From http://www.westonaprice.org/soy/soy_update2000.html
Dr. Lon White of Hawaii presented evidence that consumption of two or more servings of tofu per week in midlife is associated with accelerated “brain aging” in late life, resulting in Alzheimers and dementia. Dr. Daniel Doerges’ research confirmed that soy causes thyroid problems by interfering with enzymes that produce thyroid hormones. And Dr. Claude Hughes reported that rats born to mothers that consumed genistein (an estrogen-like compound found in soy) had decreased birth weight and earlier onset of puberty compared to controls. A study just released indicates that vegetarian mothers are five times more likely to give birth to a boy with a birth defect of the penis than non-vegetarian mothers. Researchers blamed the problem on the estrogenic effect of soy consumed during pregnancy.
The evidence in both human and animal studies all points in the same direction—that soy consumed in more than small amounts contributes to problems with the nervous system, the thyroid gland and the digestive system. High levels of soy consumption can cause infertility and premature sexual development in girls and birth defects of the reproductive system in boys.
From http://www.mothering.com/articles/growi ... story.html
(please note, I am not posting the whole article, but it is at the above link)
Scientists have known since the mid-1940s that phytoestrogens can impair fertility. Fertility problems in cows, sheep, rabbits, cheetahs, guinea pigs, birds, and mice have all been reported.63, 64 Although scientists discovered only recently that soy lowers testosterone levels,65 tofu has traditionally been used in Buddhist monasteries to decrease the libido, and by Japanese women to punish straying husbands. Humans and animals appear to be the most vulnerable to the effects of soy estrogens prenatally, during infancy and puberty, during pregnancy and lactation, and during the hormonal shifts of menopause
A crucial time for the programming of the human reproduction system is right after birth-the very time when bottles of soy formula are given to many non-breastfed babies. Normally during this period, the body surges with natural estrogens, testosterones, and other hormones that are meant to program the baby's reproductive development from infancy through puberty and into adulthood. For infants on soy formula, this programming may be interrupted.68-70
Male infants experience a testosterone surge during the first few months of life and produce androgens in amounts equal to those of adult men. So much testosterone at such a tender age is needed to program the body for puberty, the time when a male's sex organs should develop and he should begin to express male characteristics such as facial and pubic hair and a deep voice. If receptor sites intended for the hormone testosterone are occupied by soy estrogens, however, appropriate development may never take place.71-74 To date, most of the evidence damning soy formula can be found only in animal studies, because investigations in which humans' sex hormone levels are lowered experimentally cannot ethically be done. However, in the years since soy formula has been in the marketplace, parents and pediatricians have reported growing numbers of boys whose physical maturation is either delayed or does not occur at all. Breasts, underdeveloped gonads, undescended testicles (cryptorchidism), and steroid insufficiencies are increasingly common. Sperm counts are also falling.7
Soy formula is bad news for girls as well. Natural estrogen levels approximately double during the first month of life, then decline and remain at low levels until puberty. With increased estrogens in the environment in the diet, an alarming number of girls are entering puberty much earlier than normal.80-82 One percent of girls now show signs of puberty, such as breast development or pubic hair, before the age of three. By the age of eight, 14.7 percent of Caucasian girls and 48.3 percent of African American girls had one or both of these characteristics.83 The fact that blacks experience earlier puberties than whites is not a racial difference but a recent phenomenon.
Early maturation in girls heralds reproductive problems later in life, including amenorrhea (failure to menstruate), anovulatory cycles (cycles in which no egg is released), impaired follicular development (follicles failing to mature and develop into healthy eggs), erratic hormonal surges, and other problems associated with infertility. Because the mammary glands depend on estrogen for their development and functioning, the presence of soy estrogens at a susceptible time might predispose girls to breast cancer, another condition that is on the rise and definitively linked to early puberty
Most of the fears concerning soy formula have focused on estrogens. There are other problems as well, notably much higher levels of aluminum, fluoride, and manganese than are found in either breastmilk or dairy formulas.90-96 All three metals have the potential to adversely affect brain development. Although trace amounts of manganese are vital to the development of the brain, toxic levels accrued from ingestion of soy formula during infancy have been found in children suffering from attention-deficit disorders, dyslexia, and other learning problems.
Limited evidence, however, suggests that vegetarian women who eat a lot of soy foods during pregnancy may put their infants at risk in terms of their future reproductive health, fertility, and possibly increased risk of breast cancer. All of the problems that have befallen infants on soy formula, as well as estrogen-related birth defects, have occurred (in animal studies, at least) to the offspring of mothers who were given high doses of soy during pregnancy.102 One of these birth defects that has been linked to vegetarian diets in humans is hypospadias, a developmental disorder in which the opening of the penis is located on the underside of the shaft.
From http://www.mayanmajix.com/art1854.html
Israeli manufacturers of soya products were rattled by the recommendation issued by the country’s health ministry that consumption of soya products be limited in young children and avoided, if possible, in infants. After a year’s work, a committee of experts also advised that adults who eat soya products do so in moderation, pending authoritative future studies.
Although research showing possible harm—a higher risk of cancer, male infertility, or other problems—from soya is based on animal or retrospective human studies, the committee of 13 issued recommendations based on the precautionary principle. Soya contains phytoestrogens that may have some of the effects of the human hormone if consumed in large quantities.
the ministry decided not to prohibit the sale of soya based formula without a doctor's prescription, which is already required in New Zealand and Australia.
Paediatricians will monitor the thyroxine concentrations in infants and toddlers who have hypothyroidism who drink soya based formula or soya foods. And women with breast cancer or a high risk of it will be advised to consult their doctors about soya in their diets.
From http://www.soyonlineservice.co.nz/articles/MOHANZFA.htm (1999)
Warning Statement: We are pleased that ANZFA will be considering strategies to deter the use of soy-based infant formula. We note that ANZFA are not proposing to require a warning statement on product labels. However, we think that the message required under clause 19(3)(b) for all formulas could be altered slightly for soy-based formulas, as follows: Soy infant formula should not be used except on the advice of a health professional. This provides a stronger message in the case of soy infant formula.
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