed to continue because researchers considered that migration of
nitrites from the box into the food contents would be too small to constitute
a cancer risk. FDA officials called for safety specifications and monitoring
procedures before granting of GRAS status for food. These were never
performed. To this day, use of soy protein is codified as GRAS only
for limited industrial use as a cardboard binder.
This means that soy protein must be subject to premarket
approval procedures each time manufacturers intend to use it as a food
or add it to a food. Soy protein was introduced into infant formula
in the early 1960s. It was a new product with no history of any use
at all. As soy protein did not have GRAS status, premarket approval
was required. This was not and still has not been granted. The
key ingredient of soy infant formula is not recognized as safe.
The Next Asbestos?
“Against the backdrop of widespread praise. . . there
is growing suspicion that soy — despite its undisputed benefits — may
pose some health hazards,” writes Marian Burros, a leading food writer
for the New York Times. More than any other writer, Ms. Burros’
endorsement of a lowfat, largely vegetarian diet has herded Americans
into supermarket aisles featuring soy foods. Yet her January 26, 2000
article “Doubts Cloud Rosy News on Soy” contains the following alarming
statement: “Not one of the 18 scientists interviewed for this column
was willing to say that taking isoflavones was risk free.” Ms. Burros
did not enumerate the risks, nor did she mention that the recommended
25 daily grams of soy protein contain enough isoflavones to cause problems
in sensitive individuals, but it was evident that the industry had recognized
the need to cover itself.
Because the industry is extremely exposed. Contingency
lawyers will soon discover that the number of potential plaintiffs can
be counted in the millions and the pockets are very, very deep. Juries
will hear something like the following: “The industry has known for
years that soy contains many toxins. At first they told the public that
the toxins were removed by processing. When it became apparent that
processing could not get rid of them, they claimed that these substances
were beneficial. Your government granted a health claim to a substance
that is poisonous and the industry lied to the public to sell more soy.”
The “industry” includes merchants, manufacturers, scientists,
publicists, bureaucrats, former bond financiers, food writers, vitamin
companies and retail stores. Farmers will probably escape because they
were duped like the rest of us. But they need to find something else
to grow before the soy bubble bursts and the market collapses – grass-fed
livestock, designer vegetables…or hemp to make paper for thousands and
thousands of legal briefs.
Sally Fallon is the author of Nourishing Traditions:
The Cookbook that Challenges Politically Correct Nutrition and the Diet
Dictocrats, Second Edition 1999 (New Trends Publishing 877-707-1776
or 219-268-2601) and President of the Weston A Price Foundation, Washington,
DC, www.WestonAPrice.org
Mary G. Enig, PhD is the author of Know Your Fats:
The Complete Primer for Understanding the Nutrition of Fats, Oils and
Cholesterol 2000 (www.BethesdaPress.com), President of the Maryland
Nutritionists Association and Vice President of the Weston A Price Foundation,
Washington, DC. The authors wish to thank Mike Fitzpatrick, PhD and
Valerie & Richard James for their help in preparing this article.
References
47. D J Woodhams, Phytoestrogens and parrots: The anatomy
of an investigation, Proceedings of the Nutrition Society of New
Zealand, 1995 20:22-30.
48. G Matrone et al, Effect of Genistin on Growth and
Development of the Male Mouse, Journal of Nutrition, 1956, 235-240.
49. Y Ishizuki, et al, The effects on the thyroid gland
of soybeans administered experimentally in healthy subjects, Nippon
Naibunpi Gakkai Zasshi 1991 767: 622-629.
50. R L Divi, et al, Anti-thyroid isoflavones from the
soybean, Biochemical Pharmacology, 1997 54:1087-1096.
51. A Cassidy, et al. Biological Effects of a Diet of
Soy Protein Rich in Isoflavones on the Menstrual Cycle of Premenopausal
Women, American Journal of Clinical Nutrition 1994 60: 333-340
(1994).
52. P A Murphy, Phytoestrogen Content of Processed Soybean
Foods, Food Technology, 1982, pages 50-54.
53. Bulletin de L’Office Federal de la Sante Publique,
No 28, July 20, 1992.
54. W M Keung, Dietary estrogenic isoflavones are potent
inhibitors of B-hydroxysteroid dehydrogenase of P testosteronii, Biochemical
and Biophysical Research Committee 1995 215:1137-1144; S I Makela,
et al, Estrogen specific 12 B-hydroxysteroid oxidoreductase type 1 (E.C.
1.1.1.62) as a possible target for the action of phytoestrogens, PSEBM,
1995 208:51-59.
55. K D R Setchell , et al, Dietary estrogens - a probable
cause of infertility and liver disease in captive cheetahs, Gastroenterology
93: 225-233 (1987); A S Leopold, Phytoestrogens: Adverse effects on
reproduction in California Quail, Science 1976 191: 98-100; Drane
HM et al, Oestrogenic activity of soya-bean products, Food Cosmetics
and Technology 1980 18: 425-427; S Kimura, et al. Development of
malignant goiter by defatted soybean with iodine-free diet in rats,
1976, Gann 67: 763-765; C Pelissero, et al, Estrogenic effect
of dietary soy bean meal on vitellogenesis in cultured Siberian Sturgeon
Acipenser baeri, Gen Comp End 83: 447-457; Braden et al, The
oestrogenic activity and metabolism of certain isoflavones in sheep,
Australian Journal of Agricultural Research 1967 18:335-348.
56. Jean Ginsburg and Giordana M Prelevic, Is there
a proven place for phytoestrogens in the menopause? Climacteric,
1999 2:75-78.
57. K D Setchell et al, Isoflavone content of infant
formulas and the metabolic fate of these early phytoestrogens in early
life, American Journal of Clinical Nutrition, December 1998 Supplement
1453S-1461S.
58. C Irvine, et al, The Potential Adverse Effects of
Soybean Phytoestrogens in Infant Feeding, New Zealand Medical Journal,
May 24, 1995, page 318.
59. C Hagger and J Bachevalier, Visual habit formation
in 3-month-old monkeys (Macaca mulatta): reversal of sex difference
following neonatal manipulations of androgen, Behavior and Brain
Reserach 1991 45:57-63.
60. R K Ross et al, Effect of in-utero exposure to diethylstilbesterol
on age at onset of puberty and on post-pubertal hormone levels in boys,
Canadian Medical Association Journal, May 15m 1983 128:(10):1197-8.
61. Marcia E Herman-Giddens, et al Secondary Sexual
Characteristics and Menses in Young Girls Seen in Office Practice: A
Study from the Pediatric Research in Office Settings Network, Pediatrics
April 1997, 99:(4):505-512.
62. Rachel’s Environment & Health Weekly,
#263, The Wingspread Statement, Part 1, December 11, 1991; Theo Colborn,
Dianne Dumanoski and John Peterson Myers, Our Stolen Future,
Little Brown and Company, London, 1996.
63. L W Freni-Titulaer, Premature Thelarch in Puerto
Rico, A search for environmental factors, American Journal of Diseases
of Children, December 1986 140:(12):1263-1267
64. Lon White, Association of High Midlife Tofu Consumption
with Accelerated Brain Aging, Plenary Session #8: Cognitive Function,
The Third International Soy Symposium, Program, November 1999, page
26.
65. Helen Altonn, Too much tofu induces ‘brain aging,’
study shows, Honolulu Star-Bulletin, November 19, 1999.
66. Journal of the American Geriatric Society,
1998 46:816-21.
67. Daniel R Doerge, Inactivation of Thryoid 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.
68. Claude Hughes, Center for Women’s Health and Department
of Obstetrics & Gynecology, Cedars-Sinai Medical Center, Los Angeles,
CA.
69. Soy Intake May Affect Fetus, Reuters News Service,
November 5, 1999.
70. Vegetarian diet in pregnancy linked to birth defect,
British Journal of Urology International, January 2000 85:107-113.
71. FDA ref 72/104, Report FDABF GRAS - 258
72. Evaluation of the Health Aspects of Soy Protein
Isolates as Food Ingredients, Prepared for FDA by Life Sciences Research
Office, Federation of American Societies for Experimental Biology, 9650
Rockville Pike, Bethesda, MD 20014, Contract No, FDA 223-75-2004, 1979.