posted July 19, 2004 08:19 PM         

Apologists for soy dismiss such claims, saying that food processing and home cooking remove most of these antinutrients. In fact, modern processing removes most of them, but not all. The levels of heat and pressure needed to remove all protease inhibitors, for example, severely damage soy protein and make it harder to digest. The trick is to eliminate the most antinutrients while doing the least damage to the soy protein. Success varies widely from batch to batch.41-44

For years, the soy industry tried to improve the quality of animal feeds by finding better ways to get rid of these undesirable antinutrients. Having failed, they routinely supplement animal feeds heavily with vitamins, minerals, and methionine, a sulfur-containing amino acid that is low in soy. Even so, makers of animal chows are still limited in the amount of soy they can add without causing growth and fertility problems. Food processors making soy-protein products for people may or may not add these supplements. Generally, calcium and vitamin D are added to soy milk so it can compete with dairy products.

Today, the soy industry has switched tactics-from trying to remove unwanted antinutrients to trying to convince people that they are actually a good thing. Protease inhibitors, saponins, and lectins are being touted as curers of cancer or lowerers of cholesterol, while phytates are being recommended for their ability to remove toxic minerals such as cadmium and excess iron from the body.45-51 Although some of these uses look promising, it is important to note that researchers are not achieving these successes using regular soy foods. Most take carefully extracted components and administer them in carefully measured and monitored pharmaceutical doses. News headlines to the contrary, there is no reason to think that just eating a lot of soy foods will do the trick.

Soy Allergens
Soy is one of the top eight allergens that cause immediate hypersensitivity reactions such as coughing, sneezing, runny nose, hives, diarrhea, difficulty swallowing, and anaphylactic shock. Delayed allergic responses are even more common and occur anywhere from several hours to several days after the food is eaten. These have been linked to sleep disturbances, bedwetting, sinus and ear infections, crankiness, joint paint, chronic fatigue, gastrointestinal woes, and other mysterious symptoms.52, 53

Soy allergies are on the rise for three reasons: the growing use of soy infant formula (now 20 to 25 percent of the formula market), the increase in soy-containing foods in grocery stores, the possibility of the greater allergenicity of genetically modified soybeans.54 Although severe reactions to soy are rare compared to reactions to peanuts, tree nuts, fish, and shellfish, soy has been underestimated as a cause of food anaphylaxis. Recently, after a young girl in Sweden suffered an asthma attack and died after eating a hamburger that contained only 2.2 percent soy protein, Swedish researchers looked into a possible soybean connection. They concluded that the soy-in-the-hamburger case was not a fluke, and that minute amounts of soy "hidden" in regular food had caused four of the total of five deaths caused by allergic reactions in Sweden between 1993 and 1996. Of the children who suffered fatal attacks, all had been able to eat soy without any adverse reactions right up until the dinner that caused their deaths.55 According to the Swedish Ministry of Health and Social Affairs, children at highest risk are those who suffer from peanut allergies and asthma; parents of such children should make every effort to eliminate all soy from their children's diets.56

Soy and the Thyroid: A Pain in the Neck
More than 70 years of human, animal, and laboratory studies show that soybeans put the thyroid at risk. The chief culprits are the plant hormones in soy known as phytoestrogens or isoflavones.57-59 The United Kingdom's Committee on Toxicology has identified several populations at special risk: infants on soy formula, vegans who use soy as their principal meat and dairy replacements, and men and women who self-medicate with soy foods and/or isoflavone supplements in an attempt to prevent or reverse menopausal symptoms, cancer, or heart disease.60

Infants with congenital hypothyroidism need 18 to 25 percent higher doses of thyroxine drug than usual if they are bottle-fed with soy formula.61 Likewise, adults who boost their thyroid with drugs such as Synthroid while also eating thyroid-inhibiting foods such as soy put extreme stress on their thyroids. Toxicologist Michael Fitzpatrick, PhD, points out that this is the way that researchers induce thyroid cancers in laboratory animals.62

Soy and Reproduction: Breeding Discontent
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. Of all these groups, infants on soy formula are at the highest risk because of their small size and developmental phase, and because formula is their main source of nutrient.66, 67

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.75-79

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.84, 85

Most experts blame this epidemic of "precocious puberty" on environmental estrogens from plastics, pesticides, commercial meats, etc., but some pediatric endocrinologists believe that soy is a contributor.86 Of all the estrogens found in the environment, soy is the likeliest explanation of why African American girls reach puberty so quickly. Since its establishment in 1974, the federal government's Women, Infants and Children (WIC) program has provided free infant formula to teenage and other low-income mothers while failing to encourage breastfeeding. Because of perceived or real lactose intolerance, black babies are much more likely to receive soy formula than Caucasian babies.

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.87

Recently, a team of researchers headed by Brian L. Strom, MD, studied the use of soy formula and its long-term impact on reproductive health. They announced only one adverse finding: longer, more painful menstrual periods among women who'd been fed soy formula in infancy.88 Dr. Strom's conclusion that the results were "reassuring" made newspaper headlines all over the world, though the data in the body of the report were anything but. Indeed, data left out of the headlines and buried in the report revealed higher incidences of allergies and asthma, and higher rates of cervical cancer, polycystic ovarian syndrome, blocked fallopian tubes, and pelvic inflammatory disease.89 Although thyroid damage from soy formula has been the principal concern of critics for decades, the researchers excluded thyroid function as a subject for study. Not surprisingly, this study was funded in part by the infant-formula industry.

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.97, 98

Soy apologists sometimes argue that the plant hormones in soy formula could not possibly be harmful because Japanese women eat a lot of soy products and so must have high levels of phytoestrogens in their breastmilk. Researchers, however, have measured the soy isoflavones in breastmilk and found them low even in vegetarian women who consume copious quantities of tofu, soy milk, soy protein shakes, and other soy foods.99-101

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.103

Until soy estrogens are definitely linked to reproductive-tract abnormalities, infertility, and other health problems in humans, most health authorities recommend that we "wait and see." This could be a terrible mistake.

In the 1940s and 1950s, another estrogen, diethylstilbestrol (DES), was widely given to Western women early in their pregnancies in a misguided attempt to prevent miscarriage. That fact is relevant not only because DES bears a striking structural similarity to some plant estrogens-including soy isoflavones-but because it took more than 20 years before the full spectrum of harmful effects was observed.104, 105

DES is 100,000 times more potent than soy phytoestrogens. However, the large quantities of phytoestrogens in soy products are more than enough to counteract their lower potency. When the effects of isoflavones in fetal and neonatal animals have been studied, they have paralleled those observed in human infants exposed to DES.106, 107 Recent studies indicate that the soy isoflavone known as genistein may be even more carcinogenic than DES.108

Yet the belief persists that soy hormones are "safe" because they are "weak" and "natural." Although the soy industry has claimed that soy estrogens are anywhere from 10,000 to 1,000,000 times weaker than the human estrogen estradiol, the correct figure is only 1,200 times as weak.109 Though this still sounds quite weak, it is not-because of the quantity of these estrogens ingested by infants on soy formula, and by children and adults who eat soy every day. These individuals consume far more soy estrogens than were ever part of a traditional diet in Asia. The average isoflavones intake in China is 3 milligrams, or 0.05 mg per kilogram of body weight. In Japan, the figures range from 10 to 28 mg, or 0.17 to 0.47 isoflavones per kg of body weight. In contrast, infants receiving soy formula average 38 mg of isoflavones, which comes to a shocking 6.25 mg/kg of body weight. Compare that dose to the 0.47 mg/kg per day fed to healthy Japanese adult men and women who experienced thyroid suppression after just three months-or to the 0.75 mg/kg of isoflavones fed to American women who experienced hormonal changes sufficient to skew their menstrual cycles after just one month.110 Although children and teenagers are less vulnerable than infants, their young bodies are still developing, and highly vulnerable to endocrine-system disruption by soy. And soy has been shown to pass through the placentas of pregnant women to their unborn babies.

Meanwhile, the jury is still out on whether soy might help alleviate menopausal symptoms or prevent osteoporosis and breast cancer. The soy industry's top scientists, convened at the Fifth International Symposium on the Role of Soy in the Preventing and Reversing Chronic Disease (held in Orlando, Florida, September 21-24, 2003), conceded that the data are confusing and contradictory, with some studies suggesting that soy might be helpful, and others showing that soy contributes to osteoporosis and promotes breast cancer.

What's certain is that the levels of soy estrogens that might possibly have a beneficial effect on hormonally related diseases have been proven to jeopardize the health of the thyroid. Likewise, the 25 grams of soy protein per day touted by the FDA to lower cholesterol (see sidebar, "Boon to the Industry: The FDA's Soy Protein Health Claim") is very likely to harm the thyroid, and thus increase one of the risk factors for heart disease.

The bottom line is that the safety of soy foods has yet to be proven, and that human beings have become guinea pigs in what Daniel M. Sheehan, formerly senior toxicologist with the FDA's National Center for Toxicological Research, has called a "large, uncontrolled and basically unmonitored human experiment.

We now have a soy explosion in this country and also in western Europe. I am veggie and do not eat meat. I am concerned about the amount of soy products in veggie food. Please guys beware as it's way too much. It's too much for the body to cope with at any one time. Think twice before you overdo the triple soy latte.

Gia

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posted July 19, 2004 10:35 PM         

juniperb

posted July 19, 2004 10:49 PM         

Are you back Gia?

posted July 20, 2004 11:56 AM         

Those numbers relate to research notes I got in the mail and was supposed to type out so that you guys could read them. Sorry I don't have them with me now as I just came in to check if a long awaited email had finally been mailed. It was not. So I dedcided to pop in quickly and see what you've all been up to.

Philbird you make me smile as always. You are always right on the button and so much more clued on then you make out. I think you are smart indeed.

Look forward to finishing off here and getting back to normal soon. My hubby is into classic cars at the moment and we have a few shows to visit. He paints bikes and cars on huge stainless steel plates. He's become quite busy locally. Which is good because he's not busy with engineering at this time. Painting is something he's always done along with sculpture. He did a huge painting of Saint Bonaventure last year for a church in Clayton. We didn't know what this 14th century saint looked like and a special wooden effigy was sent to us from Rome. I had Saint Bonaventure in my house for 9 months. I was so sad when he had to leave. I got used to swiffering him every other day. Nothing like swiffering a saint you know!

Libra Sparkle if it's urgent you can email me. It's fine as long as you don't pass it on. I'll check it again in two days.

posted April 20, 2005 07:35 PM         

I'll also try to find the info on soy we have in H&H. I had read a book, _Politically Incorrect Nutrition_, which is filled with valuable information, including the studies on soy which expose it for what it is (detrimental to our health). And Yin found a link to the author's website, which she posted in H&H. I'll try to unearth it soon.

posted April 25, 2005 11:40 AM         

Tempeh, tamari soya sauce and miso soup are safe soya products to have due to the long fermentation process. (The monks always did use to ferment it before tofu was introduced).

Rice milk is quite nice on cereal, I have found, and I now use coconut oil for cooking/as a spread. (A bit expensive but I have been fascinated by information on coconut oil).